Selenium in the Battle Against Alzheimer's

This is the space where we usually tell men about some lesser known mineral or D-list vitamin that, if taken regularly, will help them live longer, cure their erectile dysfunction, clear their head, or just make them happier and peppier.

Not today. Today it's all about an A-lister that's letting everybody down.

Selenium is a trace mineral known for being an antioxidant powerhouse with anti-cancer properties. It's found in foods such as seafood, garlic, sunflower seeds and Brazil nuts, and has been highly regarded for its immune system and thyroid support as well. But medicine had high hopes for selenium in the fight against dementia and Alzheimer's disease in older men, and selenium has dropped the ball.

Because of selenium's powerful and reliable antioxidant properties, researchers believed it could help prevent damage to the brain cells involved in dementia. When scientists at the Sanders-Brown Center on Aging and the department of neurology at the University of Kentucky in Lexington finally had the opportunity to test that theory, selenium came up short.

"After an average of five years of supplementation, and up to 11 years of follow-up, we did not observe fewer new cases of dementia among men who took any of the supplements compared to neither supplement," said study co-author Frederick Schmitt. "Based on these results, we do not recommend vitamin E or selenium supplements to prevent dementia at these doses.”

The study enrolled more than 7,500 men across the U.S. and Canada, all aged 60 or older. Participants were divided into four groups: a vitamin E group; a selenium group; a combination group; and a placebo group (the "control" group).

By the end of the study, 25 men developed dementia at some point. Of these, 71 had been in the vitamin E group, 78 in the selenium group, 91 in the combination group, and 85 in the control group that took no supplements.

As much as Schmitt and his colleagues had hoped for an Alzheimer's silver bullet, it was not to be. "For consumers specifically concerned about brain health and cognition, they should be aware that no scientifically rigorous studies have identified any supplement as an effective treatment or prevention for dementia," he noted.

The authors advised men looking to prevent or off-set dementia to engage in regular physical activity, such as walking, and follow a heart-healthy diet – both paths with much more evidence supporting their effectiveness for reducing dementia risk.

The study was published in JAMA Neurology.