Drinking “in moderation”
Q. I read your comments in the last Brain Bulletin about wine and supposed benefits to the heart. But what about the brain? Doesn’t wine or other mild alcoholic drinks help the brain to relax? I mean loads of people drink in moderation.
A. Your question reflects many that I receive. Yes, alcohol use is widespread across the planet and historically has been viewed as relatively harmless in moderation. More recently there’s been an emerging trend to play up alcohol’s supposed benefits to the heart and to the brain and ignore or play down links with cancer. I know of no research to suggest that the active principle in wine, alcohol, helps the brain relax.
I am familiar with a study involving a dozen researchers and led by Anya Topiwala, clinical lecturer in old age psychiatry. Published in the British Medical Journal just a few months ago, the title is: “Moderate alcohol consumption as risk factor for adverse brain outcomes and cognitive decline: longitudinal cohort study.” (BMJ 2017;357:j2353) The objectives were to investigate whether moderate alcohol consumption has a favorable or adverse association or no association with brain structure and function. It was a longitudinal observational cohort study with weekly alcohol intake and cognitive performance measured repeatedly over 30 years (1985-2015). Multimodal magnetic resonance imaging (MRI) was performed at study endpoint (2012-15). Structural brain measures included hippocampal atrophy, grey matter density, and white matter microstructure.
The study reported that higher alcohol consumption over the 30-year follow-up was associated with increased odds of hippocampal atrophy in a dose dependent fashion. As you may know, the hippocampus is analogous to a computer’s search engine. Study participants who consumed over 30 units a week of alcohol were at the highest risk compared with abstainers. However, even those drinking moderately (14-21 units/week) had three times the odds of right sided hippocampal atrophy. There was no protective effect of light drinking (1 to less than 7 units/week) over abstinence. Higher alcohol use was also associated with differences in corpus callosum microstructure and faster decline in lexical fluency.
Study conclusions include:
- Higher alcohol use was associated with reduced grey matter density, hippocampal atrophy, and reduced white matter microstructural integrity.
- Alcohol consumption, even at moderate levels, is associated with adverse brain outcomes including atrophy of the hippocampus.
The researchers posit that these study results support the recent reduction in alcohol guidance in the United Kingdom and call into question the current limits recommended in the United States. You may like to read a recent article in PsyBlog discussing this study and its potential implications. [http://www.spring.org.uk/2017/06/very-popular-drink-linked-to-brain-damage.php?omhide=true]