People who have sworn off alcohol for decades or longer run a higher risk of dementia late in life than moderate drinkers, according to a study published Wednesday.
Long-term teetotallers were roughly 50 percent more likely to suffer Alzheimers or another form of neurodegenerative disease, scientists reported in the BMJ, a medical journal.
With heavy drinking, however, dementia became even more prevalent, though for different reasons.
Unlike earlier research, the study did not find a link between abstinence and a shorter life expectancy, as compared to occasional drinkers.
The results were based on a review of medical records rather than the more scientifically rigorous clinical trials used to assess new drugs, and the number of cases examined was relatively small.
But the startling results are robust, and should prompt government-funded trials to assess "the possible protective effect of light-to-moderate alcohol use on risk of dementia," commented Sevil Yasar, an associate professor at the John Hopkins School of Medicine who was not involved in the study.
Worldwide, about seven percent of people over 65 suffer from some form of dementia, a percentage that rises to 40 percent above the age of 85. The number of sufferers is expected to triple by 2050.