A combined observational and genetic study indicates that all levels of alcohol consumption may raise dementia risk, and reducing alcohol use disorder (AUD) could help lower dementia incidence at the population level. The study investigated the relationship between alcohol consumption and dementia using prospective cohort, case–control, and Mendelian randomization analyses in over 559,000 adults from the US and UK cohorts, supplemented with genetic data from GWAS consortia involving 2.4 million participants. During follow-up, 14,540 developed dementia and 48,034 died. Observational analyses suggested a U-shaped pattern, with higher dementia risk in non-drinkers, heavy drinkers (>40 drinks/week), and those with AUD, compared with light drinkers. However, genetic analyses showed a consistent monotonic increase in dementia risk with higher alcohol consumption, with a one standard deviation increase in alcohol intake associated with a 15% higher dementia risk, and a twofold increase in AUD prevalence linked to a 16% dementia increase. Importantly, declines in alcohol use among individuals developing dementia suggest that reverse causation may explain the apparent protective effect of light drinking in observational studies. The findings have key public health implications, and challenge the longstanding notion that moderate alcohol intake might have a protective effect on the brain. The World Health Organization issued a statement that no amount of alcohol is safe in 2023. Source: https://ebm.bmj.com/
