In an open access narrative review published in the journal Nutrients, the epidemiological evidence is examined for the associations between alcohol consumption, including average alcohol consumption, drinking patterns, and alcohol use disorders, and CVDs, including ischaemic heart disease (IHD), stroke, hypertension, atrial fibrillation, cardiomyopathy, and heart failure. Methodological shortcomings, such as exposure classification and measurement, reference groups, and confounding variables (measured or unmeasured) are discussed.
The authors state that epidemiological studies indicate a complex relationship between various dimensions of alcohol consumption (i.e., life course drinking patterns) and CVD outcomes. Indeed, substantial heterogeneity is evident. Most epidemiological studies to date have relied on a single measurement of alcohol intake at baseline. It is assumed that the self-reported drinking levels, preferably including drinking patterns, remains the same before and after the baseline measurement. For many people this is clearly not the case, and even lifetime abstainers are hard to identify.
Does some alcohol consumption protect some people against ischaemic diseases to some degree? Epidemiological data, as outlined in the review, suggest that this is the case. For example, a J-shaped relationship emerges for average alcohol consumption and IHD and IS (ischaemic stroke). On the other hand, the relationship with incident hypertension, which is a potent risk factor for most if not all CVDs, is quite different between men and women, with an increased risk for any amount of alcohol consumption in men. While potential sources of bias, such as the reference group, i.e., separating lifetime abstainers, former drinkers, and heavy episodic drinkers, have been systematically investigated for the relationship between alcohol and IHD, their impact on other CVD outcomes remains less clear.
The review authors state that while there is a lack of large-scale randomised studies on the long-term effect of alcohol consumption on various CVD endpoints, short-term clinical trial data indicate a sizable effect of alcohol consumption on HDL-C and fibrinogen. However, the heterogeneity found in epidemiological studies points to more than just biological differences. Socio economic status, for example, might influence the impact of alcohol on CVD. More research is necessary to advance knowledge on this topic.
Source: Roerecke M. Alcohol’s Impact on the Cardiovascular System. Nutrients. 2021; 13(10):3419.