[TTFX]

Alcohol consumption and risk of dementia

Conclusion The risk of dementia was increased in people who abstained from alcohol in midlife or consumed >14 units/week.

https://www.bmj.com/content/362/bmj.k2927

[Right Brother]

From the study you linked:

"We show that both long term alcohol abstinence and excessive alcohol consumption may increase the risk of dementia".

Well, that clears it up.