Phytosterols are oil soluble phytochemicals, which can be found in many plant foods such as nuts, cereals and legumes. The most common phytosterols are
beta-sitosterol, campesterol and stigmasterol. Phytosterols have a chemical structure that is very similar than that of cholesterol. Studies have shown that phytosterols may reduce cancer risk. Populations who consume more phytosterols have lower cancer risks.
The aim of this study was to investigate the intake of phytosterols by postmenopausal women. The study was carried out on 104 women who were divided in a control group and a dietary intervention group, which consumed more plant based foods. The dietary intervention group consumed more soy, flax seed, seaweed, rice, whole cereal products, walnuts, almonds, cruciferous vegetables and berries. The serum levels of phytosterols were measured at the end of the intervention period. Because the human body does not produce phytosterols, as opposed to cholesterol, serum levels of beta-sitosterol is the result of absorption.
The researchers found that the plant-based diet increased serum levels of only beta-sitosterol significantly. The cholesterol level was also about 10 percent lower in the intervention group. The plant-based diet also resulted in increased weight loss.
The study concluded that a plant-based diet, rich in fibre, soy and flax seed, can increase serum levels of beta-sitosterol and that beta-sitosterol could be used as indicator in dietary intervention studies.
Source: Muti P, Awad AB, Schunemann H, Fink CS, Hovey K, Freudenheim JL, Wu YW, Bellati C, Pala V and Berrino F. A plant food-based diet modifies the serum beta-sitosterol concentration in hyperandrogenic postmenopausal women.. Journal of Nutrition. 2003 December;133(12):4252-5