Essential Beta-Sitosterol

Beta-Sitosterol Supplement Description

Beta-sitosterol is one of hundreds of plant-derived "sterol" compounds (including sterols and sterolins) that have structural similarity to the cholesterol made in our bodies. The most prevalent phytosterols in the diet are beta-sitosterol, campesterol and stigmasterol. Plant oils contain the highest concentration of phytosterols - so nuts and seeds contain fairly high levels and all fruits and vegetables generally contain some amount of phytosterols. Perhaps the best way to obtain beta-sitosterol is to eat a diet rich in fruits, vegetables, nuts and seeds (which obviously brings numerous other benefits as well).

There Have Been Numerous Clinical Studies of Beta Sitosterol That Have Established the Following Benefits:

• Immune system support (especially during stress)
• Relieves allergies
• Reduces cancer risk (prostate, breast, colon)
• Anti-inflammatory and Pain relieving activity
• Relieves symptoms of enlarge prostate (benign prostatic hyperplasia, BPH)

Why Beta Sitosterol Works

Beta-sitosterol is the major phytosterol in most plants. Although sitosterol and its related compound, sitosterolin, are chemically similar to cholesterol, they are poorly absorbed from the gastrointestinal tract. This poor absorption makes sitosterol/sitosterolin a popular supplement for controlling cholesterol levels -- due largely to an interference with normal cholesterol absorption from the diet.

Beta-sitosterol also appears to modulate immune function, inflammation and pain levels through its effects on controlling the production of inflammatory cytokines. This modulation of cytokine production and activity may help control allergies and reduce prostate enlargement.

Scientific Support

Epidemiologic and experimental studies show that dietary phytosterols offer protection from the most common cancers in Western societies, such as colon, breast and prostate cancer. From laboratory (test tube and animal) studies, it appears that phytosterols, such as beta-sitosterol, can influence the structure and function of cell membranes in both healthy and cancerous tissue. This effect is known to alter cellular signaling pathways that regulate tumor growth and apoptosis (cell death) and providing a possible explanation for the stimulation of immune function observed following beta-sitosterol supplementation.

In several animal studies examining the effect of beta-sitosterol consumption on experimentally induced cancer, the animals fed phytosterols had a 30%-40% lower serum cholesterol and 20-30 fold higher levels of the primary phytosterols (beta-sitosterol and campesterol) in their blood. Interestingly, tumor size in animals fed phytosterols is 30-80% smaller and the incidence of metastases to lymph nodes and lungs is 10-30% lower in phytosterol-fed animals than in the control group (fed cholesterol). From these animal studies, there is strong preliminary evidence that dietary phytosterols do indeed retard the growth and spread of breast cancer cells.

In terms of cholesterol control, several human feeding studies have shown that phytosterol-containing margarine (40 grams of phytosterols in a mixture of beta-sitosterol, campesterol and stigmasterol), consumed for 3-4 weeks, can reduce total and LDL cholesterol concentrations by about 20%. Smaller doses (2-6 g/day) have also been associated with a reduction in total and LDL cholesterol levels of about 5-15% in subjects with elevated cholesterol levels.

The scientific evidence for the "prostate-health" benefits of beta-sitosterol is excellent. In terms of prostate health, there are at least four good studies (randomized, double-blind, placebo-controlled) supporting the effect of beta-sitosterol for alleviating the symptoms of BPH (frequency and volume of urination).

In terms of immune function, beta-sitosterol has been shown (in humans) to normalize the function of T-helper lymphocytes and natural killer cells following stressful events (such as marathon running) which normally suppress immune system function. In addition to alleviating much of the post-exercise immune suppression that occurs following endurance competitions, beta-sitosterol has also been shown to normalize the ratio of catabolic stress hormones (cortisol) to anabolic (rebuilding) hormones such as DHEA.

Safety of Beta Sitosterol

Long-term safety studies have not been performed on beta-sitosterol as a dietary supplement -- but the compound is so widespread in the diet, that it is generally regarded as quite safe (GRAS).

No significant side effects or drug interactions have been reported in any of the studies investigating beta-sitosterol.

Why Beta Sitosterol Is An Essential Nutrient

Beta-sitosterol has good evidence of effectiveness in treating BPH far better than other supplements such as Saw palmetto and Pygeum. As a cholesterol-lowering supplement, again, the evidence for beta-sitosterol is good, but not quite as strong as either red yeast rice (no longer available as a supplement) or policosanol. As an immune-enhancer, beta glucan has much more evidence of effectiveness, but beta-sitosterol appears to be quite beneficial in maintaining immune function during periods of heightened stress (such as exercise recovery). As a cancer-preventive agent, the animal and test-tube data for beta-sitosterol is certainly tantalizing, but preliminary, and needs further substantiation in humans.

Dosage

The typical daily dosage of beta-sitosterol for immune-function benefits is 300-600 mg. BPH ususaly requires 600 mg daily and the cholesterol lowering beenfits usually require at least 300 mg per day and up to 1000 mg daily. A handful of roasted peanuts or a couple of tablespoons of peanut butter will contain about 10-30 mg of beta-sitosterol -- so a few handfuls of Planters or a scoop of Skippy will supply an effective dose of immune-enhancement following exercise (but also a whopping dose of calories).

References