Modifiable risk factors for dementia, such as heavy alcohol consumption, have been extensively documented in past research. However, the link between light to moderate drinking and dementia risk has remained less clear—until now. A recent study led by Zheng and colleagues, due for publication in The Lancet in October 2024, reveals a linear relationship between alcohol consumption and dementia risk in current drinkers. The findings suggest that there may be no safe level of alcohol consumption when it comes to protecting against dementia.
Dementia is a growing public health issue, contributing significantly to disease-related deaths and disabilities each year. Data from GlobalData’s epidemiologists predict that in the UK, there will be just over 827,000 cases of dementia among men and women aged 60 and above, with that number expected to rise to nearly one million by 2032. As these numbers climb, understanding risk factors such as alcohol consumption becomes increasingly crucial.
While previous epidemiological studies assessing the relationship between alcohol consumption and dementia have been subject to bias and confounding factors, the Zheng study is notable for using Mendelian randomization as its analytical method. This approach provides a more robust and unbiased understanding of the relationship between alcohol exposure and dementia risk, as it mimics a genetic randomized controlled trial.
The study analyzed data from the UK Biobank, collected between 2006 and 2010, involving 313,958 White British participants who were current drinkers. These individuals were followed for an average of 13.2 years, until 2021. The study found that 48.6% of participants consumed more than the recommended 14 units of alcohol per week. Interestingly, men were more likely to exceed the recommended limits, while women tended to stay within the guidelines. The median weekly alcohol consumption for both men and women was 13.6 units.
A significant and linear causal relationship between alcohol consumption and dementia risk was discovered. The lowest dementia risk occurred at an alcohol consumption level of 11.9 units per week, which is below the current recommendation for safe drinking. This discovery challenges conventional thinking and aligns with the results of recent meta-analyses, which suggest that even light to moderate alcohol consumption may increase the risk of dementia.
Traditional epidemiology studies have often recommended moderation, rather than abstinence, for current drinkers due to the potential for bias. However, this new research calls for caution when interpreting such findings, highlighting that there could be other unrecognized lifestyle factors that also contribute to dementia risk. Nonetheless, the study offers important insights into the relationship between alcohol consumption and dementia, suggesting that current drinking guidelines in the UK may need to be reconsidered based on these findings.