Alcohol Consumption in Predementia and Dementia Syndromes

Dementia is an age-related progressive disorder with an enormous unmet medical need. It is characterized by relatively slow but progressive and chronic impairment in cognition, behaviour, and functionality. In several longitudinal studies, light to moderate drinking of alcoholic beverages has been proposed as being protective against the development of age-related changes in cognitive function, predementia syndromes, and cognitive decline of degenerative (Alzheimer’s disease, AD) or vascular origin (vascular dementia, VaD). However, contrasting findings also exist. The equivocal findings may relate to many of the studies being limited to cross-sectional designs, restrictions by age or gender, or incomplete ascertainment. Different outcomes, beverages, drinking patterns, and study follow-up periods or possible interactions with other lifestyle-related (e.g., smoking) or genetic factors (e.g., apolipoprotein E (APOE) gene variation) may all contribute to the variability of findings. Light to moderate alcohol consumption may be associated with a reduced risk of unspecified incident dementia and AD; however, protective benefits afforded to VaD, cognitive decline, and predementia syndromes are less clear. In conclusion, since intervention studies to further test this thesis would be problematic, the most appropriate evidence that can be interpreted is that from an overview of epidemiological studies where protective effects are suggested to be more likely in the absence of the AD-associated APOE ε4 allele and where wine is the beverage. At present, there is no indication that light to moderate alcohol drinking would be harmful to cognition and dementia and attempts to define what might be deemed beneficial levels of alcohol intake in terms of cognitive performance would be highly problematic and contentious.