Does moderate drinking protect against heart disease?

For decades, researchers have studied the impact of alcohol on cardiovascular health, often with mixed results. Scientists at Monash University in Australia set out to answer the question definitively using data from more than 18,000 people aged over 70 in the US and Australia.

The landmark study found that moderate drinking of alcohol is associated with a reduced risk of cardiovascular disease and a lowering of mortality from all causes – compared to zero alcohol consumption.

Excess alcohol consumption is a leading contributor to the global burden of disease and a major risk factor for mortality. Yet, prior studies suggested that moderate alcohol consumption may be associated with a lower risk of cardiovascular disease (CVD) events.

This new paper, published in the European Journal of Preventive Cardiology, is the first to investigate the risk of CVD events and mortality, from all causes, associated with alcohol consumption in initially healthy, older individuals.

This study, led by Dr Johannes Neumann, from the Monash University School of Public Health and Preventive Medicine, analysed data from almost 18,000 participants in the ASPirin in Reducing Events in the Elderly (ASPREE) clinical trial.

Participants in the study did not have prior CVD events, diagnosed dementia or independence-limiting physical disability. CVD events included coronary heart disease death, non-fatal myocardial infarction, fatal and non-fatal stroke, non-coronary cardiac or vascular death, and hospitalisation for heart failure. Information on alcohol consumption (days of drinking per week and average standard drinks per day) was assessed by self-reported questionnaire at baseline.

The study excluded former alcohol consumers who may have stopped alcohol consumption for various health reasons, possibly introducing bias from reverse causality.

Based on this information, the alcohol intake was calculated as grams per week – for US participants a standard drink was equivalent to 14 g and 10 g for Australian participants.

In the study, alcohol consumption was categorised as 0 (never drinks) and those who drink 1–50; 51–100; 101–150, and >150g/week. For Australians that is up to 5; 5-10; 10-14 and over 15 standard drinks per week. For Americans – that is up to 3.5; 3.5-7; 7-10 and over 10 standard drinks per week.

Of the almost 18,000 eligible participants with median age 74 years, 57% were female; 43.3% were current or former smokers; and mean BMI was 28.1 kg/m².

The participants were followed for an average of 4.7 years and the study found that there was a reduced risk of CVD events for individuals consuming alcohol of 51–100, 101–150, and >150 g/week, compared to never consuming alcohol, regardless of gender. Consumption of 51–100 g/week was also associated with a reduced risk of all-cause mortality.

Lead author, Dr Neumann, says the findings need to be interpreted with caution, as study participants were all initially healthy without prior CVD or other severe diseases, and may have been more physically and socially active than the wider ageing population. Furthermore, prior evidence showed that excess alcohol consumption increases the risk of other chronic diseases, such as cancer, liver disease or pancreatitis.

Dr Neumann said modest alcohol intake in this group of healthy older adults was not harmful for CVD or overall mortality, but further research is needed to evaluate the biological effects of alcohol on health and possible behavioural advantages of social drinking and engagement.