In recent years, researchers have found evidence that a daily glass of wine may bolster brain health, but scientists still debate whether alcohol, in any amount, should be recommended to lower dementia risk. Many studies point to the damaging effects it has on the brain and new evidence, published this week, shows that drinking too much alcohol regularly can increase risk for all types of dementia, especially early-onset Alzheimer’s.
A recent study published in the journal Lancet Public Health showed that data from over a million adults points to excessive alcoholism as a dangerous risk factor for dementia. Researchers looked at data from the French National Hospital Discharge database and found that alcohol-use disorders were present in 16.5 percent of men with dementia and 4 percent of women with dementia—that’s twice as much as in those without dementia in the case of both men and women.
The study paid special attention to the link between early-onset dementia, classified as anyone with a diagnosis under the age of 65. Of the 57,000 cases of early-onset dementia, researchers found that 57 percent were related to chronic drinking.
But how much alcohol is too much alcohol? The World Health Organization defines chronic drinking as more than 60 grams of pure alcohol per day for men (four to five drinks) and more than 40 grams of pure alcohol per day for women (three drinks).
“We’ve known for a while that heavy drinking can increase your risk of developing dementia. This study suggests that alcohol abuse disorders may be responsible for more cases of early-onset dementia than previously thought,” said Doug Brown, Chief Policy and Research Officer at Alzheimer’s Society.
However, Brown points out that this study was limited to France, and other countries may have different drinking habits that could affect risk of early-onset differently.
“This study in no way suggests that moderate alcohol intake could cause early-onset dementia. The study doesn’t change the advice to stick to no more than 14 units [one unit is how much pure alcohol an adult can process in an hour] of alcohol a week,” said Brown.
Researchers who led the study suggested that this information should lead to screenings for alcohol use and interventions and treatment for alcohol disorders in order to curb dementia.
“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 and Director of the Centre for Addiction and Mental Health (CAMH) Institute Dr. Jürgen Rehm. “Alcohol-induced brain damage and dementia are preventable, and known-effective preventive and policy measures can make a dent into premature dementia deaths.”
And not only does heavy alcohol use increase dementia risk; it also increases risk for a number of other factors associated with dementia, like tobacco smoking, high blood pressure, diabetes, lower education, depression and hearing loss. According to Rehm, alcohol-use disorders shorten life expectancy by more than 20 years, on average. For many of those people, dementia is the cause of death.
“As a geriatric psychiatrist, I frequently see the effects of alcohol-use disorder on dementia, when unfortunately alcohol treatment interventions may be too late to improve cognition,” said CAMH Vice President of Research Dr. Bruce Pollock. “Screening for and reduction of problem drinking, and treatment for alcohol-use disorders need to start much earlier in primary care.”
This study was published in the journal Lancet Public Health.