We want stability, safety, and bio-availability from our selenium supplement. The high-selenium yeast supplement – also known as the selenium-enriched yeast supplement – is the best formulation to achieve these goals.
High-selenium yeast supplements are produced using the selenium that has been grown with Saccharomyces cerevisiae yeast (baker’s yeast). Those of us who take a daily high-selenium yeast supplement know that the yeast used in the making of the supplement is dead. The yeast cells cannot get into our bodies and multiply because they are not alive.
Various forms of selenium supplements
There are both inorganic and organic forms of selenium in commercially available selenium supplements. There are supplements made with inorganic forms containing selenium salts like sodium selenite and sodium selenate. Their absorption is not nearly as good as the absorption of the best organic selenium-enriched yeast supplements.
Note: When we use the terms “organic” and “inorganic” in the context of the selenium supplement, we mean that the selenium compounds do contain the elements carbon and hydrogen (organic) or do not (inorganic).
Among the organic forms of selenium in commercially available selenium supplements, there is the selenomethionine form (C5 H11 NO2 Se). Selenomethionine is the form commonly found in Brazil nuts and cereal grains, and legumes.
Unfortunately, supplements containing a synthetic version of selenomethionine have been used in some human studies, and the results have not been the hoped for results, most notably not in the Selenium and Vitamin E Cancer Prevention Trial (SELECT) trial [Lippman 2009].
A good high-selenium yeast supplement contains naturally occurring organic selenomethionine in addition to methylselenocysteine (C4 H9 NO2 Se), the form found in garlic and broccoli, and a total of as many as 30 different species of selenium [Larsen 2004]. Many of these 30 various selenium species may well have biological functions that an inorganic or synthetic selenomethionine supplement cannot serve.
Even among the commercially available high-selenium yeast supplements, there can be variations in the standardization of the preparation. Variation in the composition and species contained in the different high-selenium yeast supplements suggests, then, that there may be differences in the bio-availability of the selenium.
Best documented European produced high selenium yeast
The best documented high-selenium yeast supplement, produced in Denmark and commercially available in the USA, consistently has the following properties [Larsen 2004; Bügel 2008]:
- Absorption rate of 89-90%
- Approximately 60% organic selenomethionine content
- A total of 30 organic selenium species
- No more than 1% inorganic selenium
Absorption of the high-selenium yeast supplement
The selenium from a high-selenium yeast supplement is better absorbed and better retained than the selenium from a synthetic selenomethionine supplement or an inorganic selenium supplement [Bügel 2008].
In the United Kingdom pilot study for the PREvention of Cancer by Intervention with Selenium (PRECISE) trial, study participants aged 60 – 74 years who had low baseline selenium status achieved the following dose-dependent increases in plasma selenium levels after six months of daily supplementation with SelenoPrecise®:
- 100 micrograms daily: 61% increase in selenium status
- 200 micrograms daily: 113% increase in selenium status
Daily dosage of the high-selenium supplement
It is difficult to make a general statement about the amount of selenium adults need on a daily basis. Selenium is not synthesized in the human body. The primary source of selenium is the diet, and diets vary from region to region and culture to culture.
- The amount of selenium obtained through the diet can vary considerably according to the region of the world where our food is produced. Some soils and plants are selenium-rich; other soils and plants are selenium-poor.
- There are seasonal variations in the selenium content of the foods we eat.
- There are variations in the types of foods we eat.
All in all, it is advisable to have a blood test of one’s selenium level done. The family doctor can order such a test.
Then we can see if we are below the beneficial range of 120 – 150 micrograms of selenium per liter of plasma [Hurst 2010]. Accordingly, we may need a daily 50-microgram or 100-microgram supplement.
Functions of selenium in the body
We know that we need adequate selenium intakes for the production of the selenoproteins (many of them are selenoenzymes) that are needed for the following health benefits:
- antioxidant protection against oxidative damage to cells
- optimal immune system function
- optimal thyroid hormone metabolism
- reduction of cancer risk
- sperm cell production
High-selenium yeast and reduced risk of oxidative stress
In a randomized, double-blind, placebo-controlled study, healthy men taking a selenium-enriched yeast supplement for 9 months had significantly reduced levels of known bio-markers for oxidative stress. Healthy men taking a selenomethionine supplement with a similar amount of selenium did not [Richie 2014].
High-selenium yeast and reduced risk of cancer
Supplementation with a high-selenium supplement containing many selenium forms including organic selenocysteine, selenomethionine, and methylselenocysteine has been associated with reduced cancer risk in several studies [Blot 1993; Prasad 1995; Clark 1996; Hercberg 2004].
Supplementation with a synthetic 100% selenomethionine supplement did not yield cancer-preventive benefits [Lippman 2009].
Conclusion: High-selenium yeast is the best choice
It is important to choose carefully when we choose a selenium supplement.
- We don’t want a supplement with inorganic selenium.
- We don’t want a supplement with synthetic selenomethionine.
- We don’t want a supplement that is 100% selenomethionine.
What do we want?
- We do want an organic supplement that is yeast-bound and contains various species of selenium including methylselenocysteine.
- We do want a supplement that has been tested in randomized controlled trials.
In a future article, I will summarize some of the scientific research done with a high-selenium yeast supplement.
Blot, W. J., Li, J. Y., Taylor, P. R., Guo, W., Dawsey, S., Wang, G. Q., & Li, B. (1993). Nutrition intervention trials in Linxian, China: supplementation with specific vitamin/mineral combinations, cancer incidence, and disease-specific mortality in the general population. Journal of The National Cancer Institute, 85(18), 1483- 1492.
Bügel, S., Larsen, E. H., Sloth, J. J., Flytlie, K., Overvad, K., Steenberg, L. C., & Moesgaard, S. (2008). Absorption, excretion, and retention of selenium from a high selenium yeast in men with a high intake of selenium. Food & Nutrition Research, 52doi:10.3402/fnr.v52i0.1642.
Clark, L. C., Combs, G. J., Turnbull, B. W., Slate, E. H., Chalker, D. K., Chow, J., & … Taylor, J. R. (1996). Effects of selenium supplementation for cancer prevention in patients with carcinoma of the skin. A randomized controlled trial. Nutritional Prevention of Cancer Study Group. JAMA, 276(24), 1957-1963.
Hercberg, S., Galan, P., Preziosi, P., Bertrais, S., Mennen, L., Malvy, D., & Briançon, S. (2004). The SU.VI.MAX Study: a randomized, placebo-controlled trial of the health effects of antioxidant vitamins and minerals. Archives of Internal Medicine, 164(21), 2335-2342.
Hurst, R., Armah, C. N., Dainty, J. R., Hart, D. J., Teucher, B., Goldson, A. J., & Fairweather-Tait, S. J. (2010). Establishing optimal selenium status: results of a randomized, double-blind, placebo-controlled trial. The American Journal of Clinical Nutrition, 91(4), 923-931.
Larsen, E. H., Hansen, M., Paulin, H., Moesgaard, S., Reid, M., & Rayman, M. (2004). Speciation and bioavailability of selenium in yeast-based intervention agents used in cancer chemoprevention studies. Journal of AOAC International, 87(1), 225-232.
Lippman, S. M., Klein, E. A., Goodman, P. J., Lucia, M. S., Thompson, I. M., Ford, L. G., & … Coltman, C. J. (2009). Effect of selenium and vitamin E on risk of prostate cancer and other cancers: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). Jama, 301(1), 39-51.
Prasad, M. P., Mukundan, M. A., & Krishnaswamy, K. (1995). Micronuclei and carcinogen DNA adducts as intermediate end points in nutrient intervention trial of precancerous lesions in the oral cavity. European Journal of Cancer. Part B, Oral Oncology, 31B(3), 155159.
Richie, J. J., Das, A., Calcagnotto, A. M., Sinha, R., Neidig, W., Liao, J., & … El-Bayoumy, K. (2014). Comparative effects of two different forms of selenium on oxidative stress biomarkers in healthy men: a randomized clinical trial. Cancer Prevention Research (Philadelphia, Pa.), 7(8), 796-804. doi:10.1158/1940-6207.CAPR-14-0042
The information presented in this review article is not intended as medical advice and should not be construed as such.