How well does your alcohol metabolism work?

Alcohol is a cell toxin that is broken down in stages by various enzyme systems in the body.

Alcohol is almost completely absorbed and can be detected in the blood after around 30 minutes even when consumed in very small quantities and on an empty stomach. Warm drinks, sugar and drinks rich in carbohydrates accelerate absorption, whereas high-fat meals delay absorption.

Alcohol is mainly broken down in the liver. There it is first converted to acetaldehyde with the help of the enzyme alcohol dehydrogenase (ADH). Acetaldehyde is even more dangerous than alcohol itself and must be broken down quickly. This task is performed by the enzyme aldehyde dehydrogenase (ALDH), which converts acetaldehyde into relatively harmless metabolites that are then metabolized in the body and excreted. Incidentally, acetaldehyde is partly responsible for the well-known hangover symptoms such as headaches, nausea and vomiting.

The breakdown of alcohol depends on genetic factors as well as lifestyle, drinking habits, diet, state of health and detoxification capacity and can vary greatly from person to person. Nevertheless, genetic polymorphisms determine how the body reacts to the consumption of alcohol and how efficiently alcohol is broken down.

A well-known example is the enzyme aldehyde dehydrogenase ALDH-2, which remains inactive due to a genetic change and massively restricts the breakdown of alcohol. Carriers of this variant react to alcohol consumption with severe facial flushing (flushing syndrome), nausea, severe hangover-like symptoms and a clear aversion to alcohol. Around 25-50% of the Asian population are affected by this genetic variation.

Why is alcohol so dangerous?

Biochemically speaking, alcohol is a cell poison, not only for the liver but also for the brain. For this reason, the body endeavors to deactivate the alcohol consumed as quickly as possible. In the process, an intermediate product is formed which is even more harmful in higher concentrations and is partly responsible for the hangover the next morning. Acetaldehyde, a highly reactive molecule which, according to studies, can have a mutagenic (mutagenic) and carcinogenic (cancer-causing) effect. Regular, high alcohol consumption can lead to serious cell damage in all tissues of the body. This includes changes to the liver, heart, pancreas, nervous system and muscles.

What Does Genetics Have to Do with It?