• ALCOHOL-RELATED PROBLEMS
• CEREBROVASCULAR DISEASE
• NEUROEPIDEMIOLOGY
• STROKE

While red wine has been touted to reduce myocardial infarction, the association between alcohol and cardiovascular disease and stroke is more nuanced.1 Metaanalyses indicate that haemorrhagic stroke is increased with alcohol.2 While mild alcohol intake might be associated with a neutral or reduced risk of ischaemic stroke, regular intake of large amounts or episodic binge drinking has been consistently associated with ischaemic and haemorrhagic stroke. It is not known how alcohol exerts its harmful (and possibly protective) effects. There have been questions about ischaemic stroke subtype, differential effects by sex, alcohol type and amount, and how race and ethnicity play in the risk.

Young patients with ischaemic strokes have been a challenge since many do not have an apparent cause. As the incidence of ischaemic stroke in the younger age group appears to be increasing in many countries, the impact on subsequent disability is a concern.3 Since younger individuals drink more than the elderly, alcohol might have greater importance in ischaemic strokes among the young, including contributing to cryptogenic ischaemic strokes. Martinez-Majander and colleagues analysed alcohol intake in a large prospectively collected sample from the SECRETO study.4 As the name ‘Searching for Explanation for Cryptogenic stroke in the young: Revealing the Etiology, Triggers and Outcome’ suggests, the prospective study of stroke centres in Europe carefully collected data regarding a subset of patients who had ischaemic stroke without apparent cause. The relatively large sample size of 540 patients with cryptogenic ischaemic strokes allowed adjustment of multiple confounders in the logistic regression model as well as further analysis into the quantity of alcohol and subgroups.

The study confirmed both heavy alcohol consumption and binge drinking with young cryptogenic strokes. The study demonstrated that just not heavy or binge drinking but men in the youngest strata (18–34 years) of these young strokes might have the highest risk exerted by alcohol. The associated ischaemic stroke risk was OR of approximately 3 overall, but only significant among men. Men in the youngest strata with heavy drinking might have 12 times the risk, though there was no significant statistical interaction with age strata. Heavy and binge drinking behaviours are more prevalent in this youngest age group than in older age groups. Why wasn’t a similar finding seen among women? It is unclear since the prevalence of heavy drinking does not appear to be much different among men and women. Perhaps the difference in the definition of heavy drinking for men and women in this and other studies or other risk factors for stroke that are specific to women, such as hormonal use or pregnancy, may have had greater importance. As with all studies of alcohol, the SECRETO study is observational, and the case-control study design raises concerns about unmeasured confounders and an appropriate control group.

The cumulative evidence of the risk posed by heavy and binge drinking suggests to the young group that alcohol might be considered to be the cause of stroke. The current study suggests an association between cryptogenic stroke and a higher risk, particularly at age <35. In this age group, the early development of atherosclerosis or small vessel disease would be unlikely. If one expects alcohol to be the cause, one might consider temporal relationships as a trigger. However, the association of alcohol with triggering stroke occurrences has been conflicting. While binge drinking and heavy drinking within 24 hours have been associated with ischaemic stroke,5 another study of young strokes failed to find an association between ischaemic stroke and alcohol consumption within 1 hour.6 Therefore, the stroke mechanism in alcohol remains cryptogenic.

Interventions to reduce stroke in potentially more vulnerable younger adults should be considered. The public health message should also incorporate risks beyond stroke. If one considers the risks of cancer, injury, dependence and ultimately death due to alcohol and the disability of stroke, alcohol offers no benefit.7 Reducing previously heavy alcohol consumption appears to reduce cardiovascular risk, including stroke risk.8 Lifestyle interventions for these young individuals with the potential for behaviour modification would be important.