Many people experience a prompt reddening on their face after few drinks of alcohol. It is called “Alcohol flush reaction” and is also known as “Asian flush syndrome” due to its greater prevalence among Asians. The reaction is often considered to be a sign of natural body protection mechanism from excessive drinking. What might seem like an unexpected natural reaction is, in fact, a sign of alcohol intolerance. An associated risk factor to many health conditions.
Alcohol tolerance vs Intolerance
Alcohol tolerance is the ability of the body to metabolize alcohol and reduce its concentration in the blood. When the body and the brain are subjected to alcohol, it activates the liver to produce large amounts of liver enzymes for the breakdown of alcohol to flush out any toxic products of alcohol out of the body.
Alcohol intolerance is the inability of the liver to break down alcohol. It is related to a genetic disorder of aldehyde dehydrogenase gene (ALDH2) that is responsible for normal functioning of the liver enzymes. Due to its absence, a toxic by-product of alcohol called acetaldehyde builds up in the blood which causes intolerance.
Acetaldehyde in the blood triggers Alcohol flush reaction. It also releases a chemical called histamine in the body that causes inflammation and aids allergic reaction.
Signs and Symptoms of high levels of blood acetaldehyde
- Redness and flushing
One of the earliest reaction of Alcohol flush involves a persistently red face (refer Fig 1) due to enlarged blood vessels. This may also be seen on the chest and neck region.
Acetaldehyde increases palpitation which is a sensation within the chest that brings awareness of an irregular or racing heartbeats.
- Increased heart rate
An increase in heart rate is seen with increased levels of acetaldehyde. It causes the blood vessels to dilate, making the heart pump harder and faster for the blood to flow through relaxed blood vessels.
- Low blood pressure
Blood pressure is the pressure of blood in the circulatory system. Due to the alcohol reaction, the heart beats faster pumping out less volume of blood and dropping the blood pressure. One may feel light headed and dizzy which can get severe.
- Extreme drowsiness and headaches
The direct cause is unknown, however, it is believed that due to the expansion of the blood vessels in the brain, histamine release and low blood pressure one may get extreme drowsiness and headaches.
- Pruritus (Itching)
This is an unpleasant sensation that provokes the desire to itch or scratch. This happens due to irritated nerve endings on the skin caused by histamine released by the acetaldehyde levels in the blood.
A feeling of vomiting starts as the acetaldehyde levels in the body irritate the stomach lining, leading to inflammation (gastritis).
- Alcohol-induced asthma
Increased levels of acetaldehyde and histamine release in the body can trigger breathlessness due to constriction of the airway. It is often reported to appear after approximately 30 minutes post-alcohol consumption.
Risk Factors associated with people who get Alcohol Flush Reaction
- Esophageal Cancer
Acetaldehyde in the blood is known to interfere with the DNA synthesis and repair mechanism and increases the risk of cancer by producing free radicals that are known to destroy healthy cells.
- Alzheimer’s disease:
Alzheimer’s disease is a neurological disorder in which the death of brain cells causes memory loss and affects brain function. Research has claimed that genetic disorder related to the aldehyde enzyme also interact with the brain cells which are believed to be a risk factor of Alzheimer’s disease.
- Heart disease
Continual drinking of alcohol among people with Alcohol flush reaction will affect the functioning of the heart and may lead to the risk of heart problems.
- Liver disease
Acetaldehyde causes oxygen deficits in the liver (hypoxia), including formation of harmful compounds that damage the cells of the liver leading to a liver disease.
Are you sensitive to alcohol or is it something else?
If you are only experiencing this reaction with specific alcohol beverages. This may suggest that it is not alcohol intolerance but could be due to other ingredients involved that triggered the reaction.
What can be done about the Alcohol flush reaction?
There is medication available to help with the flush. However, these drugs can only curb the redness but will not be able to break down the acetaldehyde levels in the body. Thus, individuals who drink often and use drugs to suppress the flushing will still be at risk of developing a health problems.
The best way to prevent alcohol flush reaction and minimise health issues is by not drinking alcohol at all. This may however be an unrealistic solution to many especially during social events.
There are few things one could consider that may help reduce the alcohol flush reaction:
- Eating before alcohol consumption.
- Having drinks with lower alcohol content.
- Alternate alcoholic drinks with water or non-alcoholic drinks.
Like all things, always consume alcohol in moderation. Alcohol is a depressant, but it’s also an indirect stimulant. Never drink and drive. Medication can help mask the reaction but if you feel that it’s more than just a flush, always seek immediate medical attention.