How do genes affect alcohol tolerance?

Genetic factors significantly influence alcohol tolerance and the risk of alcohol use disorders. Andrew Huberman explains that genes affecting serotonin receptors, GABA receptors, and the hypothalamic-pituitary-adrenal (HPA) axis are crucial. These genetic pathways, when combined with environmental factors such as social settings and personal experiences like trauma, contribute to varying responses to alcohol and the development of alcohol-related issues.

Additionally, genetic variations in the production of alcohol dehydrogenase, an enzyme vital for metabolizing alcohol, play a role in how individuals tolerate alcohol. For example, some people, especially in certain Asian cultures, have lower levels of this enzyme. This leads to adverse reactions to alcohol, such as facial flushing and nausea, because they cannot efficiently metabolize alcohol, leading to a buildup of acetaldehyde, a toxic byproduct. In contrast, individuals with higher levels of alcohol dehydrogenase can metabolize alcohol more efficiently, potentially leading to higher consumption and increased risk of alcoholism in those environments 1.