Ethanol with a mixed meal increases postprandial triacylglycerol but decreases postprandial non-esterified fatty acid concentrations

Abstract

Plasma triacylglycerol concentrations increase after the acute ingestion of alcohol (specifically ethanol). However, the effect of ethanol when consumed with a mixed meal has not been well studied. The objective of the present study was to determine the perturbations of lipid metabolism that occur after ingestion of ethanol in combination with a mixed meal of specific fatty acid composition. Blood samples were taken from seven healthy male subjects before and after a mixed meal, with and without ethanol. The specific fatty acid composition of the test meal allowed the fatty acids to be traced into the plasma non-esterified fatty acid pool during the postprandial period. Statistical analysis by repeated measures ANOVA showed significant effects of ethanol. For example, postprandial lipaemia was enhanced after the ethanol test meal compared with the control (P< 0·05), mainly due to increases in triacylglycerol-rich lipoproteins in the flotation range Sf60–400 (VLDL1) (P< 0·05); those in the range Sf20–60 (VLDL2) and also Sf> 400 (chylomicrons) were not significantly affected. The later postprandial increase in plasma non-esterified fatty acid concentrations was reduced after the ingestion of ethanol (P< 0·001), but the proportions of palmitoleic acid (a marker of fatty acid content of the test meal) and of linoleic acid (a marker of endogenous lipolysis) were not affected. The results suggest a primary effect of ethanol on the stimulation of secretion of large VLDL particles, which then compete for clearance with chylomicrons by lipoprotein lipase. The results do not support an effect of ethanol on the release of non-esterified fatty acid into the plasma. The suppression of plasma non-esterified fatty acid concentrations during the postprandial period may contribute towards the beneficial effects of moderate ethanol consumption.