The people who will be interested in this study are people who already don’t drink much, or have cut back. Others will say something to the effect of, “Even water can be toxic!” and then, “Killjoy!” Welp.

Here it is anyway.

One Alcoholic Drink A Day Linked With Reduced Brain Size, University of Pennsylvania Press Release, 4 March 2022

The research, using a dataset of more than 36,000 adults, revealed that going from one to two drinks a day was associated with changes in the brain equivalent to aging two years. Heavier drinking was linked with an even greater toll.

More Alcohol, Less Brain: Association Begins With An Average Of Just One Drink A Day, Science Daily, 4 March 2022

Summary: Even light-to-moderate drinking is associated with harm to the brain, according to a new study*. Researchers analyzed data from more than 36,000 adults that found a link between drinking and reduced brain volume that begins at an average consumption level of less than one alcohol unit a day — the equivalent of about half a beer — and rises with each additional drink.

A bit more:

But according to a new study, alcohol consumption even at levels most would consider modest — a few beers or glasses of wine a week — may also carry risks to the brain. An analysis of data from more than 36,000 adults, led by a team from the University of Pennsylvania, found that light-to-moderate alcohol consumption was associated with reductions in overall brain volume.

The link grew stronger the greater the level of alcohol consumption, the researchers showed. As an example, in 50-year-olds, as average drinking among individuals increases from one alcohol unit (about half a beer) a day to two units (a pint of beer or a glass of wine) there are associated changes in the brain equivalent to aging two years. Going from two to three alcohol units at the same age was like aging three and a half years. The team reported their findings in the journal Nature Communications.

“The fact that we have such a large sample size allows us to find subtle patterns, even between drinking the equivalent of half a beer and one beer a day,”

“These findings contrast with scientific and governmental guidelines on safe drinking limits,” says Kranzler, who directs the Penn Center for Studies of Addiction. “For example, although the National Institute on Alcohol Abuse and Alcoholism recommends that women consume an average of no more than one drink per day, recommended limits for men are twice that, an amount that exceeds the consumption level associated in the study with decreased brain volume.”

To gain an understanding of possible connections between drinking and the brain, it was critical to control for confounding variables that could cloud the relationship. The team controlled for age, height, handedness, sex, smoking status, socioeconomic status, genetic ancestry, and county of residence. They also corrected the brain-volume data for overall head size.

* Associations Between Alcohol Consumption And Gray And White Matter Volumes In The UK Biobank, Nature Communications, 4 March 2022

So, as little as a couple ounces of wine or half a beer a day could reduce the size of one’s brain. That is something else. I wonder how adding a few joints affects that, or some other recreational drug. How about a sleeping pill, or something for anxiety? Maybe an anti-depressant? Oh, and the statins and blood pressure meds and diabetes meds on top, if applicable. Then there’s the calcium supplements and antacids that have been shown to increase risk for dementia.

As a society, I think, we don’t seem concerned about how drugs may be impacting brain health. And we sure do like our drugs.