INHIBITION OF ATHEROSCLEROSIS BY DIETARY PECTIN IN MICROSWINE WITH SUSTAINED HYPERCHOLESTEROLEMIA

Sustained hypercholesterolemia is a known risk factor for development of atherosclerosis. In animal studies, grapefruit pectin fed concurren tly with a high-lipid diet inhibits hypercholesterolemia and atherogen esis. The purpose of the present study was to determine if grapefruit pectin affects cholesterol levels and atherogenesis of animals with es tablished hypercholesterolemia. Microswine were fed an atherogenic die t to establish hypercholesterolemia. Plasma cholesterol levels rose ra pidly and for 360 days were sustained at levels 6- to 12-fold the norm al level. Then, half the microswine, selected at random, were fed a di et in which 3% grapefruit pectin was substituted for cellulose, and th e remaining animals received the original diet. Animals were killed 27 0 days later, and the extent of atherosclerosis was determined. In ani mals with established hypercholesterolemia, pectin did not lower their cholesterol levels. However, pectin reduced the extent of atheroscler osis in both the aorta and coronary arteries. The mean surface area co vered by atherosclerosis in the aorta was 13.6% in the group that did not receive pectin compared with 5.3% in the group that did receive pe ctin. The mean coronary artery narrowing was 45% without pectin and 24 % with pectin. We conclude that pectin may have a direct beneficial ef fect on atherosclerosis by a mechanism independent of cholesterol leve ls.