Yeasts (of
Saccharomyces cerevisiae) are widely used in Beer and Wine Brewing,
Baking of foods such as bread and cookies and in Feeding of humans
and animals. It is very important to emphasize that yeast
are able to naturally metabolize inorganic minerals into organic
forms, similar to what plants do. Plants do the conversion for us
taking the minerals from the soil. Mineral enriched yeast do this by
taking the minerals from enriched molasses providing one of the best
natural food forms of minerals human can consume.
Furthermore, yeast have an excellent storage mechanism for
B-vitamins, as do other organisms, for factors needed for
growth and life. Yeast is a naturally rich source of proteins,
minerals and B-complex vitamins. Not only does mineral enriched
yeast offer a natural form of mineral, it also provides other
nutrients when consumed.
IMPORTANT CONCEPTS ON SELENIUM
YEAST
As the use of nutritional supplements
increase, there is a growing consumer demand for more
sophisticated information on the products they are consuming. Some
of the questions on Selenium Yeast concern the importance of
selenium in the diet, the bioavailability of organic Selenium Yeast
versus inorganic sources, cancer reduction capabilities of selenium
yeast and toxicity issues. We hope that this information will be
useful to those considering using selenium supplements. Selenium
enriched yeast is the natural, convenient, sate and economical way
to increase selenium intake.
IMPORTANCE OF
SELENIUM YEAST IN HUMAN DIET
Selenium is
an essential mineral in human nutrition. Selenium Yeast is
a natural dietary selenium supplement with clinically proven
physiological value in improving the selenium status in man.
Selenium is
a known anti oxidant and is an essential component of
Glutathione peroxidase enzyme, which inactivates tree radicals.
Selenium is
required in thyroid metabolism while converting active
thyroid hormone (14) into the inactive thyroid hormone (13).
lnactivates
heavy metals, especially mercury, lead and cadmium.
Selenium
Yeast is reported to protect against radiation damage, even
it given after exposure.
A maternal
selenium intake of 500-750 micrograms in the form of
Selenium Yeast is a safe daily intake, adequate for infant and
maternal needs. This is based on a study on selenium status of
exclusively breast fed infants as influenced by maternal organic
(Selenium Yeast) or non-organic (selenite) supplementation in 200
lactating women in Finland.
BIOAVAILABILITY
Nutritecks Selenium
Yeast, grown under a carefully monitored fermentation process,
binds the selenium into the same organic compounds as found in
natural foods.
Several
studies have shown that organic selenium such as high
Selenium Yeast is more bioavailable than inorganic sources of
selenium such as selenate or selenite.
In a study
with Finnish men, selenium blood levels of subjects given
organic forms (wheat and yeast) of selenium increased up to 10 weeks
whereas in the selenate group, selenium blood levels plateaued at a
lower levels after 4 weeks (Levander, et al. 1983). In addition, the
study also showed that organic forms of selenium were stored in the
body and then used at a later time.
A study of
selenium supplementation in breast feeding mothers and
infants clearly showed that Selenium Yeast was safe and more
effective than inorganic selenite in increasing selenium
concentrations of maternal blood serum and milk and infant serum (Kumpulainen
et. al., 1985).
A Danish
study of selenium supplementation in humans, illustrated
that organic selenium is more bioavailable than selenate and
selenite (Clausen and Nielsen, 1988). Organic selenium compounds,
selenomethionine and high Selenium Yeast gave significantly higher
blood serum levels and glutathione peroxidase activities than either
selenate or selenite.
CANCER REDUCTION
RESEARCH
Selenium
Yeast provides a natural protection against several kinds of cancer.
Some recent studies have indicated that Selenium Yeast can reduce
the incidence of some cancers.
Large scale
studies with nutritional supplementation of micronutrients
such as selenium have been carried out in China. Selenium Yeast in
combination with beta carotene and vitamin F showed that it might
reduce the risk of stomach cancer (Blot, a al., 1993). A trial using
inorganic selenium and a mixture of 26 micronutrients did not detect
any reduction on the incidence or mortality for this type of cancer
(Li, et. al., 1993).
A recent study
showed that Selenium Yeast had a significant effect on cancer
(Clark, et. al. 1996). The large scale American study showed that
patients treated with Selenium Yeast had a significant reduction in
total cancer mortality, total cancer incidences and incidences of
lung, colorectal and prostrate cancers.
TOXICITY OF
SELENIUM VERSUS SELENIUM YEAST
The "safe
and adequate range" for selenium consumption, established
by the US. Food and Nutrition Board, has been set at 50 to 200 mcg/day.
Natural
selenium that humans consume is in the form of organic seleno-proteins
such as seleno-methionine and seleno-cysteine. Foods such "
as fish and whole grain cereals are especially rich in organic
selenium compounds (Schrauzer and White 1978).
Selenium
Yeast contains high levels of seleno-methionine. It has
been estimated that up to700/1000of the selenium in Selenium
Yeast is in the form of seleno-methionine.
Evaluations
of toxicity of different forms of selenium have shown that
high Selenium Yeast is less toxic than inorganic forms of selenium
such as sodium selenate and selenite.
A study with rats
showed that high doses (1.5 and 3.0 mg/kg body weight) of organic
selenium in Selenium Yeast did not have any toxic effects after 14
days. This level of selenium is much higher than the theoretical
toxic level for inorganic selenium (Leiras, internal report).
A
comparison of the toxicity of a selenite and a Selenium Yeast diet
in rats showed that Selenium Yeast was much less toxic (Spallholz
and Raftery 1987). No hepatotoxicity, cardiotoxicity or splenomegaly
to 16 ppm dietary Se was observed in rats fed high Selenium Yeast
over an 8 week period. Animals fed selenite at the same level showed
signs of various toxicities.
WARNING
Selenite
and selenate are inorganic chemicals. Simple blends of
these with yeast do not make organically bound selenium. One should
request the selenomethionine analysis of each lot to ensure that the
effective nutritional form of selenium is present.
QUALITY
CRITERIA FOR SELENIUM YEAST
Selenium is
an essential trace element which occurs in cereals and
primarily in the form of selenomethionine. This naturally occurring
amino acid is the most important food form of selenium.
Selenomethionine is well absorbed and retained. From
selenomethionine, all other needed selenium compounds are produced
in the body. On the other hand, selenomethionine, like its sulfur
analog, methionine, cannot be synthesized efficiently in the human
organism.
All quality
nutritional selenium supplements should therefore contain
selenomethionine
Selected
yeast strains incorporate selenium in the form of selenomethionine
and thus are excellent sources of this natural organic food form of
selenium.
However, low-grade
selenium yeasts containing little or no selenomethionine are also
marketed. These yeasts are often claimed to contain organically
bound" selenium when in fact their selenium is inorganic!
Inorganic
selenium compounds are not normal food forms of selenium;
they are less well absorbed and retained.
Quality of selenium
yeasts contain virtually all of the selenium in the form of
selenomethionine.
When ordering
Selenium Yeast, make sure to request analytical certification as to
its selenomethionine content for each batch.
REFERENCES
Blot et.al., 1993
Nutrition intervention trials in Linxian China:
Supplementation
with specific vitamin/ mineral combinations, cancer incidence and
disease-specific mortality in the general population. J. Natl. Clin.
Inst. 85 1483- 1492.
Leiras. Single dose
toxicity of selenium yeast. Internal report # 64013-8530.
Borglund, M and
Akesson, B. 1988 Effect of selenium supplementation on the
distribution of selenium in plasma proteins of health subjects.
lnternat. J. Vit. Nutr. Res. 58, 97-102.
Clark, L C. et.
al., 1996 Effects of selenium supplementation cancer prevention in
patients with carcinoma of the skin. iouri American Medical Assoc.
276 (24), 1957-1963.
Clausen, J. and
Nielsen, S. A. 1998 Comparison of whole blood se nium values and
erythrocytes of glutathione peroxidase activities normal individuals
on supplementation with selenate, seleni L-selenomethionine and high
selenium yeast. Biol. Trace EIem. R15, 125-138.
Kumpulainen,
i., Salmenpera, L, Siimes, M.A.,
Koivistoinen, P., a Perheentupa, i. 1985 Selenium status of
exclusively breast-I infants as influences by maternal organic or
inorganic selenium si plementation. i. Amer. Clin. Nutr. 42,
829-835.
Levander, O.A.,
Alfthan, G., Arvilommi, H., Gref C.G., Huttunen, i Kataja, M.
Koivistoinen, P. and Pikkarainen, i. 1983 Bioavailability selenium
to Finnish men as assessed by platelet glutathic peroxidase activity
and other blood parameters. Amer. Soc. CIin N37, 887-897.
Li., et. al., 1993
Nutrition intervention trials in Linxian China Multiple vitamin/
mineral supplementation, cancer incidence, disease-specific
mortality among adults with esophageal dyspla i. Natl. Clin Inst.
85, 1492- 1498.
Schrauzer, G.N. and
White D. A. 1978 Selenium in human nutritition dietary intakes and
effects of supplementation. Bioorgan. Chem 303-318.
Spallholz, i. E.
and Raftery, A. 1987 Nutritional, chemical toxicological evaluation
of high selenium yeast. In The International Symposium of Se in
Biology and Medicine 516- 52
Dietary
Supplement Information 
