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 dietary supplement.

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), such as waking up many times at night to urinate. How beta-sitosterol works is not known. It may be related to cholesterol metabolism or anti-inflammatory effects.

There is limited evidence that beta-sitosterol does relieve the symptoms of BPH.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 dietary supplement are not yet known.

The Natural Health Products Directorate (NHPD), within the Health Products and Food Branch of Health Canada, regulates dietary supplements in Canada. Dietary supplements, including beta-sitosterol, must be reviewed and approved by the NHPD before they can be sold in Canada.

Always tell your doctor if you are using a dietary supplement or if you are thinking about combining a dietary supplement with your conventional medical treatment. It may not be safe to forgo your conventional medical treatment and rely only on a dietary supplement. This is especially important for women who are pregnant or breast-feeding.

When using dietary supplements, keep in mind the following:

• Like conventional medicines, dietary supplements may cause side effects, trigger allergic reactions, or interact with prescription and non-prescription medicines or other supplements you might be taking. A side effect or interaction with another medicine or supplement may make other health conditions worse.
• The way dietary supplements 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 supplement 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 dietary supplements are not known.