Phytosterols are phytonutrients that occur widely throughout the plant kingdom and are present in many edible fruits, vegetables, nuts, seeds, cereals, and legumes. The most common phytosterols, B-sitosterol, campesterol, and stigmasterol, are health-promoting relatives of cholesterol – the small differences between their chemical structures and the structure of cholesterol make all the difference in the world.
Similar in form and function to cholesterol in animals and humans, phytosterols function to regulate the fluidity of cell membranes in plants. Phytosterols have received a great deal of attention from researchers seeking safer means of helping people maintain healthy blood cholesterol concentrations, healthy cardiovascular systems and healthy hearts. It appears that phytosterols interfere with the intestinal recycling of the cholesterol produced by the liver, effectively reducing the availability of cholesterol to the body and may also inhibit a percentage of dietary cholesterol absorption. This is likely due to the structural similarity of these compounds with cholesterol. The most effective way of dosing plant sterols seems to be with or near a meal. While some research shows that plant sterols can be effective regardless of when they are taken, other research suggests that taking phytosterols in divided doses increases their beneficial effect.
Essentially all of the research conducted on phytosterols – including mathematical analyses of this research – show strong affiliations between phytosterol intake and the promotion of healthy blood cholesterol concentrations, healthy cardiovascular systerms and healthy hearts.
U.S. FDA: “Phytosterols Lower LDL-Cholesterol”
After conducting an intensive and extensive detailed review of “the totality of publicly available scientific evidence,” the US Food and Drug Administration has concluded that 1) “there is significant scientific agreement to support a relationship between consumption of plant sterol esters (especially ß-sitosterol, campesterol, and stigmasterol) and reduction in the risk of developing heart disease”; 2) “plant sterol esters reduce blood total and/or LDL (the “bad” cholesterol) levels to a significant degree”; 3) blood HDL(the “good” cholesterol) levels are not decreased by the consumption of plant sterol esters; and 4) these benefits can be obtained by individuals with either elevated blood cholesterol levels or normal healthy blood cholesterol levels.2 In addition, the blood cholesterol-lowering response occurs regardless of the composition of the rest of the diet.
New Scientific Research: “Phytosterols Lower LDL-Cholesterol”
New research findings have mentioned the conclusions reached by the US Food and Drug Administration, and have been published since the government’s decisions. One such example is a study published in the Journal of Nutrition, showing that the cardiovascular health of men and women with blood LDL cholesterol concentrations within the “normal” range (blood LDL cholesterol concentration less than 100 mg/dL) received additional support after phytosterols were added to their daily diets, regardless of the nature of their diets. In a study of men and women with initially elevated blood cholesterol concentrations, similar results and benefits were experienced. Studies persistently have shown that phytosterols that are taken in amounts of 2 to 3 grams per day are able to lower LDL (low density lipoprotein) cholesterol levels by approximately 10 percent. Furthermore, besides their beneficial effects on blood lipid levels, phytoserols can also normalize the inflammatory response of the immune system.
A comprehensive meta-analysis published earlier this year (2009) analyzed the results of 84 clinical trials using phytosterols.6 The authors concluded that their rigorous analysis confirmed the ability of phytosterols to significantly lower LDL cholesterol levels. The ability of phytosterols to reduce LDL concentrations was found to be dose-dependent. Again, they concluded that approximately 2 grams of phytosterols taken on a daily basis seemed to reduce LDL cholesterol by nearly 10%.
Phytosterols are found in many types of nuts, oils and seeds. One can either add phytosterols to their diet by ingesting these substances, or by taking a high-quality dietary supplement. These substances are peanut oil, extra virgin olive oil, sesame oil, soybean oil, raw or roasted peanuts, hazelnuts, macadamia nuts, flax seed, cashews, almonds, pecans, pistachios, sunflower seeds and walnuts.