Alcohol consumption is a well-known global public health problem and it is recommended not to regularly drink more than 5 glasses of wine or 4 pints of beer a week. According to the WHO, about 5% of the diseases that occur each year on the planet are caused by alcohol intake.
Now, a new study by the University of Oxford and University College London (UK) concludes that even moderate alcohol consumption is linked to an increased risk of decreased mental health and cognitive abilities. The work has been published in the BMJ magazine.
The researchers explain that the link between binge drinking and what it does to the brain – including dementia and degeneration of brain tissue – has already been well studied. However, very few studies have examined the relationship between moderate alcohol consumption and brain health, and their evidence is largely inconsistent.
To analyze this, the experts examined 30 years of data (collected between 1985 and 2015) of 550 healthy men and women with an average of 43 years who participated in the Whitehall II study. None of them had alcohol dependence at the beginning of the study.
The data included information on weekly alcohol consumption and measures of brain function and mental performance. Participants also underwent a brain MRI at the beginning and end of the study.
The results revealed that higher alcohol intake was linked to an increased risk of atrophy or degeneration of tissue in the hippocampus , a part of the brain crucial for spatial orientation and memory. This nefarious link remained even after taking into account factors that could influence the outcome such as gender, age, years of education, socioeconomic status, social and physical activity, medical history, smoking, and risk of stroke .
Participants whose alcohol intake exceeded 30 units per week had the highest risk of hippocampal atrophy (as expected); however, the analysis also showed a link with moderate alcohol consumption, which they defined as 14 to 21 units per week (14 units = 5 generous glasses of wine). That is, in comparison with people who did not drink, people who drank moderately (up to 7 glasses of wine) showed a three times greater risk of hippocampal atrophy.
Although the study has limitations, because alcohol consumption affects a large proportion of the population, the implications for public health could be significant, the authors conclude.
Reference: Moderate alcohol consumption as risk factor for adverse brain outcomes and cognitive decline: longitudinal cohort study BMJ 2017; 357 doi: https://doi.org/10.1136/bmj.j2353 (Published 06 June 2017) Cite this as: BMJ 2017; 357: j2353
