No amount of alcohol can be considered "healthy" [1]. The downsides dwarf the upsides and as Marc says the previous studies were fraught with problems. Newer studies like the one below are a little more honest and better run. I gave up alcohol a month ago and the biggest net benefit I've noticed is that my quality of sleep has dramatically gotten better (I made sure that no other variables changed because I wanted to test the effects).
[1] https://www.thelancet.com/journals/lancet/article/PIIS0140-6...
