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 57,000 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).