This is not the first study to find this:
Studies Examine Prostate Cancer-Nutrition Links
By DELTHIA RICKS
Newsday
May 29 2007
Two large, unrelated studies recently renewed the focus on prostate health and nutrition, raising questions about vitamin supplements and a pigmented compound in tomatoes that colors the fruit red.
How safe are multivitamins?
Does lycopene, which is added to many vitamin supplements aimed at men, actually protect them from prostate cancer?
Researchers at the National Cancer Institute found that men who took more than one multivitamin daily had a 32 percent increased risk of advanced prostate cancer with a fatal outcome, nearly double the risk of men who did not take the pills.
But Dr. Michael Leitzmann, an institute investigator and author of the analysis, says the study is not a condemnation of multivitamins.
"Men should not stop taking multivitamins," he says. "It was only the men who were taking multivitamins in excessive doses where we saw an increase in risk."
The study was published in the Journal of the National Cancer Institute.
Leitzmann and his colleagues studied 300,000 men in a six-year period who had filled out questionnaires about vitamin use. Taking more than seven multivitamin tablets per week was associated with advanced prostate cancer. Curiously, excessive vitamin intake was not a factor in early-stage tumors. Exactly how the pills could be associated with advanced disease remains unanswered.
European cancer experts writing in an accompanying editorial said the study questions "the beneficial value of antioxidant vitamin pills in generally well-nourished populations." In an even more sobering assessment of the data, the editorialists noted that "antioxidant supplements could have unintended consequences for our health."
Dr. Iris Granek, an associate professor of clinical medicine at Stony Brook University Medical Center, says the basic take-home message is not to exceed the recommended dosage of multivitamins. There are many variables, she says, in how vitamins are metabolized from one person to the next.
Still, a study by the American Cancer Society demonstrated two years ago that the death rate from prostate cancer was marginally higher in men who took multivitamins compared with those who avoided the pills. That research involved 500,000 men and the findings set the scientific community astir. But scientists have not given up on vitamins.
Granek is principal investigator of Long Island's contribution to an ongoing 12-year federal study examining whether vitamin E or the mineral selenium prevent the disease. The two supplements had shown in smaller studies in the 1990s that men were protected from prostate cancer. Government health officials six years ago embarked on the larger study to find more definite answers.
Yet much of the old wisdom seems to be falling by the wayside. NCI scientists and those at the Fred Hutchinson Cancer Research Center in Seattle found that lycopene apparently does not prevent prostate cancer. "Our study adds an important piece to the puzzle," says Dr. Ulrike Peters, lead author of the study. "It's disappointing, because lycopene might have offered a simple way to lower risk."
Supplement manufacturers are not abandoning lycopene. Bayer, which makes a vitamin supplement aimed at boosting prostate health, plans to continue adding lycopene to the product, according to a company spokesman.
Copyright © 2007, Newsday, Inc.
