Brewer's yeast
Brewer's yeast is made from a one-celled fungus called Saccharomyces cerevisiae and is used to make beer. It has been grown and used as a nutritional supplement for years. Brewer's yeast is a rich source of minerals -- particularly selenium; protein; B-complex vitamins, and chromium, an essential trace mineral that helps the body maintain normal blood sugar levels.
Brewer's yeast tastes bitter and should not be confused with baker's yeast, nutritional yeast, or torula yeast. All those types of yeast are low in chromium.
General
The B-complex vitamins in brewer's yeast include B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B9 (folic acid), and H or B7 (biotin). These vitamins help break down carbohydrates, fats, and proteins, which provide the body with energy. They also support the nervous system, help maintain the muscles used for digestion, and keep skin, hair, eyes, mouth, and liver healthy.
Brewer's yeast does not contain vitamin B12, an essential vitamin found in meat and dairy products.
Diabetes
Some studies suggest that chromium supplements may help people with diabetes control blood sugar levels. People with diabetes either do not produce enough insulin -- a hormone needed to change sugar, starches and other food into energy -- or cannot use the insulin that their bodies make. Chromium may lower blood sugar levels as well, improving glucose tolerance and reducing the amount of insulin needed. Because brewer's yeast is a rich source of chromium, scientists think it may help treat high blood sugar.
High Cholesterol
A few studies suggest that brewer's yeast may help lower LDL ("bad") cholesterol levels in the blood and raise HDL ("good") cholesterol levels. Researchers aren't sure whether that is due to the chromium in brewer's yeast or another substance. Not all studies have found positive results.
Weight Loss
Although some studies suggest that chromium may help reduce body fat, the amount of fat lost is small compared to what can be lost with exercise and a well-balanced diet. Brewer's yeast is also used as a protein supplement and energy booster. So it may help maintain a healthy weight.
Other Uses
At least one study has found that brewer's yeast may improve acne. Another linked it to a reduced risk of a second skin cancer. One large, preliminary study found that taking a specific kind brewer's yeast product (EpiCor) may help prevent colds and flu.
Available Forms
Brewer's yeast is available in powder, flakes, tablet, and liquid forms.
How to Take It
Pediatric
Brewer's yeast is not recommended for use in children, because it hasn't been studied.
Adult
1 to 2 per day; may be added to food or dissolved in juice or water.
Precautions
Supplements may have side effects or interact with medications. You should take them only under the supervision of your doctor.
Side effects from brewer's yeast are generally mild and may include gas.
People who have frequent yeast infections or who are allergic to yeast should avoid brewer's yeast.
People with diabetes should talk to their doctors before taking brewer's yeast because it could interact with medications for diabetes and cause low blood sugar.
People with Crohn's disease should also talk to their doctors before taking brewer's yeast.
Possible Interactions
If you are being treated with any of the following medications, you should not use brewer's yeast without first talking to your doctor.
Monoamine Oxidase Inhibitors (MAOIs)
Brewer's yeast contains a large amount of tyramine, a substance that can interact with MAOIs and cause a hypertensive crisis. A hypertensive crisis is a very fast and dangerous rise in blood pressure that can cause heart attack or stroke. MAOIs are used to treat depression and include:
- Phenelzine (Nardil)
- Tranylcypromine (Parnate)
- Selegiline (Ensam, Eldepryl)
- Isocarboxazid (Marplan)
Meperidine (Demerol)
As with MAOI antidepressants, brewer's yeast may also lead to a high blood pressure crisis if it is taken with Demerol, a narcotic medication used to relieve pain.
Medications for Diabetes
Brewer's yeast may lower blood sugar levels. When combined with diabetes medications, taking brewer's yeast could raise the risk of having low blood sugar. If you take medications for diabetes, talk to your doctor before taking brewer's yeast.
Supporting Research
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Anderson RA. Chromium in the prevention and control of diabetes. Diabetes Metab. 2000;26(1):22-27.
Anderson RA. Elevated intake of supplemental chromium improved glucose and insulin variables in individuals with type 2 diabetes. Diabetes. 1997;46(11):1786-1791.
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Hosseinzadeh P, Djazayery A, Mostafavi SA, et al. Brewer's Yeast Improves Blood Pressure in Type 2 Diabetes Mellitus. Iran J Public Health. 2013;42(6):602-609.
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Moyad MA, Robinson LE, Zawada ET Jr, et al. Effects of a modified yeast supplement on cold/flu symptoms. Urol Nurs. 2008;28(1):50-55.
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Yoshida Y, Yokoi W, Wada Y, Ohishi K, Ito M, Sawada H. Potent hypocholesterolemic activity of the yeast Kluyveromyces marxianus YIT 8292 in rats fed a high cholesterol diet. Biosci Biotechnol Biochem. 2004;68(6):1185-1192.
Zager SH. Acne vulgaris and acne rosacea. Rakel D, ed. Integrative Medicine. 3rd ed. Philadelphia, PA: Elsevier Saunders; 2012: chap 73.