New Margarines Appear Safe

Benecol and Take Control, two new margarine products, appear to work. Both these products work primarily by reducing the absorption of cholesterol in the gut. Benecol contains sitostanol, which is a hydrogenated or saturated plant sterol. The hydrogenation of plant sterols actually enhances their capacity to lower serum cholesterol compared to the more common plant sterols. Take Control contains a plant sterol isolated from soybeans so it may prove less effective in lowering LDL than Benecol.The addition of 2-3 grams of sitostanol per day to a typical American diet, in the form of 3 pats of margarine, was shown to lower LDL-C by about 10 to 15%. It has no effect on HDL-C or triglyceride levels. Since both plant sterols and stanols work primarily by displacing cholesterol from micelles, a high ratio of these compounds relative to the amount of cholesterol in the gut will block the absorption of most of the cholesterol. Less than 5% of plant sterols are absorbed but stanols are not absorbed at all so it seems likely that they’ll prove safe for long-term cholesterol control.A typical American diet already contains about 200 to 300 mg of plant sterols (mostly beta-sitosterol) mainly from vegetable oils. Legumes, nuts, seeds and corn are all high in plant sterols and vegetarian diets average about twice the plant sterol content of more typical Western diets. Because vegetarians already consume more plant sterols and less cholesterol, it is likely that these margarines will prove of less value in lowering the cholesterol of vegetarians than others.Besides dietary cholesterol, a significant amount of cholesterol is released in the bile. Both dietary fiber and plant sterols may act to reduce the re-absorption of this endogenous cholesterol. A diet very low in fat also reduces the release of bile compared to a higher fat diet and this would reduce the amount of endogenous cholesterol in the gut. Resin drugs (Cholestipol) also greatly reduce the absorption of both dietary and endogenous cholesterol. It seems likely then that Benecol and Take Control will have a more modest cholesterol lowering impact on people who are consuming a very low-fat, near vegetarian diet that is high in fiber and plant sterols. Their impact would also probably be negligible in patients taking resin drugs to control their serum cholesterol. However, their impact on patients taking statin drugs or niacin to lower cholesterol is likely to beadditive or synergistic.