Even Low-Moderate Drinking Negatively Affects the Brain

· A study with a UK sample size of almost 37,000 has found that drinking two or more units a day (less than a medium glass of wine) is associated with significant ageing and shrinking of the brain

· Each extra drink increases the likelihood and severity of ageing and shrinking significantly – which leaves us wondering about whether ‘just having a few’ is more dangerous than it first seems

People know that heavy alcohol consumption is bad for them. We have all heard horror stories about the various mental and physical issues that excessive drinking can cause. What we often neglect to address is the impact of low-level and moderate drinking. Even drinking a few glasses of wine or beer a week (which, let’s face it, is pretty low for most people) can hurt your brain.

A group of researchers at the University of Pennsylvania conducted a study that looked at the associations between alcohol intake and brain structure using a sample of 36,678 healthy middle-aged adults from the UK. With such a large sample size, Gideon Nave – a co-author of the study – says that they were able to detect subtle patterns that you might not notice in a smaller sample size. They found that alcohol intake is associated with lower brain volume, less grey matter, and less white matter microstructure. In other words, alcohol intake is associated with shrinkage of the brain.

White and grey matter in the brain are extremely important, meaning these findings are a little alarming. White matter has the role of connectivity and brain communication; a loss of white matter can lead to difficulties processing information, a diminished attention capacity, and increased forgetfulness. Grey matter is equally important; loss of it can cause a decline in many cognitive functions and fine motor skills, and can even lead to diseases such as Alzheimer’s disease and Parkinson’s disease.

Those working on this study wanted to highlight that it is not just people with alcohol-use disorder (AUD) that are negatively impacted by alcohol. Not only is your brain impacted by relatively low levels of alcohol consumption, but the difference between consuming 1 unit and 2 units per day is stark. They found that adults who increased their consumption from 1 unit to 2 units caused the brain to age by two years. By contrast, adults who went from 0 units to 4 units caused their brain to age by 10 years. Essentially, it’s not linear, rather, the more you drink, the quicker your brain ages.

What seems like a relatively insignificant change in lifestyle could actually have a huge impact on the body. Most people take drinking 1-2 units a day to be normal (or even desirable) and wouldn't think twice about having one solitary extra unit. We are simply not taught to question the effects of alcohol on our brain and body, especially in small quantities.

Whilst studies such as these cannot for sure talk about causation (only correlation), the researchers involved are encouraging people to think about how much they drink. Many of us know that alcohol is a harmful substance, but few of us take the time to read up on what that actually means. These findings even contrast with the government guidelines of ‘safe’ alcohol consumption, which leaves us wondering if there is any safe level of alcohol consumption at all.

Source

Daviet, R., Aydogan, G., Jagannathan, K., Spilka, N., Koellinger, P.D., Kranzler, H.R., Nave, G. and Wetherill, R.R., 2022. Associations between alcohol consumption and gray and white matter volumes in the UK Biobank. Nature Communications, 13(1), pp.1-11.