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Common names: Beta sitosterol also is known as plant sterol and phytosterol.
ÒÒÒ...Positive clinical trials
Safety rating:●...No safety concerns despite wide use.
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 β-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.
Plant sterols were chemically described in 1922. Later 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. Subsequently, it has been recognized that, as naturally occurring substances, plant sterols can be added to foods. Margarine appears to be an ideal vehicle.Cholesterol lowering
Beta-sitosterols have shown some cholesterol lowering effects. Plant sterols in fortified margarine reduce the absorption of cholesterol from the gut by about half. Several clinical studies have shown similar results.Immunomodulator/Anti-inflammatory
Over the last 15 years, there also have been several reports in the literature indicating that phytosterols have some immunological activity. Initial studies have shown that beta-sitosterol can increase the proliferation of lymphocytes and enhance the cytotoxic effects of natural killer cells. Further investigation revealed anti-inflammatory properties and has led to suggestions of a role in the control of chronic inflammatory conditions. More clinical studies are needed to verify the benefits of beta-sitosterol in these conditions.Benign prostatic hyperplasia
In clinical studies, beta-sitosterol has been shown to improve urinary symptoms and flow. It has been suggested that beta-sitosterol may be useful for men with mild to moderate BPH, particularly those who would like to avoid the adverse effects of prescription medication.Immunomodulator
Over the last 15 years, there also have been several reports in the literature indicating that phytosterols have some immunological activity.
Beta sitosterol is incorporated in margarine, yogurt, or other foods to give a daily intake of 1.5 to 3 g.
Contraindications have not yet been identified.Pregnancy/nursing
Information regarding safety and efficacy in pregnancy and lactation is lacking.Interactions
None well documented.Side Effects
No major adverse effects at recommended dose. Reduced absorption of carotenes and vitamin E may occur.Toxicities
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