Under the Microscope: A Texan walked into an Irish bar. "I hear you Irish are a bunch of drinking idiots. Here's a challenge. I will give any man $500 who can drink 10 pints back to back without pause," he said.
His challenge met with an embarrassed silence and one man even left. The Texan ordered a drink for himself and sat cogitating. Thirty minutes later, the man who had left returned and asked the Texan if the challenge still stood. "Yes," answered the Texan. "Well, I'll take it up," said the man.
The barman lined up 10 pints on the bar. The man drank the pints off one by one without a pause. The Texan was amazed and handed over the $500. "By the way," the Texan asked the man, "where did you go earlier when you left the bar for 30 minutes?" "I went to the bar down the street to see if I could do it," he answered.
Most of us have experienced a hangover at some stage, and after drinking far less than the man in the story. Hangovers are unpleasant, but, despite their common occurrence, relatively little is known about their underlying causes and there is no generally accepted cure for the hangover. Indeed, ethical objections could be raised against research into a cure on the basis that it would encourage even greater intemperance.
A cluster of unpleasant physical and mental symptoms constitute the hangover that occurs after a heavy alcohol (ethanol) drinking session. The physical symptoms include headache, fatigue, high sensitivity to light and sound, aching muscles, thirst and redness of the eyes. Blood pressure and heartbeat may be raised, accompanied by sweating. Mental symptoms include depression, anxiety and irritability. Dizziness and vertigo may occur.
A hangover typically begins within several hours after the cessation of drinking. The symptoms peak when blood alcohol concentration declines to zero and they may continue up to 24 hours thereafter.
Several causes have been proposed to explain hangover symptoms. These include the direct effects of alcohol on the brain and other organs; the later effects of alcohol removal from these organs; the effects of compounds produced by the body's metabolism of alcohol; non-alcoholic factors such as toxic effects of other chemicals in the drink; use of other drugs; restricted food intake; disruption of normal sleep; and certain personal characteristics (e.g. personality).
Ingestion of alcohol affects hormonal balance causing increased urinary output. Consumption of about four standard drinks causes the elimination of 0.6 to one litre of water over several hours. Resulting dehydration causes thirst, dizziness and light-headedness. Alcohol irritates the stomach and intestines and delays stomach emptying. This can cause abdominal pain, nausea and vomiting.
The sedative effects of alcohol promote onset of sleep but disturb overall sleep pattern. Alcohol-induced sleep is usually of shorter duration and poorer quality. Alcohol decreases dreaming and increases the time spent in deep sleep. Alcohol relaxes the throat muscles and induces snoring.
Alcohol is metabolised in two steps by the liver. First, the enzyme alcohol dehydrogenase converts alcohol into acetaldehyde. Then another enzyme, aldehyde dehydrogenase (ALDH) transforms acetaldehyde to acetic acid. At higher concentrations, acetaldehyde causes toxic effects such as rapid pulse, sweating, nausea and vomiting. In most people, ALDH quickly removes acetaldehyde. However, acetaldehyde accumulates in some people with a genetic variation of the ALDH enzyme and such people sweat profusely and become ill after drinking small amounts of alcohol. Antabuse is the trade name for a chemical used to treat alcoholics. It inhibits ALDH resulting in very unpleasant symptoms if alcohol is consumed.
Factors besides alcohol may also contribute to hangover. Most alcoholic drinks contain small amounts of chemicals in addition to ethanol. These compounds are known as congeners and contribute to the taste, smell and appearance of the drinks.
The only sure way to avoid a hangover is to avoid ethanol. However, if a person drinks only small non-intoxicating amounts hangover effects are quite unlikely. In general the less alcohol drunk, even when drinking to intoxication, the less severe are the hangover symptoms.
There are many folk-remedies for ameliorating hangover symptoms or for entirely curing the hangover. However, very few such treatments have been rigorously tested. The consumption of fruits or other fructose containing foods is reported to decrease hangover intensity. Also, taking non-alcoholic drinks during and after alcohol consumption may reduce alcohol-induced dehydration.
Certain medications may relieve hangover symptoms. Antacids may alleviate nausea and aspirin may reduce headaches and muscle aches but these remedies should be used sparingly. Coffee is often used to relieve the fatigue and malaise of hangover.
Some people believe that taking a drink of alcohol - "hair of the dog that bit you" - greatly alleviates hangover symptoms, but it is best to avoid further alcohol use. Additional drinking enhances the existing toxicity of the alcohol already consumed.
* William Reville is associate professor of biochemistry and director of microscopy at UCC.