Selenium yeast: the preferred mineral source.
When it comes to mineral supplements, yeast represents a highly valuable source of safe and ready-to-use minerals such as zinc and selenium, coupled with a natural reservoir of proteins and B vitamins. During the past few months, new health benefits have been documented for these vitamins and minerals, such as their potential to reduce age-related cognitive decline or the risk of atherosclerosis. Furthermore, selenium yeast has been recognized by the European Food Safety Authority (EFSA); its Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food has given a positive Scientific Opinion for the use of selenium yeast in foods and food supplements and concluded that organically bound selenium yeast complying with specific characteristics is safe for use in foods, supplements and foods for particular nutritional use (PARNUTS). (1)
As a consequence, Lalmin Se Yeast will now be included in Annex II of Directive 2002/46/EC (The Positive List). Not only did EFSA rule that selenium yeast is completely safe, the panel also looked at the bioavailability and metabolism of the mineral source. The panel identified the high level of selenomethionine (60-85% of the Se content) to be responsible for the superior bioavailability of the material. The panel concluded that organically bound selenium yeast is up to two times more bioavailable than inorganic forms of selenium such as selenite or selenate. These conclusions relate only to selenium-enriched yeasts produced in compliance with the product characteristics described in the Opinion: "Selenium-enriched yeasts produced by culture in the presence of sodium selenite as the selenium source and containing, in the dried form as marketed, not more than 2.5 mg Se/g. The predominant organic selenium species present in the yeast is selenomethionine, which constitutes between 60 and 85% of the total selenium in the product. The content of other organic selenium compounds, including selenocysteine, does not exceed 10%. Levels of inorganic selenium in selenium-enriched yeast do not normally exceed 1%."
In addition to Lallemand's usual and vigorous Quality Control procedures, which demonstrate the incorporation of minerals into Lalmin Se Yeast, several analyses that specifically document the incorporation of selenium into yeast proteins were also performed. In one of them, done in collaboration with Dr Lobinski from the University of Pau, France, it was observed that the inter-batch variation of selenium content was extremely low and that all of the chromatograms obtained typically represented selenium-enriched yeast grown in optimized conditions. An important conclusion was that no inorganic selenium (selenite or selenate) was detected and, consequently, that all selenium present in the fermentation was absorbed by the yeast and only present in an organic form. Therefore, the selenium present in Lalmin Se is 100% organically bound and highly bioavailable.
Se-yeast is more bioavailable than inorganic sources of selenium; it is both able to increase selenoenzyme activity and, furthermore, unlike selenite or selenate, it can be stored as SeMet in tissues, giving it a slower whole-body turnover rate and allowing it to support greater tissue selenium concentrations than inorganic selenium. Reported whole-body half-lives for SeMet and selenite in humans were 252 and 102 days, respectively, implying that SeMet is retained 2.5 times longer in the body than selenite. (2) Accordingly, humans or animals supplemented with Se-yeast can maintain higher activities of selenoenzymes during selenium depletion for longer periods than those supplemented with inorganic selenium--owing to the recycling of SeMet following catabolism from protein stores. These factors confer an advantage in situations of low to marginal selenium status, which is the situation in some European countries or in certain population groups, such as infants. Yeast selenium is also more effective than inorganic selenium in its ability to transfer selenium to breast-fed infants or suckling animals, thereby preventing the risk of deficiency.
Selenium as a Supplement
The essential trace mineral, selenium, is of fundamental importance to human health. The body has developed defences--such as antioxidants--to control the levels of free radicals produced during normal oxygen metabolism because they can damage cells and contribute to the development of some chronic diseases. Selenium, as a constituent of selenoproteins, is an important component of antioxidant enzymes (such as the glutathione peroxidases) that protect cells against the effects of free radicals. It also has other important roles; it catalyses the production of active thyroid hormone, for example, and is an important structural component of human sperm. Although selenium-deficiency diseases have been recognized for some time, evidence is mounting to suggest that less-overt deficiency can also cause adverse health effects. Furthermore, supranutritional levels of selenium may provide additional protection against disease susceptibility. There is growing evidence that higher selenium intakes are associated with reduced cancer risk. In addition, selenium supplementation appears to enhance the immune response. Selenium appears to be a key nutrient in counteracting certain viral infections. It has long been recognized as being essential for successful animal reproduction. And, deficiency has been linked to adverse mood states.
New Benefits: Cognitive Health and Artherosclerosis
Recently, French researchers have established a relationship between low selenium plasma levels in elderly subjects and the probability of cognitive decline. (3) Because oxidative stress in the brain represents one of the causes of cognitive impairment, this probably explains the protective role of selenium against age-related cognitive decline. A recently published study shows that selenium yeast supplementation (Lalmin Se) could prevent atherosclerosis formation in a hamster model of the disease. (4) When atherosclerosis was induced with a high fat, high cholesterol diet, selenium, as well as selenium- and glutathione-enriched yeast, were efficient in preventing an increase in blood triglycerides levels. Atherosclerosis formation (measured in the aorta) was reduced by 44% and, in parallel, the animals' blood selenium content was twice as high as in the controls.
Formulating with Lalmin Se
Lalmin Se yeast is stable and heat resistant, which makes it suitable for different galenic forms such as tablets, soft and hard capsules and functional foods. The current European Recommended Daily Allowance for selenium is 65 [micro]g, but most mineral supplements provide a daily selenium dose of 100 [micro]g per day. Lalmin Se yeast is offered in two concentrations--0.1% and 0.2%--which means only 50 or 100 mg is required to achieve the European RDA. Lalmin Se yeast is also available with reduced odour and in a soluble form. In conclusion, Lalmin Se yeast brings a natural source of selenium to the market through a safe vehicle. The high quality of Lalmin Se is extensively documented and the form is suitable for all nutraceutical applications.
(1.) F. Aguilar, et al, "Selenium-Enriched Yeast as Source for Selenium Added for Nutrition Purposes in Foods for Particular Uses and Foods (including food supplements) for the General Population," EFSA Journal 766, 1-42 (2008).
(2.) G.N. Schrauzer, "Selenomethionine: A Review of the Nutritional Significance, Metabolism and Toxicity," J. Nutr. 130, 1653-1656 (2000).
(3.) N.T. Akbaraly, et al., "Plasma Selenium Over Time and Cognitive Decline in the Elderly," Epidemiology 18, 52-58 (2007).
(4.) G.A. Agbor, et al., "Effect of Selenium- and Glutathione-Enriched Yeast Supplementation on a Combined Atherosclerosis and Diabetes Hamster Model," J. Agric. Food Chem. 55(21), 8731-8736 (2007).
For more information
Lallemand Health Ingredients
DK-3460 Birkerod, Denmark.
Tel. +45 4595 0850
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|Title Annotation:||vitamins and minerals|
|Publication:||Nutraceutical Business & Technology|
|Date:||Nov 1, 2008|
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