Improvement of cholesterol levels and reduction of cardiovascular risk via the consumption of phytosterols
Sommaire de l'article
Hypercholesterolaemia is one of the main factors contributing to the appearance and progression of CVD, which is the main cause of death in the adult population of industrialized societies. By 2020, projections suggest that it will continue to hold first place, by then causing 37 % of all deaths. Therapeutic life-style changes to reduce cardiovascular risk include dietary modifications, such as the inclusion of phytosterols or plant sterols (known since the 1950s to reduce cholesterol levels). These help prevent the absorption of cholesterol and thus condition a reduction in total cholesterol and LDL-cholesterol levels, and ultimately in cardiovascular mortality. The fat-soluble nature of these sterols rendered margarine one of the best vehicles by which to supply them in the diet. Indeed, margarine was the first food to contain cholesterol-reducing phytosterols to be approved by the EU (in agreement with its regulations on new foods and food ingredients, 258/97/CE). Presently, phytosterols can be emulsified with lecithin and thus delivered in non-fat or low-fat foods and beverages. Margarine and dairy products (yoghurt and milk) enriched in phytosterols have proved better at lowering total cholesterol and LDL-cholesterol levels than have enriched cereals and their derivatives, although all can be of help, depending on the characteristics of each subject. The reduction in carotenoid bioavailability caused by sterols is minimized by increasing fruit and vegetable consumption. Individuals who habitually consume phytosterols should also follow traditional advice such as eating less dietary fat and increasing their physical activity. Phytosterols have been shown to be safe and effective in lowering cholesterol levels in many rigorous studies. In few areas of nutrition is there such consensus. Diet professionals should feel comfortable in prescribing phytosterols/stanols for the treatment of hypercholesterolaemia. They are safe whether taken alone or in combination with cholesterol-reducing drugs, such as statins and fibrates. Reinforcement counselling is essential, as therapy is effective only if compliance is good.