To Drink or Not to Drink That is the Question? Skol

Alcohol and MS Risk. #MSBlog #MSResearch

"Wow; I simply love the Scandinavian population databases and registries that allow you to do these the kinds of studies published below. This one shows that alcohol consumption is associated with a reduced risk of developing MS. I wonder how this association is working. It does blow a theory of one of our collaborators, Professor Chris Hawkes, out of the water; Chris has been saying for years that MSers are more likely to be risk takers and show high risk behaviors. When it comes to alcohol this is clearly not the case; MSers are less likely to consume alcohol."

"When it comes to causation theory we must be able to explain this observation. How does alcohol consumption protect against MS? Does it alter immune function? Does it work via epigenetic mechanisms? These questions will need be answered and explained when we find the cause of MS."

"It is interesting, and important to note, that smoking and alcohol have opposite effects. This points against the link between these two exposures being lifestyle driven and indicates that they must be exerting their effect on MS susceptibility via biological mechanisms. Interesting, very interesting. I love it when research poses more questions than it answers. Don't you?"

Epub: Hedström et al. Alcohol as a Modifiable Lifestyle Factor Affecting Multiple Sclerosis Risk. JAMA Neurol. 2014 Jan.

IMPORTANCE: Alcohol consumption may be a modifiable lifestyle factor that affects the risk of developing multiple sclerosis (MS). Results of previous studies have been inconsistent.

OBJECTIVE: To investigate the possible association of alcohol consumption with the risk of developing MS and to relate the influence of alcohol to the effect of smoking.

DESIGN, SETTING, AND PARTICIPANTS: This report is based on 2 case-control studies: Epidemiological Investigation of Multiple Sclerosis (EIMS) included 745 cases and 1761 controls recruited from April 2005 to June 2011, and Genes and Environment in Multiple Sclerosis (GEMS) recruited 5874 cases and 5246 controls between November 2009 and November 2011. All cases fulfilled the McDonald criteria. Both EIMS and GEMS are population-based studies of the Swedish population aged 16 to 70 years. In EIMS, incident cases of MS were recruited via 40 study centers, including all university hospitals in Sweden. In GEMS, prevalent cases were identified from the Swedish national MS registry. In both studies, controls were randomly selected from the national population register, matched by age, sex, and residential area at the time of disease onset.

RESULTS: There was a dose-dependent inverse association between alcohol consumption and risk of developing MS that was statistically significant in both sexes. In EIMS, women who reported high alcohol consumption had an odds ratio (OR) of 0.6 (95% CI, 0.4-1.0) of developing MS compared with non-drinking women, whereas men with high alcohol consumption had an OR of 0.5 (95% CI, 0.2-1.0) compared with non-drinking men. The OR for the comparison in GEMS was 0.7 (95% CI, 0.6-0.9) for women and 0.7 (95% CI, 0.2-0.9) for men. In both studies, the detrimental effect of smoking was more pronounced among non-drinkers. 

CONCLUSIONS AND RELEVANCE: Alcohol consumption exhibits a dose-dependent inverse association with MS. Furthermore, alcohol consumption is associated with attenuation of the effect of smoking. Our findings may have relevance for clinical practice because they give no support for advising patients with MS to completely refrain from alcohol.