This is the result of the study, published at the beginning of June 2017 in the British Medical Journal, which monitored the weekly alcohol consumption of 550 among healthy men and women for a period of 30 years, from 1985 to 2015.
The subjects participating in the study, called Whitehall II, were subjected to periodic evaluations of brain functioning through cognitive tests and at the end of the study were subjected to a Nuclear Magnetic Resonance of the brain, a neuroradiological examination that thoroughly assesses the structure and morphology of the brain. The average age of the participants was 43, and none of them had any problems related to alcohol dependence.
Analyzing the data obtained, the researchers found onedirect correlation between the amount of alcohol consumed and the increased risk of atrophy of the hippocampus , a brain region that is responsible, among other things, for maintaining memory and spatial orientation. In particular, subjects who consumed more than 30 alcoholic units per week during the 30 years of observation had the greatest risk of atrophy of the hippocampus.
It should be borne in mind that one Alcoholic Unit (AU) corresponds to about 12 grams of ethanol, which represents the alcohol content of a small glass (125 ml) of medium alcoholic wine, of a can or bottle of beer (330 ml) of medium strength or one bar dose (40 ml) of spirits.
However, while this data could be intuitive and in any case already amply demonstrated by numerous other studies, the novelty of this research is that even those who consumed what is considered a moderate amount of alcohol (14-21 units per week) had three times the risk of developing hippocampal atrophy compared to abstainers .
Another novelty of the study is that no cerebral protective effect from mild alcohol consumption (less than 7 units per week) was demonstrated compared to complete abstinence.
The study also showed that high weekly alcohol consumption is associated with poorer brain white matter integrity(crucial for the control of numerous cognitive functions) and a more rapid worsening of verbal fluency (the number of words that can be recalled in a minute starting with a single letter).
The authors, albeit with the cautions related to the fact that this is an observational study, underline the need to review the current levels of alcoholic consumption considered safe for health, considering that the current English guidelines (which consider safe for health a alcohol consumption of 24.5 units per week) are already above the levels that the study identified as carriers of increased risk of long-term brain damage (14-21 units per week) and above all in consideration of the fact that no cerebral protective effect from the mild consumption of alcoholic beverages (up to 7 units per week).
According to the same authors, we tend to justify persistent harmful behaviors on the basis of rationalization (consuming “tot” alcohol is good for me or not bad for me). From now on, justifying even mild alcohol consumption becomes more difficult, at least from the point of view of long-term brain health.
Anya Topiwala, Charlotte L Allan, Vyara Valkanova, Eniko Zsoldos, Nicola Filippini, Claire Sexton, Abda Mahmood, Peggy Fooks, Archana Singh-Manoux, Clare E Mackay, Mika Kivimaki, Klaus P Ebmeier. Moderate alcohol consumption as risk factor for adverse brain outcomes and cognitive decline: longitudinal cohort study. BMJ, 2017; j2353 DOI: 10.1136 / bmj.j2353
