Álcool provoca mutações genéticas em células estaminais...

E os dois níveis de protecção que o vão evitando:
https://www.theguardian.com/science/2018/jan/03/alcohol-can-cause-irreversible-genetic-damage-to-stem-cells-says-study

Citando:
"During the past decade, there has been mounting evidence of the link between drinking and the risk of certain cancers.

Alcohol is a direct cause of seven forms of cancer, finds study

“This paper provides very strong evidence that an alcohol metabolite causes DNA damage [including] to the all-important stem cells that go on to make tissues.”

(...)

The latest work showed that acetaldehyde slices through DNA, causing permanent damage, if the effects of the toxin are not neutralised by two natural defence mechanisms. The first tier of defence clears away the acetaldehyde and the second repairs the DNA damage.

By genetically “knocking out” these two layers of defence, scientists were able to show DNA damage accumulating until cells eventually stopped working entirely.

The study revealed that DNA damage was exacerbated when mice lacked the first tier of defence – a protective enzyme called aldehyde dehydrogenase 2 (ALDH2), which prevents potentially toxic build-ups of acetaldehyde. About 8% of the world’s population, mostly those of East Asian ancestry, have an inherited deficiency in ALDH2 (sometimes known as the flushing mutation), which could explain the high prevalence of oesophageal cancers in countries such as China."