Opinion: Does drinking alcohol cause dementia or prevent it?

Recently there was a headline “Even a moderate amount of drinking could cause brain decline,” which was no doubt troubling to anyone who enjoys an evening cocktail.
But just a few weeks later another headline read, “Cheers! Regular drinkers might live longer lives without dementia” and oenophiles the world over breathed a collective sigh of relief.
The casual reader could be forgiven for being confused as he or she ponders whether to pour a glass of wine with dinner.