2009 November 16 Monday
Low Vitamin D Boosts Heart Death Risks?

Okay, weeks have gone by without a vitamin D post. Well, with big turkeys on the horizon it is time to think about heart health. Patients over 50 years old with the lowest vitamin D levels died at higher rates.

MURRAY, UT – While mothers have known that feeding their kids milk builds strong bones, a new study by researchers at the Heart Institute at Intermountain Medical Center in Salt Lake City suggests that Vitamin D contributes to a strong and healthy heart as well – and that inadequate levels of the vitamin may significantly increase a person's risk of stroke, heart disease, and death, even among people who've never had heart disease.

For more than a year, the Intermountain Medical Center research team followed 27,686 patients who were 50 years of age or older with no prior history of cardiovascular disease. The participants had their blood Vitamin D levels tested during routine clinical care. The patients were divided into three groups based on their Vitamin D levels – normal (over 30 nanograms per milliliter), low (15-30 ng/ml), or very low (less than 15 ng/ml). The patients were then followed to see if they developed some form of heart disease.

Researchers found that patients with very low levels of Vitamin D were 77 percent more likely to die, 45 percent more likely to develop coronary artery disease, and 78 percent were more likely to have a stroke than patients with normal levels. Patients with very low levels of Vitamin D were also twice as likely to develop heart failure than those with normal Vitamin D levels.

Those are startling differences. But what is the direction of causation?

If men have low vitamin D and low estrogen (yes, that's right, estrogen) then that's bad news for arteries.

Researchers at Johns Hopkins are reporting what is believed to be the first conclusive evidence in men that the long-term ill effects of vitamin D deficiency are amplified by lower levels of the key sex hormone estrogen, but not testosterone.

In a national study in 1010 men, to be presented Nov. 15 at the American Heart Association's (AHA) annual Scientific Sessions in Orlando, researchers say the new findings build on previous studies showing that deficiencies in vitamin D and low levels of estrogen, found naturally in differing amounts in men and women, were independent risk factors for hardened and narrowed arteries and weakened bones. Vitamin D is an essential part to keeping the body healthy, and can be obtained from fortified foods, such as milk and cereals, and by exposure to sunlight.

"Our results confirm a long-suspected link and suggest that vitamin D supplements, which are already prescribed to treat osteoporosis, may also be useful in preventing heart disease," says lead study investigator and cardiologist Erin Michos, M.D., M.H.S.

Do you think you ought to take vitamin D but just do not seem to get around to starting the habit?

By Randall Parker    2009 November 16 10:52 PM   Entry Permalink | Comments (3)
2009 November 15 Sunday
High Selenium Boosts Blood Cholesterol?

Too much selenium probably boosts blood cholesterol.

A new study from the University of Warwick has discovered taking too much of the essential mineral selenium in your diet can increase your cholesterol by almost 10%.

Selenium is a trace essential mineral with anti-oxidant properties. The body naturally absorbs selenium from foods such as vegetables, meat and seafood. However, when the balance is altered and the body absorbs too much selenium, such as through taking selenium supplements, it can have adverse affects.  

A team led by Dr Saverio Stranges at the University's Warwick Medical School has found high levels of selenium are associated with increased cholesterol, which can cause heart disease. 

In a paper recently published in the Journal of Nutrition, the research team examined the association of plasma selenium concentrations (levels of selenium in the blood) with blood lipids (fats in the blood). 

The researchers found in those participants with higher plasma selenium (more than 1.20 µmol/L) there was an average total cholesterol level increase of 8% (0.39 mmol/L (i.e. 15.1 mg/dL). Researchers also noted a 10% increase in non-HDL cholesterol levels (lipoproteins within your total cholesterol that can help predict the risk of someone suffering a heart attack or chest pain). Also, of the participants with the highest selenium levels, 48.2% admitted they regularly took dietary supplements. 

It is not easy to choose an optimal diet.

This reminds me of a study that illustrates the potential for genetic testing to optimize diet choices (nutrigenomics): Whether selenium helps or hurts against prostate cancer risk depends on which genetic variant you have for the enzyme manganese superoxide dismutase (SOD2). So Brazil nuts probably cut prostate cancer risk in some while boosting risk for others.

Higher selenium levels in the blood may worsen prostate cancer in some men who already have the disease, according to a study by researchers at Dana-Farber Cancer Institute the University of California, San Francisco.

A higher risk of more aggressive prostate cancer was seen in men with a certain genetic variant found in about 75 percent of the prostate cancer patients in the study. In those subjects, having a high level of selenium in the blood was associated with a two-fold greater risk of poorer outcomes than men with the lowest amounts of selenium.

By contrast, the 25 percent of men with a different variant of the same gene and who had high selenium levels were at 40 percent lower risk of aggressive disease. The variants are slightly different forms of a gene that instructs cells to make manganese superoxide dismutase (SOD2), an enzyme that protects the body against harmful oxygen compounds.

You can imagine how two different studies on selenium and prostate cancer could come to opposite conclusions if their patient groups had different distributions of SOD2 variants.

If you are a guy and can find a genetic testing service that will test for SOD2 variants you could find out whether you should eat high selenium foods or avoid them. I wonder whether these SOD2 variants modify the risks for other diseases.

By Randall Parker    2009 November 15 09:39 PM   Entry Permalink | Comments (6)
2009 November 02 Monday
80 Min Exercise Per Week Prevents Visceral Weight Gain

Fat around your internal organs is thought to be a much bigger risk factor for heart disease than fat near the surface of the skin. Well, if you go on a diet, exercise, get your weight down, and then eventually go off the diet continued exercise will prevent the resulting weight gain from happening where the risk factor is greatest.

BIRMINGHAM, Ala. - A study conducted by exercise physiologists in the University of Alabama at Birmingham (UAB) Department of Human Studies finds that as little as 80 minutes a week of aerobic or resistance training helps not only to prevent weight gain, but also to inhibit a regain of harmful visceral fat one year after weight loss.

The study was published online Oct. 8 and will appear in a future print edition of the journal Obesity.

Unlike subcutaneous fat that lies just under the skin and is noticeable, visceral fat lies in the abdominal cavity under the abdominal muscle. Visceral fat is more dangerous than subcutaneous fat because it often surrounds vital organs. The more visceral fat one has, the greater is the chance of developing Type 2 diabetes and heart disease.

80 minutes per week of either aerobic or resistance training prevents any fat weight gain around the internal organs. This is good news.

"What we found was that those who continued exercising, despite modest weight regains, regained zero percent visceral fat a year after they lost the weight," Hunter said. "But those who stopped exercising, and those who weren't put on any exercise regimen at all, averaged about a 33 percent increase in visceral fat.

It takes at least an hour a day of exercise to prevent weight gain. But 80 minutes per week to prevent the harmful form of weight gain is only 19% of the hour per day amount. So this is a lot easier.

By Randall Parker    2009 November 02 06:32 AM   Entry Permalink | Comments (7)
2009 October 29 Thursday
Fructose Causes High Blood Pressure?

Beware a diet high in fructose.

A diet high in fructose increases the risk of developing high blood pressure (hypertension), according to a paper being presented at the American Society of Nephrology’s 42nd Annual Meeting and Scientific Exposition in San Diego, California. The findings suggest that cutting back on processed foods and beverages that contain high fructose corn syrup (HFCS) may help prevent hypertension.

Over the last 200 years, the rate of fructose intake has directly paralleled the increasing rate of obesity, which has increased sharply in the last 20 years since the introduction of HFCS. Today, Americans consume 30% more fructose than 20 years ago and up to four times more than 100 years ago, when obesity rates were less than 5%. While this increase mirrors the dramatic rise in the prevalence of hypertension, studies have been inconsistent in linking excess fructose in the diet to hypertension.

Fructose is starting to look like a more plausible villain than fat. Perhaps Diane Keaton in Sleeper was right to praise "Deep fat".

Diana Jalal, MD (University of Colorado Denver Health Sciences Center), and her colleagues studied the issue in a large representative population of US adults. They examined 4,528 adults 18 years of age or older with no prior history of hypertension. Fructose intake was calculated based on a dietary questionnaire, and foods such as fruit juices, soft drinks, bakery products, and candy were included. Dr. Jalal’s team found that people who ate or drank more than 74 grams per day of fructose (2.5 sugary soft drinks per day) increased their risk of developing hypertension. Specifically, a diet of more than 74 grams per day of fructose led to a 28%, 36%, and 87% higher risk for blood pressure levels of 135/85, 140/90, and 160/100 mmHg, respectively. (A normal blood pressure reading is below 120/80 mmHg.)

I've gradually become more concerned about fructose. Robert H. Lustig, MD, a UCSF Professor of Pediatrics in the Division of Endocrinology, takes a look at the harms that come from excessive fructose consumption. Note that he says we are eating an order of magnitude more fructose than our ancestors did historically.

Is high fructose consumption from high fructose corn syrup and sucrose sugar responsible for the obesity epidemic? He says our ancestors got about 15 grams per day. Well, a medium sized apple has about 10 grams. So 2 apples will give you more fructose than most of our ancestors consumed. Our bodies are probably not well adapted to handle 150 grams of fructose per day.

Anyone know of a good detailed list of fructose levels in various foods? I've only found short lists of fructose levels in foods.

By Randall Parker    2009 October 29 11:00 PM   Entry Permalink | Comments (6)
2009 October 05 Monday
Mercury From Fish Boosts Blood Pressure

Mercury is bad. If we got more electricity from nuclear power rather than coal we'd put less mercury into the environment.

DALLAS, Oct. 5, 2009 — The negative impact of high amounts of methylmercury in seafood on blood pressure may outweigh the protective effects of fish nutrients, researchers report in Hypertension: Journal of the American Heart Association.

Researchers found that even when blood pressure was within the normal range and numerous other factors, including omega-3 fatty acids (essential fats that your body needs to function properly but does not make) and selenium (a dietary essential mineral) were carefully controlled for, the environmental mercury was associated with higher blood pressure and pulse pressure among Nunavik Inuit adults in a recent study.

Keep in mind that few eat as much fish as the Nunavik.

Researchers conducted a survey in the 14 Nunavik communities in northern Quebec, Canada, where the traditional diet is based mainly on fish and marine mammals, and thus, residents regularly ingest higher levels of environmental mercury. Individuals taking medication for high blood pressure during data collection were excluded. The survey featured two-stage stratified random sampling and data from 732 Inuit adults (319 men and 413 women), average age 34.

The average total mercury blood concentration in people in the United States is now 4 nanomoles per liter (nmol/L) (NHANES study) compared to 50 nmol/L in the Inuit population.

Higher blood mercury means higher blood pressure.

Researchers found a 10 percent increase in blood mercury was associated with an increase of 0.2 mm Hg in systolic blood pressure after controlling for other factors.

You can get lots of omega 3 fatty acids by eating fish that have almost undetectable amounts of mercury such as sardines and salmon. Check out this US Food and Drug Administration chart of mercury levels in fish. The big fish at the top of the food chain such as shark and swordfish have high mercury levels. Compare them to tilapia and oysters. Salmon are the best to eat to my thinking because they have very low mercury while having some of the highest levels of omega 3 fatty acids such as DHA.

A study back in April 2009 found that consumption of one portion of fatty fish per week cut men's risk of heart failure.

BOSTON – Eating salmon or other fatty fish just once a week helped reduce men's risk of heart failure, adding to growing evidence that omega-3 fatty acids are of benefit to cardiac health. Led by researchers at Beth Israel Deaconess Medical Center (BIDMC) and reported in today's on-line issue of the European Heart Journal, the findings represent one of the largest studies to investigate the association.

"Previous research has demonstrated that fatty fish and omega-3 fatty acids help to combat risk factors for a range of heart-related conditions, such as lowering triglycerides [fats in the blood] reducing blood pressure, heart rate and heart rate variability," explains first author Emily Levitan, PhD, a research fellow in the Cardiovascular Epidemiology Research Center at BIDMC. "Collectively, this may explain the association with the reduced risk of heart failure found in our study."

Studies of fish consumption are problematic because they typically do not collect detailed information about the types of fish consumed. Well, omega 3 fatty acid levels vary considerably between types of fish.Omega 3 fatty acid levels in fish vary over a few orders of magnitude. Caviar is the best followed by salmon.

There might be an ideal daily dose of omega 3 fatty acids.

The findings were similar when the researchers looked at fish oil consumption: Among five groups based on fish oil consumption, the middle group, who consumed 0.36 grams per day of omega-3 fatty acids showed a 33 percent reduced risk of heart failure, while the men who consumer greater quantities (approximately 0.46 grams per day or 0.71 grams per day) had a risk of heart failure similar to the men who consumed little or no fish oils.

Though the researchers leave open the possibility that people suffering from heart disease up their omega 3 fatty acid intake to help treat their disease. So the lack of benefit from the larger dose might not be real.

By Randall Parker    2009 October 05 11:42 PM   Entry Permalink | Comments (3)
2009 September 30 Wednesday
Dutch Study Finds No Fish Heart Benefit

A prospective study does not find a heart benefit from fish.

With heart failure treatments often limited to palliative care, much rests on prevention; this latest report from the Rotterdam Study was to investigate whether intake of the long-chain n-3 polyunsaturated fatty acids (PUFAs) found in fish conferred protection against heart failure as they seem to do against coronary heart disease.(3)

The analysis comprised 5299 subjects (41% men, mean age 67.5 years) who were free from heart failure and for whom dietary data were available. During 11.4 years of follow-up, 669 subjects developed heart failure. Their habitual diet had been assessed at baseline (in a self-reported checklist and by expert interview), with subjects specifically asked to indicate the frequency, amount, and kind of fish they had eaten, either as a hot meal, on a sandwich, or between meals.

Results showed that the dietary intake of fish was not significantly related to heart failure incidence. This relative risk was measured according to five levels of fish consumption as reflected in intake of two long chain n-3 PUFAs (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]), both of which have been shown to exert some cardiovascular benefit via anti-inflammatory mechanisms, anti-arrhythmic effects and/or a reduction in serum triglycerides, blood pressure, and heart rate.

I am pretty confident that we should eat lots of fruits and vegetables and when eating grains they should be whole grain and high in fiber. But just how much omega 3 fatty acids to consume?

One of the problems is that there's genetic variability in determining what's the ideal diet. We need a level of understanding of nutritional genomics that does not exist yet. Though with the big drops in DNA sequencing costs I'm hopeful genetic alleles for dietary guidance will become known in a few years.

Update: Note that the problem with the Dutch study might be a dosing problem. Not enough people in the sample might have eaten enough fish for enough time to deliver a benefit. This study does contradict a lot of other studies. You can't conclude from just this study that eating fish doesn't help.

Also, omega 3 fatty acid concentrations vary greatly between species of fish. For example, you are going to get a lot more DHA and EPA from salmon than from tuna. Take a lot at the table at the bottom of this page for omega 3 in various fish. Salmon, anchovy, and sardines have the most omega 3 fats.

By Randall Parker    2009 September 30 11:08 PM   Entry Permalink | Comments (12)
2009 September 26 Saturday
Vitamin D Lack, Fructose Excess Linked To High Blood Pressure

Among women enrolled in the Michigan Bone Health and Metabolism Study high blood pressure developed at 3 times the rate in women who were vitamin D deficient before menopause. Do not wait until you get older before starting to take nutrition seriously. If you wait the damage will already be done before you act.

Women who have vitamin D deficiency in the premenopausal years are at three times increased risk of developing high blood pressure in mid-life.

Hypertension rose from 6 percent to 25 percent over 15 years in this study population of women average age 38.

The age range was 24 to 44 at the start of the study in 1992. So the oldest at the end of the study were 59. A 25% overall high blood pressure rate seems pretty high.

You can get a blood test on your vitamin D to see where you stand. A blood test in winter will be especially telling due to shorter days and less sunshine.

Vitamin D deficiency was defined as less than 80 nanomoles per liter (nmol/L), while normal levels were considered more than 80 nmol/L. Experts in the medical community generally agree that vitamin D deficiency among women is widespread. Some researchers report many women don’t get enough sunlight exposure to help keep vitamin D levels near to normal, nor do they have diets or practice supplementation that support normal levels of vitamin D, Griffin said. Vitamin D is either synthesized in the skin through exposure to ultraviolet B rays in sunlight or ingested as dietary vitamin D.

Another cause of higher blood pressure: large amounts of fructose.

CHICAGO, Sept. 23, 2009 — A high-fructose diet raises blood pressure in men, while a drug used to treat gout seems to protect against the blood pressure increase, according to research reported at the American Heart Association’s 63rd High Blood Pressure Research Conference.

“This is the first evidence of a role of fructose in raising blood pressure and a role for lowering uric acid to protect against that blood pressure increase in people,” said Richard Johnson, M.D., co-author of the study and professor and head of the division of Renal Diseases and Hypertension at the University of Colorado–Denver medical campus in Aurora, Colo.

They used 200 grams of fructose per day. Since href="http://en.wikipedia.org/wiki/Fructose">grapes appear to be about 8% fructose by weight You'd have to eat about 5 lbs of grapes per day to get 200 grams of fructose from grapes.

Johnson and co-author Santos Perez-Pozo, M.D., a nephrologist at Mateo Orfila Hospital in Minorca, Spain who led the study, evaluated 74 adult men, average age 51, who consumed a diet that included 200 grams (g) of fructose per day in addition to their regular diet. The amount is much higher than the estimated U.S. daily intake of 50 g to 70 g of fructose consumed by most U.S. adults. Half of the men were randomly assigned to get the gout drug allopurinol and the other half acted as controls.

After only two weeks on the diet, the high-fructose plus placebo group experienced significant average blood pressure increases of about 6 millimeters of mercury (mm Hg) in systolic blood pressure (the pressure when the heart beats) and about a 3 mm Hg rise in diastolic blood pressure (the pressure between heartbeats). They were measured with strap-on monitors that record blood pressure periodically around the clock.

Gout drug allopurinol blocked this effect. The main threat comes from high fructose corn syrup used in soda and processed foods.

Fruits contain good stuff that isn't present in high fructose corn syrup.

Fruit, which has just 4 g to 10 g of fructose per serving, also contains many beneficial substances including antioxidants, vitamin C, potassium and fiber that are believed to counter the effects of fructose alone. The main risk for excessive fructose consumption in the Western diet comes from sweetened drinks and foods rich in sugar or high fructose corn syrup, he said.

I'd really like to know if there's a fructose health threat from eating lots of fruits. I happen to eat at least 1 apple a day and lots of grapes daily as well. I've come across a number of scientific reports showing a positive correlation between fruit consumption and health. So I'm still eating lots of fruits. Curiously, the ratio of fructose to total sugar varies greatly between fruits. Note in table 1 how apricot and peach have especially low ratios of fructose to total sugar.

By Randall Parker    2009 September 26 02:50 PM   Entry Permalink | Comments (6)
2009 September 21 Monday
Lower Vitamin D And Higher Heart Death Rates

Older people with lower levels of vitamin D die from heart disease at higher rates.

A new study by researchers at the University of Colorado Denver and Massachusetts General Hospital (MGH) shows vitamin D plays a vital role in reducing the risk of death associated with older age. The research, just published in the Journal of the American Geriatrics Society, evaluated the association between vitamin D levels in the blood and the death rates of those 65 and older. The study found that older adults with insufficient levels of vitamin D die from heart disease at greater rates that those with adequate levels of the vitamin.

"It's likely that more than one-third of older adults now have vitamin D levels associated with higher risks of death and few have levels associated with optimum survival," said Adit Ginde, MD, MPH, an assistant professor at the University of Colorado Denver School of Medicine's Division of Emergency Medicine and lead author on the study. "Given the aging population and the simplicity of increasing a person's level of vitamin D, a small improvement in death rates could have a substantial impact on public health."

Older adults are at high risk for vitamin D deficiency because their skin has less exposure to the sun due to more limited outdoor activities as well as reduced ability to make vitamin D.

The skin syntheses vitamin D in the presence of sunlight. But aged skin syntheses less vitamin D when exposed to sunlight. Old folks engage in fewer outside activities also get less sun exposure. Of course, there's the possibility that the lower level of outside activity is due to underlying illnesses and therefore that the lower levels of vitamin D are a result of illness which also is causing the higher death rate.

What is needed: a large prospective study on whether vitamin D supplementation lowers death rates.

By Randall Parker    2009 September 21 10:28 PM   Entry Permalink | Comments (5)
2009 September 01 Tuesday
Optimal DHA Daily Dosage?

Can blood and urine tests point toward the ideal daily dosage of the omega 3 fatty acid DHA.

A team of French scientists have found the dose of DHA (docosahexaenoic acid) that is "just right" for preventing cardiovascular disease in healthy men. In a research report appearing in the September 2009 print issue of The FASEB Journal (http://www.fasebj.org), the scientists show that a 200 mg dose of DHA per day is enough to affect biochemical markers that reliably predict cardiovascular problems, such as those related to aging, atherosclerosis, and diabetes. This study is the first to identify how much DHA is necessary to promote optimal heart health.

"This study shows that regularly consuming small amounts of DHA is likely to improve the health status of people, especially in regards to cardiovascular function," said Michel Lagarde, co-author of the study.

Now, the press release above is not clear. Do they see the optimal response at 200 mg of DHA per day? Does the response stay the same, get worse, or get better above 200 mg? Well, okay, so lets move on to the abstract.

Twelve healthy male volunteers (aged 53–65 yr) were assigned to consume an intake of successively 200, 400, 800, and 1600 mg/d DHA, as the only omega-3 fatty acid, for 2 wk each dose. Blood and urine samples were collected before and after each dose of DHA and at 8 wk after arrest of supplementation. DHA was incorporated in a dose-response fashion in platelet phospholipids. After supplementation with 400 and 800 mg/d DHA, platelet reactivity was significantly decreased. Platelet vitamin E concentration increased only after 200 mg/d DHA, while p38 MAP kinase phosphorylation decreased. Urinary isoprostane was also significantly lowered after 200 mg/d DHA but was increased after 1600 mg/d. Therefore, supplementation with only 200 mg/d DHA for 2 wk induced an antioxidant effect.

Okay, that's still not perfectly clear. I can imagine why vitamin E would drop at higher DHA levels as DHA gets oxidized and vitamin E gets depleted reducing it. What happened with isoprostane between 200 and 1600 mg? What is urinary isoprostane? Turns out isoprostanes are an indication of free radicals reacting with fats. Higher isoprostanes probably mean more bad stuff going on.

Isoprostanes are prostaglandin-like compounds produced primarily from esterified arachidonic acid in tissues by non-enzymatic reactions catalysed by free radicals in vivo.

Higher circulating concentrations of F2-isoprostanes are associated with coronary artery calcification (CAC) and CAC is definitely a bad thing.

So maybe there's an ideal dose level of DHA and maybe it is in the hundreds of milligrams per day. I emphasize the maybe.

By Randall Parker    2009 September 01 09:00 PM   Entry Permalink | Comments (1)
2009 August 23 Sunday
How Vitamin D Deficiency Causes Clogging In Diabetics

Diabetics especially should get enough vitamin D or run the risk of macrophage immune cells filling with cholesterol.

Aug. 21, 2009 -- Low levels of vitamin D are known to nearly double the risk of cardiovascular disease in patients with diabetes, and researchers at Washington University School of Medicine in St. Louis now think they know why.

They have found that diabetics deficient in vitamin D can't process cholesterol normally, so it builds up in their blood vessels, increasing the risk of heart attack and stroke. The new research has identified a mechanism linking low vitamin D levels to heart disease risk and may lead to ways to fix the problem, simply by increasing levels of vitamin D.

"Vitamin D inhibits the uptake of cholesterol by cells called macrophages," says principal investigator Carlos Bernal-Mizrachi, M.D., a Washington University endocrinologist at Barnes-Jewish Hospital. "When people are deficient in vitamin D, the macrophage cells eat more cholesterol, and they can't get rid of it. The macrophages get clogged with cholesterol and become what scientists call foam cells, which are one of the earliest markers of atherosclerosis."

Inflammation combined with cholesterol-laden macrophages lead to stiffened clogged blood vessels

Macrophages are dispatched by the immune system in response to inflammation and often are activated by diseases such as diabetes. Bernal-Mizrachi and his colleagues believe that in diabetic patients with inadequate vitamin D, macrophages become loaded with cholesterol and eventually stiffen blood vessels and block blood flow.

So get sun light or take vitamin D.

By Randall Parker    2009 August 23 11:50 AM   Entry Permalink | Comments (8)
2009 August 04 Tuesday
Review Finds Omega 3 Fatty Acids Benefit Heart

The omega 3 fatty acids found in fish oil benefit people who have heart disease.

There is mounting evidence that omega-3 fatty acids from fish or fish oil supplements not only help prevent cardiovascular diseases in healthy individuals, but also reduce the incidence of cardiac events and mortality in patients with existing heart disease. A new study, published in the August 11, 2009, issue of the Journal of the American College of Cardiology, extensively reviews data from a broad range of studies in tens of thousands of patients and sets forth suggested daily targets for omega-3 consumption.

"This isn't just hype; we now have tremendous and compelling evidence from very large studies, some dating back 20 and 30 years, that demonstrate the protective benefits of omega-3 fish oil in multiple aspects of preventive cardiology," said Carl Lavie, M.D., F.A.C.C., medical director of Cardiac Rehabilitation and Prevention, Ochsner Medical Center, New Orleans, LA, and lead author of the article. "The strongest evidence of a cardioprotective effect of omega-3s appears in patients with established cardiovascular disease and following a heart attack with up to a 30 percent reduction in CV-related death."

Dietary intake of fish oil can also decrease the risk of atherosclerosis, arrhythmias, heart attack, sudden cardiac death and even health failure. Dr. Lavie adds that although there is a smaller benefit in reducing heart failure death—9 percent mortality benefit in a major recent randomized controlled trial—this is still very impressive given patients' grave prognosis.

Get at least 500 mg of omega fatty acids per day and double that if you have heart disease.

Based on these findings, and because the body does not produce its own essential fatty acids, the authors recommend that healthy individuals should consume 500 mg daily of omega-3 fish oil containing EPA and DHA, and people with known heart disease or heart failure aim for at least 800 to 1,000 mg daily.

I find it a lot easier to take fish oil pills than to eat fish regularly.

By Randall Parker    2009 August 04 10:46 PM   Entry Permalink | Comments (10)
2009 July 14 Tuesday
Heart Healthy DASH Diet Cuts Alzheimers Risk

What's good for your heart is good for your brain too.

The Dietary Approaches to Stop Hypertension (DASH) diet is often recommended by physicians to people with high blood pressure or pre-hypertension. The DASH diet eating plan has been proven to lower blood pressure in studies sponsored by the National Institutes of Health. High blood pressure is considered a risk factor for Alzheimer's and dementia.

Heidi Wengreen, RD, PhD, Assistant Professor of Nutrition at Utah State University, and colleagues examined associations between how closely people adhered to the DASH diet and risk of cognitive decline and dementia among older participants in the Cache County Study on Memory, Health and Aging.

In 1995, 3,831 study participants 65 years of age or older completed a survey that included a food frequency questionnaire and cognitive assessment. Cognitive function was checked again during four assessments over 11 years using the Modified Mini-Mental State examination (3MS), which is graded on a 100 point scale. A DASH diet adherence score was created based on consumption levels of nine food-group/nutrient components -- fruit, vegetables, nut/legumes, whole grains, low-fat dairy, sodium, sweets, non-fish meat, and fish. Participants were ranked by DASH score into five groups, or quintiles.

The researchers found that higher DASH scores were associated with higher scores for cognitive functioning at the beginning of the study and over time. Those in the highest quintile scored 1.42 points higher at baseline and 1.81 points higher after 11 years on the 3MS than did those in the lowest quintile of the DASH score (p-values < 0.001).

Of course this could result from smarter people choosing to eat a healthier diet. They start out smarter and they continue to be smarter. But a poor cardiovascular system is going to mess up your brain. Other research finds that reduced blood flow precedes Alzheimer's.

Eat your vegetables.

They also found that four of the nine food-group/nutrient components used to create the DASH score were independently associated with 3MS scores -- vegetables, whole grains, low-fat dairy, nut/legumes. The scientists created a diet adherence score based on just these four components which they then tested for association with changes in cognitive abilities on the 3MS. Those in the highest quintile scored 1.72 points higher at baseline and 3.73 points higher after 11 years than did those in the lowest quintile of the four-component score (p-values < 0.001).

Previous research finds that vegetable and fruit juice consumption are correlated with a large reduction in Alzheimer's risk. Yet another study found the Mediterranean Diet is associated with lowered Alzheimer's risk.

Eat fruit, nuts, vegetables, beans. Cut back on meats. Doing this delivers many benefits. A delay in brain decay is likely one of them.

By Randall Parker    2009 July 14 11:05 PM   Entry Permalink | Comments (3)
2009 June 09 Tuesday
Low Carb High Plant Protein Diet Good For Heart And Weight

A low carb, high plant protein diet took off about 4 kilograms or 8.8 pounds in 4 weeks.

Overweight individuals who ate a low-calorie, low-carbohydrate diet high in plant-based proteins for four weeks lost weight and experienced improvements in blood cholesterol levels and other heart disease risk factors, according to a report in the June 8 issue of Archives of Internal Medicine, one of the JAMA/Archives journals. A high-carbohydrate, low-fat vegetarian diet also resulted in weight loss but without the additional cardiovascular benefits.

The fact that this diet also improved blood lipids is the notable result here. Jenkins is researching diets that are closer to those eaten by our evolutionary ancestors. He's also incorporating research results about dietary components to try to come up with a heart healthier way to take off and keep off the weight.

"There is a dilemma relating to the proportion and source of fat, protein and carbohydrate that constitutes the optimal weight loss and cholesterol-lowering diet," the authors write as background information in the article. Newer dietary approaches for the prevention and treatment of chronic disease emphasize increased fruit and vegetable intake and reduced meat consumption.

However, low-carbohydrate diets with increased meat consumption have also been promoted for body weight reduction and the prevention and treatment of diabetes and coronary heart disease. These diets have been shown to be effective in inducing weight loss, reducing insulin resistance, lowering blood fats known as triglycerides and raising high-density lipoprotein cholesterol (HDL-C, or "good" cholesterol) levels, but have tended to increase low-density lipoprotein cholesterol (LDL-C, or "bad" cholesterol) levels. "This lack of a benefit for LDL-C control is a major disadvantage in using this dietary strategy in those already at increased risk of coronary heart disease," the authors write.

Eat more plant matter. But choose lower carb plant matter.

David J.A. Jenkins, M.D., of St. Michael's Hospital and the University of Toronto, Ontario, Canada, and colleagues tested the effects of a low-carbohydrate diet high in vegetable proteins from gluten, soy, nuts, fruits, vegetables, cereals and vegetable oils among overweight men and women with high LDL cholesterol levels. A total of 25 participants were randomly assigned to consume this diet—the "Eco-Atkins" diet—for four weeks, while an additional 25 participants ate a control diet that was high-carbohydrate, lacto-ovo vegetarian and based on low-fat dairy and whole grain products. Study food was provided to participants at 60 percent of their estimated calorie requirements.

This is similar to a previous diet Jenkins reported on in 2003. See my post Ape Man Diet Lowers Cholesterol And Inflammation Marker.

Strive to eat more fruits and vegetables. What to fill up your stomach without a lot of calories? 1 pound of cauliflower is only about 100 calories. How about a cauliflower diet? Eat a head of cauliflower before every meal and then see what else you can eat with the remaining room in your stomach. You heard it here first.

By Randall Parker    2009 June 09 04:08 AM   Entry Permalink | Comments (3)
2009 April 13 Monday
Review Finds Predictable Set Of Healthy Foods

A review of a large set of diet and heart studies finds that the Mediterranean diet and predictably healthy foods like vegetables are good for you.

A review of previously published studies suggests that vegetable and nut intake and a Mediterranean dietary pattern appear to be associated with a lower risk for heart disease, according to a report published in the April 13 issue of Archives of Internal Medicine, one of the JAMA/Archives journals. However, intake of trans-fatty acids and foods with a high glycemic index may be harmful to heart health.

"The relationship between dietary factors and coronary heart disease has been a major focus of health research for almost half a century," the authors write as background information in the article. Although "a wealth of literature" has been published on the topic, "the strength of the evidence supporting valid associations has not been evaluated systematically in a single investigation."

Andrew Mente, Ph.D., of the Population Health Research Institute, and colleagues conducted a systematic search for articles investigating dietary factors in relation to heart disease published between 1950 and June 2007. A total of 146 prospective cohort studies (looking back on the habits of a particular group of individuals) and 43 randomized controlled trials (where participants are randomly assigned to a dietary intervention or a control group) were identified and included in the systematic review.

The Mediterranean diet looks beneficial. No surprise there. Vegetables, nuts, and foods with low glycemic index are good for you.

When the researchers pooled the study results and applied a predefined algorithm, "we identified strong evidence of a causal relationship for protective factors, including intake of vegetables, nuts and monounsaturated fatty acids and Mediterranean, prudent and high-quality dietary patterns, and harmful factors, including intake of trans–fatty acids and foods with a high glycemic index or load and a western dietary pattern," they write. "Among these dietary exposures, however, only a Mediterranean dietary pattern has been studied in randomized controlled trials and significantly associated with coronary heart disease."

In addition, modest relationships were found supporting a causal relationship between intake of several other foods and vitamins and heart disease risk, including fish, omega-3 fatty acids from marine sources, folate, whole grains, alcohol, fruits, fiber and dietary vitamins E and C and beta carotene. Weak evidence also supported causal relationships between vitamin E and ascorbic acid supplements, saturated and polyunsaturated fatty acids and total fats, alpha-linoleic acid, meat, eggs and milk.

No one food shows a strong causal relationship. You have to get a lot of things right or a lot of things wrong to push you firmly toward lower or higher disease risk. Where to start? Find out what are the low and high glycemic index foods. I lowered my own average food glycemic index by changing rice brands (Uncle Ben's Converted is one of the more surefire ways to shift to lower glycemic index foods - and they ought to pay me to say that ;)) and eating more beans and vegetables.

By Randall Parker    2009 April 13 11:05 PM   Entry Permalink | Comments (2)
2009 March 31 Tuesday
Lipoic Acid Cuts Triglyceride Levels In Rats

At least in rats a widely available supplement cuts blood triglycerides. Confirmation with humans is needed.

CORVALLIS, Ore. – Studies done with laboratory rats suggest that supplementation of their diet with lipoic acid had a significant effect in lowering triglycerides, which along with cholesterol levels and blood pressure are one of the key risk factors in cardiovascular disease.

In the lab animals, supplements of lipoic acid lowered triglyceride levels up to 60 percent. If the effect were the same in humans – which is not yet clear – that would be a greater impact than found with other dietary supplements, and similar to the effects of some prescription drugs.

The results were just published in the Archives of Biochemistry and Biophysics, a professional journal.

"The extent of triglyceride reduction was really dramatic, we didn't expect it to be this profound," said Regis Moreau, an assistant professor with the Linus Pauling Institute at Oregon State University. "The potential is good that this could become another way to lower blood triglycerides and help reduce the risk of atherosclerosis. It's pretty exciting."

Lipoic acid seems to work 2 ways.

In this research, it was found that supplements of lipoic acid appeared to affect triglyceride levels through two pathways. After eating, lipoic acid supplementation increased the rate of disappearance of triglycerides in the bloodstream. And supplements also reduced the genetic expression of enzymes in the liver that synthesize triglycerides.

I wonder what other common compounds produce such benefit but haven't been noticed yet.

By Randall Parker    2009 March 31 12:23 AM   Entry Permalink | Comments (4)
2009 March 29 Sunday
Most Americans Need To Cut Down On Sodium

Most Americans should eat no more than 1500 mg of salt per day. That is two thirds of a teaspoon - not very much. But the average consumption is more than twice that amount.

Most Americans consume more than double the amount of their daily recommended level of sodium. A new study by the Centers for Disease Control and Prevention shows that more than 2 out of 3 adults are in population groups that should consume no more than 1,500 milligrams (mg) per day of sodium. During 2005-2006 the estimated average intake of sodium for persons in the United States age 2 years and older was 3,436 mg per day.

A diet high in sodium increases the risk of having higher blood pressure, a major cause for heart disease and stroke. These diseases are the first and third leading causes of death in the United States.

“It’s important for people to eat less salt. People who adopt a heart healthy eating pattern that includes a diet low in sodium and rich in potassium and calcium can improve their blood pressure,” said Darwin R. Labarthe, M.D., Ph.D., director of the CDC’s Division for Heart Disease and Stroke Prevention. “Reducing sodium intake can prevent or delay increases in blood pressure for everyone.’’

Easiest way to reduce salt consumption is to cut back on processed foods. At this McDonald's site choose "Sandwiches" from the right side combo box pop-down. You'll see that a cheeseburger contains 750 mg of sodium and a Quarter Pounder with Cheese contains 1190 mg of sodium. Note how cheese adds 230 mg of sodium to the hamburger and 460 mg to the Quarter Pounder.

Another way to look at sodium in the diet is in ratio to calories. A straight McDonald's hamburger has only 300 calories but 520 mg sodium. So if you ate 7 of them to get 2100 calories for a day you'd blow out your sodium budget with 3700 mg of sodium. But people don't eat most of their meals at fast food places. Processed foods eaten at home are a big problem too.

So how are people getting all that sodium at home? If you ate 2100 calories of Pepperidge Farm Double Chocolate Milano Distinctive Cookies you'd get only 1050 mg of sodium. Thinking about those cookies as a health food now? That's one of the advantages of reading this blog. I come up with things like this. Well, those Double Chocolate Milanos are way better than Nabisco Oreos on sodium If you ate 2100 calories of Oreos you'd get 2494 mg of sodium. Way more. I would have expected Nabisco Fig Newtons to be closer to a health food. But no. 2100 calories of Fig Newtons would give you 2625 mg of sodium. Most of the cookies I looked at deliver almost 1 mg sodium per calorie or even worse. But the Health Valley Chocolate Chip Oatmeal Cookies had the same 2:1 ratio of calories to sodium as the Pepperidge Farm Double Chocolate Milano Distinctive Cookies. So those are your two health foods for today. Shop accordingly.

Do you fit any of the risk categories below? Cut your sodum. If you aren't middle-aged remember you'll have to cut back eventually. Start looking for low sodium cookies for that day.

This study is the first to use national data to show that 69.2 percent of the adult population belongs to a specific group that should aim to consume no more than 1,500 mg of sodium per day.  This group includes persons with high blood pressure, blacks, or middle-aged and older adults (more than 40 years old).  The 2005 Dietary Guidelines for Americans recommend that adults in general should consume less than 2,300 mg (approximately one teaspoon of salt) of sodium per day. 

Of course, you could eat lots of fruits and vegetables, stop using salt (or switch to Lite Salt), rarely use ketchup, avoid fast food places, stop eating salty processed meats, and avoid high sodium salad dressings. But barring all that you could replace the bad foods with lower sodium cookies.

By Randall Parker    2009 March 29 10:43 AM   Entry Permalink | Comments (7)
2009 February 22 Sunday
Tea And Coffee Cut Stroke Risk

Black or green, either way you cut your risk of stroking out of life. Don't want to have half your face drooping when the nerves that instruct it die? Don't want to become a drooler or become confined to a wheelchair? Really you should think about these gruesome outcomes and change your behavior accordingly.

Drinking at least three cups of green or black tea a day can significantly reduce the risk of stroke, a new UCLA study has found. And the more you drink, the better your odds of staving off a stroke.

The study results, published in the online edition of Stroke: Journal of the American Heart Association, were presented Feb. 19 at the American Heart Association's annual International Stroke Conference in San Diego, Calif.

The UCLA researchers conducted an evidence-based review of all human observational studies on stroke and tea consumption found in the PubMed and Web of Science archives. They found nine studies describing 4,378 strokes among nearly 195,000 individuals, according to lead author Lenore Arab, a professor of medicine in the division of general internal medicine and health services research at the David Geffen School of Medicine at UCLA.

"What we saw was that there was a consistency of effect of appreciable magnitude," said Arab, who is also a professor of biological chemistry. "By drinking three cups of tea a day, the risk of a stroke was reduced by 21 percent. It didn't matter if it was green or black tea."

And extrapolating from the data, the effect appears to be linear, Arab said. For instance, if one drinks three cups a day, the risk falls by 21 percent; follow that with another three cups and the risk drops another 21 percent.

This effect was found in tea made from the plant Camellia sinensis, not from herbal teas.

What I want to know: If one eats a lot of berries and other fruits does one get equivalent compounds (e.g. flavonoids) from them that provide the same benefits?

Since coffee may provide a similar (though perhaps smaller) reduction of stroke risk..

But after considering factors such as cigarette and alcohol consumption, van Dam and his colleagues found that healthy women who consumed two to three cups of caffeinated coffee a day had, on average, a 19 percent lower risk for any kind of stroke than did women who drank less than one cup a month. Drinking four or more cups a day lowered risk by 20 percent.

Women who drank five to seven cups of coffee a week were 12 percent less likely to have a stroke than were those who downed just one cup a month, the study found.

But among women who do not smoke the stroke risk reduction from coffee rivals that from tea.

When the results were stratified by smoking status, women who had never smoked or who had quit and drank four cups of coffee or more had a 43% reduced risk of stroke (RR 0.57, 95% CI 0.39 to 0.84).

Tea is just one element in a total stroke risk-reducing lifestyle.

The study involved 20,040 men and women aged 40-79 years old who were taking part in the European Prospective Investigation into Cancer Study (EPIC). Between 1993 and 1997, participants completed a detailed health and lifestyle questionnaire and underwent a thorough health examination by trained nurses.

Participants scored one point for each of four healthy behaviours: current non-smoking, physically not inactive, moderate alcohol intake (1-14 units per week) and blood vitamin C levels of 50 µmol/l or more, indicating fruit and vegetable intake of at least five servings a day.

An individual could therefore have a total health behaviour score ranging from zero to four, with a higher score indicating more protective behaviour.

Participants were then followed for an average of 11 and a half years. Strokes were recorded using death certificates and hospital discharge data.

There were a total of 599 incident strokes during the follow-up period. After adjusting for other factors that may have affected the results, the risk of stroke was 2.3 times greater in those with a score of zero compared to those with a score of four.

A significantly higher percentage of women scored four compared to men.

The risk of stroke increased in linear fashion with every point decrease in health behaviour score. So, for example, those with a score of two were one and a half (1.58) times more likely to have a stroke than those with a score of four, while those with a score of just one were just over twice (2.18) as likely to have a stroke.

Also, number of fast food restaurants in a neighborhood correlates with stroke risk.

By Randall Parker    2009 February 22 02:27 PM   Entry Permalink | Comments (8)
2009 February 05 Thursday
Omega 3 Fatty Acids Prevent Clogged Arteries In Mice

Mice should eat lots of cold water fish to avoid accumulation of fat in their aortas.

NEW YORK (Feb. 5, 2009) – New research from Columbia University Medical Center continues to shed light on the benefits of making fish a staple of any diet.

Fish are generally rich in omega-3 fatty acids, which have shown benefit in many health areas such as helping to prevent mental illness and delaying some of the disabilities associated with aging. Eating tuna, sardines, salmon and other so-called cold water fish appears to protect people against clogged arteries. Omega-3 fatty acids can also lower triglycerides, a type of fat often found in the bloodstream.

Now, a CUMC research team led by Richard J. Deckelbaum, M.D., Director of the Columbia Institute of Human Nutrition, has found that a diet rich in fish oils can prevent the accumulation of fat in the aorta, the main artery leaving the heart. The beneficial actions of fish oil that block cholesterol buildup in arteries are even found at high fat intakes.

The study was conducted in three separate populations of mice: one that was fed a balanced diet, one that was fed a diet resembling a "Western" diet high in saturated fat, and a third that was fed a high fish fat diet rich in omega-3 fatty acids.

Researchers in Dr. Deckelbaum's laboratory, including Chuchun Liz Chang, a Ph.D. student in nutritional and metabolic biology, found that the fatty acids contained in fish oil markedly inhibit the entry of "bad," or LDL, cholesterol into arteries and, as a result, much less cholesterol collects in these vessels.

They found that this is related to the ability of those fatty acids to markedly decrease lipoprotein lipase, a molecule that traps LDL in the arterial wall. This will likely prove to be important as a new mechanism which helps explain benefits of omega-3 fatty acids on heart health.

Hey, if lab mice live longer before getting heart disease they'll be able to put in more work searching for cures for cancer.

By Randall Parker    2009 February 05 11:06 PM   Entry Permalink | Comments (10)
2009 February 03 Tuesday
Sodium Potassium Ratio Most Important For Heart

The ratio of sodium to potassium in urine is more important than the level of sodium alone for cardiovascular disease risk.

Researchers found that the ratio of sodium-to-potassium in subjects' urine was a much stronger predictor of cardiovascular disease than sodium or potassium alone.

"There isn't as much focus on potassium, but potassium seems to be effective in lowering blood pressure and the combination of a higher intake of potassium and lower consumption of sodium seems to be more effective than either on its own in reducing the risk of cardiovascular disease," said Dr. Paul Whelton, senior author of the study in the January 2009 issue of the Archives of Internal Medicine. Whelton is an epidemiologist and president and CEO of Loyola University Health System.

Researchers determined average sodium and potassium intake during two phases of a study known as the Trials of Hypertension Prevention. They collected 24-hour urine samples intermittently during an 18-month period in one trial and during a 36-month period in a second trial. The 2,974 study participants initially aged 30-to-54 and with blood pressure readings just under levels considered high, were followed for 10-15 years to see if they would develop cardiovascular disease. Whelton was national chair of the Trials of Hypertension Prevention.

Those with the highest sodium levels in their urine were 20 percent more likely to suffer strokes, heart attacks or other forms of cardiovascular disease compared with their counterparts with the lowest sodium levels. However this link was not strong enough to be considered statistically significant.

By contrast, participants with the highest sodium-to-potassium ratio in urine were 50 percent more likely to experience cardiovascular disease than those with the lowest sodium-to-potassium ratios. This link was statistically significant.

You should consume half as much sodium as potassium.

Whelton was a member of a recent Institute of Medicine panel that set dietary recommendations for salt and potassium. The panel said healthy 19-to-50 year-old adults should consume no more than 2,300 milligrams of sodium per day -- equivalent to one teaspoon of table salt. More than 95 percent of American men and 75 percent of American women in this age range exceed this amount.

To lower blood pressure and blunt the effects of salt, adults should consume 4.7 grams of potassium per day unless they have a clinical condition or medication need that is a contraindication to increased potassium intake. Most American adults aged 31-to-50 consume only about half as much as recommended in the Institute of Medicine report.

How to double your potassium intake? Turns out that high potassium foods are things you ought to eat for other reasons too. Beans, tomatoes, prunes, bananas, acorn squash, artichoke, spinach, sunflower seeds, almonds, winter squash, soybeans, cantaloupe, honeydew melon, and lentils all provide high potassium.

By Randall Parker    2009 February 03 11:25 PM   Entry Permalink | Comments (3)
2009 January 27 Tuesday
Omega 6 Fatty Acid Inflammation Risk Seen As Low

You can find lots of diet advice to balance your omega 6 fatty acid consumption with omega 3 fatty acids. The thinking is that omega 6 fatty acids increase inflammation and therefore cause heart disease and other health problems. However, an advisory published in Circulation: Journal of the American Heart Association argues that a higher omega 6 fatty acid diet will lower heart risk when omega 6 fatty acids replace saturated fats in the diet.

Linoleic acid (LA) is the main omega-6 fatty acid in foods, accounting for 85 percent to 90 percent of the dietary omega-6 PUFA.

There has been some debate within the nutrition community regarding the benefits of omega-6 based on the belief that they may promote inflammation, thus increasing cardiovascular risk. “That idea is based more on assumptions and extrapolations than on hard data,” said Harris, a research professor for the Sanford School of Medicine at the University of South Dakota and director of the Metabolism and Nutrition Research Center at Sanford Research/USD.

This advisory questions the belief that omega-6 fats increase inflammation.

The linking of omega-6 intake to inflammation stems from the fact that arachidonic acid (AA), which can be formed from LA, is involved in the early stages of inflammation. However, the advisory explains that AA and LA also give rise to anti-inflammatory molecules.

For example, in the cells that form the lining of blood vessels, omega-6 PUFA have anti-inflammatory properties, suppressing the production of adhesion molecules, chemokines and interleukins — all of which are key mediators of the atherosclerotic process. “Thus, it is incorrect to view the omega-6 fatty acids as ‘pro-inflammatory,’” Harris explained. “Eating less LA will not lower tissue levels of AA (the usual rationale for reducing LA intakes) because the body tightly regulates the synthesis of AA from LA.”

A meta-analysis of several trials finds that omega 6 polyunsaturated fatty acids (PUFAs) cut heart risks by a quarter.

In controlled trials in which researchers randomly assigned people to consume diets containing high versus low levels of omega-6 and then recorded the number of heart attacks over several years, those assigned to the higher omega-6 diets had less heart disease.

A meta-analysis of several trials indicated that replacing saturated fats with PUFA lowered risk for heart disease events by 24 percent. “When saturated fat in the diet is replaced by omega-6 PUFA, the blood cholesterol levels go down,” Harris said. “This may be part of the reason why higher omega-6 diets are heart-healthy.”

But would a diet where monounsaturated fats displaced the PUFAs cut heart risk even further?

Getting omega 3 fatty acids in your diet is still a good idea. Also, how you get your omega 6 fatty acids probably matters. For example, Nuts which are high in omega 6 also contain magnesium, vitamin E, and other beneficial nutrients. Whereas cooking oil delivers the omega 6 fats without as much of other nutrients.

By Randall Parker    2009 January 27 10:53 PM   Entry Permalink | Comments (3)
2009 January 05 Monday
Type 2 Diabetes Reduced By Very Low Carbo Diet

For people with type 2 (insulin resistant) diabetes a diet with very little carbs lowers blood sugar more than a diet with low glycemic index carbs.

DURHAM, NC -- In a six-month comparison of low-carb diets, one that encourages eating carbohydrates with the lowest-possible rating on the glycemic index leads to greater improvement in blood sugar control, according to Duke University Medical Center researchers.

Patients who followed the no-glycemic diet experienced more frequent reductions, and in some cases elimination, of their need for medication to control type 2 diabetes, according to lead author Eric Westman, MD, director of Duke's Lifestyle Medicine Program. The findings are published online in Nutrition and Metabolism.

"Low glycemic diets are good, but our work shows a no-glycemic diet is even better at improving blood sugar control," he says. "We found you can get a three-fold improvement in type 2 diabetes as evidenced by a standard test of the amount of sugar in the blood. That's an important distinction because as a physician who is faced with the choice of drugs or diet, I want a strong diet that's shown to improve type 2 diabetes and minimize medication use."

Eight-four volunteers with obesity and type 2 diabetes were randomized to either a low-carbohydrate ketogenic diet (less than 20 grams of carbs/day) or a low-glycemic, reduced calorie diet (500 calories/day). Both groups attended group meetings, had nutritional supplementation and an exercise regimen.

After 24 weeks, their glycemic control was determined by a blood test that measured hemoglobin A1C, a standard test used to determine blood sugar control in patients with diabetes. Of those who completed the study, the volunteers in the low-carbohydrate diet group had greater improvements in hemoglobin A1C. Diabetes medications were reduced or eliminated in 95 percent of the low-carbohydrate volunteers, compared to 62 percent in the low-glycemic group. The low-carbohydrate diet also resulted in a greater reduction in weight.

Eating low glycemic index carbohydrates is a good bet if you are going to eat carbohydrates. Probably for someone who does not have obesity or type 2 diabetes a ketogenic very low carb diet is too extreme. There are risks with putting your body into ketosis.

Type 2 diabetes is worth controlling for a number of reasons. For example type 2 diabetes impairs a couple of types of cognitive function.

WASHINGTON — Adults with diabetes experience a slowdown in several types of mental processing, which appears early in the disease and persists into old age, according to new research. Given the sharp rise in new cases of diabetes, this finding means that more adults may soon be living with mild but lasting deficits in their thought processes.

A full analysis appears in the January issue of Neuropsychology, which is published by the American Psychological Association.

Researchers at Canada's University of Alberta analyzed a cross-section of adults with and without adult-onset Type 2 diabetes, all followed in the Victoria Longitudinal Study. At three-year intervals, this study tracks three independent samples of initially healthy older adults to assess biomedical, health, cognitive and neurocognitive aspects of aging. The Neuropsychology study involved 41 adults with diabetes and 424 adults in good health, between ages 53 and 90.

The research confirmed previous reports that diabetes impairs cognition and added two important findings. First, it teased out the specific domains hurt by diabetes. Second, it revealed that the performance gap was not worse in the older group. Thus, the reductions in executive function and processing speed seem to begin earlier in the disease.

Healthy adults performed significantly better than adults with diabetes on two of the five domains tested: executive functioning, with significant differences across four different tests, and speed, with significant differences or trends across five different tests. There were no significant differences on tests of episodic and semantic memory, verbal fluency, reaction time and perceptual speed.

Another example of the high stakes for controlling type 2 diabetes: Type 2 diabetes at least triples risk of heart attack.

Men with type 2 diabetes and men with previous heart attack or stroke had a 3 to 4 fold risk of cardiovascular death compared to men without either disease in the years following the first acute event, according to a study in CMAJ http://www.cmaj.ca/press/pg40.pdf.

The study underscores the high risk of diabetes, as "men with type 2 diabetes and no previous cardiovascular disease had a 3-fold cardiovascular mortality risk compared with men with neither cardiovascular disease nor diabetes at the beginning of the follow-up," write Dr. Gilles Dagenais and colleagues from Laval University and the University of Montreal. However, the study was limited to white men and diabetes was self-reported in two-thirds of cases.

Stay skinny, get a lot of exercise, and eat healthy food so that you do not develop type 2 diabetes. It'll age you more rapidly. Worth avoiding.

By Randall Parker    2009 January 05 11:17 PM   Entry Permalink | Comments (3)
2008 December 16 Tuesday
Low Glycemic Index Diet Cuts Heart Risk With Diabetics

A diet very much like the Mediterranean diet causes favorable blood chemistry changes in peope with type II insulin-resistant diabetes.

A new study found that a diet of "low-glycemic foods" -- such as beans, nuts, peas, lentils and pasta -- was superior to a high-cereal-fiber diet -- think pumpernickel, rye pita, quinoa, large flake oatmeal and oat bran -- when it comes to lowering blood sugar and other risk factors for heart disease in people with diabetes.

"These findings fit with the general tenor of what's gone before. The trouble is that those studies tended to be considerably smaller and for shorter periods of time, and they didn't always show the effects significantly," said study author Dr. David J.A. Jenkins, Canada research chair in nutrition and metabolism at the University of Toronto and St. Michael's Hospital in Canada. "I think this certainly supports a recommendation to people that this is an extra tool in the tool kit."

Nuts and beans are good. Cut back on refined grains.

Pasta is in the lower glycemic index diet in this study. Surprised? Pasta has a much lower glycemic index than bread. It is made from different kinds of wheat.

In the St. Michael's study, roughly half the 210 participants were fed such a diet, which included includes beans, peas, lentils and nuts, as well as pasta, rice boiled briefly, large-flake oatmeal, oat bran and pumpernickel, rye, pita, quinoa and flaxseed breads.

A second group was fed a high-cereal diet that included whole-grain breads and cereals, brown rice, potatoes with skins and whole-wheat bread and crackers. The high-cereal diet did not contain nuts, beans or lentils, which are among the foods with the lowest glycemic indexes.

My reaction to rice on the higher glycemic index diet: Types of rice vary substantially in their glycemic index. The sticky rice has a very high glycemic index. Search the database at that link for rice. The higher amylose rices have much lower glycemic index. I wish rices in stores came with percent amylose ratings on their labels.

The Hemoglobin A1c (HbA1c) is a measure of sugar exposure levels.

"Low glycemic index diets may be useful as part of the strategy to improve glycemic control in patients with type 2 diabetes taking antihyperglycemic medications," Dr. Jenkins and colleagues wrote.

"The reduction in HbA1c was modest, but we think it has clinical relevance," they said, noting that improvements only slightly larger had been found to reduce microvascular complications by 21% to 37% in other prospective studies.

David Jenkins also developed the "Ape Diet". He also found that pistachios reduce blood sugar rise after meals. So the presence of nuts in the low glycemic index diet has a purpose.

By Randall Parker    2008 December 16 11:29 PM   Entry Permalink | Comments (4)
2008 December 04 Thursday
Wine Boosts Blood Omega 3 Fatty Acids?

A possible explanation for the claimed heart health benefits from drinking wine:

Moderate alcohol intake is associated with higher levels of omega-3 fatty acids in plasma and red blood cells. This is the major finding of the European study IMMIDIET that will be published in the January issue of the American Journal of Clinical Nutrition, an official publication of the American Society for Nutrition and is already available on line (www.ajcn.org ). The study suggests that wine does better than other alcoholic drinks. This effect could be ascribed to compounds other than alcohol itself, representing a key to understand the mechanism lying behind the heart protection observed in moderate wine drinkers.

Alcohol consumption seems to boost blood omega 3 fatty acids. It is not clear how.

"Several studies have shown that moderate alcohol consumption, including wine, is associated with protection against coronary heart disease and ischemic stroke - says Romina di Giuseppe, lead author of the study, from the Research Laboratories at Catholic University of Campobasso - Although the mechanisms are not completely defined, there was some evidence that alcohol intake might influence the metabolism of essential polyunsaturated fatty acids, as omega-3. That is exactly what we found in our population study. People drinking moderate amounts of alcohol, one drink a day for women and two for men, had higher concentration of omega-3 fatty acids in plasma and red blood cells independently of their fish intake".

What I'd like to know: Can one boost plasma and red blood cell omega 3 as high by consuming more omega 3 as by drinking wine?

"Analysis carried out on different alcoholic beverages –argues Licia Iacoviello coordinator of the IMMIDIET study at Catholic University of Campobasso - showed that the association between alcohol and omega-3 fatty acids was present in both wine drinkers and beer or spirits drinkers. However, the association was stronger between wine drinking and omega-3 fatty acids levels. This suggests that components of wine other than alcohol is associated with omega-3 fatty acids concentration. We may guess this effect can be ascribed to polyphenols".

If polyphenols cause this effect it should be possible to cause this same effect by eating cranberries or blueberries or some other polyphenol source. Anyone aware of any studies showing an omega 3 boost from consuming high polyphenol foods?

By Randall Parker    2008 December 04 11:24 PM   Entry Permalink | Comments (4)
2008 November 11 Tuesday
Childhood Obesity Adds 30 Years To Vascular Age

Fat kids have the arteries of middle aged people.

NEW ORLEANS, La., Nov. 11, 2008 – The neck arteries of obese children and teens look more like those of 45-year-olds, according to research presented at the American Heart Association’s Scientific Sessions 2008.

“There’s a saying that ‘you’re as old as your arteries,’ meaning that the state of your arteries is more important than your actual age in the evolution of heart disease and stroke,” said Geetha Raghuveer, M.D., M.P.H., associate professor of pediatrics at the University of Missouri Kansas City School of Medicine and cardiologist at Children’s Mercy Hospital. “We found that the state of the arteries in these children is more typical of a 45-year-old than of someone their own age.”

Researchers used ultrasound to measure the thickness of the inner walls of the neck (carotid) arteries that supply blood to the brain. Increasing carotid artery intima-media thickness (CIMT) indicates the fatty buildup of plaque within arteries feeding the heart muscle and the brain, which can lead to heart attack or stroke.

We are not designed for the environment we have created for ourselves. Some of our responses to that environment are maladaptive. Historically calorie malnutrition was the biggest killer of our ancestors. So we have genes that make us like food, especially fatty sweet food. As a result some kids have vascular systems that are undergoing accelerated aging.

The children’s “vascular age” — the age at which the level of thickening would be normal for their gender and race — was about 30 years older than their actual age, Raghuveer said.

A high fat diet for pregnant rats predisposes the rat offspring for obesity. If this same phenomenon is at work in humans then childhood obesity will probably get worse and cause more adult obesity in a vicious cycle.

A study in rats shows that exposure to a high-fat diet during pregnancy produces permanent changes in the offspring's brain that lead to overeating and obesity early in life, according to new research by Rockefeller University scientists. This surprising finding, reported in the Nov. 12 issue of the Journal of Neuroscience, provides a key step toward understanding mechanisms of fetal programming involving the production of new brain cells that may help explain the increased prevalence of childhood obesity during the last 30 years.

"We've shown that short-term exposure to a high-fat diet in utero produces permanent neurons in the fetal brain that later increase the appetite for fat," says senior author Sarah F. Leibowitz, who directs the Laboratory of Behavioral Neurobiology at Rockefeller. "This work provides the first evidence for a fetal program that links high levels of fats circulating in the mother's blood during pregnancy to the overeating and increased weight gain of offspring after weaning."

We need the ability to control human appetite and to activate cells to burn off excess calories.

By Randall Parker    2008 November 11 10:26 PM   Entry Permalink | Comments (8)
2008 October 31 Friday
Grapes Slow Development Of High Blood Pressure In Rats

Rats genetically engineered to develop high blood pressure developed it more slowly when grapes were added to their feed.

The researchers studied the effect of regular table grapes (a blend of green, red, and black grapes) that were mixed into the rat diet in a powdered form, as part of either a high- or low-salt diet. They performed many comparisons between the rats consuming the test diet and the control rats receiving no grape powder — including some that received a mild dose of a common blood-pressure drug. All the rats were from a research breed that develops high blood pressure when fed a salty diet.

In all, after 18 weeks, the rats that received the grape-enriched diet powder had lower blood pressure, better heart function, reduced inflammation throughout their bodies, and fewer signs of heart muscle damage than the rats that ate the same salty diet but didn't receive grapes. The rats that received the blood-pressure medicine, hydrazine, along with a salty diet also had lower blood pressure, but their hearts were not protected from damage as they were in the grape-fed group.

Says Mitchell Seymour, M.S., who led the research as part of his doctoral work in nutrition science at Michigan State University, "These findings support our theory that something within the grapes themselves has a direct impact on cardiovascular risk, beyond the simple blood pressure-lowering impact that we already know can come from a diet rich in fruits and vegetables." Seymour manages the U-M Cardioprotection Research Laboratory, which is headed by U-M heart surgeon Steven Bolling, M.D.

The researchers think flavanoids in grapes might be providing the heart protection.

"Although there are many natural compounds in the grape powder itself that may have an effect, the things that we think are having an effect against the hypertension may be the flavanoids – either by direct antioxidant effects, by indirect effects on cell function, or both. These flavanoids are rich in all parts of the grape - skin, flesh and seed, all of which were in our powder." Bolling explains.

You can get flavanoids from berries and cherries as well. The amount of grapes used is equivalent to a human eating 9 servings of grapes per day.

He notes that the popular DASH diet, which is low in salt and high in fruits and vegetables, has been proven to reduce mild high blood pressure without medication. The dose of whole table grape powder that was consumed in the study was roughly equivalent to a person eating nine human-sized servings of grapes a day. Currently, five to nine servings of fruits and vegetables are recommended as part of the DASH diet.

Other measures of heart function were better in the grape-fed group.

The researchers also measured the distortion of the heart size, weight and function that occurred over time – characteristics of heart failure – and found that the high-salt grape group had less of a change than the high-salt hydrazine group. Parameters related to the diastolic blood pressure – an important factor in human heart failure — and to the heart's relaxation during the diastolic phase also changed in just the high-salt grape group. Finally, the grape-fed rats had improved cardiac output, or more blood pumped per unit of time.

The researchers also looked for signs of inflammation, oxidative damage and other molecular indicators of cardiac stress. Again, the rats that received the high-salt grape diet had lower levels of these markers than rats that received the high-salt diet with hydrazine – and even the low-salt grape-eating rats had lower levels than the rats that received a low-salt diet alone.

Eat more fruits and vegetables or die before your time.

Update: A recent survey of grape health benefit research finds grapes provide health benefit in humans too.

So far, most of the evidence on grape polyphenols comes from laboratory experiments and animal studies. However, a few studies support the disease-preventing benefits of grapes in humans. Studies in patients treated with grape seed extracts have shown improvements in blood flow and cholesterol levels. In other studies, drinking Concord grape juice has improved measures of blood flow in patients with coronary artery disease and lowered blood pressure in patients with hypertension.

By Randall Parker    2008 October 31 05:30 AM   Entry Permalink | Comments (1)
2008 October 27 Monday
Whole Grains Cut Heart Risks

Don't eat that white bread.

October 27, 2008, St. Louis, MO – - About 5 million people in the United States suffer from heart failure (HF). While some reports indicate that changes to diet can reduce HF risk, few large, prospective studies have been conducted. In a new study researchers observed over 14,000 participants for more than 13 years and found that whole grain consumption lowered HF risk, while egg and high-fat dairy consumption raised risk. Other food groups did not directly affect HF risk. The results are published in the November 2008 issue of the Journal of the American Dietetic Association.

Diet is among the prominent lifestyle factors that influence major HF risk factors: coronary artery disease, obesity, diabetes and insulin resistance and hypertension. Using data from the Atherosclerosis Risk in Communities (ARIC) study, researchers from the Division of Epidemiology and Community Health, University of Minnesota and the Department of Epidemiology and Cardiovascular Diseases Program, University of North Carolina, analyzed the results of baseline exams of more than 14,000 White and African American adults conducted in 1987-89, with follow-up exams completed during 1990-92, 1993-95, and 1996-98. Four field centers participated in the study: Forsyth County, NC; Jackson, MS; northwest Minneapolis suburbs, MN; and Washington County, MD. The study also collected demographic characteristics and lifestyle factors, as well as other medical conditions such as cardiovascular disease, diabetes and hypertension.

Beware of eggs. Avoid milk fat.

Writing in the article, Jennifer A. Nettleton, Ph.D., states, "Although risk estimates were modest (7% lower risk per 1-serving increase in whole grain intake; 8% greater risk per 1-serving increase in high-fat dairy intake; 23% greater risk per 1-serving increase in egg intake), the totality of literature in this area suggests it would be prudent to recommend that those at high risk of HF increase their intake of whole grains and reduce intake of high-fat dairy and eggs, along with following other healthful dietary practices consistent with those recommended by the American Heart Association."

One of the reasons some potentially beneficial dietary factors tend not to show up in big dietary studies is that some potentially healthy foods aren't eaten much. How many people eat nuts or berries every day? I happen to eat berries every day. But I'm a statistical outlier.

If we are going to go to the trouble of genetically engineering foods to have more healthful compounds in them then we need to know which compounds would be best to engineer into foods. Are anthocyanins really the ticket?

In this study the scientists expressed two genes from snapdragon that induce the production of anthocyanins in snapdragon flowers. The genes were turned on in tomato fruit. Anthocyanins accumulated in tomatoes at higher levels than anything previously reported for metabolic engineering in both the peel and flesh of the fruit. The fruit are an intense purple colour.

The scientists tested whether these elevated levels actually had an effect on health. In a pilot test, the lifespan of cancer-susceptible mice was significantly extended when their diet was supplemented with the purple tomatoes compared to supplementation with normal red tomatoes.

It'll be easier to eat healthily 20 years from now both because we'll know better what helps and also because food will be genetically engineered to contain what helps and not to contain what hurts.

By Randall Parker    2008 October 27 11:12 PM   Entry Permalink | Comments (8)
2008 October 20 Monday
High Fruit And Vegetable Diet Cuts Heart Risk 30%

The news is the same all around the world: Eat a lot more fruits and vegetables.

DALLAS, Oct. 21, 2008 — The typical Western diet — fried foods, salty snacks and meat — accounts for about 30 percent of heart attack risk across the world, according to a study of dietary patterns in 52 countries reported in Circulation: Journal of the American Heart Association.

Researchers identified three dietary patterns in the world:
• Oriental: higher intake of tofu, soy and other sauces;
• Prudent: higher intake of fruits and vegetables; and
• Western: higher intake of fried foods, salty snacks, eggs and meat.

The Prudent diet was associated with a lower heart attack risk than the Oriental, researchers said.

“The objective of this study was to understand the modifiable risk factors of heart attacks at a global level,” said Salim Yusuf, D.Phil., the study’s senior author.

Previous studies have reached similar conclusions about the Prudent and Western diet in the United States and Europe. This study broadens those findings and identifies a unique dietary pattern that researchers labeled “Oriental” (because of a higher content of food items typical of an Oriental diet.) The dietary pattern recommended by the American Heart Association is similar to the Prudent diet described in this study.

Eat more fruits and vegetables. Never mind that in other posts I delve into the concentrations of flavanols or pectin or other antioxidants in different fruits and vegetables. The main thing is to get more fruits and vegetables and less of everything else (with the possible exception of nuts and high omega 3 fish).

After adjusting for known risk factors, researchers found:
• People who consumed the Prudent diet of more fruits and vegetables had a 30 percent lower risk of heart attack compared to people who ate little or no fruits and vegetables.
• People who consumed the Western diet had a 35 percent greater risk of having a heart attack compared to people who consumed little or no fried foods and meat.
• The Oriental pattern showed no relationship with heart attack risk.

Researchers said that while some components of the Oriental pattern may be protective, others such as the higher sodium content of soy sauces, may increase cardiovascular risk, neutralizing any relationship.

You know what you need to do. But can you manage to make yourself do it? Most people who know better still do not act on the information. French fries and burgers just taste too good because your ancestors generally died of calorie malnutrition and its complications before getting a chance to die of a heart attack. So appetite-regulating genes were selected by natural selection to make us go for fats and meats and sweets.

By Randall Parker    2008 October 20 11:06 PM   Entry Permalink | Comments (6)
2008 September 26 Friday
Only Low Doses Of Chocolate Reduce Inflammation Marker

Less than a full candy bar of dark chocolate appears to be the ideal dose for inflammation reduction.

Maybe gourmands are not jumping for joy. Probably they would have preferred bigger amounts to sup-port their passion. Though the news is still good for them: 6.7 grams of chocolate per day represent the ideal amount for a protective effect against inflammation and subsequent cardiovascular disease. A new effect, demonstrated for the first time in a population study by the Research Laboratories of the Catholic University in Campobasso, in collaboration with the National Cancer Institute of Milan.

That 6.7 grams per day is only 47 grams per week or about 1.7 ounces. We aren't even talking a full candy bar.

The scientists looked for benefits from chocolate by measuring the level of inflammation by checking C-reactive protein (CRP) in the blood. Whether lowering CRP with chocolate really will provide a long term health benefit remains unproven.

"We started from the hypothesis", says Romina di Giuseppe, 33, lead author of the study, "that high amounts of antioxidants contained in the cocoa seeds, in particular flavonoids and other kinds of polyphenols, might have beneficial effects on the inflammatory state. Our results have been absolutely encouraging: people having moderate amounts of dark chocolate regularly have significantly lower levels of C-reactive protein in their blood. In other words, their inflammatory state is considerably reduced." The 17% average reduction observed may appear quite small, but it is enough to decrease the risk of cardiovascular disease for one third in women and one fourth in men." It is undoubtedly a remarkable outcome".

Chocolate amounts are critical. "We are talking of a moderate consumption. The best effect is obtained by consuming an average amount of 6.7 grams of chocolate per day, corresponding to a small square of chocolate twice or three times a week. Beyond these amounts the beneficial effect tends to disappear".

The researchers didn't bother studying the effects of milk chocolate since they expected the milk to interference with absorption of polyphenols.

From a practical point of view, as the common chocolate bar is 100 grams, the study states that less than half a bar of dark chocolate consumed during the week may become a healthy habit. What about the milk chocolate? "Previous studies", the young investigator continues, "have demonstrated that milk interferes with the absorption of polyphenols. That is why our study considered just the dark chocolate".

I wonder whether interference with polyphenol absorption is one of the reasons why some studies find harmful effects from milk products consumption.

From the paper's abstract: If you ate about 3/4ths of an ounce of dark chocolate every third day you'd get the optimal benefit.

A J-shaped relationship between dark chocolate consumption and serum CRP was observed; consumers of up to 1 serving (20 g) of dark chocolate every 3 d had serum CRP concentrations that were significantly lower than nonconsumers or higher consumers. Our findings suggest that regular consumption of small doses of dark chocolate may reduce inflammation.

So perhaps eat small amounts of dark chocolate a couple of times a week. But why do higher doses of dark chocolate fail to provide a benefit? Is it really the size of the dose or the frequency of the dose that makes consumption of larger amounts of chocolate fail to lower CRP? Maybe more frequent consumption of dark chocolate up-regulates enzymes that break down polyphenols.

By Randall Parker    2008 September 26 11:46 PM   Entry Permalink | Comments (8)
Pistachios Improve Blood Cholesterol

Pistachios are good for your heart and arteries.

The participants began the study by eating a typical American diet consisting of 35 percent total fat and 11 percent saturated fat for two weeks. They then tested three diets for four weeks each with about a two-week break between each diet. All three diets were variations on the Step I Diet, a cholesterol-lowering diet in general use. The diets included, as a control, a Step I Diet with no pistachios and about 25 percent total fat and 8 percent saturated fat. The pistachio enhanced diets were Step I Diets with 10 and 20 percent of the energy supplied by pistachio nuts, respectively. The 10 percent pistachio diet had 30 percent total fat and 8 percent saturated fat and the 20 percent pistachio diet had 34 percent total fat and 8 percent saturated fat.

The pistachios change cholesterol metabolism.

The participants ate half their pistachios as a snack and the rest incorporated into meals.

The researchers report in the most recent issue of the American Journal of Clinical Nutrition that "Inclusion of pistachios in a healthy diet beneficially affects cardiovascular disease risk factors in a dose-dependent manner, which may reflect effects on Stearoyl CoA Desaturase (SCD). " The researchers used the ratio of two fatty acids, 16:1 and 16:0 in plasma as a marker for SCD, an enzyme that is involved in the body's synthesis of fatty acids.

"SCD is an important enzyme involved in cholesterol metabolism," says Gebauer.

They found the ratio of 16:1/16:0 was significantly lower, suggesting a decrease in SCD activity, after eating the 20 percent energy pistachio diet compared to the control diet which had no pistachios. Also, the change in the 16:1/16:0 ratio was correlated with the change in cholesterol, suggesting that SCD activity may contribute to the lipid-lowering effects of pistachios. That, accompanied by the dose-dependent effects of the pistachios, begins to unravel the way in which pistachios improve cardiovascular health.

So pistachios contain some to-be-discovered compound(s) that help improve your blood lipids. Foods are pharmaceuticals, mostly by accident.

Note that the pistachio fats did not displace the other fats in the diet. They added to total dietary fat but in a way that improved blood lipids.

Compared to the control diet, the 20 percent pistachio diet lowered LDL cholesterol -- bad cholesterol -- about 12 percent and the 10 percent energy pistachio diet lowered LDL cholesterol by 9 percent that suggests a 9 to 12 percent decrease in coronary heart disease risk. The relationships of total cholesterol to HDL cholesterol and LDL cholesterol to HDL cholesterol may be more powerful predictors of cardiovascular risk. The effects of the 10 and 20 percent energy diets showed a dose dependent effect on these ratios.

Phytosterols in pistachios might be behind the protective effect.

However, the researchers note that the reduction in LDL cholesterol observed was seven times greater than would be expected from only the fatty acid profile of pistachios. They suggest that the lipid lowering effects not only reflect the fatty acid profile of the diet, but also are the result of other bioactive substances in pistachios, perhaps phytosterols and fiber.

I'd like to see this experiment repeated with other kinds of nuts to see the relative potencies of different nuts.

By Randall Parker    2008 September 26 11:05 PM   Entry Permalink | Comments (3)
2008 September 01 Monday
Fish Oil Better Than Statin For Chronic Heart Failure

Omega 3 fatty acids work better than a popular statin to extend life of those already diagnosed with an enlarged failing heart.

In the group of patients taking the fish oil pills, 1,981 died of heart failure or were admitted to the hospital with the problem. In the patients on placebo pills, 2,053 died or were admitted to the hospital for heart failure.

In a parallel study, the same team of Italian doctors gave 2,285 patients the drug rosuvastatin, also known as Crestor, and gave placebo pills to 2,289 people. Patients were then tracked for about four years. The doctors found little difference in heart failure rates between the two groups.

This is not an argument against taking statins to lower cholesterol. A cholesterol lowering drug can prevent artery clogging that will eventually cause cardiovascular failure. But once the damage has already reached a critical phase statins basically come too late to make much difference.

I see this result as more evidence that the type of fat you eat is probably more important than the amount of fat you eat.

Heart disease is not the only degenerative disease whose progress you can slow or stop once you have it. A vitamin supplement formula including omega 3 fatty acids appears to slow or stop the progress of atrophic (dry) age-related macular degeneration (AMD). Other diseases such as insulin resistant diabetes can be made less bad by diet. But better to improve the diet decades before you become old enough to be at risk for these degenerative diseases of old age.

Update: A new study finds that higher dietary omega 3 fatty acids the most likely cause of lower heart disease risk in Japan.

If you're fishing for ways to reduce the risk of heart disease, you might start with the seafood-rich diet typically served up in Japan. According to new research, a lifetime of eating tuna, sardines, salmon and other fish appears to protect Japanese men against clogged arteries, despite other cardiovascular risk factors.

The research, published in the August 5, 2008, issue of Journal of the American College of Cardiology (JACC), suggests that the protection comes from omega-3 fatty acids found in abundance in oily fish. In the first international study of its kind, researchers found that compared to middle-aged white men or Japanese-American men living in the United States, Japanese men living in Japan had twice the blood levels of omega-3 fatty acids—a finding that was independently linked to low levels of atherosclerosis.

"The death rate from coronary heart disease in Japan has always been puzzlingly low," said Akira Sekikawa, M.D., Ph.D, an assistant professor of epidemiology at the University of Pittsburgh, PA, and an adjunct associate professor at Shiga University of Medical Science, Otsu, Japan. "Our study suggests that the very low rates of coronary heart disease among Japanese living in Japan may be due to their lifelong high consumption of fish."

Click thru to read all the details of how the researchers came to this conclusion. Or just start eating fish or taking DHA/EPA capsules.

Update: Still not ready to change your diet? Also remember my recent post Fish Reduce Aging Brain Lesions.

Update II: If you want to be hungry like a wolf then eat salmon.

Wolves are not quite the red-blooded hunters we thought they were. It appears they prefer to dine on a nice piece of salmon rather than deer.

By Randall Parker    2008 September 01 07:22 PM   Entry Permalink | Comments (3)
2008 August 18 Monday
Cocoa Flavanols Improve Brain Blood Flow

The purpose of this post is to provide you with health advice that you will enjoy following. Too many forms of health advice are joyless. Use cocoa powder without guilt.

McLEAN, VA (August 18, 2008) – Cocoa flavanols, the unique compounds found naturally in cocoa, may increase blood flow to the brain, according to new research published in the Neuropsychiatric Disease and Treatment journal. The researchers suggest that long-term improvements in brain blood flow could impact cognitive behavior, offering future potential for debilitating brain conditions including dementia and stroke.

In a scientific study of healthy, older adults ages 59 to 83, Harvard medical scientists found that study participants who regularly drank a cocoa flavanol-rich beverage made using the Mars, Incorporated Cocoapro® process had an eight percent increase in brain blood flow after one week, and 10 percent increase after two weeks.

In this first-of-its-kind study, the researchers found both short and long-term benefits of cocoa flavanols for brain blood flow, offering future potential for the one in seven older Americans currently living with dementia. When the flow of blood to the brain slows over time, the result may be structural damage and dementia. Scientists speculate that maintaining an increased blood flow to the brain could slow this cognitive decline.

I see from Googling that Mars sells this high flavanol chocolate under the CocoaVia brand. Some comments on the web say it is bitter. That is why flavanols get removed by most chocolate companies from chocolate during processing. But I'll put up with the bitter (more likely drown the bitter in honey) for the health benefits. Worth a try.

By Randall Parker    2008 August 18 10:07 PM   Entry Permalink | Comments (5)
2008 July 08 Tuesday
Potassium Cuts Heart Risks

A diet high in vegetables will raise your potassium intake and cut your risk of high blood pressure, heart attack, and stroke. It'll probably reduce your risk of dementia too.

Nashville, Tenn. – July 7, 2008 – A new article indicates that an increased intake in minerals such as potassium, and possibly magnesium and calcium by dietary means may reduce the risk of high blood pressure and decrease blood pressure in people with hypertension. A high intake of these minerals in the diet may also reduce the risk of coronary heart disease and stroke. These findings are published in a supplement appearing with the July issue of The Journal of Clinical Hypertension.

Potassium, specifically, has been hypothesized as one reason for the low cardiovascular disease rates in vegetarians, as well as in populations consuming primitive diets (generous in potassium and low in sodium). In isolated societies consuming diets high in fruits and vegetables, hypertension affects only 1 percent of the population, whereas in industrialized countries which consume diets high in processed foods and large amounts of dietary sodium, 1 in 3 persons have hypertension. Americans consume double the sodium and about half of the potassium that is recommended by current guidelines.

According to the paper, if Americans were able to increase their potassium intake, the number of adults with known hypertension with blood pressure levels higher than 140/90 mm Hg might decrease by more than 10 percent and increase life expectancy. Similar studies show that diets high in magnesium (at least 500 to 1,000 mg/d) and calcium (more than 800 mg/d) may also be associated with both a decrease in blood pressure and risk of developing hypertension. Data regarding these minerals, however, are not definitive.

"If we were to achieve the correct potassium/sodium ratio through dietary means, there would be less hypertension and cardiovascular disease in the population as a whole," says Mark C. Houston, M.D., author of the study.

Lots of different lines of research keep converging on more vegetables, more fruits, more nuts, more fish, and more beans and legumes. Displace red meat and grains with these foods and you'll live longer and feel better.

Have a look: Dietary sources of potassium.

By Randall Parker    2008 July 08 10:46 PM   Entry Permalink | Comments (4)
2008 June 24 Tuesday
Vitamin D Linked To Lower Mortality Risk

Older folks with more vitamin D in their blood die off at a slower rate.

Individuals with lower blood levels of vitamin D appear to have an increased risk of death overall and from cardiovascular causes, according to a report in the June 23 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

A recent consensus panel estimated that about 50 percent to 60 percent of older individuals in North America and the rest of the world do not have satisfactory vitamin D status, and the situation is similar for younger individuals, according to background information in the article. Blood levels of 25-hydroxyvitamin D, a measure of blood vitamin D levels, lower than 20 to 30 nanograms per milliliter have been associated with falls, fractures, cancer, immune dysfunction, cardiovascular disease and hypertension. These effects are thought to be mediated by the compound 1,25-dihydroxyvitamin D, which is produced by the body and also converted from 25-hydroxyvitamin D.

Harald Dobnig, M.D., of Medical University of Graz, Austria, and colleagues studied 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels in 3,258 consecutive patients (average age 62 years) who were scheduled for coronary angiography testing at a single medical center between 1997 and 2000.

During about 7.7 years of follow-up, 737 (22.6 percent) of participants died, including 463 (62.8 percent) who died of cardiovascular causes. Death rates from any cause and from cardiovascular causes were higher among individuals in the lower one-half of 25-hydroxyvitamin D levels and the lowest one-fourth of 1,25-dihydroxyvitamin D levels. These associations remained when the researchers accounted for other factors, including coronary artery disease, physical activity level and co-occurring diseases.

Low 25-hydroxyvitamin D levels also were correlated with markers of inflammation such as C-reactive protein, as well as signs of oxidative (oxygen-related) damage to cells, the authors note.

"Apart from the proved effects that vitamin D has on bone metabolism and neuromuscular function, appropriate serum levels (that may also be higher than in the present investigation) are associated with a decrease in mortality," they conclude. "Although not proved, it seems possible that at least part of this effect may be due to lowering of a risk profile promoting atherosclerosis [narrowing of the arteries] and preventing cardiovascular end points."

"Based on the findings of this study, a serum 25-hydroxyvitamin D level of 20 nanograms per milliliter or higher may be advised for maintaining general health."

Lower vitamin D is associated with a substantially higher risk of mortality.

While cross-sectional studies have linked vitamin D to cardiovascular disease, these findings are the first to show elevated mortality, they noted.

Notably, even vitamin D insufficiency increased mortality risk 33% to 54%, so Dr. Dobnig's group recommended a serum 25-hydroxyvitamin D level of 20 ng/mL or higher for maintaining general health.

Most older folks in Europe have low vitamin D levels.

Dobnig et al say that these results show that a low 25-hydroxyvitamin-D level can be considered a strong risk indicator for all-cause mortality in women and in men.

They note that while the percentage of patients with low 25-hydroxyvitamin-D values in this study may seem unexpectedly high, with roughly two-thirds of those included having levels below 20 ng/mL, they point out that the mean value of 17.3 ng/mL compares well with values reported from other large trials performed in middle European countries such as France, Italy, and Germany.

This study by itself does not prove the direction of causality. For example, people who get more exercise outside will get more vitamin D from the sun shining on them. But they will also get more exercise. Also, people who eat fish will get more vitamin D in their diet. But they'll also get heart healthy omega 3 fatty acids. But this study fits with a larger pattern in studies of vitamin D and health and so I think it likely that vitamin D is providing some benefit. But if you get the vitamin D by exercising outside and eating salmon you won't have to worry which factor is delivering the benefit.

By Randall Parker    2008 June 24 09:20 PM   Entry Permalink | Comments (1)
2008 June 09 Monday
Low Vitamin D Associated With More Heart Attacks

The stream of research reports on the health benefits of vitamin D just keeps coming. Today we learn that vitamin D probably cuts our risk of heart attacks.

Low levels of vitamin D appear to be associated with higher risk of myocardial infarction (heart attack) in men, according to a report in the June 9 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

Studies have shown that the rates of cardiovascular disease-related deaths are increased at higher latitudes and during the winter months and are lower at high altitudes, according to background information in the article. "This pattern is consistent with an adverse effect of hypovitaminosis D [vitamin D deficiency], which is more prevalent at higher latitudes, during the winter and at lower altitudes," the authors write. While other explanations are possible, vitamin D has been shown to affect the body in ways that may influence the risk of heart attack or heart disease.

Edward Giovannucci, M.D., Sc.D., of Harvard School of Public Health and Brigham and Women's Hospital, Boston, and colleagues reviewed medical records and blood samples of 454 men (age 40 to 75) who had non-fatal heart attack or fatal heart disease from the date of blood collection (between January 1993 and December 1995) until January 2004. They then compared the data from these men with records and blood samples of 900 living men who did not have a history of cardiovascular disease. The men's diet and lifestyle factors, recorded by self-administered questionnaires were also noted.

Men with a vitamin D deficiency (having 15 nanograms per milliliter of blood or less) had an increased risk for heart attack compared with those with a sufficient amount (having 30 nanograms per milliliter of blood or more) of vitamin D. "After additional adjustment for family history of myocardial infarction, body mass index, alcohol consumption, physical activity, history of diabetes mellitus and hypertension, ethnicity, region, marine omega 3 intake, low- and high-density lipoprotein cholesterol levels and triglyceride levels, this relationship remained significant," the authors write. Men with intermediate levels of vitamin D had a higher risk of heart attack than those with sufficient vitamin D levels.

How's your dietary vitamin D? Do you get much sun?

Also, vitamin D deficiency is common among children.

Many healthy infants and toddlers may have low levels of vitamin D, and about one-third of those appear to have some evidence of reduced bone mineral content on X-rays, according to a report in the June issue of Archives of Pediatrics & Adolescent Medicine, one of the JAMA/Archives journals.

Reports of a resurgence of vitamin D deficiency and rickets, the resulting bone-weakening disease, have emerged in several states, according to background information in the article. Vitamin D deficiency also appears to be high in other countries, including Greece, China, Canada and England.

We spend a lot more time indoors than our distant ancestors did. We do not live in our natural environments. This creates problems such as not enough sunlight hitting our skin to synthesize vitamin D.

By Randall Parker    2008 June 09 10:41 PM   Entry Permalink | Comments (0)
2008 March 16 Sunday
Fish Reduce Heart Attack Risks

Eat fish.

Author James O’Keefe, M.D., a cardiologist from the Mid America Heart Institute in Kansas City, Mo., cites the results of several large trials that demonstrated the positive benefits associated with omega-3 fatty acids, either from oily fish or fish oil capsules.

“The most compelling evidence for the cardiovascular benefit provided by omega-3 fatty acids comes from three large controlled trials of 32,000 participants randomized to receive omega-3 fatty acid supplements containing DHA and EPA or to act as controls,” explains Dr. O’Keefe. “These trials showed reductions in cardiovascular events of 19 percent to 45 percent. Overall, these findings suggest that intake of omega-3 fatty acids, whether from dietary sources or fish oil supplements, should be increased, especially in those with or at risk for coronary artery disease.”

How much fish oil should people attempt to incorporate into their diets" According to Dr. O’Keefe, people with known coronary artery disease should consume about 1 gram per day, while people without disease should consume at least 500 milligrams (mg) per day.

“Patients with high triglyceride levels can benefit from treatment with 3 to 4 grams daily of DHA and EPA,” says Dr. O’Keefe. “Research shows that this dosage lowers triglyceride levels by 20 to 50 percent.”

About two meals of oily fish can provide 400 to 500 mg of DHA and EPA, so patients who need to consume higher levels of these fatty-acids may choose to use fish oil supplements to reach these targets.

How much EPA and DHA you are going to get from eating fish depends heavily on which fish you eat. They differ on the total amount of fat per serving and also in terms of what percentage of the fat is DHA or EPA.

See this chart of EPA and DHA per 3 oz serving of various types of fish. Their amounts of EPA and DHA vary by more than 2 orders of magnitude. If you choose to eat 3 ounces per day of the higher EPA and DHA fish you can easily get 1 gram of EPA and DHA per day. Though doing that day after day might get tedious and time consuming. The pills have their appeal.

By Randall Parker    2008 March 16 10:53 PM   Entry Permalink | Comments (7)
2008 March 02 Sunday
Low Fat Diets Better For Heart Than Low Carbo Diets?

I'm far from convinced. But here's yet another round in the ideal diet debate.

Low-fat diets are more effective in preserving and promoting a healthy cardiovascular system than low-carbohydrate, Atkins’-like diets, according to a new study by researchers at the Medical College of Wisconsin in Milwaukee.

The study, published in the February edition of the scientific journal Hypertension, was led by David D. Gutterman, M.D., Northwestern Mutual Professor of Cardiology, professor of medicine and physiology, and senior associate dean of research at the Medical College. Shane Phillips, M.D., a former Cardiology faculty member at the Medical College, and now assistant professor in the department of physical therapy at the University of Illinois - Chicago, was the lead author.

Mind you, this is not the first study to address the question of fats versus carbohydrates for heart health and it likely won't be the last. The issue is not settled.

These scientists are quite sure that higher fat content does you more harm than higher carbohydrate content. My reaction: it depends.

“Low-carbohydrate diets are significantly higher in total grams of fat, protein, dietary cholesterol and saturated fats than are low-fat diets. While a low-carbohydrate diet may result in weight loss and improvement in blood pressure, similar to a low-fat diet, the higher fat content is ultimately more detrimental to heart health than is the low-fat diet suggested by the American Heart Association,” points out Dr. Phillips.

“The higher fat content of a low-carbohydrate diet may put dieters at an increased risk of atherosclerosis (hardening of the arteries) because low-carbohydrate diets often reduce protection of the endothelium, the thin layer of cells that line the blood vessels of the circulatory system. The reduced production from the endothelium of nitric oxide, a specific chemical, puts the vessel at higher risk of abnormal thickening, greater clotting potential, and cholesterol deposition, all part of the atherosclerosis process,” says Dr. Gutterman.

What does the carbs versus fats debate depend on? Which fats. Which carbohydrates. Also, what particular genes do you have?

Take carbohydrates for example. They do not all break down into simple sugars in the intestines at the same speed. The ones that break down slowly (they have low glycemic index) enter the blood stream more slowly than the ones that break down quickly (they have high glycemic index). A rapid rise in blood sugar has harmful effects. Plus, the simple sugars fructose and glucose do not get metabolized the same way. Glucose transport gets regulated with insulin for example. So not all carbohydrates are equal.

What I really want to see: A comparison where one group eats unrefined very low glycemic index carbs while another group eats refined high glycemic index carbs. Then 3 other groups should eat polyunsaturated, monounsaturated, and saturated fats. But even that split isn't fine enough. Still, such a comparison would be a good start.

These researchers see fats as worse for the cardiovascular system because the low carb diet participants showed less artery dilation than the low fat diet participants.

Over a six-week period, the researchers found reduced flow-mediated dilation in the arm artery in participants who were on the low-carbohydrate diet. Reduced flow-mediated dilation, as measured in this study, is an early indicator of cardiovascular disease. On the other hand, flow-mediated dilation improved significantly in participants on the low-fat diet suggesting a healthier artery which is less prone to developing atherosclerosis.

“We observed a reduction in brachial artery flow-mediated dilation after six weeks of weight loss on a low-carbohydrate, Atkins’-style diet,” Dr. Gutterman says.

A diet high in nuts would be high in fats. But it would be higher in less saturated fats and higher in arginine that promotes nitric acid production and capillary dilation. So I don't think the question of ideal diets is as easy as these researchers make it sound.

For the sake of argument, imagine that those who ate the low carb diet kept their weight down for longer periods of time. That benefit might outweigh other costs and benefits. We need to know more about the longer term effects of these diets. Does the low carbo diet do a better job of keeping off weight?

The researchers point out that the low carbo diet had less folic acid. But that's easily remediable by taking a pill or by eating green leafy vegetables (which are high in fiber too and have other good stuff in them).

Low-carbohydrate diets were also found to have significantly less daily folic acid than low-fat diets. Folic acid is thought to be helpful in reducing the likeliness of heart disease. This protective effect results from the antioxidant property of folic acid and its ability to lower levels of homocysteine, a naturally occurring amino acid that can be dangerous at elevated levels.

Low glycemic index beans also are good sources of folic acid. Check out this glycemic index database and try to shift your diet toward lower glycemic index foods. Those foods tend to be healthier for other reasons as well.

By Randall Parker    2008 March 02 08:00 PM   Entry Permalink | Comments (3)
2003 July 24 Thursday
Ape Man Diet Lowers Cholesterol And Inflammation Marker

Ray Davies of the Kinks was on to something.

July 22, 2003 -- Researchers at the University of Toronto and St. Michael's Hospital have shown that a vegetarian diet composed of specific plant foods can lower cholesterol as effectively as a drug treatment. The study, published in the July 23 issue of the Journal of the American Medical Association, compared a diet of known cholesterol-lowering, vegetarian foods to a standard cholesterol-reducing drug called lovastatin. The special diet lowered levels of LDL cholesterol - the "bad" cholesterol known to cause clogging in coronary arteries - in subjects by almost 29 per cent, compared to a 30.9 per cent decrease in the lovastatin subjects. The special diet combined nuts (almonds), soy proteins, viscous fibre (high-fibre) foods such as oats and barley and a special margarine with plant sterols (found in leafy green vegetables and vegetable oils).

Lead author David Jenkins, a professor in U of T's Department of Nutritional Sciences and director of the Clinical Nutrition and Risk Factor Modification Centre at St. Michael's Hospital, believes the reason these foods work so well to reduce cholesterol is that humans may be evolutionarily adapted to what has been called the "ape diet," a diet very high in fibre, nuts, vegetable proteins and plant sterols.

He adds the study could have far-reaching implications for public health. "As we age, we tend to get raised cholesterol, which in turn increases our risk of heart disease. This study shows that people now have a dietary alternative to drugs to control their cholesterol, at least initially." Jenkins notes the diet can also be used to maintain normal cholesterol levels.

In this month-long study, a follow-up to one released December 2002, 46 men and women with raised cholesterol were randomly assigned to one of three vegetarian diet groups. The control group ate meals low in saturated fats (such as those found in animal products like beef and butter). The second group had the same low fat diet, plus a daily 20 mg treatment of lovastatin. The last group had a diet high in four foods known to have cholesterol-lowering properties. This special diet, designed to be easy to prepare and eat, included foods such as oat bran bread and cereal, soy drinks, fruit and soy deli slices. A typical dinner for people on the special diet was tofu bake with eggplant, onions and sweet peppers, pearled barley and vegetables.

The diet had 4 major categories of components.

The key components of the ape diet are plant sterols, found in plant oils and enriched margarines, viscous fibre, found in oats, barley and aubergine, and soy protein and nuts.

The margarines enriched with plant sterols (which compete with cholesterol for absorption) used in the study may have been the commercial brands Take Control, Benecol, and Benecol Light. To up your plant sterol content using natural foods one possibility is pecans with 95 milligrams of plant sterols per 100 grams. However, the level of plant sterols in the margarines is about two orders of magnitude greater (1.7 grams sterols in 14 grams of Take Control) and clinical trials in plant sterols have used about 2 grams per day. Still, the nuts have other heart-healthy benefits.

The researchers claim this diet works because it recreates the kind of diet humans evolved eating.

"We went right back in time to, hypothetically, five million years ago, when the diet would largely be leafy vegetables, fruits, nuts and seeds," Dr. Jenkins said.

While the researchers bill this diet as a return to the sort of diet that our ancestors ate for millions of years that is not exactly the case. First of all, it is unlikely that before the development of agriculture any humans or pre-humans ate soy as a major food source. If there are compounds in soy that have some sort of pharmaceutical effect upon cholesterol levels it is not clear (at least to me) that those compounds were present in diets thru some other food sources. Also, oats and barley would not have been major sources of calories. However, they are serving here as sources of soluble fiber and it does seem likely that whatever humans did eat provided a considerable amount of soluble fiber. So it seems likely there are elements in this diet which are not part of our evolutionary history while other elements have been added into the diet by using food sources that humans did not eat historically.

There is another important caveat to keep in mind when interpreting these results: various human subpopulations have split off from each other long enough and ate sufficiently different diets from each other to have evolved adaptations to local food sources. We see signs of this, for example, with northern Europeans who make more lactase enzyme for digesting milk. We also see it in the differing abilities of racial and ethnic groups to handle alcohol. It is unlikely that every ethnic and racial group has the same average ideal diet. Eventually declining costs of DNA sequencing and the identification of genetic variations that affect how we metabolise food will lead to the widespread practice of nutrigenomics where dietary recommendations will be personalized for one's specific genetic profile and risk factors.

The results of this study are sufficiently dramatic that JAMA recommends its use before cholesterol-lowering drugs are tried.

In an accompanying editorial, James Anderson, a professor of medicine at the University of Kentucky in Lexington, said the findings have dramatic public-health implications. He suggested that physicians prescribe the "ape diet" to patients before even considering drugs.

This deit is an improvement on the Garden of Eden diet the same researchers developed.

The daily volume of food was about a third of that of the Garden of Eden diet, Jenkins said, adding the people who followed it didn't complain about how much they had to eat but said they couldn't eat any more.

Those who lost weight were asked to, however.

Most of the reports on this study didn't pick up on one particularly interesting result the researchers observed.

Surprisingly, the diet also lowered the levels of C-reactive protein, considered a risk marker for heart disease.

The CRP drop was dramatic.

Equally impressive was a 28 percent drop in C-reactive protein, a substance found in the blood that is a sign of inflammation and possible heart disease. The statin group had a 33 percent drop.

The fact that this diet lowers C Reactive Protein (CRP) levels is an added bonus. CRP is a marker for inflammation that has been found to be correlated with heart disease risk. While the importance of CRP as a marker is still debated among cardiology researchers it seems important because there is growing recognition among medical researchers of the role chronic inflammation plays as a cause of the development of degenerative diseases. Any diet that lowers inflammation markers likely will yield more benefits than just lowering the risk of heart failure.

As for how this diet lowered C Reactive Protein (CRP): there are a lot of possibilities. Vitamin E, omega 3 fatty acids, and vitamin B6 are a few of the factors that are thought to lower CRP. Losing weight helps lower CRP as well. However, statin drugs for lowering cholesterol also lower CRP. So is the cholesterol-lowering effect of the diet causing CRP to drop? Maybe.

The Scientist has a good recent survey of the many ways chronic inflammation appears to contribute to the development of many diseases. (requires free registration - and I really recommend taking the trouble as they are one of the better science news sites)

Centuries ago, this trigger was pulled on a more consistent basis as humans battled a harsher environment; Johnson attributes today's toll of inflammation on the super clean environments of Western society. Also, because humans are living longer than evolutionarily designed, and in larger numbers, says Johnson, the odds are increased for disease. "You have an immune system that's looking for something to do and is basically getting into trouble," he says. "I think the problems are caused by an ongoing, aggravated, chronic response to an immune problem that the innate system imagines is there, but isn't." Also, the various byproducts associated with immune system attack, such as reactive oxygen species that decimate joints, may be causing long-term, deleterious effects.

The argument here is that the immune system no longer has enough real enemies to attack and yet it is all hyped up ready to attack something and responds inappropriately. Of course there is a large assortment of auto-immune diseases but many scientists are looking at inflammation response (and it is hard to untangle inflammation response from immune response) as another manifestation of this general problem. However, in some cases chronic inflammation may be getting triggered by chronic infections. This can happen with helicobacter pylori in the stomach. Peridontal disease also causes arterial inflammation and increased risk of heart disease.

However, many clinicians were unclear of the cause of elevated CRP levels. A study published earlier this year in the Journal of Periodontology reported that inflammatory effects from periodontal disease, a chronic bacterial infection of the gums, cause oral bacterial byproducts to enter the bloodstream and trigger the liver to make proteins such as CRP that inflame arteries and promote blood clot formation.

Keep your teeth clean and your gums healthy.

The inflammation-lowering angle is a lot more interesting because the benefits of cholesterol lowering and the methods for lowering cholesterol are a lot more widely known in comparison. We still do not understand all the factors that contribute to chronic inflammation or the best strategies to use to reduce it.

By Randall Parker    2003 July 24 09:27 PM   Entry Permalink | Comments (9)
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