What causes alcohol intolerance?
What causes alcohol intolerance?
A genetic metabolic disorder causes alcohol intolerance. When most people ingest alcohol, which contains ethanol:
- An enzyme called alcohol dehydrogenase (ADH) helps metabolize (process) the ethanol.
- Your liver converts the ethanol to acetaldehyde, a substance that can cause cell damage.
- Another enzyme called aldehyde dehydrogenase 2 (ALDH2) helps convert acetaldehyde to acetic acid (vinegar), which is nontoxic.
In people with alcohol intolerance, a genetic mutation (change) makes ALDH2 less active or inactive. As a result, your body can’t convert acetaldehyde to acetic acid. Acetaldehyde starts to build up in your blood and tissues, causing symptoms.