Beta-Sitosterol for Sports & Fitness
Why Use
Why Do Athletes Use It?*
Some athletes say that beta-sitosterol helps boost resistance to infection.
What Do the Advocates Say?*
A combination of beta-sitosterol (BSS) and BSSG, a related compound, is known to enhance some parts of the immune system in animals and humans. While not proven to prevent infections in athletes, this combination has been shown to prevent the decline in immune function often experienced at the end of an ultramarathon.
*Athletes and fitness advocates may claim benefits for this supplement based on their personal or professional experience. These are individual opinions and testimonials that may or may not be supported by controlled clinical studies or published scientific articles.
Dosage & Side Effects
How Much Is Usually Taken by Athletes?
BSS, a natural sterol found in many plants, has been shown in a double-blind trial to improve immune function in marathon runners when combined with a related substance called B-sitosterol glucoside (BSSG).1 This implies that beta-sitosterol might reduce infections in athletes who engage in intensive exercise, though studies are still needed to prove this. The usual amount of this combination used in research is 20 mg of BSS and 200 mcg of BSSG three times per day.
Side Effects
At the time of writing, there were no well-known side effects caused by this supplement.
Interactions with Supplements, Foods, & Other Compounds
Ingesting plant sterols interferes with beta-carotene and vitamin E absorption, resulting in lower blood levels of these nutrients.2
Interactions with Medicines
As of the last update, we found no reported interactions between this supplement and medicines. It is possible that unknown interactions exist. If you take medication, always discuss the potential risks and benefits of adding a new supplement with your doctor or pharmacist.
More Resources
Where to Find It
Beta-sitosterol is one of several plant sterols (cholesterol is the main animal sterol) found in almost all plants. High levels are found in rice bran, wheat germ, corn oil, and soybeans. Peanuts and its products, such as peanut oil, peanut butter, and peanut flour, are good sources of plant sterols, particularly beta-sitosterol.3
