The Harm

Death by supplements

In 1996, my colleagues and I published a study on selenium in prostate cancer prevention. In brief, we found an unprecedented 60% reduction of prostate cancer in men who received dietary supplements of selenium. Our study was imperfect and while it produced an interesting hypothesis - selenium reduces prostate cancer incidence - it had not been designed to give a definitive answer. Last year, a National Cancer Institute report found that selenium supplementation is associated with more aggressive prostate cancer and prostate cancer death. In other words, despite the hope given by our imperfect 1996 study, it may actually be that selenium supplements accelerate prostate cancer.

Doctors in Texas have now reported that two men developed aggressive prostate cancer after taking the same herbal supplement which they bought over the internet; they reportedly later died of prostate cancer. They had bought the supplement to improve muscle strength and sexual vigor. Both had had normal prostate examinations in the not-so-distant past. Both had unusually aggressive clinical courses. Laboratory analysis of the supplements revealed unlisted ingredients, including testosterone, and potent cancer-cell promoting properties of these supplements. The FDA has now become involved and the supplements have been taken off the market. But what about all the other supplements still available? What’s in them? We cannot easily know.

Why would any one buy “supplements” of the internet?