Healthy living
Medicines and supplements
Vitamins ‘do not prevent prostate cancer’
Selenium and vitamin E have no effect on preventing prostate cancer, according to studies published in the January 7 edition of the Journal of the American Medical Association (JAMA)
One of the two trials measured the effect of vitamins E and C on nearly 15,000 doctors, while the other tracked the health of more than 35,000 men taking vitamin E and/or selenium.
Vitamin E, a powerful antioxidant found in cod liver oil, sunflower and olive oils, nuts, beans, vegetables, prawns and salmon, was thought to cut the chances of developing cancer. Vitamin C, another powerful antioxidant, famously found in fresh fruit and vegetables, is also thought to protect us from the damage caused by free radicals.
Scientists have been looking at the effect of selenium since the sixties, trying to find out whether the low incidence of prostate cancer in parts of the world with selenium-rich soil could be replicated in selenium-deficient areas. Brazil nuts are a good source of selenium, but the mineral is also found in fish, kidney, liver, poultry, nuts and some vegetables.
Researchers from Brigham and Women's Hospital and VA Boston Healthcare System, Boston randomly assigned 14,641 male doctors aged over 50 to receive individual supplements of 400 IU of vitamin E every other day and 500 mg of vitamin C daily, or a placebo; 1,307 of the participants had a prior history of cancer.
During the eight years of follow up, there were 1,943 confirmed total cancer cases and 1,008 prostate cancer cases. Compared with placebo, vitamin E had no effect on the incidence of prostate cancer or any cancer, while vitamin C had ‘no significant effect’. Neither vitamin E nor vitamin C had a significant effect on site-specific cancers, including colorectal, lung, bladder and pancreatic "These data provide no support for the use of these supplements in the prevention of cancer in middle-aged and older men," the authors conclude.
The other trial followed more than 35,000 men aged over 50 for seven years. The participants were randomly divided into groups that would receive one of four treatments between August 2001 and June 2004 for a planned minimum follow-up of seven years: selenium (200 µg/day); vitamin E (400 IU/day), selenium vitamin E, or placebo. The researchers found that there were no statistically significant differences in the five-year incidence rates of prostate cancer diagnoses between the four groups.
In a JAMA editorial, Peter H Gann of the University of Illinois, commenting on the findings of the two studies, advises that "...physicians should not recommend selenium or vitamin E—or any other antioxidant supplements—to their patients for preventing prostate cancer."
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Information on this site is for interest only and is not a substitute for professional medical advice. You should consult your own doctor about any specific health concerns.
