This condition is known as an 'Alcohol flush reaction' and is often accompanied by symptoms such as nausea, headaches, increased heart rate, and feeling dizzy. These signs are usually associated with drinking alcohol in excess or even small quantities. Ultimately, it varies from person to person. To understand the origin of this phenomenon we first need to know what happens to our bodies when we drink alcohol. Once ingested, most of the alcohol (about 90 to 95%) is flushed out by the liver. This metabolic process is done in two stages which is put in place by two different enzymes.In the first stage, alcohol or rather ethanol is converted into acetaldehyde (ethanal) by an enzyme called alcohol dehydrogenase (ADH). The problem is that acetaldehyde is much more toxic than ethanol. Incidentally, this chemical is responsible for hangover symptoms.The second stage, it is converted into acetate or acetic acid, an inactive and harmless substance, by an enzyme called acetaldehyde dehydrogenase (ALDH). This is where the problem of redness originates. For the people who are affected by this phenomenon it’s this metabolism that is affected.After new research was carried out, it was found that the 'Alcohol flush reaction' has its origins in genetics. This is because of the presence of certain versions of gene code for the ADH enzyme. For people who suffer from this problem, alcohol dehydrogenase is converted from alcohol to acetaldehyde quicker than in non-sufferers.As the liver takes time to convert this substance to ethanal, acetaldehyde accumulates in the body. For some people this phenomenon is emphasised by the presence of another genetic mutation that affects the gene of the enzyme ALDH. The result of this is that the conversion to acetaldehyde is much slower, which makes its accumulation worse.If this accumulation causes redness, it is because of the accumulation of acetaldehyde accompanied by the release of histamine. This immune system molecule is involved in allergies and can cause vasodilation. This causes redness of the face and other parts of the body.The 'Alcohol flush reaction' is common among East Asian people. It is estimated that more than a third of people of East Asian origin could be affected. Researchers have also suggested that the genetic variants involved first appeared in central China before spreading to a large part of Asia and then around the world.This acetaldehyde metabolism malfunction makes people particularly vulnerable to the effects of alcohol. Studies have indicated that this reaction can be associated with an increased risk oesophageal cancer. However, it is also linked to a lower risk of alcoholism as people affected by this want to limit the side effects of drinking.This phenomenon is of genetic origin so there is no cure for it. Some molecules, such as antihistamines can help to reduce redness. However, drinking alcohol in moderation is the best solution. Check out the video above for more!