A metabolite of alcohol known as acetaldehyde, which occurs naturally at low levels, causes double-stranded breaks in the DNA of mouse blood stem cells, according to a study published (January 3) in Nature. Unrepaired breaks can lead to large deletions and chromosome rearrangements, and the mutations are passed on to daughter cells that make up the blood.
Normally, the enzyme aldehyde dehydrogenase 2 (ALDH2) quickly oxidizes acetaldehyde into acetate, which cells use as a source of energy. But many people, including millions in Southeast Asia, carry mutations in the ALDH2 gene that causes the accumulation of acetaldehyde. These people, who are known to have an increased risk of developing esophageal cancer, may also be more susceptible to blood cancers, if the new results hold true in humans: ALDH2 knockout mice suffered four times as much DNA damage as their wildtype counterparts after alcohol consumption, according to the study.
Research provides very strong evidence that an alcohol metabolite causes DNA damage to the important stem cells that go on to make tissues.