Acetaldehyde is a toxic substance which occurs naturally in coffee, bread, ripe fruit, and is produced by plants. It is also a breakdown product of alcohol and may be contributing factor to hangovers from alcohol consumption.
People with a normally functioning aldehyde dehydrogenase gene (ALDH2) are able to convert acetaldehyde into a harmless substance called acetate. Some people have a mutation in the aldehyde dehydrogenase gene (ALDH2) that prevents this, resulting in a build-up of acetaldehyde and in some cases, increased risk for esophageal cancer. Other factors that increase risk of esophageal cancer include smoking cigarettes, heavy alcohol consumption, chronic acid reflux disease and advanced age.
The odds of esophageal cancer for heavy drinkers with the ALDH2 mutation is much higher than in those without the mutation who do not smoke or drink.4