Brewer's yeast

Description

Brewer's yeast is an ingredient that is used to ferment sugars to alcohol in the brewing of beer. It consists of the ground, dried cells of Saccharomyces cerevisiae, a one-celled plant that is a variety of fungus.

Brewer's yeast contains all the essential amino acids , 14 minerals, and 17 vitamins. It is one of the best natural sources of the B-complex vitamins thiamin, riboflavin, niacin , B₆, pantothenic acid, biotin , and folic acid . It is also high in minerals, including chromium, zinc, iron, phosphorus , and selenium . Brewer's yeast is also a good source of protein. It contains approximately 16 g of protein per 30 g of powdered yeast. Brewer's yeast is a good source of RNA, an immune-enhancing nucleic acid that may help in the prevention of degenerative diseases and slowing the aging process.

General use

Vegetarians have used brewer's yeast as a source of protein, vitamins, and minerals for many years. In addition to being an excellent nutritional supplement, brewer's yeast is often recommended to regulate blood sugar levels, improve the health of the skin, control diarrhea , lower cholesterol , and repel insects.

Brewer's yeast is one of the best sources of the mineral chromium. Two tablespoons of brewer's yeast yields about 120 micrograms (μg) of chromium, an amount equal to the recommended daily allowance. Chromium is an important factor in regulating blood sugar levels. High levels of chromium increase glucose tolerance. Diabetes and hypoglycemia are two conditions in which blood sugar levels are unstable. Brewer's yeast has been reported to help improve symptoms of diabetes and hypoglycemia, and may act to prevent diabetes from developing in persons with a family history of diabetes and in those who have problems with blood sugar metabolism. One Danish study reported that people with hypoglycemia showed an improvement in their symptoms after taking 2 tbsp of brewer's yeast every day for one month.

B-complex vitamins are important for healthy skin and nails. Persons deficient in these vitamins may benefit from taking brewer's yeast as it is rich in B-complex vitamins. A compound derived from brewer's yeast, skin respiratory factor (SRF) reportedly has wound healing properties. SRF has been a component in over-the-counter hemorrhoid remedies for more than four decades. SRF also has been used to treat skin problems. Brewer's yeast has been used in the treatment of contact dermatitis , a condition of the skin characterized by red, itchy, and inflamed skin.

Another component of brewer's yeast also has wound healing properties. Glucan, a substance derived from the yeast, has been shown to improve wound healing in mice by activating macrophages and promoting the growth of skin cells and capillaries.

Brewer's yeast may help to prevent constipation . Thirty grams of brewer's yeast contains approximately 6 grams of dietary fiber (24% of the recommended daily amount). Fiber is an important part of the diet as it helps increase the bulk of fecal matter, thereby promoting healthy bowels and intestines. Brewer's yeast has also been found to be helpful in cases of diarrhea. The yeast acts to encourage the growth of good bacteria in the intestines.

Studies show that brewer's yeast may be helpful in decreasing cholesterol and raising HDL levels (the good cholesterol). A study performed at Syracuse University in New York reported that persons who consumed 2 tbsp of brewer's yeast daily for two months reduced their cholesterol levels by 10%.

Pet owners have known about the ability of brewer's yeast ability to repel ticks and fleas for many years. Wafers that contain brewer's yeast can be given to animals for this purpose. Powdered brewer's yeast may be sprinkled on the animal's food also. The large amounts of thiamine in brewer's yeast may act to repel mosquitoes from humans as well.

Generous doses of brewer's yeast may help to prevent cancers such as prostate cancer . When combined with wheat germ , brewer's yeast is helpful in preventing heart problems. Brewer's yeast may also be helpful in the treatment of fatigue or low energy.

Preparations

Brewer's yeast is available at most health food stores in tablets, flakes, and a powdered form. Brewer's yeast can be added to foods (soups, casseroles, baked goods) to increase their nutritional value. It is also a popular addition to drinks, juices, and shakes. Brewer's yeast does not require refrigeration and has a long shelf life.

Do not confuse brewer's yeast should not be confused with torula yeast, nutritional yeast, or baker's yeast. These yeasts are not a high source of chromium. Brewer's yeast should also not be confused with the yeast that causes vaginal infections , Candida albicans, although persons who are sensitive to these conditions should use caution when taking brewer's yeast.

The quality of brewer's yeast varies depending upon the manufacturer. Some packaged brewer's yeasts are processed to remove the alcohol and/or chemical byproducts that may be left behind in the brewing process. This processing phase lowers the nutritional quality of the yeast. High quality brewer's yeast is grown on molasses or sugar beets and is grown specifically for supplemental purposes. As a result, there is no need for further processing. Brewer's yeast powder is often bitter tasting. Some powders are "debittered."

Brewer's yeast contains higher levels of phosphorus than calcium . Too much phosphorus may deplete the body of calcium. To create a balance, some manufacturers add calcium to their brewer's yeast.

When prescribing brewer's yeast as a food supplement, doctors often recommend a daily dosage of 1-2 tbsp.

Ticks and fleas can be prevented by sprinkling in pets sprinkle powdered brewer's yeast on the animal's food in a dosage of 1 tsp for cats and 1 tsp per pound of body weight for dogs.

Precautions

Daily dosage on the product label should not be exceeded.

Those allergic to yeast or susceptible to yeast infections should contact their health care practitioner before taking brewer's yeast.

Persons with gout , vaginal infections, or Candida albicans should avoid using brewer's yeast.

Persons with diabetes should consult their health care practitioner before using brewer's yeast. Brewer's yeast may interfere with insulin requirements.

The use of brewer's yeast in persons with an impaired immune system may lead to an infection.

Persons with an intestinal disease should not take brewer's yeast.

Brewer's yeast is safe in pregnant or nursing women at doses of 1-2 tbsp per day.

Side effects

Initial use may cause bloating and gas . To lessen these effects, it is best to begin with small amounts of brewer's yeast (less than 1 tsp daily) and gradually work up to the recommended dosage.

If nausea or diarrhea occur, one should stop taking brewer's yeast and contact a health care practitioner.

Interactions

There are no known interactions.

Resources

BOOKS

Griffith, H. Winter. Minerals, Supplements & Vitamins: The Essential Guide. Arizona:Fischer Books, 2000.

Prevention Magazine. The Complete Book of Alternative Nutrition. Pennsylvania: Rodale Press, Inc., 1997.

Jennifer Wurges

Saccharomyces cerevisiae

Unicellular Fungi (Yeast Phylum) are one of the most studied single-cell Eukaryotes . Among them, Saccharomyces cerevisiae is perhaps the biological model most utilized for decades in order for scientists to understand the molecular anatomy and physiology of eukaryotic cells, such as membrane and transmembrane receptors, cell cycle controls, and enzymes and proteins involved in signal transduction to the nucleus .

Many strands of S. cerevisiae are used by the wine and beer industry for fermentation . S. cerevisiae is a member of the group of budding yeasts that replicate (reproduce) through the formation of an outgrowth in the parental cell known as a bud. After nuclear division into two daughter nuclei, one nucleus migrates to the bud, which continues to grow until it breaks off to form an independent daughter cell. Most eukaryotic cells undergo symmetric cell division, resulting in two daughter cells with the same size. In budding yeast, however, cell division is asymmetric and produces at cell separation a large parental cell and a small daughter cell. Moreover, after separation, the parental cell starts the production of a new bud, whereas the daughter cell continues to grow into its mature size before producing its own bud. Cell cycle times are also different between parental and young daughter cells. Parental (or mother cells) have a cell cycle of 100 minutes, whereas daughter cells in the growing process have a cycle time of 146 minutes from birth to first budding division.

The study of cell cycle controls, enzymatic systems of DNA repair, programmed cell death, and DNA mutations in S. cerevisiae and S. pombe greatly contributed to the understanding of pre-malignant cell transformations and the identification of genes involved in carcinogenesis. They constitute ideal biological models for these studies because they change the cellular shape in each phase of the cell cycle and in case of genetic mutation, the position defect is easily identified and related to the specific phase of the cell cycle. Such mutations are known as cdc mutations (cell division cycle mutations).

See also Cell cycle (eukaryotic), genetic regulation of; Yeast genetics