Alcohol can cause inflammation, triggering various parts of the immune system to kick in. This could result in the release of free radicals from these immune cells, which promotes DNA mutations.
And surprisingly no mass deaths from cancer of Russians or Irish were detected, with both nations famous for alcohol abuse. Yes, alcohol is harmful, but like Russians joke, it only kills weak brain cells.
Maybe a lot of people die before they get cancer from it? Like organ failure (liver, kidney, heart) way before they develop cancer (symptoms)? Or get into accidents (car, freezing to death) etc. It is like people saying smoking can prevent Alzheimer as statistically people who smoke a lot have less instances of it. Because they die from that habit before the Alzheimer shows up.
OTOH moderate intake of alcohol, despite the risks, also has positive effects on the cardiovascular system. Wine has antioxidants which are associated with longevity, beer is good for bone strength, and so on. While an alcoholic may have a higher chance of dying before cancer gets them due to organ failure and accidents, a glass-of-wine-a-day drinker might live longer with a higher quality of life with the increased cancer risks than they otherwise might have with their congenital heart disease or whatever. Cancer typically gets you when you're old, heart disease gets a lot of people in their 40s and 50s.
And while the first world doesn't benefit directly anymore, typical brewing and fermenting processes ensured a drink was sanitary due to lengthy boiling times or yeast out-competing other microbes. Alcohol and hops/flavorings provide antimicrobial effects, acetobacter competed and inhibited against other water-born bacterial and mold growth. Alcoholic beverages are an easy way to store and preserve calories in times of scarcity, etc. It's quite likely that those who chose low-alcohol beverages were saved from other water-born diseases and lived longer thanks to it.
Well, if they die close to their 90-ies, and with no cancer, its a decent lifespan. This is what I learned from my granddad, who was great chess player, famous school teacher, and volcanic smoker.
At least here in the EU and especially this year for some reason, a lot of news has been doing the rounds that push research like [0] to the public. My parents doctor, since only a few months, now calls alcohol dangerous poison and something you should never use, like smoking. Although it's not new research, it seems more people are listening recently.
It causes swelling which cause more blood to be in that area which make the organs hotter. But I really doubt you could get any real burns from an inflammation.
1. http://www.cancer.org/cancer/cancercauses/othercarcinogens/g...