Brewer's yeast has been used as a nutritional supplement for many years, but which properties make it so popular and who can benefit from taking it?
What is brewer's yeast?
Brewer's yeast is so called because it is an essential ingredient in beer-making. Its official name is Saccharomyces cerevisiae, and this single celled fungus is also specifically grown for making into a nutritional supplement.
What does brewer's yeast do?
Brewer's yeast is particularly rich in chromium, amongst other nutrients. Chromium has been shown to play a useful role in stabilising blood-glucose levels and so could be helpful in managing diabetes. However, research giving supplements of brewer's yeast or chromium to elderly adults proved both these supplements effective in raising blood chromium levels - but with no effect on blood sugar control.
Diabetes UK takes the stance that it's better to get essential minerals and vitamins from food than to take a supplement and asserts that people with diabetes should not see supplements as a replacement for prescribed medication.
Brewer's yeast is also rich in selenium, a mineral essential for antioxidant benefits, and possibly offering some protection against heart disease by encouraging the production of 'good' HDL cholesterol and reducing levels of 'bad' (LDL) cholesterol.
It's also a good source of B-complex vitamins, including B1 ( thiamine), B2 ( riboflavin), B3 ( niacin), B5 (pantothenic acid), B6 ( pyridoxine), B9 ( folic acid), and biotin, all of which are essential to provide energy, support the nervous system, promote good digestion and keep the skin, hair, eyes and liver in tip-top condition.
It's a nutritional myth that Brewer's yeast is a rich source of vitamin B12 - it isn't. In nature, Brewer's yeast naturally grows alongside bacteria that can make B12, but the purified forms of yeast found in supplement pills are B12 free. Some supplements are fortified with B12, listed on the ingredient label.
Other potential uses
Brewer's yeast may be modified to help deliver vaccines designed to reduce the risk of skin cancer, (but this research is at an early stage) improve acne and even prevent colds and flu. Further investigation and broader studies need to be conducted before these preliminary findings can be verified.
How is it taken?
Brewer's yeast is most commonly available in tablet and powder form and can be taken in doses of up to 3,000mg per day, usually split into three doses of 1,000mg taken with meals.
Can everyone take it?
It's not known whether brewer's yeast has any impact on pregnancy or breastfeeding, so it's best to avoid it during these times. Similarly, it shouldn't be given to children as it's not yet known whether it's safe for them. People with atopic dermatitis should avoid yeast supplements as they may worsen this skin condition. Brewers yeast should also be avoided in those with impaired immunity (eg during chemotherapy), active inflammatory bowel disorders (such as Crohn's disease and ulcerative colitis), the very young and the very old.
Avoid brewer's yeast supplements if you have gout as the high purine content increases blood uric acid levels and potential for gout flare-up.