Variants in certain genes lower the risk of various types of cancers in individuals who consume alcohol, reports a study published online this week in Nature Genetics. The genes, which encode enzymes that metabolize alcohol, reduce cancers of the mouth, larynx, pharynx and oesophagus.
Alcohol consumption is a risk factor for cancers of the upper aerodigestive tract, and some published evidence supports the notion that variation in the enzymes that metabolize alcohol ? alcohol dehydrogenases (ADH) ? might influence cancer susceptibility.
Paul Brennan and colleagues genotyped 6 ADH variants in more than 3,800 individuals with aerodigestive cancer and over 5,200 controls. One variant each in ADH1B and ADH7 were significantly protective against aerodigestive cancer specifically in individuals who were alcohol drinkers, and most strongly in those who had higher alcohol intake. Individuals with the protective variant in ADH1B are known to metabolize alcohol up to 100 times faster than those without it, suggesting that lower exposure to alcohol is protective against the disease.