Selenium: A Trace Mineral that’s Great for Your Brain

June 10, 2007

Selenium:  A Trace Mineral that’s Great for Your Brain 

 Competency # 16 Mighty Minerals.                            ReferenceAmerican Journal of Epidemiology, Jan 31, 2007, Page 955 S Gao 

 Selenium is a trace mineral you can find on your multivitamin bottle.  It comes from the soils that plants grow in.  Any given food crop can have as much as a 10 fold difference in the amount of selenium in it, depending on the soils that it is grown in.  That makes the part of the world you live in have an impact on your intake of this vital trace element.  And your brain collects it and stores it for a long time.  

It takes as much as 200 days for a trace dose to wash out of your system. What we know about selenium is that it is a crucial component of many enzymes in your brain, liver, and throughout much of our bodies.  It has an antioxidant effect that seems to correlate with less cognitive decline.  It has been hypothesized that it works by having an impact on your memory, both short and long term.  What has been frustrating for American epidemiologists has been finding a population that stays put in one area, eating food from one area, getting a constant amount of selenium.  We have been able to measure selenium levels and cognitive decline, but the level you have may be from recent food grown in Chile, or California, or the multivitamin you took with selenium in it.  

American populations are so mobile, we can’t easily make the connection that selenium helps with avoiding cognitive decline, unless we can first show a steady dose of selenium, all your life, makes a difference. Our researchers in the article above, Gao et al, went to four villages in different parts of China where over 70 % of the over 65 year old adults had lived in their village all their lives.  They were tested by multiple visits with state-of-the-art cognition tests, and that was compared to their fingernail selenium levels.  The villages were chosen for the variety in the selenium levels in their soils, and the attendant selenium levels in the population that lived in those villages.  

Finally, a life-long natural laboratory where the question could be asked as to whether life-long selenium exposure had an impact on your brain. The answer?  Yes!  It does!  Life-long low selenium results in lower cognitive function and greater decline with aging. 

 WWW.  What Will Work for Me?  This is simple.  We all should take a multivitamin every day.  It will have selenium in it.  And if you are on your DASH diet and getting 8-10 servings of fruits and vegetables every day, you get a little bit more, depending on where the food came from.  But you wash out the extra and there hasn’t been any reported toxicity from a multivitamin.  I’m not taking extra, for now.  My brain needs all the help it can get.  It’s the only place I’ve got to keep all my hopes and dreams, and memories.  How about that Brazil nut a day hypothesis?  I think I'm in.  That has selenium.  (68-91 mcg per nut)

The column is written by Dr. John E. Whitcomb, MD, Brookfield Longevity, Brookfield, WI (262-784-5300)