There's Something Fruits and Veggies Appear Not to Prevent
WebMD News Archive
Oct. 31, 2000 -- From a health point of view, there are hundreds, if not thousands, of good reasons to eat your fruits and vegetables, but it turns out that protecting yourself against colon cancers may not be among them.
For years, people have been told that diets rich in fruits and veggies protected against colon cancers. Now, results from the nation's largest ongoing nutrition study suggest that this is not the case. The study, which followed participants from 10 to 16 years, found that those who ate the most fruits and vegetables had the same risk of colon cancer as those who ate the least. The findings were reported in the Nov. 1 issue of the Journal of the National Cancer Institute.
The results come less than two years after startling findings from the same study group suggested that diets high in fiber offered little, if any, protection against colon cancer. Both studies used data gathered from almost 90,000 women. The fruit and vegetable study, reported by researchers from Boston's Brigham and Women's Hospital and the Harvard School of Public Health, also included some 47,000 men followed since 1990.
"Our findings were certainly surprising to us, but less so because of the results from the fiber study," lead researcher Karin B. Michels, tells WebMD. "It will surprise a lot of people, though, because colorectal cancer is generally considered to be the cancer that is most affected by diet. These studies suggest that this may not be the case."
Michels says earlier colon cancer studies showing fruits and vegetables had a protective effect may have been too small or too limited in scope to accurately access their impact. She also suggested that her group's results could reflect the fact that most Americans get plenty of the nutrients believed to protect against colon cancer, even if they eat few fruits and vegetables.
"Antioxidants and folates appear to play an important role in colorectal cancer risk, and fruits and vegetables are rich in these," she says. "But in the U.S., we get these vitamins and minerals through the fortification of certain processed foods and supplements we take. This could have contributed to the fact that we didn't find anything."