Lay Summary

The purpose of this multi-national prospective study was to examine the effect of alcohol consumption on cognitive decline in older adults. The results indicate a significant non-linear correlation between alcohol consumption and cognitive decline. In this population, alcohol was shown to be a relevant risk factor of cognitive decline hence, focus on preventive measures is fundamental.

Background

Concurrent to the increase of the proportion of older adults among the population, the prevalence of cognitive decline and dementia, are rising globally. As no causal treatment of cognitive decline and dementia are available, identifying risk factors and preventing the onset or progression of cognitive decline is of utmost importance. Importantly, a heightened vulnerability for the possible detrimental health consequences of alcohol consumption is reported among older adults. Our aim was to estimate this potentially negative effect of consuming alcohol on cognitive functioning.

Methods

Longitudinal data of the Survey of Health, Age and Retirement in Europe (SHARE) database from 2004 until 2019 were included. The 6,967 participants were monitored for changes in their cognitive abilities (immediate and delayed recall) and verbal fluency. Additionally, the effect of non-modifiable risk factors, including sex and age, on these cognitive functions were analysed. For this, a generalised estimating equation (GEE) linear model was estimated for each of the three assessed cognitive domains.

Results

Consistent results were revealed in all three regression models (i.e. for all three cognitive domains): Moderate alcohol intake was significantly (p < 0.0001) associated with overall better global cognitive function than both, elevated alcohol consumption, and low consumption or complete abstinence – similar to a u-shaped association. Furthermore, female sex and higher educational obtainment were significantly associated with better cognitive functioning (p < 0.0001), whereas higher age and depression were associated with a decline in cognitive functioning (p < 0.0001). Notably, no significant association was found for smoking.

Conclusion

This longitudinal analysis revealed a significant non-linear association between alcohol consumption and cognitive functioning – moderate alcohol consumption was associated with better cognitive functioning than elevated levels of consumption or complete abstinence. Considering the effect of the so-called ›abstainer bias‹, however, any notions claiming the protective effect of alcohol consumption in older adults should be assessed critically. Certainly, evidence-based therapeutic concepts to reduce alcohol consumption should be offered to the increasing proportion of the older adults.