Alcohol consumption ranging from 1-2 drinks/day associates with a lower risk of coronary heart disease in some studies.
The underlying mechanisms are unclear. The Metabolic Imprints of Alcoholic Beverages (MetAl) trial aimed to explore the short-term effects of moderate alcohol consumption on cardiovascular biomarkers. A 2 x 3-week cross-over single-blinded intervention trial investigating the effect of 1-2 drinks/day (~12-24 g) compared with abstention on (1)H Nuclear Magnetic Resonance-measured main lipoproteins and subfractions was performed in 26 healthy adults.
Volunteers were classified as occasional or habitual drinkers based on their habitual alcohol intakes (/=2 drinks/week).
Compared with abstention, 1-2 drinks/day increased HDL(2a)-C (p = 0.004), HDL(3)-C (p = 0.008), and HDL non-significantly (p = 0.19).
Total apoA1 and apoA1 in HDL and its subfractions increased (p < 0.05). Novel findings were a decreased apoB/apoA1 ratio (p = 0.02), and increased HDL(2a) phospholipid content (p = 0.04). In women alone, the results were similar but attenuated, and LDL-P decreased. Thus, changes in apoA1- and HDL-related biomarkers occur within weeks in moderate drinkers. Compared with abstention, 1-2 drinks/day increased total apoA1 more strongly than HDL-C and increased the cholesterol, apoA1, and phospholipid content of several HDL subfractions.
Whether this provides a cardiovascular benefit requires further study. Clinicaltrials.gov: NCT03384147.