Another Look at Alcohol and Stroke

Source: Tufts University
March 28, 2003

A moderate intake of alcohol appears to lower a person's risk of heart disease, but its effect on stroke risk is not as clear. To get a better idea of the relationship between alcohol intake and stroke, US researchers recently took a second look at dozens of studies on the subject. Their findings are published in the Journal of the American Medical Association.

Effect of alcohol

Researchers from Tulane University conducted an analysis of 35 studies that looked at alcohol consumption and risk of stroke. They consolidated the results of these studies into one set of findings, and then analyzed this information for a connection between the two.

They found that compared with people who did not drink alcohol, those who consumed less than 1 drink per day (equal to 12 grams of alcohol) were about 20% less likely to suffer an ischemic stroke. (This is a common type of stroke caused by a blockage of blood flow to the brain.) However, those who consumed more than 5 drinks per day were at significantly greater risk for both ischemic stroke and hemorrhagic stroke, a less common type that is triggered by bleeding in the brain.

How alcohol both helps and hurts

Doctors suspect that moderate intake of alcohol cuts ischemic stroke risk for the same reasons that it is associated with a reduced risk of heart disease - alcohol increases levels of 'good' HDL cholesterol and makes the blood less likely to clot. Both factors help keep blood vessels healthy, reducing the chance that a blood clot might dislodge from a damaged blood vessel and block blood flow to the brain.

On the other hand, too much alcohol can contribute to high blood pressure and interfere with the blood's ability to clot normally - both serious medical problems that increase the risk of suffering a hemorrhagic stroke.

Advice to consumers

The authors point out that given the widespread use of alcohol in the general population and the fact that stroke is a leading cause of death and disability, the results of their analysis are 'both important and timely.' It must be emphasized, however, that certain individuals should not drink alcohol in spite of its reported health benefits, since even a moderate amount can complicate some medical problems and interfere with the effectiveness of certain medications.

The authors caution that an across-the-board recommendation to consume alcohol is not warranted, and that the use of alcohol is an issue best discussed between adults and their own healthcare providers.

Source

• Alcohol consumption and risk of stroke: a meta-analysis. K. Reynolds, L. Lewis, J. Nolen,  et al., JAMA, 2003, vol. 289, pp. 579--588

Related Links
Should You Drink to Your Health?
Stroke Can be Prevented
Vegetable Fats Figure into Reduced Stroke Risk
Regular Alcohol Intake Cuts the Heart Attack Risk
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