We know that Alcohol causes cancer, mostly breast cancer and gastro-esophageal cancers. Alcohol is also a toxin that the liver has to metabolize and which leads to destruction of the liver if consumed in large and regular amounts. There is no amount of alcohol that can be considered "safe" from the oncological perspective.
But wasn't alcohol supposed to be "heart healthy"? Wasn't there a benefit from drinking a glass of red wine each night?
The substance that is supposed to be providing this benefit is called "resveratrol" and it naturally occurs on certain plants (most common: red grapes, peanuts, cocoa, blueberries). It is a way for the fruit to fight off fungal infections. Studies done in rodents showed a benefit from ingesting resveratrol and this was HIGHLY marketed! Great news for the wine industry, is it not? However, the amounts given to rodents was excessive, much, much more than what humans would ingest from drinking some wine. The amount given to them would correlate somewhere between resveratrol found in 100-1000 glasses of wine. Even then most enthusiastic wine lover couldn't survive that!
Keep in mind, all this was still only concluded from rodent studies and then highly marketed (as Dr. John MacDougal likes to say "We like good news about our bad habits!").
A study published in July 2014 in JAMA (Semba RD, Ferrucci L, Bartali B, et al. Resveratrol Levels and All-Cause Mortality in Older Community-Dwelling Adults. JAMA Intern Med. 2014;174(7):1077–1084. doi:10.1001/jamainternmed.2014.1582) examined this question in regards to human. The study was done in Italy and its objective was "To determine whether resveratrol levels achieved with diet are associated with inflammation, cancer, cardiovascular disease, and mortality in humans." It turns out that humans consuming resveratrol from their diets did not have a mortality benefit when compared to those not taking in as much resveratrol.
I believe people in the Blue Zones live such healthy lives that even drinking a small-moderate amount of alcohol does not bring them down.
I would say they live healthy and long lives DESPITE the alcohol NOT BECAUSE.
Physicians usually don't pay too much attention to this subject in general. A lot of physicians enjoy the occasional drink as well. Research has shown that physicians who drink alcohol are less likely to counsel their patients about the dangers. And it makes sense - it seems really hypocritical to give advice you are not following yourself.
Personally, I do not drink any alcohol at all and I can tell you I don't miss a thing. It is all about the mindset: should I feel sorry for myself for missing out on something so incredibly special or should I be grateful that I have this information which could potentially save my life? I chose to be grateful. You don't need alcohol to enjoy life... not at all!