This has been a dismal year for vitamin supplements. People continue to buy them
but data from numerous controlled clinical trials published this year have
failed to show that vitamin supplements decrease the risk of various diseases,
such as cancer. An overview of the findings was published in the Los Angeles
Times earlier this month by reporter Karen Kaplan.
Adding to the tally of failed vitamin trials is a study published yesterday in
the Journal of the National Cancer Institute that found women who took beta
carotene or vitamin C or E or a combination of supplements had a similar risk of
cancer as women who did not take the supplements. The study by researchers at
Brigham and Women's Hospital and Harvard Medical School tested the supplements
on 7,627 women. After more than nine years of follow-up, there was no difference
in cancer risk.
Studies following the health habits of large groups of people have shown that
eating lots of fruits and vegetables is linked to a lower risk of cancer and
other diseases, and the advice to eat multiple servings of fruits and vegetables
each day has not changed. It will take more research to understand why a healthy
diet seems to have disease-prevention powers that are lacking in use of
supplements.
In an editorial accompanying the study, Dr. Demetrius Albanes of the National
Cancer Institute points out that the new study still contributes to a better
understanding of cancer processes. For example, the study found some evidence
that vitamin E may reduce colon cancer risk and beta carotene was linked to a
modest rise in lung cancer risk. These findings have also been shown in previous
trials.
Source : Los Angeles Times
