"So many people drink 'moderately,' and think this is either harmless or even protective," says Oxford University researcher Anya Topiwala. The opposite is true, according to Topiwala's new study, which finds any amount of alcohol consumption reduces the volume of gray matter in the brain, which is crucial to information processing, per CNN. For the study—yet to be peer-reviewed—researchers analyzed brain scans and the self-reported alcohol intake of 25,378 people in the UK. They found "any alcohol is worse [than none]" and "pretty much the whole brain seems to be affected—not just specific areas, as previously thought," Topiwala tells the Guardian. And "the more people drank, the less the volume of their gray matter," she adds, per CNN. Alcohol intake resulted in up to a 0.8% decrease in gray matter volume, according to the study.
While that number might seem small, it's greater than that of any other risk factor that a person has control over and is four times the impact that smoking has. Alcohol was also determined to affect the brain's white matter, which facilitates information transfer, with negative associations amplified by conditions like high blood pressure and obesity. The research team found no sign that the type of alcohol mattered and suggested previous studies pointing to benefits of drinking wine are flawed. It is often "better educated, wealthier people" who drink wine in moderation, Topiwala tells the Guardian. These same people "would do much better on a memory test … just because of who they are, than people that are less educated." (This study found heavy drinking to be a risk factor for dementia, which is associated with a severe reduction in brain volume.)