Selenium is the Brain Boosting Mineral

The trace mineral selenium has a huge impact on brain function. Nerve cells must have selenium to produce glu­tathione, one of the brain’s most important antioxidants. The brains of animals, for example, fed a low selenium diet make less glutathione. Such selenium-deprived brains also show disturbances in the activity of prominent neuro­transmitters serotonin, dopamine, and adrenaline, signify­ing potential brain damage and dysfunction, according to recent research. Further blood levels of selenium drop as you age—by 7 percent after age sixty and 24 percent after age seventy-five, according to one study.


Skimping on selenium does disturb human moods, possi­bly because of disruptions in neurotransmitter activity. U.S. Department of Agriculture researchers fed a group of young men either a low-selenium or high-selenium diet for about three-and-a-half months. The high selenium diet raised men’s spirits considerably. They said they felt more clear­headed, elated, agreeable, composed, confident, and ener­getic. Further, the more selenium in the men’s red blood cells, the better they felt. USDA research psychologist James G. Penland, who conducted the study, said the extra selenium lifted the men’s moods even though they had no signs of selenium deficiency. This implies that Americans do not eat enough selenium for optimal well-being, but are unaware of a problem. In other words, undetected sub-clinical deficiencies may be ruining our moods. The study’s high-selenium diet contained 220 micrograms daily, the low-selenium diet 33 micrograms. A typical American diet contains from 40 to 60 micrograms of selenium per day.

Foods high in selenium: grains, garlic, meat, seafood—especially tuna, swordfish and oysters—and Brazil nuts. Eating a Brazil nut is like taking a selenium pill, say experts. A shelled Brazil nut averages 12 to 25 micrograms a nut. If you buy them in the shell and extract them, the nut con­tains about 100 micrograms of selenium.


British psychologist David Benton also found “marked improvement in mood” in fifty subjects, ages fourteen to seventy-four, who took a 100 microgram selenium pill daily for five weeks—even though they had no obvious signs of

deficiency. Some got a placebo, the others the real thing. Selenium takers, on a standard mood inventory test, felt strikingly more clear-headed, composed, energetic, elated, confident, agreeable—or conversely, less confused, anxious, tired, depressed, unsure, and hostile. Selenium’s greatest benefit was reducing anxiety.

Researchers also noted that subjects who usually ate the least selenium benefited most from the supplement. Their mood scores shot up more than 40 percent after five weeks on the selenium supplement. Even those on relatively high selenium diets had a striking improvement—their mood scores jumped 25 percent. The explanation: A subclinical unsuspected selenium deficiency, manifested as low mood, was alleviated by the supplements.

It’s not the first time selenium supplements have improved mental function. In one Dutch study, geriatric patients given selenium and vitamin E tablets had less anxiety, depression, and more mental alertness. Other research found that a mixture of selenium, zinc, and evening prim­rose oil improved mood and some aspects of mental func­tion in a group of older people with memory loss.

How much? Experts advise taking 200 micrograms of selenium a day to protect your brain as well as discourage heart disease and cancer. But beware of high doses. Sele­nium is one of the few supplements that can be extremely toxic. Although toxicity may not kick in until you eat 2500 micrograms a day, there is no reason to exceed 200 micro­grams of selenium daily in a supplement.

BOTTOM LINE: Subtle, widespread deficiencies of sele­nium upset brain function, particularly lowering mood and raising anxiety. You must have adequate selenium for optimal brain functioning. The solution: a 200 microgram daily supplement.


Several researchers have reported that garlic elevates mood. Garlic’s high selenium content may be one explanation. Indian researchers testing garlic’s bene­fits for heart attack patients have noted a favorable side effect: better mood and more energy. French sci­entist Dr. Gilles Fillion of the Pasteur Institute found that garlic promotes the release of feel-good serotonin. “I suspect garlic is antistress, antianxiety, and acts as a sort of antidepressant like Prozac, although with a much milder effect,” he said. “Eating garlic may just make you feel better.” In mice, Japanese researchers pronounced garlic extract 60 percent as effective as Valium in relieving stress.

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Jean-Paul Marat

Many tips are based on recent research, while others were known in ancient times. But they have all been proven to be effective. So keep this website close at hand and make the advice it offers a part of your daily life.

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