Fruit and vegetables no protection against breast cancer: study

Contrary to earlier research, a new study suggests a diet rich in fruit and vegetables does not decrease a woman's risk of breast cancer.

But other studies released Tuesday suggest eating a lot of red meat or having high blood sugar may increase the risk of other types of cancer.

The research on cancer and diet uses data from the European Prospective Investigation Into Cancer and Nutrition, a collaborative project with more than 500,000 participants since 1992, the largest ever study of its kind.

The study examined data from nearly 300,000 women from 10 European countries between the ages of 25 and 70. The participants filled out a questionnaire on their eating habits between 1992 and 1998. The women were examined for breast cancer in 2002.

The researchers found no evidence that diets high in vegetables and fruit decreased a woman's risk of breast cancer. They also examined six groups of vegetables for protective effects and found none.

"The absence of a protective association was observed among almost all of the participating countries," wrote researcher Carla van Gils of the University Medical Centre in Utrecht, Netherlands.

"This does not exclude the possibility that protective effects may be observed for specific nutrients in specific subgroups of women, such as those with a family history of breast cancer," wrote van Gils.

The authors also stressed that there are many other reasons to eat a lot of fruits and vegetables, noting that such a diet can make the heart healthier and keep one's weight down.

The study was published in this week's issue of the Journal of the American Medical Association.

In another study published in the journal, researchers found eating beef, pork, lamb and processed meats such as bacon more than once a day over several years increased the risk of cancers of the lower colon by about 50 per cent.

On the other hand, people who ate more chicken and fish had a lower risk of such cancers.

The data showed an association between red meat and cancer when corrected for age and calorie intake, but it disappeared when such risk factors as smoking and body mass index were taken into account.

"The relation between red meat consumption and colorectal cancer may not be conclusive, but prudence would suggest that red meat, and processed meats in particular, should be eaten sparingly to minimize risk," wrote Dr. Walter Willet of the Harvard School of Public Health in an editorial accompanying the study.

In a third study, involving more than 1.2 million South Koreans, researchers found an association between high blood sugar and diabetes, and cancers of the liver, pancreas, esophagus and colon.

However, the authors of the study said its findings may not apply to U.S. and European populations because the Korean participants were "substantially leaner than the typical Western population."