Heavy drinking linked to high dementia risk

FRANCE/BRITAIN: Heavy drinking triples the risk of dementia, and most early cases of the disorder are caused by alcohol misuse, the largest study of its kind has concluded.

Scientists say severe alcohol misuse can directly cause brain damage but that the priority now is to pin down exactly what level of daily drinking increases the risk of dementia. While some research has linked heavy drinking to dementia, other studies have found that moderate levels of alcohol might protect against the disease.

In the latest study, French researchers looked at people with a hospital diagnosis of alcohol dependence or other drink-related conditions among 1.1 million people with dementia. Alcoholrelated disorders were the lifestyle habit most strongly related to having dementia, higher even than smoking and high blood pressure, they reported in The Lancet Public Health.

Not only were problem drinkers 3.3 times as likely to get dementia, but the majority of the 57,353 cases in which the disease appeared before the age of 65 were linked to alcohol, the researchers concluded.

Michael Schwarzinger, of the Translational Health Economics Network, who led the study, said: ‘‘Our findings suggest that the burden of dementia attributable to alcohol use disorders is much larger than previously thought, suggesting that heavy drinking should be recognised as a major risk factor for all types of dementia.’’ He said the link was ‘‘likely a result of alcohol leading to permanent structural and functional brain damage’’.

Alcohol is implicated in about 8 per cent of all dementia cases, the study suggests, rising to 57 per cent of early-onset dementia.

Tara Spires-jones, of the University of Edinburgh, said: ‘‘There are other studies that indicate that moderate amounts of red wine as part of a healthy diet may protect against developing dementia. However, it is crystal clear that alcohol abuse is bad for your brain.’’

Sara Imarisio, of Alzheimer’s Research UK, said the findings ‘‘lend even more weight to calls for people to drink within recommended guidelines’’.

‘‘As this study only looked at the people who had been admitted to hospital due to chronic heavy drinking, it doesn’t reveal the full extent of the link between alcohol use and dementia risk,’’ Imarisio said.

‘‘Previous research has indicated that even moderate drinking may have a negative impact on brain health, and people shouldn’t be under the impression that only drinking to the point of hospitalisation carries a risk.’’

Doug Brown, of the Alzheimer’s Society, said: ‘‘This study in no way suggests that moderate alcohol intake could cause earlyonset dementia. The study doesn’t change the advice to stick to no more than 14 units of alcohol a week.’’

Clive Ballard, of the University of Exeter, said researchers needed to pin down whether there was a clear level at which alcohol became harmful.

Julie Breslin, of Addaction, who runs a project targeting British drinkers over 50, said: ‘‘Alcohol consumption and related harms are increasing in older adults but reducing in younger people, and as our ageing population grows we may start to see conditions such as alcohol-related dementia become more common.’’