What is Acetaldehyde?

Acetaldehyde is a metabolic compound that is known to be carcinogenic to humans, and unfortunately, can be found everywhere in our modern environment. Acetaldehyde enters our bodies in greatest concentration as a toxic byproduct from drinking alcohol. The toxin also enters our bodies through air pollution (both indoor and outdoor), cigarette smoking and our everyday food and diet.

In cigarette smoking and air pollution, acetaldehyde is the most abundant carcinogen found. Second-hand smoke can also be a major contributor of the toxin, particularly in indoor environments where people are regularly smoking. Additionally, acetaldehyde occurs naturally in our everyday diet such as fermented foods, coffee, carbs and high sugar foods like bread, pasta, fruit and yogurt. The sugar in foods can be converted into acetaldehyde in the gut through our naturally occurring yeast.

Understanding Acetaldehyde Metabolism

By far, the biggest source of acetaldehyde exposure is alcohol. As soon as we take a sip of an alcoholic beverage, the enzymes that naturally live in our mouth and saliva instantly convert the ethanol in alcohol into acetaldehyde, a compound that is more toxic than the alcohol itself.

We have further natural enzymes called aldehyde dehydrogenase (ALDH2) that break down the toxic acetaldehyde into harmless acetic acid (i.e., vinegar) before leaving the body. This metabolic process usually takes place relatively efficiently, except in people who have ALDH2 Deficiency. An estimated 1 billion people worldwide (40% of East Asians) have genetically mutated ALDH2 enzymes that are too weak to break down acetaldehyde quickly, resulting in acetaldehyde accumulation in the body. People with ALDH2 Deficiency experience Alcohol Flush Reaction when drinking alcohol due to the rapid acetaldehyde accumulation. Symptoms of Alcohol Flush Reaction include flushing or redness of the skin, rapid heart rate, nausea, vomiting, and headache. Even though the acetaldehyde accumulation is eventually broken down into acetic acid and leaves the body, it has the potential to cause significant damage.

What are the Health Risks of Acetaldehyde?

The International Agency for Research on Cancer has categorized acetaldehyde as a Group 1 Carcinogen to humans. As a harmful compound, acetaldehyde is absorbed through respiratory and oral passages and then distributed throughout the body through metabolic tracts such as the respiratory and liver tracts. During the metabolic process, acetaldehyde acts as a reactive free radical compound and binds to proteins in the body, causing cellular and tissue damage as it travels throughout the bloodstream.

In particular, for people with ALDH2 Deficiency and cannot metabolize acetaldehyde efficiently, scientific studies show that they experience double the rate of gastrointestinal & esophageal cancer, triple the rate of liver cirrhosis, and 1.5 times the rate of Alzheimer’s disease.

How Can I Protect Myself from Acetaldehyde?

Having an understanding and awareness of acetaldehyde is a big step towards living and enjoying a healthier life. There are ways we can minimize acetaldehyde exposure in our daily lifestyle:

1. Reduce alcohol consumption, especially if you have ALDH2 Deficiency
2. Limit cigarette and cannabis smoking
3. Limit time in traffic and cities with air pollution, or areas with indoor pollutants
4. Avoid foods that are high in sugar or fermented
5. Take dietary supplements that aid in acetaldehyde metabolism and reduce acetaldehyde accumulation