PARIS - 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 new study. 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, on Wednesday. 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.