Beta sitosterol is structurally related to cholesterol and is the main phytosterol, or plant fat, found in all plants, including fruits and vegetables. Human and animal research has shown beta sitosterol to have anti-inflammatory, anti-tumor, immune-modulating and cholesterol-lowering effects. Because of these properties, beta sitosterol may be useful for chronic diseases such as rheumatoid arthritis, multiple sclerosis, benign prostatic hyperplasia and cancer.
History
Research into the properties and effects of beta sitosterol and other plant sterols has been ongoing for decades. In 1995 these sterols came into widespread use as cholesterol-lowering agents through the introduction of phytosterol-fortified margarine. Beta sitosterol can also be found as a dietary supplement.
Anti-inflammatory
Beta sitosterol reduces inflammation by balancing levels of pro- and anti-inflammatory cytokines.
Anti-tumor
Beta sitosterol may be effective against colon, breast and prostate cancer. Mechanisms of action on cancer cells include reduction in tumor cell proliferation, inhibition of testosterone metabolism and stimulation of programmed cell death.
Cholesterol
Beta sitosterol lowers cholesterol primarily by blocking its intestinal absorption. It also inhibits the enzyme HMG -CoA reductase, the rate-limiting enzyme in cholesterol production.
Sources
The best dietary sources of beta sitosterol are seeds, nuts, beans and unrefined vegetable oils.
