They identified alcohol use disorders by discharge codes of mental and behavioral disorders stemming from former or current chronic, harmful alcohol use, or chronic diseases attributable to alcohol use disorders like alcoholic liver disease.
Dr Sara Imarisio, of Alzheimer's Research UK, added: 'Previous research has indicated 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'.
"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.
The median age of dementia onset was 82 for men and 85 for women.
That's the message from the team of French scientists which just released a new study in The Lancet Public Health today, linking heavy drinking to an increased risk of dementia.
"We've known all along that alcohol can cause damage to the brain".
It included all patients over 20 discharged with alcohol-related brain damage, vascular dementia or other forms of brain-wasting diseases like Alzheimer's. Therefore, it is important to note that lower levels of drinking likely don't carry the same risk.
In a linked comment, Prof Clive Ballard of the University of Exeter Medical School in the United Kingdom, said that this study is "immensely important".
Dr Doug Brown, of Alzheimer's Society, said: "This study suggests alcohol abuse disorders may be responsible for more cases of early-onset dementia than thought". Now, a new study claims to have found another worrying link between the bottle and the brain. "Screening for and reduction of problem drinking, and treatment for alcohol use disorders need to start much earlier in primary care". In the same period, 945,512 of patients discharged had a diagnosis of alcohol use disorders, with alcohol dependency coded in 86% of those cases (816,160/945,512).
Prof Woodward is sceptical about the introduction of such measures in Australia without harder evidence to prove that alcohol causes dementia. About 3% of all dementia cases (35,034/1,109,343 cases) were associated with alcohol-related brain damage.
"But people who are drinking moderate amounts of alcohol shouldn't cut back because of this study".
Of the test group, 57% of the 57,000 patients diagnosed with early-onset dementia had chronic heavy drinking problems where in they would consume more than four drinks a day.
Government guidelines for both sexes suggest no more than 14 units of alcohol a week - equivalent to a pint of beer or small glass of wine daily. "And do everything in moderation". Basically, he says, "just do what's good for your heart and brain".