Drinking alcohol seems to have no influence on the risk of developing amyotrophic lateral sclerosis (ALS), a large population-based European study suggests.
While about 10 percent of ALS cases are familial (caused by genetic mutations that are inherited), the vast majority of ALS is considered sporadic and of unknown cause.
Among the several environmental factors investigated, only smoking has shown the potential to increase the risk for ALS.
Other studies have tried to figure out if there is a link between drinking alcohol and ALS development, but so far the findings have been inconsistent.
Some reports revealed no significant association between the two. More recently, however, Dutch and Swedish studies suggest that alcohol intake may exert a protective role against ALS, decreasing the disease risk.
To shed light on this matter, researchers set up a large multi-center, population-based, case-control study.
The study, called Euro-MOTOR, enrolled 1,557 patients with ALS and 2,922 controls recruited in three European countries — the Netherlands, Ireland, and Italy.
Participants were asked to complete a survey that collected information about their lifestyle, education, physical activity, health condition, smoking and alcohol drinking habits. Clinical data related to ALS was collected from patient medical records.
From all beverages, exposure to red wine was analyzed in more detail. Red wine is rich in antioxidants and these molecules are supposed to block death of nerve cells induced by glutamate, one of the proposed causes of ALS.
Exposure to alcohol was assessed just until the three years before the date of the survey, to avoid interference of recent or present drinking habits.
Researchers detected significant differences in cumulative exposure to alcohol between cases and controls. Specifically, patients drank more in Apulia, a region in the south of Italy, and less in the Netherlands, compared with controls.
But overall, intake of alcoholic drinks in general, or red wine in particular, was not significantly associated with risk of ALS.
A categorized analysis by patient groups, showed that only patients from Apulia and the Netherlands displayed a significant association, but again, with opposite trends.
Alcohol consumption was associated with more than double the risk in the region of Apulia, while among Dutch alcohol consumers the ALS risk was reduced by one third.
Comparing current and former drinkers with those who never drink, former drinkers were at higher risk while current alcohol consumers were less likely to have ALS — but in the Dutch group only.
Red wine consumption followed a similar trend with former drinkers nearly doubling ALS risk.
Cumulative exposure to alcoholic beverages, either general drinks or red wine, were not significantly linked with ALS risk.
“Overall, intake of alcohol was not significantly associated with ALS, although a decreased risk of developing ALS for current drinkers (significant only in The Netherlands) and an increased risk for former drinkers was detected,” the researchers wrote, adding that these findings are in agreement with other American and Japanese case-control studies.
The link between alcohol and ALS requires “a thorough exploration, using different approaches and methods, and taking into account different alcohol intake patterns and the type of alcoholic beverages.” the researchers advised.
“Further investigations are needed to better determine the role of alcohol in developing ALS,” they said.