Brewer’s Yeast

Also indexed as: Saccharomyces cerevisiae

What does it do? Brewer’s yeast is the dried, pulverized cells of Saccharomyces cerevisiae, a type of fungus. It is a rich source of B-complex vitamins, protein (providing all essential amino acids), and minerals, including a biologically active form of chromium known as glucose tolerance factor (GTF). Brewer’s yeast should not be confused with nutritional yeast or torula yeast, which are low in chromium.

Brewer’s yeast, perhaps by changing the microbial flora in the large intestine, might be helpful in the treatment of some cases of infectious diarrhea.

Where is it found? Brewer’s yeast, which has a very bitter taste, is recovered after being used in the beer-brewing process. Brewer’s yeast can also be grown specifically for harvest as a nutritional supplement. “De-bittered” yeast is also available, though most yeast sold in health food stores that does not taste bitter is not real brewer’s yeast.

Brewer’s yeast has been used in connection with the following conditions (refer to the individual health concern for complete information):

Rating Health Concerns
3Stars Diabetes
High cholesterol
2Stars Diarrhea (infectious)
3Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star An herb is primarily supported by traditional use, or the herb or supplement has little scientific support and/or minimal health benefit.

Who is likely to be deficient? Brewer’s yeast is not an essential nutrient, but it can be used as a source of B-complex vitamins and protein. It is by far the best source of chromium, both in terms of quantity and bio-availability.

How much is usually taken? Brewer’s yeast is often taken as a powder, or as tablets or capsules. High-quality brewer’s yeast powder or flakes contain as much as 60 mcg of chromium per tablespoon (15 grams). When doctors recommend brewer’s yeast, they will often suggest 1–2 tablespoons (15–30 grams) of this high-potency bulk product per day. Remember, if it is not bitter, it is not likely to be real brewer’s yeast and therefore will not contain biologically active chromium. In addition, “primary grown” yeast (i.e., that grown specifically for harvest, as opposed to that recovered in the brewing process) may not contain GTF.

Are there any side effects or interactions? Side effects have not been reported from the use of brewer’s yeast, although allergies to it exist in some people. It is not related to Candida albicans fungus, which causes yeast infection.

Because it contains a highly biologically active form of chromium, supplementation with brewer’s yeast could potentially enhance the effects of drugs for diabetes (e.g., insulin or other blood sugar-lowering agents) and possibly lead to hypoglycemia. Therefore, people with diabetes taking these medications should supplement with chromium or brewer’s yeast only under the supervision of a doctor.

Saccharomyces boulardii is registered in Europe under the name Saccharomyces cerevisiae, though the manufacturer states that S. boulardii is not the same as brewer’s yeast (S. cerevisiae). There is a case report of a person with severely impaired immune function who, after receiving treatment with S. boulardii, developed an invasive fungal infection identified as S. cerevisiae.1 People with severe impairment of the immune system should therefore not take brewer’s yeast or S. boulardii unless supervised by a doctor.

Are there any drug interactions? Certain medications may interact with brewer’s yeast. Refer to the drug interactions safety check for a list of those medications.

References:

1. Bassetti S, Frei R, Zimmerli W. Fungemia with Saccharomyces cerevisiae after treatment with Saccharomyces boulardii. Am J Med 1998;105:71–2.