How much do you agree with this statement?
"...light drinking (<7 units weekly) is protective against adverse brain outcomes and cognitive decline and heavier drinking (above recommended guidelines) is associated with adverse brain and cognitive outcomes." - Hypotheses by Anya Topiwala, clinical lecturer in old age psychiatry, et al.
Many of us would no doubt say that we agree with the hypotheses expressed by Topiwala and the researchers. Read on. You might be surprised. You might also want to think about your own drinking habits.
The researchers set out to discover whether moderate alcohol consumption had a favourable, adverse or no association with brain structure and function. They did so by studying 550 healthy men and women over the course of 30 years. At the start of the study the average age was 43 years old and none had any alcohol-related conditions. During the 30 years the men and women underwent cognitive functioning tests and at the end of the study underwent MRI scans.
For those that had consumed alcohol for the 30 years there was significant evidence of hippocampus shrinkage. The hippocampus is heavily involved in memory formation. Further, consuming alcohol at this level was also associated with impacting the corpus callosum (a region that provides complex interconnections between the hemispheres).
What might come as more of a surprise, or even shock to many of us, is the following: "...there was no protective effect of light drinking (1-<7 units/week) over abstinence." Some other studies have suggested that there are protective benefits but this study challenges that conclusion.
To end with here are the findings that you can read in the BMJ:
What this study adds
Compared with abstinence, moderate alcohol intake is associated with increased risk of adverse brain outcomes and steeper cognitive decline in lexical fluency
The hippocampus is particularly vulnerable, which has not been previously linked negatively with moderate alcohol use
No protective effect was found for small amounts of alcohol over abstinence, and previous reports claiming a protective effect of light drinking might have been subject to confounding by associations between increased alcohol and higher social class or IQ
Topiwala, A., et al. (2017). Retrieved from the Word Wide Web June 15, 2017: http://www.bmj.com/content/357/bmj.j2353