Alcohol use disorders are a major risk factor for onset of all types of dementia, especially early-onset dementia, according to a French nationwide observational study including over one million adults diagnosed with dementia between 2008-2013, published in The Lancet Public Health journal.
Of the 57000 cases of early-onset dementia (before the age of 65), the majority were either alcohol-related by definition (39%) or had an additional diagnosis of alcohol use disorders (18%).
Previous research has showed mixed results regarding the effect of alcohol on cognitive health, with some studies showing a possible benefit of light to moderate drinking, while others have found detrimental effects of heavy drinking on dementia risk.
The World Health Organisation (WHO) defines chronic heavy drinking as consuming more than 60g of pure alcohol a day for men (around 6 or more standard drinks per day on average) and more than 40g per day for women (around 4 or more standard drinks per day).
This study looked specifically at the effect of alcohol use disorders, and included people who had been diagnosed with mental and behavioural disorders or chronic diseases that were attributable to chronic harmful use of alcohol.
As a result of the strong association found in this study, the authors suggest that screening, brief interventions for heavy drinking, and treatment for alcohol use disorders should be implemented to reduce the alcohol-attributable burden of dementia.
“The link between dementia and alcohol use disorders needs further research, but is likely a result of alcohol leading to permanent structural and functional brain damage,” says lead author Dr Michaël Schwarzinger, Translational Health Economics Network, France.
“Alcohol use disorders also increase the risk of high blood pressure, diabetes, stroke, atrial fibrillation, and heart failure, which may in turn increase the risk of vascular dementia.
“Lastly, heavy drinking is associated with tobacco smoking, depression, and low educational attainment, which are also risk factors for dementia.”