Alcoholic beverages were classified as a Group 1 carcinogen by the International Agency for Research on Cancer (IARC) in 1988.[3] An estimated 3.6% of all cancer cases and 3.5% of cancer deaths worldwide are attributable to consumption of alcohol (more specifically, acetaldehyde, a metabolic derivative of ethanol).[8] 740,000 cases of cancer in 2020 or 4.1% of new cancer cases were attributed to alcohol.[3][2]
Alcohol is thought to cause cancer through three main mechanisms: (1) DNA methylation,[8] (2) Oxidative stress, and (3) Hormonal alteration. Additional mechanisms include microbiomedysbiosis, reduced immune system function, retinoid metabolism, increased levels of inflammation, 1-Carbon metabolism and disruption of folate absorption.[9]
Heavy drinking consisting of 15 or more drinks per week for men or 8 or more drinks per week for women beverages/week contributed the most to cancer incidence compared with moderate drinking. The rate of alcohol related cases is 3:1 male:female, especially in oesophageal and liver cancers.[3] Some nations have introduced alcohol packaging warning messages that inform consumers about alcohol and cancer. The alcohol industry has tried to actively mislead the public about the risk of cancer due to alcohol consumption, in addition to campaigning to remove laws that require alcoholic beverages to have cancer warning labels.