Oxidation of LDL in baboons is increased by alcohol and attenuated by polyenylphosphatidylcholine

Alcohol taken in moderation may prevent atherosclerosis, whereas heavy drinking has the opposite effect, in part by promoting oxidation of low density lipoproteins (LDL), a pathogenetic factor in atherogenesis. We assess here: 1 ) whether similar alterations can be reproduced in baboons fed 50% of energy as ethanol (the average intake of alcoholics) for 7- 8 years, and 2 ) whether such alterations are affected by supplementation with polyenylphosphatidylcholine (PPC), a mixture of polyunsaturated phosphatidylcholines, shown to prevent alcoholic fatty liver, fibrosis, and cirrhosis. Ten animals were given the ethanol-containing diet and ten were pair-fed isocaloric control diets. In half of the pairs, the diets were supplemented with 2.8 g of polyenylphosphatidylcholine/1000 kcal. Alcohol feeding increased LDL-lipoperoxides and made LDL-proteins more negatively charged, changes that were attenuated or prevented by PPC. The oxidizability of LDL was determined in vitro by the formation of conjugated dienes after oxidation with copper. Alcohol shortened the lag time (which measures LDL antioxidant capacity); this effect was normalized by PPC supplementation. By contrast, PPC produced no changes in the controls. Thus polyenylphosphatidylcholine, by markedly attenuating the ethanol-induced increase in LDL oxidation, opposes one of the effects whereby alcohol promotes atherosclerosis.