What causes a hangover?
The worst hangovers are caused by sparkling wine and other carbonated alcoholic drinks. Carbon dioxide speeds up the absorption of alcohol, which makes blood alcohol levels rise quickly. A high blood alcohol concentration is a strong predictor of a severe hangover. But what exactly causes a hangover, and how does genetics influence how we experience it?
A hangover is caused by the by-products of alcohol metabolism
Nausea, headache, rapid heartbeat, sweating, trembling, insomnia, overall malaise, hangover symptoms are numerous. Some of them may be explained by poor sleep quality, but most are caused by alcohol itself. The main culprit is ethanol, the type of alcohol in drinks, which is broken down into acetaldehyde. Smoking also produces acetaldehyde, which means that smoking can make hangover symptoms even worse.
So, is there an effective treatment for acetaldehyde? In Finland, L-cysteine has been studied as a potential hangover remedy. L-cysteine is an essential amino acid obtained from food and also produced by the body itself. It binds to acetaldehyde, preventing it from causing hangover symptoms. However, this amino acid does not speed up the breakdown of alcohol itself—the relief of symptoms is based specifically on neutralizing acetaldehyde.
(Alkoholivieroitusoireyhtymä [“hangover”]. Duodecim Terveyskirjasto. 2018)
(L-Cysteine Containing Vitamin Supplement Which Prevents or Alleviates Alcohol-related Hangover Symptoms: Nausea, Headache, Stress and Anxiety. Alcohol and Alcoholism, Volume 55, Issue 6, November 2020, Pages 660–666.)
5 hangover symptoms that make exercise better left for the next day
Under normal circumstances, it is recommended to follow physical activity guidelines and exercise daily. But exercising while hungover is not advisable. During a hangover, heart rate and blood pressure are higher than normal, and both fluid balance and metabolism have fluctuated drastically due to drinking. Blood sugar levels are low, and the liver’s energy reserves have been depleted in the process of metabolizing alcohol. With such low energy availability, exercise can even lead to fainting. Fatigue and depleted glycogen stores in the liver also impair coordination, concentration, and judgment. As can be seen, a severe hangover throws the body completely off balance and recovery takes time. Light exercise may be safe during a hangover, but high-intensity or strenuous physical activity should be postponed until the following days.
(Alcohol and exercise. Duodecim Terveyskirjasto. 2018.)
The hangover gene partly determines how bad it feels
The metabolism of alcohol, meaning its breakdown into a form that can be excreted, is controlled by the ALDH2 gene. Two out of the three possible variants of this gene lead to a functionally defective version, in which alcohol is not broken down normally. Dysfunction in this gene is visible when drinking as redness in the face and neck. Afterwards, the result is an especially severe hangover that may even lead to a dangerous condition. These gene variants are most common in people of Asian descent, although they can occur in other populations as well.
(SNPedia)