While some research has suggested that moderate drinking may lower a person’s odds of suffering a stroke, a new study finds that it may have little long-term impact on stroke risk or stroke severity.

The findings, reported in the journal Stroke, come from a more than two-decade follow-up of nearly 22,000 U.S. male doctors. Researchers found that overall, there was no strong association between the men’s drinking habits and their odds of suffering a stroke.

Nor was there a clear connection between alcohol intake and the severity of disability following a stroke.

Some past studies, though not all, have suggested that light-to-moderate drinking may be protective against stroke - as it appears to be against heart disease. But the current study, which followed participants for an average of 22 years, was longer term than those earlier studies, the researchers point out.

In addition, a number of other studies have found that the protective effect of moderate drinking is generally weak and fades with longer-term follow-up, noted senior researcher Dr. Tobias Kurth, of the French national health institute INSERM, in Paris, and Brigham and Women’s Hospital in Boston.

As for the potential effects of drinking habits on stroke outcomes, few studies have looked at that question, Kurth told Reuters Health in an email.

The current findings, he said, suggest that moderate drinking before a stroke has no “great benefit” on a man’s ability to function after a stroke.

The findings are based on data from the Physicians’ Health Study, which included roughly 22,000 U.S. male doctors between the ages of 40 and 84 at its start in 1982. At the outset and each year afterward, the men reported on their lifestyle habits, including alcohol intake, and any new medical diagnoses.

Over an average of 22 years, the men suffered a total of 1,393 strokes and 766 transient ischemic attacks, or “mini-strokes.”

There was evidence that very light drinking - one drink per week - lowered the risk of stroke slightly, compared with no drinking at all. Men who drank at that level also had a lower risk of having a severely disabling stroke.

However, more-moderate levels of drinking showed no effect on stroke risk or disability after a stroke.

The findings, Kurth’s team writes, “do not support a strong association” between alcohol intake and the risk of stroke or stroke outcomes.

There is good evidence, however, that heavier drinking - several drinks per day or more - may raise stroke risk. Few men in the current study said they had more than one drink per day.

“This is quite important,” Kurth said, “since our study should not be taken as evidence that heavy drinking has no consequences on stroke risk.”

He noted that future studies should look at whether similar findings are seen among women.

SOURCE: Stroke, January 2010.