Tag Archives: selenium

Why supplements including anti-oxidants should be taken seriously.

Here are a few simple things to know about nutritional supplements, selenium and deer antler velvet

CrossFit Seven and Womens reistance training
Summer and Bill discuss womens resistance training, deer antler velvet and supplements at CrossFit Seven

I was recently informed by the well-meaning  president of a supplement company that there is no upper limit of safety for selenium.  The company president may be well-meaning and sincere in her beliefs, but her belief about selenium is incorrect.  Selenium overdoses occur.  Its hard to do that eating whole foods although it has happened.  Selenium poisoning from food happens only in areas where selenium in soil is extremely high and people eat locally grown food.  Birds and animals can also get selenium poisoning in such areas.  In most cases, selenium poisoning happens when people over do it on nutritional supplements.  Nutritional supplements (unless they are simply inert) contain biologically active ingredients. They are sold with promises of improved health, improved athletic performance or of some other form of improved well-being.   Nutritional supplements are, for the most part, drugs/medicine.

  • Products that are classified as drugs/medicine are required to meet standards of quality and consistency in manufacturing and of safety.    Studies are done in vitro, on animals, and finally on humans.  Drug interactions are checked.  Information is gathered on how the drug is metabolized. Drugs are sometimes metabolized into something deadly before being rapidly metabolized into something safe.  Tylenol is an example.  Not a problem unless something, like alcohol, blocks a metabolic step and traps Tylenol in its deadly form.  This is why people sometimes die when they drink alcohol and then take Tylenol.  This should be common knowledge, but it isn’t, yet.
  • Another important thing to know about a drug or supplement is its “Effective Dose.”  How much is needed to give a desired effect?  How much selenium is needed for health?  How much is too much?   How much is “optimal”?  These are unanswered questions for many nutritional supplements.  What happens if you take too much?  Frequently the answer to that question is unknown as well.
  • Anti-Oxidants should not be assumed to be safe.   Recent research has indicated that anti-oxidants, like oxidants, can harm DNA.  DNA damage can lead to cancer, the very thing anti-oxidants in nutritional supplements are supposed to prevent.
  • The last point to raise for this article is a manufacturing issue.  Like most people, I used to assume that vitamins and supplements contained what was written on the package.   But this is not always the case.  An example is the recent report of human growth factors added to deer antler velvet supplements.  It is hard to believe human growth factors were accidentally added to deer antler velvet supplements.   You’d have to hear the manufacturer out on that one.  However, problems like poor mixing and poor calculations can and do happen.  Our research group found that out the hard way when we tried to use a well-known brand of vitamins for a human health study.

So, how much of what is in a multi-vitamin?   How much of what is in Deer Antler Velvet, DHEA supplements, or “high performance packets?”  Deer antler velvet, especially if it is secretly spiked with human growth hormone may quite unsafe.  Secret additions to supplements may or may not be added carefully or consistently.  There is no way to know unless you are the one doing the spiking . . . or if you have the technical expertise and expensive equipment needed to test it yourself.

The supplement industry is an important economic entity, employing possibly hundreds of thousands of people.  That deserves respect.  It can be very difficult to make a living in what have lately been very difficult economic times.  That said, please understand we fully support the efforts of small businesses and individuals to make a little extra money.     However, we do believe people will be better off knowing more about what they are taking.

Lu LY, Ou N, & Lu QB (2013). Antioxidant induces DNA damage, cell death and mutagenicity in human lung and skin normal cells. Scientific reports, 3 PMID: 24201298
Cox HD, & Eichner D (2013). Detection of human insulin-like growth factor-1 in deer antler velvet supplements. Rapid communications in mass spectrometry : RCM, 27 (19), 2170-8 PMID: 23996390

Morris JS, & Crane SB (2013). Selenium toxicity from a misformulated dietary supplement, adverse health effects, and the temporal response in the nail biologic monitor. Nutrients, 5 (4), 1024-57 PMID: 23538937

CrossFit Nutrition: Should men increase selenium intake to increase testosterone?

What is Selenium and Will Increasing Selenium intake increase Testosterone?

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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?

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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

Brozmanová J, Mániková D, Vlčková V, & Chovanec M (2010). Selenium: a double-edged sword for defense and offence in cancer. Archives of toxicology, 84 (12), 919-38 PMID: 20871980 

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

Selenium and Brazil Nuts and Testosterone

Can brazil nuts and selenium increase testosterone?

There seems to be a lot out in the popular press or online material that incresing selenium intake will increase a healthy man’s testosterone production (example and example II from Forbes Magazine: what were they thinking?), but little, if anything, in the scientific literature to support that idea. (I like the scientificky approach used by that website, especially the graph that shows no effect, and no indication of variability in the data points). There has also been recent emphasis on consumption of brazil nuts as a natural source of selenium that will boost testosterone and increase virility.

Can brazil nuts and selenium increase testosterone?

What do we know about selenium and Brazil nuts?

Selenium is protective against prostate cancer, and good for testicular development (fetal period . . . sorry guys) and possibly protective against other oxidative-stress-induced ailments, testicular or not. On the other hand, selenium, at high concentrations can result in 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.

As for 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 probably varies. This turns out to be the case, with nuts grown in Manaus-Belem more than ten times higher in selenium than those grown in Acre-Rondia. Someone consuming Brazil nuts may or may not be making a significant increase in selenium intake.
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

Brozmanová J, Mániková D, Vlčková V, & Chovanec M (2010). Selenium: a double-edged sword for defense and offence in cancer. Archives of toxicology, 84 (12), 919-38 PMID: 20871980
Henderson, B. (2000). Hormonal carcinogenesis Carcinogenesis, 21 (3), 427-433 DOI: 10.1093/carcin/21.3.427