Diabetes MellitusSelenium

More thoughts on the role of selenium in preventing diabetes

A recently published study concluded, “Selenium supplementation does not seem to prevent type 2 diabetes, and it may increase risk for the disease.”

The study was summarized here. Now, an article on HealthNotesNewswire by Dr. Allan Gaby, a specialist in nutrition and preventive medicine, lists criticisms of the research. Dr. Gaby’s article is instructive because in addition to the relevance of the criticisms to the selenium study, it provides a checklist of basic questions to ask when reading any retrospective review.

His criticisms
Be cautious in accepting results that were not the original intent of the study.

  • Statisticians will tell you that if one combs through data after the fact, looking for associations that had not been thought of originally, some seemingly important associations will appear simply by chance.
  • Therefore, the higher incidence of diabetes among people who took selenium may have been just a random occurrence, rather than an indication that selenium is harmful.

Be sure the placebo really has no effect on its own.

  • The placebo in this study was baker’s yeast (Saccharomyces cerevisiae)
  • It’s similar, if not identical, to brewer’s yeast (also Saccharomyces cerevisiae)
  • It contains 2 compounds that improve the ability to regulate blood sugar.
  • If the placebo had a beneficial effect on blood sugar control, then high-selenium yeast might have appeared to increase the risk of diabetes only because the placebo decreased the risk.

Don’t ignore the evidence that came before.

  • In animal studies, selenium supplementation improves glucose metabolism — not promote diabetes.
  • Diabetes is not one of the reported manifestations of selenium toxicity in humans.

These facts cast further doubt on the idea that taking moderate doses of selenium causes diabetes.

8/3/07 09:28 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at www.Vicus.com, a complementary and alternative medicine website.