"The most intriguing finding from this study was the significantly increased risk of dementia among abstainers, including long term abstainers and participants who became abstainers, and that association was only present in those who abstained from wine.

Abstainers were mainly women, had lower education and physical activity, were obese, and had a higher prevalence of cardiometabolic risk factors, all associated with an increased risk of dementia,11,12 which could explain the differences; however, adjustment for confounding factors did not alter the findings."

It's not clear what the intersection between "long term abstainers" and "became abstainers" is.