1 glas of alhocol drink/day for women and 2 glasses for men is considered to be safe for our health and our brain. More than that can lead to changes in brain structure and brain size, resulting in brain health issues. Moreover, several studies argued that light drinking could benefit the brain in older adults. HOWEVER, a recent large study warned that even few beers or glasses of wine a week might lead to reductions in overall brain volume. Less brain volume = worse brain function.
The study analyzed the data from 36.678 middle-aged adults and showed that the greater the level of alcohol consumption was, the stronger was the reduction in brain volume. Of course, it is normal for our brain to shrink with age. We lose around 5% of brain volume per decade after age of 40 and even more over the age of 70. However, according to this study, by drinking alcohol you accelerate the natural aging of your brain. So, in 50-year-olds, an increase of an average drinking from 1 alcohol unit/day (10 ml or 8 g of pure alcohol is equal to f.e. single small short of spirits or about 284 ml of lower strength beer) to 2 units (568 ml of beer or 175 ml of wine) were linked to the changes in the brain equivalent to aging by extra 2 years. Going from 2 to 3 alcohol units at the same age was like aging by extra 3,5 years. To impress you even more, the difference between 0 and 4 drinks was more than 10 years of brain aging! As for those, going from 0 to a daily average of 1 alcohol unit was equivalent to ½ year of brain aging. By the way, the lower brain volume due to alcohol was not localized to any one brain region.
The researchers concluded that the relation between alcohol consumption and brain volume is exponential and gets worse with each additional glass of alcohol drink.
The researchers also took into account other factors that could influence this relationship, such as age, height, handedness, sex, smoking status, socioeconomic status, genetic ancestry, and county of residence. Furthermore, they corrected the brain-volume data for overall head size and considered other individual characterics of the participants.
Whether drinking 1 beer a day is better than no drinking during the week and then catching up 7 on the weekend is the question for further investigation.