Association between alcohol consumption and multiple sclerosis risk

Multiple Sclerosis (MS) has been linked to a variety of environmental risk factors, including smoking, Epstein-Barr Virus infection, and childhood obesity. There is some evidence to support a relationship between alcohol consumption and MS risk, but this finding has been inconsistent across cohorts. A protective link between alcohol consumption and MS risk is seen in Swedish and Danish cohorts, however evidence from other cohorts and mendelian randomisation studies have failed to support this relationship.
Researchers assessed the relationship between alcohol consumption (never vs. ever drinking) and MS in 409,228 individuals (2100 with MS) from UK Biobank (UKB). To determine whether there was evidence of statistical interaction between alcohol consumption and HLA-DRB1*15:01 genotype, the researchers calculated interaction on the additive and multiplicative scales.
The human leukocyte antigen (HLA) DRB1*1501 has been consistently associated with MS in nearly all populations tested. Researchers investigated whether there was evidence of statistical interaction between alcohol consumption and HLA-DRB1*15:01 genotype.
No evidence was found for an association between alcohol consumption and MS risk (OR = 1.12, 95% CI 0.61-2.08). As expected, the HLA-DRB1*15:01 allele was strongly associated with MS risk (OR = 2.72, 95% CI 2.72-2.72). No evidence was found of a statistical interaction between non-drinking and MS risk on either the multiplicative scale or on the additive scale (Attributable Proportion = 0.03, 95% CI – 0.43-0.29). Empirical power calculations indicated reasonable statistical power (85%) to detect a protective effect of alcohol consumption of Relative Risk ≤ 0.7.
The researchers say that they were unable to replicate findings from other cohorts within UK Biobank and that the inconsistent association seen between studies may reflect limited statistical power to detect a weak effect, differences in population characteristics, or the lack of a true causal association.
Source: Dreyer-Alster S, Achiron A, Giovannoni G, Jacobs BM, Dobson R. No evidence for an association between alcohol consumption and Multiple Sclerosis risk: a UK Biobank study. Sci Rep. 2022 Dec 22;12(1):22158.