Beta-sitosterol is a plant sterol found in various foods and some dietary supplements and functional foods, such as margarines or spreads. It is primarily used for lowering cholesterol and relieving symptoms of an enlarged prostate. Beta-sitosterol works by decreasing the absorption of cholesterol in the intestine and reducing the amount of DHT in the body. Potential side effects include nausea, gas, and constipation.
Beta-sitosterol is a plant sterol, a compound that is closely related to cholesterol but comes from plants. Although many foods contain small amounts of beta-sitosterol, there is much interest in using it as a dietary supplement, especially in the form of functional foods, such as margarines or spreads. The substance is claimed to be beneficial for the following conditions
- High cholesterol
- Heart disease
- An enlarged prostate (known medically as benign prostatic hyperplasia, or BPH).
There are many other purported uses of beta-sitosterol as well, some of which are more valid than others.
(Click Benefits of Beta-Sitosterol for more information on what it is used for.)
Beta-sitosterol is a plant sterol, a compound similar to cholesterol. It is not absorbed much from the digestive system to the rest of the body, so it works mostly within the digestive system. It works by blocking the absorption of cholesterol from the intestine. Cholesterol in the intestine comes from two sources: food and the liver. The liver secretes cholesterol into the intestines in the form of bile, and some of this cholesterol is reabsorbed back into the body. Because beta-sitosterol decreases the absorption of cholesterol in the intestine, it can decrease cholesterol levels in the body, even if you do not eat much cholesterol, because of the cholesterol from the liver.
Beta-sitosterol may work for an enlarged prostate by inhibiting an enzyme called 5-alpha-reductase, blocking the conversion of testosterone into DHT (dihydrotestosterone), thereby decreasing the amount of DHT in the body. Since DHT is important for enlargement of the prostate, this may be how beta-sitosterol works for BPH. In fact, several prescription prostate medications work in a similar way. Since these medications are also effective for hair loss (particularly male pattern baldness), it is possible that beta-sitosterol may also work for hair loss, although no adequate research has shown this to be the case.