Beta-sitosterol is a plant sterol -- a chemical found in all plant foods -- that appears to offer a number of health benefits. Even though it naturally occurs in foods, you'd need to eat foods fortified with sterols or use them in supplement form to achieve therapeutic benefit. The amount present in fruits, vegetables and the like is just too small to exert a medicinal effect. Not all purported benefits, however, have strong scientific backing behind them.

Treating High Cholesterol

Beta-sitosterol is probably best known as a treatment for high cholesterol. The University of Maryland Medical Center reports several studies indicate its ability to lower levels of LDL, or “bad” cholesterol. Beta-sitosterol does not appear to affect levels of HDL, or “good” cholesterol, or triglycerides. The plant sterol works by reducing the absorption of cholesterol in the intestines by about 50 percent, according to Drugs.com. This mechanism of action leads to more being excreted and less circulating in the bloodstream.

Prostate Health

Beta-sitosterol has a long history of use in Europe for treating an enlarged prostate. According to a report in the June 2005 issue of “Life Extension” magazine, studies have found that beta-sitosterol reduced symptoms of enlarged prostate, such as reduced urinary flow. Beta-sitosterol appears to work by blocking the production of dihydrotestosterone, which triggers the growth of prostate cells. The report also noted that beta-sitosterol reduced the growth and spread of prostate cancer cells and induced apoptosis -- the process where cancer cells self-destruct. These studies involved animals or isolated prostate cancer cells, however, and do not firmly establish the therapeutic benefit in humans.

Other Benefits

Drugs.com notes beta-sitosterol might enhance immune function. EMedTV notes other purported uses do not have enough scientific backing behind them. They include treating colds and flu, asthma, hair loss, gallstones, enhancing sexual function and relieving symptoms of menopause.

Considerations for Use

To lower cholesterol, you require about 2 grams of beta-sitosterol daily. Many foods have been fortified with beta-sitosterol such as margarine, orange juice and yogurt. Two 8-ounce glasses of fortified orange juice, for example, would meet this requirement. You could also use supplements. The aforementioned studies looking at beta-sitosterol for enlarged prostate used between 130 milligrams and 180 milligrams daily. Talk to your doctor about the appropriate dosage for addressing symptoms of an enlarged prostate. Regular consumption of beta-sitosterol could lower levels of carotenes and vitamin E and you might require supplementation.