Medical/Scientific Council Comments.
There were a few articles in 1992 that investigated the relationship between alcohol consumption and various causes of stroke. While the authors reached no consensus, their findings, in general, continued to suggest that moderate alcohol consumption is not associated with an increased risk of stroke. Interestingly, the Longstreth, et al. article, in fact, suggests a protective effect from moderate alcohol drinking in the case of subarachnoid hemorrhage. On the other hand, the article by Ben-Shlomo, et al. is important because it indicated that the findings of epidemiologic studies can be affected by the way in which control groups for those studies are selected.
Summaries
Beghi, et al. conducted a study of 200 middle-aged and elderly stroke patients and 200 controls matched for age, sex and hospital admission date to determine whether alcohol consumption is a risk factor for stroke. Average alcohol intake was no different between cases and controls, although a diagnosis of alcoholism increased the risk of stroke nearly 2-fold. This increased risk disappeared when they controlled for other risk factors. Among stroke patients, moderate drinkers were more likely to have a mild stroke than either abstainers or heavy drinkers. "Our findings seem to suggest that alcohol is not an independent risk factor for stroke in the middle-aged and elderly."
Beghi E, et al, Cerebrovascular disorders and alcohol intake: preliminary results of a case-control study., Italian Journal of Neurological Science 1992;13(3):209-14.
Ben-Shlomo, et al. carried out a case-control study using 2 different control groups and the result of a community-based survey of alcohol consumption to look a the relationship between chronic alcohol consumption and stroke. For one control group, they found no statistically significant association between alcohol consumption and the risk of stroke. For the other controls, they found that all levels of alcohol consumption were associated with an increased risk, but "these were not significant and did not show a dose-response relationship." The authors suggest two interpretations of their results: 1) there may be no significant association between chronic alcohol consumption and the risk of ischemic stroke in a middle-aged European population, or 2)alcohoI may increase the risk of stroke by 30- 90%. "The variations of risk found in this study with different comparative groups favors a hypothesis that alcohol consumption may modestly increase the risk of stroke, despite the lack of a statically significant finding."
Ben-Shlomo Y, et al., Stroke risk from alcohol consumption using different control groups., Stroke 1992; 23(8j:1093-8.
Longstreth, et al. conducted a study of 149 patients who had suffered a subarachnoid hemorrhage (SAM) and two age-and gender-matched controls per patient in King County, Washington. According to their data, drinkers who reported no episodes of "binge drinking'' (2 5 drinks in 24 hours, drink=15 g of alcohol) were 40% less likely to suffer SAH than non- drinkers or heavier drinkers. Those reporting one or more episodes of binge drinking in a week had a 4-fold increase in the risk of SAH. The authors concluded that cigarette smoking and heavy alcohol use are associated with the occurance of subarachnoid hemorrhage. Their data suggest that moderate drinking protects against SAH.
Longstreth WT, et al, Cigarette smoking, alcohol use and subarachnoid hemorrhage., Stroke 1992; 23(9):1242-9.
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