Selenium

Selenium, an essential trace mineral found in the soil, water, and some foods, is important for many of our bodily processes, such as improving cognition and immune function. Deficiency of selenium can cause sudden cardiac death, yet too much of the mineral may have negative effects, such as brittle nails, nausea, fatigue, skin lesions, and more. In extreme cases, selenium overdose may lead to heart failure, kidney failure, and even death.

You may recall that I’ve discussed Brazil nuts’ ability to lower our cholesterol levels faster than statin drugs and keep them down. Indeed, just a single serving of four Brazil nuts almost immediately improved cholesterol levels in study participants. LDL—the so-called bad—cholesterol levels were a staggering 20 points lower just nine hours after eating the Brazil nuts. Even drugs don’t work nearly that fast. When the researchers measured the study subjects’ cholesterol thirty days later, they found that their cholesterol levels stayed down even a month after ingesting a single serving of Brazil nuts.

Brazil nuts are so high in selenium, though, that eating four every day may actually bump you up against the tolerable daily limit for selenium. Even one a day may be too much. Nevertheless, this is not something you have to worry about as long as you’re only eating four Brazil nuts once a month.

The information on this page has been compiled from Dr. Greger’s research. Sources for each video listed can be found by going to the video’s page and clicking on the Sources Cited tab. References may also be found at the back of his books.