What is Alcohol Intolerance?

By Christian Small, Medical Director, Ken Seeley Communities

Alcohol intolerance is a genetic condition by which the body lacks a particular enzyme, causing unpleasant symptoms to emerge when ingesting alcohol. People sometimes confuse alcohol intolerance with an alcohol allergy, but these are two different conditions.

Alcohol intolerance is caused by an enzyme that is not present in biology, where an alcohol allergy refers to something in the beverage itself that your body has a reaction to. This can be compared to a food allergy, such as how some people break out in hives if they consume peanuts.

It is important to learn about alcohol intolerance, as it may help explain a mysterious health quandary that you might be experiencing. Read on to learn more about alcohol intolerance.

About Alcohol Intolerance

Alcohol intolerance is a metabolic disorder, passed on through genetics. People with alcohol intolerance are lacking the aldehyde dehydrogenase 2 enzyme (ALDH2). When someone with this genetic predisposition consumes alcohol, they will exhibit uncomfortable and even painful symptoms. 

This reaction happens because the missing enzyme is not present to help metabolize the ethanol in the system. Without the ALDH2, the body cannot convert acetaldehyde to acetic acid. 

Even a small amount of alcohol can trigger the symptoms. Because the condition is genetic, there is no known cure. To avoid the painful symptoms, the person should avoid alcohol.

Symptoms of Alcohol Intolerance

When someone who is lacking the ALDH2 enzyme ingests alcohol, a cluster of symptoms can result. These include:

• Facial flushing
• Hives
• Diarrhea
• Headache
• Nausea and vomiting
• Fatigue
• Worsening asthma symptoms
• Rapid heartbeat, palpitations
• Nasal congestion
• Hot flashes
• Coughing
• Chest pain
• Fainting
• Low blood pressure
• Swelling of lips or tongue
• Hypertension

Again, alcohol tolerance symptoms are not due to the ingredients in the liquor itself. It is caused by a metabolic problem.

What is Alcohol Flush Syndrome?

The most common symptom of alcohol intolerance is something called alcohol flush syndrome. Immediately after someone with alcohol intolerance takes a drink, they experience flushing of the face, neck, and chest. Their skin becomes warm and reddish. This is a telltale sign that the body is having trouble metabolizing the alcohol in the body.

So, What is Alcohol Allergy?

An alcohol allergy involves a reaction that occurs when someone drinks who is sensitive to a certain ingredient in the spirits, beer, or wine. They may have a typical allergy reaction, such as rash, stomach cramps, and nausea. People are not allergic to the alcohol itself, but to an additive or a grain within the beverage. Some of these ingredients might include:

• Wheat, barley, hops, or rye
• Sulfates
• Yeast
• Histamines
• Traces of eggs or seafood proteins

Someone with an allergy to alcoholic beverages would need to identify what the problem ingredient is and then avoid drinks that contain it. For example, if someone has an allergy to gluten, they would need to avoid most beers, which contain barley, a grain that contains gluten.

Alcohol Intolerance and Alcoholism

It is possible for someone with alcohol intolerance to still acquire an alcohol use disorder (AUD). They may have ignored the signs of intolerance and continued to drink heavily, which resulted in an AUD. When this is the case, the individual will likely have some health issues related to the intolerance, as well as the AUD.

Alcohol use disorder is a broad category that includes mild, moderate, or severe alcohol abuse and addiction. The severity of the AUD depends on how many symptoms are present, and how extensive the history of excessive alcohol consumption is. 

A list of signs and symptoms of AUD include:

• Increased tolerance causes you to consume higher levels of alcohol to get prior effects
• Preoccupied about having alcohol available, looking forward to drinking, seeking excuses to drink
• You drink in response to stress or negative emotions
• You experience blackouts
• You neglect responsibilities
• You lie about how much you drink and hide alcohol around the house
• Isolating oneself from friends and family so you can drink
• Experiencing problems at work, diminished work performance, loss of a job
• Legal problems, such as DUI
• Your drinking is negatively impacting relationships
• Experience alcohol craving
• Want to stop drinking but cannot
• Experience withdrawal symptoms when effects of alcohol wear off

Breaking Free From an AUD

Alcoholism is a progressive disease that can have fatal results. If you have alcohol intolerance, your body is probably already showing signs of distress due to the effects of the absent enzyme. Continuing to drink with alcohol intolerance can result in cancer of the mouth and throat, liver disease, or Alzheimer’s disease.

When someone with the signs of alcoholism decides to enter treatment, they will begin the process of recovery that involves different phases. These include:

DETOX. Treatment begins with completing the detox and withdrawal process, where the body eliminates the remnants of the alcohol toxins. As this occurs, the person will experience three stages of detox:

1. Emerging symptoms. Early symptoms during the first 24 hours of detox include nausea or vomiting, sweating, irritability, shaking or trembling, increased heart rate.
2. Peak symptoms. Days 2-4 will see the withdrawal symptoms peak, including restlessness, agitation, insomnia, increased nausea, cold sweats, high blood pressure, hallucinations, fuzzy thinking, and possibly seizures. This is the phase of withdrawal when delirium tremens can occur for about 5% of individuals in alcohol detox.
3. Subsiding symptoms. Days 5-7 are when withdrawal symptoms begin to lessen in severity and gradually subside. In more severe AUD there may be lingering psychological effects, such as anxiety or depression, fatigue, and insomnia for a few weeks after detox.

The provider will intervene with medications as needed throughout the detox process. Most alcohol detoxes are completed within one week.

THERAPY. The treatment phase of recovery involves the individual participating in various types of therapy and experiential activities. These help the person to make needed changes in the way they think and react when experiencing cravings or triggers. These therapies include:

• One-on-one talk therapy
• Group therapy
• Family therapy
• 12-step group
• Addiction education
• Life skills training
• Holistic activities

If you have alcohol intolerance and have developed an AUD, there is help for you. Do not hesitate to seek out the treatment you need to begin a new healthy life in recovery.

About the Author

Dr. Christian Small is board certified in psychiatry, addiction medicine, and family medicine. Dr. Small has received his medical degrees at the University of Hawaii and completed his medical residency in Psychiatry and Family Medicine at UCSD. He is currently the Medical Director at Ken Seeley Communities, a full spectrum addiction recovery program located in Palm Springs, California.