Tuesday October 31 6:26 PM ET
Study: Adding Veggies Does Not Reduce Colon Cancer

By Maggie Fox, Health and Science Correspondent

WASHINGTON (Reuters) - Researchers said on Tuesday they were disappointed to find that Americans who eat more fruits and vegetables do not seem to have a lower risk of colon cancer.

But they stressed that a diet rich in vegetables and fruit has been clearly found to protect against other, more common diseases such as heart disease and diabetes and urged people to eat more of them.

Karin Michels of Brigham and Women's Hospital and Harvard University in Boston, who led the study, said she feared people would interpret her findings to eat junk food.

``The most important thing I want to get out is they should eat a diet rich in fruits and vegetables in spite of all these findings,'' Michels said in a telephone interview.

``Even though we couldn't find an association with colorectal cancer, fruits and vegetables definitely protect for other important diseases such as cardiovascular disease, stroke, diabetes and potentially other cancers. These are some of the best foods we can eat -- there is no doubt about it.''

Colon cancer is the second-biggest cancer killer in the United States, after lung cancer, affecting 130,000 new people every year and killing 56,000.

Michels and colleagues used two long-term, ongoing studies -- the 88,000-member Nurses Health Study, which follows various health issues, and the 47,000-man Health Professionals' Follow-Up Study.

The participants answered page after page of questions about what they ate, and then were watched for 16 years to see who of the 135,000 people developed colon cancer. The results are reported in the Journal of the National Cancer Institute.

Andrew Flood and Arthur Schatzkin of the National Cancer Institute noted that the nurses and health workers ate an average American diet for the most part.

Only Two Percent Ate Recommended Amount Of Veggies

``Only 2 percent of the nurses cohort consumes more than 4.5 servings of vegetables per day; in the health professionals cohort only 3 percent consumed more than 3.5 servings per day,'' they wrote in a commentary.

The minimum recommended intake is 5 servings of fruits and vegetables a day. Flood and Schatzkin said that perhaps if people ate more fruits and vegetables, they would lower their risk of colon cancer. Other studies have suggested that vegetarians, for instance, have a lower risk of cancer.

Fruits and vegetables are believed to help protect against cancer because of their high content of vitamins, which act as antioxidants, reducing the damage done to the body by toxins, radiation, pollution and by day-to-day wear and tear.

``No single study, however large, can supplant the convincing evidence (derived from well over 249 studies worldwide) that argues for a clear link between diets high in fruits and vegetables and lower risk for cancer,'' Melanie Polk, director of nutrition education for the American Institute for Cancer Research, which studies the role of diet in cancer, said in a statement.

``Those few study subjects who ate more fruits and vegetables consumed more calories overall,'' Polk added. ''Perhaps, then, the study subjects simply added fruits and vegetables to their existing high-fat, high-calorie diets.''

Michels said because the people studied were health professionals, they probably had a better than average diet. But she said they were certainly not all health food fanatics.

``We certainly have people among them who eat a meat diet, who eat a diet high in fats, and who also as a consequence are overweight,'' she said.

Michels, whose group also reported recently that fiber intake did not seem to protect against colon cancer, said she feared sending out the wrong message.

``I am in a dilemma. I would rather have found something else. But I have to report it. I actually was surprised by my findings,'' she said.

``I also was very concerned about the fiber findings because they got misreported and misinterpreted,'' she added.

``This is not an excuse not to eat fruits and vegetables.''

She said other factors may account for the findings.

``We know that red meat consumption increases the risk of colorectal cancer,'' she said. ``Obesity, smoking, exercise, all have an effect.''

It may also be that the study did not go back far enough.

``We did cover 16 years but maybe we didn't cover enough,'' she said. ``I think that adolescent diet may be important. Maybe it is important what we ate 30 years ago.''


http://www.royalsociety.org.nz/2000...ancer-colon-10/


Study: Adding Veggies Does Not Reduce Colon Cancer