Led by the University of Oxford, Yale University, and the University of Cambridge, the research challenges previous suggestions that light-to-moderate drinking may have a protective effect against dementia. The study is published in BMJ Evidence-Based Medicine.
Alcohol consumption is widespread and is linked with an increased risk of many diseases. Heavy drinking has previously been linked to higher risk of dementia. The connection between moderate levels of drinking and higher risk of dementia was uncertain with some studies suggesting that moderate drinking may even reduce dementia risk. However, recent studies involving brain scans have shown that drinking alcohol even at low levels may increase the risk of dementia.
This study combined observational data from more than half a million participants in two large and diverse population studies: the US Million Veteran Program and UK Biobank to assess whether self-reported alcohol use was linked with risk of developing a broad range of types of dementia.
The researchers also investigated links between genetically-predicted likelihood of drinking alcohol and alcohol use disorder for more than 2.4 million participants in 45 individual studies. This approach helped the researchers overcome some of the difficulties in distinguishing correlation from causation.