Alcohol consumption is a risk factor for a variety of chronic illnesses, making it crucial to understand the epidemiological implications of its use. Among the myriad negative health endpoints for alcohol consumption is a heightened risk for dementia and Alzheimer’s disease (AD). In a recent publication in the Journal of the American Medical Association (JAMA), Jeon and colleagues explored the association between alcohol consumption and the risk of both diseases using a retrospective study of South Korea’s national insurance claims database. Their results suggest that while heavy alcohol consumption is a significant risk factor for dementia and AD, mild or moderate consumption may have a limited protective effect compared to nondrinkers. GlobalData epidemiologists forecast that South Korea will see a growing number of diagnosed prevalent cases of both dementia and AD, emphasising the need for a more nuanced understanding of the risk factors underlying these diseases.

Jeon and colleagues measured the disease burden of AD and dementia using 2,977,137 claims for individuals aged 40 and over from the Korean National Health Insurance Service (NHIS) from 2009 and 2011. Based on self-reporting questionnaires, participants were segmented into five categories of alcohol consumption: those who maintained, reduced, increased, or quit drinking between 2009 and 2011, as well as nondrinkers. By 2011, 100,282 diagnosed incident cases of all-cause dementia and 79,982 cases of AD were documented in NHIS claims. Analysis of the data suggests that heavy drinkers exhibited an 8% risk of developing both dementia and AD, the highest risk across all categories. Similarly, those who increased their alcohol consumption during, regardless of their consumption patterns at the start of the study period, showed a higher risk of dementia.

While these findings were consistent with previous literature on alcohol and cognitive decline, data on changes in consumption patterns deviated from prior studies. Notably, those who quit drinking across consumption categories showed a higher risk of dementia than those who maintained their consumption level. The cohorts with the lowest risk of dementia were the sustained mild and moderate consumers, with a 21% and 17% decrease in risk, respectively. The authors consider these contradictions representative of the challenges in creating guidelines surrounding alcohol consumption and cognitive decline; while mild to moderate consumption may confer some protective effects, individual differences in bodily responses to alcohol may lead to inconsistent results.

The analysis performed by Jeon and colleagues sheds light on the complex interaction between individual behaviour and the risk of neurodegenerative illnesses. While heavy drinking showed predictable health endpoints based on previous studies, the decrease in risk among mild and moderate sustained drinkers suggests a more nuanced mechanism tying alcohol consumption to cognitive decline. The results should compel further inquiry into the biological underpinnings of this relationship. A holistic understanding of this relationship can better inform clinicians on how to communicate best practices for preventive lifestyle changes. GlobalData epidemiologists forecast that diagnosed prevalent cases of dementia in South Korea will increase from over 487,000 cases in 2018 to almost 745,700 cases a decade later. Similarly, AD cases are expected to growth from nearly 363,200 to approximately 563,800 diagnosed prevalent cases during the same period. In light of Jeon and colleagues’ work and the diseases’ growing disease burden, the need for effective communication on preventive practices will be a critical facet of dementia and AD management.