Heavy drinkers are at increased risk of developing dementia, a progressive brain disease that generally begins with mild memory loss, suggests the largest study of its kind ever conducted.
Alcohol use disorders are the most important preventable risk factors for the onset of all types of dementia, especially early-onset dementia, showed the study of over one million adults diagnosed with dementia in France.
This study, published in the journal The Lancet Public Health, included only the most severe cases of alcohol use disorder -- ones involving hospitalisation.
Of the 57,000 cases of early-onset dementia (before the age of 65) reported in the study, the majority (57 per cent) were related to chronic heavy drinking.
The World Health Organisation (WHO) defines chronic heavy drinking as consuming more than 60 grams pure alcohol on average per day for men (4-5 Canadian standard drinks) and 40 grams (about 3 standard drinks) per day for women.
"The findings indicate that heavy drinking and alcohol use disorders are the most important risk factors for dementia, and especially important for those types of dementia which start before age 65, and which lead to premature deaths," said study co-author Jurgen Rehm of the Centre for Addiction and Mental Health (CAMH) in Toronto, Canada.
"Alcohol-induced brain damage and dementia are preventable, and known-effective preventive and policy measures can make a dent into premature dementia deaths," Rehm said.
On average, alcohol use disorders shorten life expectancy by more than 20 years, and dementia is one of the leading causes of death for these people, Rehm pointed out
For early-onset dementia, there was a significant gender split. While the overall majority of dementia patients were women, almost two-thirds of all early-onset dementia patients (64.9 per cent) were men, the study showed.
As a result of the strong association found in this study, the researchers 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.