Epidemiological literature indicates that the relationship between alcohol consumption and health outcomes reflects a J-shaped curve such that moderate alcohol consumption confers a protective effect in comparison to abstinence, while heavy consumption is associated with poorer health. While heart rate variability (HRV) may underpin the relationship between drinking and poor health in heavy drinkers, it is unclear whether HRV is increased in moderate, habitual drinkers relative to nonhabitual drinkers. HRV and drinking habits were assessed in 47 volunteers. Results supported hypotheses suggesting that moderate, habitual drinking increases HRV. Although not supported by a significant interaction between drinking group and sex, planned follow-up analysis also revealed that these findings may be specific to males. Regardless, results highlight HRV as a candidate mechanism for the findings reported in the epidemiological literature.
Quintana, D.S., Guastella, A.J., McGregor, I.S, Hickie, I. B., Kemp, A.H. (2013). Moderate alcohol intake is related to increased heart rate variability. Psychophysiology. 50(12), 1202-1208.