Is Moderate Alcohol Consumption Bad for Brain Health?
The bad news/good news of the latest research on booze and the brain.
As a wellness writer, I’ve read a fair number of articles and studies on the effects of moderate alcohol consumption. Still, this research hasn’t answered the burning question: How much damage is this Old Fashioned really doing?
If anything, reading summaries of the latest findings only adds to my confusion, not so much because they contradict one another, but because each tends to focus on only one aspect of health.
For example, moderate drinking is said to be linked with lower rates of cardiovascular disease, but higher rates of cancer. It impairs sleep quality in some, while (anecdotally, at least) others swear it puts them right to sleep. Red wine and hoppy beer contain certain antioxidants, but the alcohol in those beverages might impair muscle growth.
I’m a whole person, see. I want to do what’s best for my whole body — not my heart today and my muscles tomorrow and my brain the next day. So the jury has been out for me, until this week, when I came across some new information that has tipped the scale decidedly in one direction for me.
Booze Makes Your Brain Shrink
The information I came across originally surfaced in the UK media over a month ago, with US news outlets picking it up a week or two later. The headlines were all variations of the Guardian’s: “Any amount of alcohol consumption harmful to the brain, finds study.”
The study behind the headline was a cohort survey collected as part of the UK Biobank Study and analyzed by researchers at England’s Oxford University. The gist: over 25,000 participants took a touch-pad survey between 2006–1010, indicating how many alcoholic drinks they had per week (along with lots of other health and lifestyle-related data). Then between 2014–2020, they had brain MRI scans and took cognitive tests.
The researchers found an inverse linear relationship between the amount of alcohol consumed and gray matter volume. In other words, the more a subject drank, the smaller their brain was, on average. For those who drank most of their reported weekly alcohol in one or two “binge” espisodes per week, and those with higher BMI and/or blood pressure, the negative association was much stronger.
It’s important to note that this study is currently an in-house paper, and has yet to be peer reviewed. However, the data look strong enough that not only the mainstream media, but several prominent brain scientists have been talking it up, so let’s assume the data is sound. The next question is: does diminished brain structure translate into diminished cognitive function? The current data suggests that for light and moderate drinkers, that’s not the case, but researchers don’t know why.
This is Your Brain on (small amounts of) Alcohol
In the Oxford study, the researchers noted an increase in functional connectivity that “predicted higher cognitive performance on tests of executive function and working memory.”
Wait, what? Yeah, that’s right. Smaller brains, but better performance. The team suggested this may be due to a “compensatory effect” of the brain going through mild withdrawal. So that’s kind of scary-weird-but-maybe-a-good-thing?
Whatever the underlying reason, this is not the first study to find that moderate, non-binge alcohol consumption is associated with higher cognitive function. Another cohort survey, published in 2020 by the JAMA Network found that “low to moderate drinking was associated with significantly better trajectories of higher cognition scores for mental status, word recall, and vocabulary and with lower rates of decline in each of these cognition domains” compared to lifelong non-drinkers.
Wait, There’s More.
Before you pop open a bottle of bubbly to celebrate, note that the scientists in both studies wrote that they would urge everyone to drink less, not more, and certainly not to start drinking if you currently don’t. The slippery slope here is that a little alcohol may be okay for brain health (if compensating for withdrawals and steadily declining brain mass is an okay thing), but drink just a bit more and the pendulum swings the other way.
There was a distinct U-shaped curve in that JAMA study, meaning that only moderate drinkers seemed to enjoy a cognitive advantage. The difference between seven and 10 drinks per week for women, or 10 and 15 drinks per week for men, could be the difference between staying sharp into your 80s and 90s, and accelerating cognitive decline in your 60s and 70s.
If you frequently consume your weekly quota on the weekend, drinking more than two drinks per day for women, or more than four for men, you instantly move to the highest alcohol-related risk for damaging both your brain structure and function.
The Brain is Only Part of the Body
Researching and writing this post makes me want to take a deep dive into all of the health implications of moderate drinking. What are the effects on heart health? Does it increase risk of cancer, stroke, diabetes, and other diseases? When I take that deep dive, I’ll write about it here.
