What is beta-sitosterol plant extract?
Beta-sitosterol is one of many sterols that come from plants (phytosterols) and have a structure like the cholesterol produced in the body. You can find phytosterols in many plants and thus in foods such as rice bran, wheat germ, corn oils, soybeans, and peanuts. Beta-sitosterol is also available as a natural health product.
What is beta-sitosterol used for?
Beta-sitosterol is said to lower cholesterol levels and reduce the risk of some cancers. It also is said to relieve symptoms of benign prostatic hyperplasia (BPH). How beta-sitosterol works is not known. It may be related to cholesterol metabolism or anti-inflammatory effects.
A review of studies done on beta-sitosterol showed that men who took it had fewer symptoms than men who took a placebo. Symptoms were measured using the International Prostate Symptom Score (IPSS). Men who took beta-sitosterol also had a better urine flow rate then men who took a placebo.footnote 1
Research supports the fact that phytosterols, including beta-sitosterol, can reduce cholesterol levels. Some studies suggest that phytosterols may reduce the risk of some cancers, but more research is needed to know how well they really work.
Is beta-sitosterol safe?
Few problems have been reported among men taking beta-sitosterol for BPH. Some men may have problems with their stomach and digestion. Beta-sitosterol's ability to prevent complications of BPH is not known.
Men who have problems urinating should see a doctor to rule out prostate cancer or other diseases. Prostate cancer is treatable, but treatment may be more successful when you find and treat the cancer as early as possible.
Some studies have shown that phytosterols can help lower cholesterol. But the long-term effects of eating foods that have phytosterols added to them (for example, some margarines) or taking phytosterols as a natural health product are not yet known.
The Natural and Non-Prescription Health Products Directorate (NNHPD), within the Health Products and Food Branch of Health Canada, regulates natural health products in Canada. Natural health products, including beta-sitosterol, must be reviewed and approved by the NNHPD before they can be sold in Canada.
Always tell your doctor if you are using a natural health product or if you are thinking about combining a natural health product with your conventional medical treatment. It may not be safe to forgo your conventional medical treatment and rely only on a natural health product. This is especially important for women who are pregnant or breastfeeding.
When using natural health products, keep in mind the following:
- Like conventional medicines, natural health products may cause side effects, trigger allergic reactions, or interact with prescription and non-prescription medicines or other natural health products you might be taking. A side effect or interaction with another medicine or natural product may make other health conditions worse.
- The way natural health products are manufactured may not be standardized. Because of this, how well they work or any side effects they cause may differ among brands or even within different lots of the same brand. The form of the natural health product that you buy in health food or grocery stores may not be the same as the form used in research.
- Other than for vitamins and minerals, the long-term effects of most natural health products are not known.
- Wilt TJ, et al. (1999). Beta-sitosterols for benign prostatic hyperplasia. Cochrane Database of Systematic Reviews (3).
Other Works Consulted
- Bradford PG, Awad AB (2007). Phytosterols as anticancer compounds. Molecular Nutrition and Food Research, 51(2): 161–70.
- Weingarter O, et al. (2008). Vascular effects of diet supplementation with plant sterols. Journal of the American College of Cardiology, 51(16): 1553.
Current as of: December 20, 2019
Author: Healthwise Staff
Medical Review: Adam Husney, MD - Family Medicine
Brian O'Brien, MD, FRCPC - Internal Medicine
Kathleen Romito, MD - Family Medicine
Current as of: December 20, 2019