Everything in moderation: alcohol and the risk of stroke

This study examined the long-term association between alcohol consumption and the risk of stroke. The authors concluded that heavy alcohol consumption increases the risk of stroke.

Because stroke is a major cause of both disability and mortality, it is important to understand what risk factors are involved. Some risk factors may be modifiable, lowering the risk of stroke in the future. Alcohol consumption, for instance, could be a modifiable risk factor. The relationship between alcohol consumption and stroke is not entirely clear. While some studies have suggested that light-to-moderate alcohol consumption may lower the risk of stroke, other studies have not found any benefit.

The current study examined the correlation between alcohol intake at midlife (ages 45-64) and the risk of stroke.

The study included 12,433 participants. Each participant completed a questionnaire detailing their alcohol intake. Those who drank 3 or fewer drinks per week (4876 participants) were considered light drinkers. Moderate drinkers (3042 participants) consumed 4 to 17 drinks per week. Heavy drinkers (664 participants) drank 18 or more drinks per week. 3851 participants had never consumed alcohol (abstainers).

During an average follow-up of 22.7 years, there were 773 reported ischemic strokes (a stroke caused by a blood clot blocking blood flow to the brain). There were also 81 intracerebral hemorrhages (ICH, bleeding inside the brain due to a ruptured blood vessel).

Compared to abstainers, heavy drinking was associated with a 31% increase in the risk of ischemic stroke. There was no difference in risk for abstainers and light-to-moderate drinkers.

The risk of ICH was higher for moderate-to-heavy drinkers compared to abstainers. There was no difference in risk between light drinkers and abstainers.

This study concluded that light-to-moderate drinking did not lower or increase the risk of stroke. Moderate drinking increased the risk of ICH, and heavy drinking increased the risk of both ICH and ischemic strokes.

This study was based on patient-answered questionnaires, which are not always reliable. The study followed participants who never suffered a stroke. Alcohol consumption among patients who previously experienced a stroke should be further assessed.