The More Fruit Eaten Earlier in Life May Reduce Cancer Risk
(HealthDay News) -- Medical research often results in findings that change or even reverse what was thought to be scientifically sound. For instance, a couple of years ago hormone replacement therapy, which had been considered the proper course for many post-menopausal women, was found actually to be harmful under many circumstances.
But often, subsequent research so strongly supports original findings that it becomes a scientific fact. That’s what has happened is concerning the antioxidant factor in fruits and vegetables. The more you eat and the earlier in life you start, the better your chances of staving off cancer.
A United Kingdom study that used data from 70 years ago confirms the value of eating lots of fruit as a child. The study had nearly 5,000 English and Scottish people give details of their diet between 1937 and 1939, and it followed nearly 90 percent of them ever since. The youngsters who ate the freshest fruits had the lowest risk of dying of cancer in the decades that followed, the researchers found.
No similar association was found for vegetables in the diet, researchers at the University of Bristol and the British Medical Research Council say. One possibility is that the custom then was to boil vegetables for up to a half hour, which removed healthy micronutrients, the scientists say. Today's cookbooks say most vegetables should be cooked for no more than 20 minutes, with five to 10 minutes in the pot advised for most. However, the researchers note that one previous British study found vegetable intake was not as closely associated with reduced cancer risk as fruit intake.
It is "quite a remarkable study," says Dr. Michael Thun, vice president of epidemiology and surveillance research for the American Cancer Society, who is impressed by the scientists’ ability to follow the participants for more than six decades. But with an epidemiologist's eye, he can pick out some of its weaknesses.
It's not definitive because it doesn't have information about risk factors other than diet, Thun says. It didn't look at individual diets, and it is "a relatively small study."
Nevertheless, Thun says, the report fits right in with the American Cancer Society's dietary guidelines, which say that people should eat "a variety of healthy foods with an emphasis on those from plant sources." At least five servings a day of fruits and vegetables are recommended.
The study did find that people who had a high calorie intake as children had a higher risk of cancer later in life, but that does not establish obesity as a risk factor, says Dr. Maria Maynard of the British Medical Research Council, a leading researcher in the trial. "We did not look at the association between body size and cancer risk in this study," she says. While there was no association between intake of specific nutrients such as vitamin C, vitamin E, and beta-carotene and cancer risk, Maynard says, "Our research does not support or refute the effect of supplements."
The mechanism by which good eating protects against cancer is not clear, Maynard says. However, she points to the conclusion of the journal report: "This study provides some support for dietary guidelines focusing on fruit consumption rather than on the intake of particular micronutrients." And, she adds, "We found no reason to reject the public health message that a diet rich in vegetables has a number of health benefits."
On the Web
You can learn more about healthy eating by consulting the guidelines of the American Cancer Society.
SOURCES: Michael Thun, M.D., Vice President of Epidemiology & Surveillance Research, American Cancer Society, Atlanta; Maria Maynard, M.D., British Medical Research Council, London; March 2003 Journal of Epidemiology and Community Health
Publication date: March 2, 2007
Author: Ed Edelson, HealthDay Reporter
Copyright © 2007 ScoutNews, LLC. All rights reserved.
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