Research Article

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

Barbara A. Fielding^a1 c1, Guy Reid Michelle Grady^a1, Sandy M. Humphreys^a1, Kevin Evans^a1† and Keith N. Frayn^a1

^a1 Oxford Lipid Metabolism Group, Nuffield Department of Clinical Medicine, Radcliffe Infirmary, Oxford OX2 6HE, UK

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 S_f 60–400 (VLDL1) (P < 0·05); those in the range S_f 20–60 (VLDL2) and also S_f > 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.

(Received July 14 1999)

(Revised October 21 1999)

(Accepted November 08 1999)

Key Words:

• Postprandial lipid metabolism;
• Non-esterified fatty acids;
• Ethanol

Correspondence:

^c1 *Corresponding author: Dr Barbara Fielding, fax +44 (0) 1865 224872, email barbara.fielding@oxlip.ox.ac.uk

Footnotes

† Department of Clinical Chemistry, Staffordshire General Hospital, Weston Road, Stafford ST16 3SA, UK.