Medically reviewed on June 7, 2018
What is Beta Sitosterol?
Dietary consumption is the main source of phytosterols. They are not synthesized inside the human body. Fortified margarines used for lowering cholesterol contain 2 g of plant sterols per daily portion. The sitosterols usually are obtained from soybean oil, peanut oil, and avocado oil. Preparations containing beta-sitosterol, derived from the South African star grass Hypoxis rooperi or from species of Pinus and Picea, are available for the treatment of benign prostatic hypertrophy. Saw palmetto berries also contain large quantities of beta-sitosterol and other plant sterols.
Beta-sitosterol is also known as plant sterol and phytosterol.
What is it used for?
Plant sterols were chemically described in 1922. In the 1950s, it was noted that these sterols lower serum cholesterol concentrations by reducing the absorption of cholesterol from the gut. However, by the 1980s, statins were introduced to the market, so the role of plant sterols in lipid lowering was diminished. Since then, it has been recognized that, as naturally occurring substances, plant sterols can be added to foods. Margarine appears to be an ideal vehicle, although cream cheese, salad dressing, and yogurt are also used. Over the last 15 years, there also have been several reports indicating that phytosterols have some effect on the immune system.
Beta-sitosterol has been used to lower cholesterol and improve symptoms in mild to moderate enlarged prostate. Beta-sitosterol has also been investigated for its immune system and anticancer effects.
What is the recommended dosage?
Beta-sitosterol is added to margarine, yogurt, or other foods to provide a daily intake of 1.5 to 3 g.
Avoid plant sterols such as beta-sitosterol in patients with sitosterolemia, a rare inherited plant sterol storage disease.
Beta-sitosterol should be avoided in pregnant women because it can stimulate the womb.
Plant sterols reduce the effects of some vitamins. Beta-sitosterol levels may decrease in patients receiving the cholesterol drug ezetimibe.
Beta-sitosterol may cause GI adverse effects as well as impotence. In 1 study, side effects related to beta-sitosterol use were gas, discoloration of the feces, appetite changes, stomach problems, leg cramps, skin rash, and low white blood cell count. A 1-year study in healthy patients consuming 1.6 g/day of plant sterols in a dietary spread showed cholesterol-lowering effects and long-term tolerance.
Clinical data are lacking.