RESUMO
BACKGROUND: Evidence that a moderate consumption of alcohol is associated with a reduced incidence of and mortality due to coronary artery disease continues to accumulate. Despite recent evidence that substances in red wine confer resistance to coronary artery disease, it is clear that at least a substantial proportion of the protective effect is due to the alcohol content of the beverage. We have previously shown that the chronic ingestion of alcohol incorporated into a total liquid diet during a 24-week period inhibits the development of fatty streak lesions in hyperlipidemic C57Bl/6 mice. We have now repeated this study and demonstrated that alcohol continues to markedly inhibit atherogenesis during a 48-week period. METHODS: Mice were fed a high fat atherogenic liquid diet with 0% or 6% alcohol or a high fat atherogenic pelleted diet with 0% or 15% alcohol in their drinking water. After 24 and 48 weeks on these diets, subgroups of mice were euthanized and the aortas were studied for extent of atherosclerosis. Plasma lipid levels were also measured and flow cytometry studies performed to characterize their T and B lymphocyte populations. Additional groups of mice were given the high fat atherogenic diets for 24 weeks to allow lesions to develop and were then treated with alcohol diets to determine whether they inhibit the progression of the lesions. RESULTS: The alcohol diets suppressed the development of atherosclerotic lesions at both 24 and 48 weeks in both the liquid and pelleted diet models. The addition of the alcohol diets after allowing lesions to form for 24 weeks halted the further progression of the lesions. The alcohol treatments also decreased the plasma levels of total cholesterol and high density lipoprotein (HDL) cholesterol at almost all time intervals. CONCLUSIONS: We conclude that alcohol not only inhibits the initial development of atherosclerotic lesions but also inhibits the progression of existing atherosclerotic lesions. The alcohol-mediated decrease in HDL cholesterol in these experiments suggests that HDL plays little or no role in amelioration of atherogenesis in this model.
