Alcohol Intolerance and Allergies: When Alcohol Is Toxic to the Body

Although most people can drink a moderate amount of alcohol without suffering serious physical effects, some people’s bodies are intolerant — or, more rarely, allergic — to alcohol. The reactions that can accompany alcohol intolerance and allergy run from fairly mild to life-threatening.

Individuals who have never consumed alcohol before may be unaware that they are intolerant of or allergic to alcohol. Those who already drink may believe their symptoms are the result of “normal” hangovers. However, alcohol intolerance and allergy are the result of the body’s impaired ability or inability to properly metabolize alcohol, which renders alcohol highly toxic to the body.

Allergic to Alcohol

True alcohol allergies are rare, but serious. When there is a true allergy to alcohol, the body produces the antibody Immunoglobulin E (or IgE).

The symptoms of an actual alcohol allergy are the same as those associated with other food allergies:

• Tingling in the mouth
• Swelling of the lips, tongue or throat
• Hives
• Difficulty breathing

True alcohol allergies are dangerous because less than an ounce of alcohol can send a person into anaphylactic shock. Anaphylactic shock, or anaphylaxis, is the same life-threatening reaction associated with severe allergies such as peanut allergies and allergies to bee stings. A person with anaphylactic shock will experience abrupt and severe life-threatening symptoms that require immediate medical attention:

• Swelling or spasm of the airways
• Difficulty breathing or inability to breath
• Loss of consciousness due to dangerously low blood pressure (also known as shock)
• Cardiac arrest

Alcohol Intolerance

Alcohol intolerance or sensitivity is much more common than true alcohol allergy. Symptoms of alcohol intolerance include flushing of the skin, increased heart rate and reduced blood pressure.

All individuals who are intolerant of or sensitive to the effects of alcohol are deficient in a particular enzyme known as Aldehyde Dehydrogenase (ALDH). ALDH is an enzyme normally found in the liver which allows the body to metabolize alcohol into acetic acid (vinegar).

Although the bodily readily absorbs alcohol from the gastrointestinal tract, alcohol is a toxic compound and cannot be stored in the body. Because of this, the body needs to oxidize it in order to get rid of it. When ALDH is inadequate, inactive or missing, the body has a much harder time ridding itself of the toxin.

Histamine

The consumption of alcohol supplies histamine to the body and may aid in the release of additional histamine by the body. Histamine is the chemical that triggers allergic reactions. Alcohol also prevents histamine from being broken down by the body, which can prolong allergic reactions.

In the case of alcohol intolerance or sensitivity to alcohol, elevated levels of histamine usually lead to common allergy symptoms such as nasal congestion and mild flushing of the skin, both of which can occur within minutes of ingesting alcohol. Other side effects may include the following:

• Heart palpitations
• Sensation of heat
• Headache
• Abdominal discomfort
• Drop in blood pressure