Moderate drinking lowers heart disease risk – if it’s consistent

Unstable drinking patterns over time may be associated with a higher risk of heart disease, whereas consistent moderate drinking within recommended health guidelines may have a cardioprotective effect, according to a new study published in the journal BMC Medicine.

A team of researchers led by University College London and the University of Cambridge found that compared to individuals who consistently followed UK drinking guidelines over a period of ten years, those who inconsistently drank in moderation, those who had stopped drinking (former drinkers) and those who reported no drinking had a higher risk of coronary heart disease, although the effect observed in non-drinkers may be confined to women.

Drinking behaviour over time was assessed by measuring intake based on the alcohol content in reported drinks; half pints of beer or cider, small glasses of wine and a single serving of spirits were recorded as containing 8g of ethanol in the UK cohorts and 10g of ethanol in the French cohort. Moderate drinking was considered to be up to 168g/ethanol per week for men and up to 112g ethanol/week for women.

Dr Dara O’Neill, the corresponding author from University College London said: ‘This study uses long-term data to distinguish between persistent non-drinkers and former drinkers, allowing us to test the established theory that only the latter have an elevated risk of CHD. We did not find this to be the case but we did observe a sex-related difference. Amongst consistent non-drinkers, women showed higher risk of developing CHD compared to consistently moderate drinkers, but their male counterparts did not.’

Overall, 4.9 per cent of the 35,132 individuals included in the six cohorts that were examined in this study developed CHD during the study period, of which 325 (0.9 per cent) were fatal CHD events. Observed CHD incidence was highest for former drinkers, 6.1 per cent of whom experienced a CHD event of which 1.2 per cent were fatal.

The findings suggest that instability in drinking behaviour over time is associated with CHD risk. This may be because unstable drinking patterns reflect wider lifestyle changes across the course of people’s lives, including periods of ill-health or life stress, according to the study’s authors.