What is Selenium and Will Increasing Selenium intake increase Testosterone?
What is selenium? Selenium is an essential nutrient that is needed create essential enzymes. That includes enzymes needed for testosterone and thyroid hormone. It is also plays an important role an anti-oxidant production. There seems to be a lot out in the popular press or online material that increasing selenium will increase a healthy man’s testosterone. However, there is little, if anything, in the scientific literature to support the idea.
There has also been recent emphasis on consumption of Brazil nuts as a natural source of selenium that will boost testosterone and increase virility. You may have heard advocates of the paleo diet talking about this. (if you want to know more about the paleo diet here is a link. It tells you what is the paleo diet and includes criticisms and controversies rather than telling you the paleo diet is the answer to all life’s problems).
Increasing selenium to increase testosterone is also promoted for athletes hoping to improve CrossFit training. Or sports performance in general. So far there is no evidence that increasing selenium will increase testosterone levels in healthy men.
Are there any problems with taking selenium to increase testosterone?
Yes. There are a lot of good things about selenium, but as with a lot of other things, you can damage yourself by overdoing it. Selenium is protective against prostate cancer, and some other cancers and is important for testicular development (during the fetal period) and possibly protective against other oxidative-stress-induced ailments, testicular or not. On the other hand, selenium, at high concentrations can cause DNA damage, and thus increase risk of cancer. The problem with supplementing, either through tablets, or through consumption of a natural product high in selenium, is that we do not know where the lines of good and evil cross. No one knows yet how much is ideal or at what point intake becomes more of a liability than a help.
Are Brazil Nuts good for testosterone?
The upper limit for selenium intake for a healthy adult is 400 mcg. You can easily get twice this much from a handful of Brazil nuts. Selenium concentrations in any plant should be dependent on the concentration of selenium in the soil in which it grows, therefore, the concentration of selenium in Brazil nuts will vary. Nuts grown in Manaus-Belem region of Brazil have more than ten times higher selenium content than those grown in the Acre-Rondia region. I’m guessing packaging doesn’t tell you where the nuts you might buy are grown.
Bottom Line: If you eat a lot of Brazil nuts and take selenium supplements you might want to lay off or do one or the other. Don’t assume that more is better. References are listed below. For a better way to increase testosterone see this earlier post.
Chang, J. (1995). Selenium content of Brazil nuts from two geographic locations in Brazil Chemosphere, 30 (4), 801-802 DOI: 10.1016/0045-6535(94)00409-N
ATIF, F., YOUSUF, S., & AGRAWAL, S. (2008). Restraint stress-induced oxidative damage and its amelioration with selenium. European Journal of Pharmacology, 600 (1-3), 59-63 DOI: 10.1016/j.ejphar.2008.09.029
Henderson, B. (2000). Hormonal carcinogenesis Carcinogenesis, 21 (3), 427-433 DOI: 10.1093/carcin/21.3.427
Shafiei Neek L, Gaeini AA, & Choobineh S (2011). Effect of zinc and selenium supplementation on serum testosterone and plasma lactate in cyclist after an exhaustive exercise bout. Biological trace element research, 144 (1-3), 454-62 PMID: 21744023