Hypocholesterolemic effects of dietary citrus juices in rabbits

Our preliminary studies showed that in mildly hypercholesterolemic rats with chemically induced breast cancer, dietary orange juice reduced total plasma cholesterol and dietary grapefruit juice tended to reduce VLDL + LDL cholesterol. We therefore investigated whether orange juice and grapefruit juice (double strength) could influence cholesterol metabolism in rabbits with high LDL cholesterol levels induced by feeding a semipurified, cholesterol-free, casein diet. In animals fed the experimental diet for 3 weeks, replacing drinking water with either:orange juice or grapefruit juice reduced serum LDL cholesterol by 43% and 32%, respectively (p < 0.05). This was associated with total liver cholesterol reduction in the orange juice group (-18%, p < 0.05) and with hepatic cholesterol ester reduction in both juice groups (-42%, p < 0.05). The juices were not acting as intestinal sequestrants since neither increased fecal cholesterol or bile acid excretion. In fact, cholesterol excretion was-decreased in both orange juice and grapefruit juice group by 44% and 48%, respectively (p < 0.05). These results suggest that the reduction of LDL cholesterol induced by dietary citrus juices could be due to endogenous effects of juice components, possibly flavonoids. (C) 1999 Elsevier Science Inc.