Vitamins May Not Prevent Prostate Cancer

Taking the vitamins E and C or the nutrient beta-carotene doesn't protect
against prostate cancer, says the latest study in the continuing, confusing
quest to determine when supplements really help health.

The government research, published Tuesday in the Journal of the National
Cancer Institute, is among many large studies examining whether these
antioxidants play a role in prostate cancer when taken as pills instead of
when they're consumed as part of an overall healthy diet.

Previous research has yielded conflicting results, and even this new study
of almost 30,000 men doesn't settle the issue. Indeed, while vitamin E
showed no effect on men overall, the study leaves open the possibility that
it might help smokers.

The men were enrolled in an NCI study whose primary aim is to test the value
of screening tests for prostate cancer. They also were surveyed about their
diet and what supplements they took relying on memory, not nearly as precise
as other research now under way that controls supplement doses.

Some 1,338 men were diagnosed with prostate cancer within eight years of
entering the study. Supplement users were just as likely to be diagnosed as
nonusers.

Smokers were 71 percent less likely to be diagnosed with advanced disease if
they had taken high doses of vitamin E for many years. But, perplexingly,
the risk of earlier-stage cancer increased among vitamin E-using smokers.

Smoking itself raises the risk of prostate cancer, and even if further
research concludes that vitamin E somehow tempers that risk, kicking the
habit would be far more protective, Harvard University scientists caution in
an accompanying editorial.