April 07, 2010
Small Cancer Protection From Fruits And Vegetables?

People who hate vegetables will be happy about this report.

An analysis of dietary data from more than 400,000 men and women found only a weak association between high fruit and vegetable intake and reduced overall cancer risk, according to a study published online April 6, 2010 in the Journal of the National Cancer Institute.

It is widely believed that a diet rich in fruits and vegetables can reduce the risk of cancer. In 1990, the World Health Association recommended eating five servings of fruit and vegetables a day to prevent cancer and other diseases. But many studies since then have not been able to confirm a definitive association between fruit and vegetable intake and cancer risk.

To address the issue, Paolo Boffetta, M.D., M.P.H., of the Mount Sinai School of Medicine in New York, and colleagues analyzed data from the EPIC study (European Prospective Investigation into Cancer and Nutrition), which included 142,605 men and 335,873 women recruited for the study between 1992 and 2000. The participants were from 23 centers in ten Western European countries--Denmark, France, Germany, Greece, Italy, the Netherlands, Norway, Spain, Sweden and the United Kingdom. Detailed information on their dietary habit and lifestyle variables was obtained. After a median follow-up of 8.7 years, over 30,000 participants were diagnosed with cancer.

The authors found a small inverse association between high intake of fruits and vegetables and reduced overall cancer risk. Vegetable consumption also afforded a modest benefit but was restricted to women. Heavy drinkers who ate many fruits and vegetables had a somewhat reduced risk, but only for cancers caused by smoking and alcohol.

Other studies have found the same results. But you can still eat fruits and vegetables for your heart and arteries.

In an accompanying editorial, Walter C. Willett, M.D., Dr.P.H., of the Harvard School of Public Health, notes that "this study strongly confirms" the findings of other prospective studies that high intake of fruits and vegetables has little or no effect in reducing the incidence of cancer, although it has been shown to affect the risk of cardiovascular disease. He suggests that future research investigate the potential cancer-reducing benefits of specific fruits and vegetables and also study the effects of fruit and vegetable consumption at earlier periods of life.

It is a lot easier you reduce your risk of cardiovascular disease than to reduce your risk of cancer. We need effective cancer cures with very low side effects.

Coincidentally, another recent report finds Vitamin K as K1 found in green leafy vegetables does not cut cancer risk but Vitamin K as K2 found in cheese does cut cancer risk.

Share |      Randall Parker, 2010 April 07 12:43 AM  Aging Diet Cancer Studies


Comments
Aron said at April 7, 2010 3:27 PM:

"In this population, a higher intake of fruits and vegetables was also associated with other lifestyle variables, such as lower intake of alcohol, never-smoking, short duration of tobacco smoking, and higher level of physical activity, which may have contributed to a lower cancer risk"

The authors note also that people consuming high veg/fruit diets also engage in other practices that one would assume are more likely than not to preserve against cancer, particularly smoking.

As far as I'm concerned, the body appears quite flexible to diet within a wide variety of ranges, centered on common sense. The principal warning sign primarily being weight gain associated with the obesity trend. I have personally tried a great number of diets, some completely devoid of fruit, and light on vegetable, and I subjectively felt the same. It seems rational to me to avoid smoking, avoid 3000+ calorie days, moderate your intake of manufactured foods, and otherwise enjoy freedom from anxieties related to obtaining a 'perfect' diet.

Sidney Raphael said at April 8, 2010 11:10 AM:

What part of the indecisive results of these studies is due to methodology? When people are asked to report food intake and lifestyle activities they lie. Everyone knows what you're "supposed to do" so they report they are goodie-goodies who do what they should. No one, no large scale study actually measures what people put in their mouths. These disappointing studies rely on self-reports. Gimme a break. Has there ever been a large-scale diet study that removed the subjective factor?

Vader said at April 8, 2010 1:41 PM:

Aron,

Well said. For persons of normal metabolism, diet is not critical.

Now if you have genes for diabetes 2 in the family, you will want to keep your weight down and it *may* help to stick with lower glycemic foods. But for the average person, being reasonable and enjoying in moderation are really all that's needed.

Simfish InquilineKea said at April 8, 2010 3:29 PM:

Another question is this: do these studies ever control for the "displacement" of other foods that oftentimes comes with fruit/veggie consumption? Since fruit/veggies fill up the stomach, they make it easier to go without eating other, calorie-rich foods. And these calorie-rich foods will definitely increase the risk of negative health outcomes.

Also, eating veggies in conjunction with meals may reduce their overall glycemic index too. That may also reduce rates of negative health outcomes.

So all in all, eating a diet full of beans (the healthiest non-fruit/vegetable food) may just be as good as eating lots of fruits/veggies. Cardiovascular risk can already be drastically lowered through calorie restriction, whereas cancer risk is only partially lowered.

TTT said at April 8, 2010 3:30 PM:

I disagree. The physics of how fiber reduces intestinal cancer is well understood.

Randall, don't you force down half a head of cabbage daily, mainly to avoid cancer? Have you stopped doing that?

Lastly, anecdotally, I know several people who have crossed the age of 90 without any cancer, and their diets consists mostly of vegetables, whole grains, a variety of spices, and no red meat or processed food.

Colin said at April 9, 2010 10:33 AM:

Did the study show the statistics for those who consumed more fruit vs. more vegetables ?? .. and if not, it was fatally flawed. It is well known that cancer thrives anaerobically, requiring sugary foods. Unlike normal cells, cancer cells cannot utilize fats or proteins. Fruits being sugary however increase the growth of cancer cells. So also do simple carbs.

Oh.. I just noted that it was published by the National Cancer Institute. Are any members of that board (directors) also members of Big Pharma?? (Just curious)

Colin

PacRim Jim said at April 9, 2010 12:03 PM:

Small Cancer Protection From Fruits And Vegetables?
If I get small cancer--whatever that may be--I'll consume more agromeat.

Randall Parker said at April 9, 2010 8:18 PM:

TTT,

I think the digestive tract is where diet can make the biggest difference in cancer incidence. There the food can either produce or snuff out carcinogens. The further away from the digestive tract you get the less ingested anti-oxidants will matter.

Aubrey de Grey has made the point that if antioxidants were capable of so much more protection then the body would likely just produce more antioxidants. But the problem is that most free radicals are going to collide with something else before hitting an antioxidant. There's just a limit to how much space in cells that antioxidants can take up. Other stuff needs to be in there doing things.

People hitting 90 and low meat diets: Sure, avoid carcinogens in your intestines. But I doubt meat raises the rate of all types of cancer.

Half a head of cabbage: Actually, half a head of cauliflower.

I'm not arguing against a high vegetables and fruit diet. They deliver other benefits. I just think diet is not the biggest cause of cancer. Mostly cancer is caused by accumulation of damage from the various processes of aging.

Tony Edwards said at September 27, 2011 3:15 AM:

An analysis of cancer among those who eat a high vegetable/fruit diet which is pesticide free compared to those who eat a high vegtable/fruit diet with pesticide residues would be interesting,though who is going to fund this? for sure there are vested interests who wont want it to happen. I know people who have had cancer after living long term on high raw vegetarian diets often recommended by alternative cancer treatment practitioners,few of them have had the funds for or access to food free from pesticides. The significant risk of pesticide residues in food needs to be acknowledged. Do we really think we can apply chemicals that poison us to our growing food and not escape the negative consequences?

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