Contrary to what was previously assumed, overweight is not increasing the overall death rate in the German population. Matthias Lenz of the Faculty of Mathematics, Computer Science, and Natural Sciences of the University of Hamburg and his co-authors present these and other results in the current issue of Deutsches Ärtzeblatt International (Dtsch Artzebl Int 2009; 106[40]: 641).
Most Germans are overweight, with a body mass index (BMI) between 25 and 29.9 kg/m2. About 20% are obese (BMI of 30 or over), with age- and gender-related differences. The authors systematically evaluated 42 studies of the relationships between weight, life expectancy, and disease.
The Süddeutsche Zeitung published an advance notice of the report (http://www.sueddeutsche.de/gesundheit/140/489526/text/), which shows that overweight does not increase death rates, although obesity does increase them by 20%. As people grow older, obesity makes less and less difference.
Keep in mind if you are gaining weight that even if your BMI is still under 30 you might be on path to a BMI up in the danger zone.
Being overweight does boost heart disease risk. But people who break their hips become less mobile and a lot less healthy. Being overweight trades off between different health risks.
For coronary heart disease, overweight increases risk by about 20% and obesity increases it by about 50%. On the other hand, a larger BMI is associated with a lower risk of bone and hip fracture.
In relation to cancer, the overall death rate among extremely obese men (BMI above 40) is no higher than among those of normal weight. Men who are overweight even have a 7% lower death rate. No significant association was found in women.
What I'm expecting: Genetic testing might show us what our relative risks are for a large variety of diseases and this knowledge could push us toward different ideal weights depending on which diseases we have the greater risks for. Also, some people are probably genetically better adapted to carrying more weight.
Note that you have other options for slowing bone decay aside from carrying more weight around. Exercise, better food, and a combination of vitamin D and vitamin K might cut bone fracture risks with age.
Weight studies are problematic because weight can vary due to muscle mass as well (albeit less often). Also, people can lose weight during the early stages of an illness before they even know they are sick. How well did the researchers adjust for these factors?
Telomere caps on chromosomes shorten with age. Obesity and stress are correlated with faster shrinking of telomere caps.
Women who maintain a healthy weight and who have lower perceived stress may be less likely to have chromosome changes associated with aging than obese and stressed women, according to a pilot study that was part of the Sister Study. The long-term Sister Study is looking at the environmental and genetic characteristics of women whose sister had breast cancer to identify factors associated with developing breast cancer. This early pilot used baseline questionnaires and samples provided by participants when they joined the Sister Study.
Two recent papers published in Cancer Epidemiology Biomarkers and Prevention looked at the length of telomeres, or the repeating DNA sequences that cap the ends of a person's chromosomes. Telomere length is one of the many measures being looked at in the Sister Study. Telomeres protect the ends of chromosomes and buffer them against the loss of important genes during cell replication. Over the course of an individual's lifetime, telomeres shorten, gradually becoming so short that they can trigger cell death. The papers show that factors such as obesity and perceived stress may shorten telomeres and accelerate the aging process.
Avoid obesity and stress. Easier said than done of course.
If you get overweight by 40 it is worse than getting overweight later. Probably it is a cumulative effect. The earlier you start the more total cellular damage builds up.
One of the studies published this week found that women who were obese for a long time had reduced telomere length. The researchers looked at the relationship between various measures of current and past body size and telomere length in 647 women enrolled in the Sister Study. They found that women who had an overweight or obese body mass index (BMI) before or during their 30s, and maintained that status since those years, had shorter telomeres than those who became overweight or obese after their 30s. "This suggests that duration of obesity may be more important than weight change per se, although other measures of overweight and obesity were also important," said Sangmi Kim, Ph.D., epidemiologist and lead author on the paper. "Our results support the hypothesis that obesity accelerates the aging process," said Kim.
If you feel stressed and your body has more stress hormones in it then that maximizes the effect of stress on telomere aging.
The other paper published in February looked at the association between telomere length and the perceived stress levels of 647 women enrolled in the Sister Study, and found that similar to the obesity finding, stress can also impact telomere length. The researchers extracted DNA from blood drawn during initial enrollment to estimate telomere length, and measured levels of stress hormones in urine samples the women provided. Additionally, the researchers used a standardized scale to characterize levels of perceived stress based on answers to questions about how stressful participants perceived their life situations. In general, the researchers report that women in the Sister Study typically reported low levels of perceived stress.
"Even so, women who reported above-average stress had somewhat shorter telomeres, but the difference in telomere length was most striking when we looked at the relationship between perceived stress and telomere length among women with the highest levels of stress hormones," said Christine Parks, Ph.D., an NIEHS epidemiologist and lead author on the paper. "Among women with both higher perceived stress and elevated levels of the stress hormone epinephrine, the difference in telomere length was equivalent to or greater than the effects of being obese, smoking or 10 years of aging."
Think about your job decisions, relationship decisions, investment decisions, and spending decisions from the standpoint of which potential decisions carry the risk of creating stress. Avoid putting yourself in situations where you stand a higher chance of feeling stressed. You'll age more slowly and live longer as a result.
•Above a healthy weight, every 5-point increase in BMI increases the risk of early death by about 30%.
•People who are overweight but not obese, with a BMI between 25 and 29.9, could be shortening their life span by a year.
•People with the lowest risk of dying early are in the high end of the healthy weight range with a BMI of about 22.5 to 25.
Since most people by middle age are overweight a substantial number of people are losing out on some years of life. Here are more details on the study. Go calculate your body mass index (BMI).
For those who are morbidly obese bariatric surgery causes a large cut in cancer risk.
Montreal, 19 June 2008 – Successful bariatric surgery allows morbidly obese patients to lose up to 70 percent of their excess weight and to maintain weight loss. The latest study by Dr. Nicolas Christou of the McGill University Health Centre (MUHC) and McGill University shows that this surgery also decreases the risk of developing cancer by up to 80 percent. Dr. Christou presented his preliminary results yesterday at the 25th Annual Meeting of the American Society for Metabolic & Bariatric Surgery.
The researchers compared 1,035 morbidly obese patients who underwent bariatric surgery at the MUHC between 1986 and 2002 with 5,746 patients with the same weight profile who did not undergo the operation. The number of cancer diagnoses in first group was 85 percent lower for breast cancer and 70 percent lower for colon and pancreatic cancers, and was also distinctly lower for several other types of cancer.
"The relationship between obesity and many forms of cancer is well established," said Dr. Christou. "This is one of the first studies to suggest that bariatric surgery might prevent the risk of cancer for a significant percentage of morbidly obese people."
Down with aging. First people gain weight and then their muscles start dissolving into fat.
Researchers have discovered that middle age spread seems to have an effect on waistlines but not weight as people get older.
Researchers, funded by the Medical Research Council, have found that people in early middle age seem to put on more weight more quickly than people slightly older. But the waistlines of the older group seem to grow more quickly.
The stage when the waistlines start expanding more rapidly is when the muscles wither.
One of the researchers Geoff Der, from the MRC’s Social and Public Health Sciences Unit in Glasgow explained:
“As people get older it seems that their bodies change… they lose muscle and get fatter – this explains why middle-age spread might not be reflected on the bathroom scales.”
He goes on: “This challenges the traditional method of measuring how fat a person is: the body mass index. The BMI is a good measure of lean body tissue, but an expanding waistline may be a more reliable measure of the amount of fatty tissue a person has gained. Although the people in the older middle age group in this study appeared to put on less weight than the younger people, their waist circumferences continued to grow over time. What appears to have been happening is that the increase in fat was being obscured by a loss of muscle mass.’’
So first you gain weight. Then your weight gain slows but some of your muscle mass gradually converts to fat. How disgusting. Really, we need rejuvenation therapies. Aging takes away your muscles and makes you fat. This is something we can do without. We should support bigger efforts to figure out how to avoid the decay of aging.
When you head into middle age the odds of keeping the weight off are definitely against you.
The researchers carried out a nine-year study of 1044 people aged either 39 or 59 in 1991. The height, waist circumference and weight of each participant was measured in 1991, 1995 and 2000, and used to measure changes in body mass index over time.
Only one in five (20%) of the people maintained a stable weight as the study progressed. Steady weight gain was measured in the younger group, more than 42% of study participants put on 10kg, 17% gained 5kg.
On average, both men and women in the younger group gained between 0.5kg and 1kg a year. This weight gain was fastest in their younger years. Those in the older age group gained least weight in the second half of the study, however, although their overall weight may not have changed their waist circumference did.
Aging is bad. The physical changes that come from the accumulation of damage to your body are a big and increasing negative. I'm talking downsides. I'm talking losses. Something to be avoided.
We need to seriously try to develop treatments that will reverse the aging process. The defeat of aging is an achievable goal and it is a goal that will be achieved in this century. But whether it comes soon enough for most of us depends on how hard we push to achieve it.