Beer affects oxidative stress due to ethanol in rats.

The relationship between chronic moderate beer consumption and oxidative stress was studied in rats. Animals were fed three different isocaloric diets for six weeks: a beer-containing diet (30% w/w), an ethanol-supplemented diet (1.1 g/100 g, the same as in the beer diet) and an alcohol-free basal diet. At the end of the feeding period, rats were analyzed for plasma and liver oxidative status. Some livers were isolated and exposed to ischemia-reperfusion to assess the additional oxidative stress determined by reperfusion. No significant differences in plasma antioxidant status were found among the three dietary groups. Lipoproteins from the beer group, however, showed a greater propensity to resist lipid peroxidation. Ischemia caused a decrease in liver energy and antioxidant status in all groups. Nevertheless, ATP was lower in the livers of rats exposed to the ethanol diet. During reperfusion, lipoperoxidation increased significantly in all groups. However, livers obtained from ethanol-treated rats showed the higher formation of lipoperoxides. In conclusion, a moderate consumption of beer in a well-balanced diet did not appear to cause oxidative stress in rats; moreover, probably through its minor components, beer could attenuate the oxidative action of ethanol by itself.