December 12, 2001. Copyright, 2000, Graphic News. All rights reserved

Hangovers: Why do we get them?

LONDON, December 12, Graphic News: HISTORY is awash with eccentric remedies to cure those who slump into a drunken stupor, waking with the Mother of all Hangovers and a body that has turned to jelly.

Pliny the ElderÕs favourite restorative back in the first century AD was a couple of fresh owl eggs. Medieval hellraisers survived on chopped eels garnished with bitter almond. Today, Americans swear by Prairie Oysters -- a raw egg mixed with tomato juice, Worcester sauce and vinegar, while the Russians resort to hair-of-the-dog: more vodka.

According to researchers, who have selflessly studied hangovers in depth, there are so many factors involved that a cure probably is unattainable; but there are a few things that can help. So, what happens when we assault our bodies with too much booze?

After you swig down your drink, the liquidÕs first stop is the stomach. As it sloshes around, some alcohol gets broken down and a small amount passes through the stomach wall, into the bloodstream and on to the brain. Here, neuropeptides, believed to control sensitivity to alcohol and mood, swing into action. Dependent on your state of mind you may begin to feel more confident, relaxed or aggressive; i.e. intoxicated.

If you donÕt have much food in your stomach, a ring-shaped muscle called the pyloric valve opens and your drink pours into the small intestine. Due to its much greater surface area, the small intestine allows alcohol to be absorbed far more rapidly, leading to sudden and powerful intoxication.

Foods containing sugars and fats tend to keep the pyloric valve closed while the stomach digests them -- hence the time-honoured idea that a glass of milk will line your stomach. A high-fat meal consumed with a bottle of wine will keep the pyloric valve shut for hours while the stomach digests the food. Your blood-alcohol level will rise relatively slowly.

The alcohol in booze is a mixture of ethanol and methanol, the wood alcohol found in antifreeze and paint thinners. Methanol is found in some fruit-based alcoholic drinks such as red wine, cognac or plum brandy, which can contain up to two percent methanol by volume. Spirits such as vodka contain least.

The liver breaks down alcohols in a strict order. First ethanol is processed at a nearly constant rate -- about 15 millilitres of ethanol per hour -- roughly the amount in a small glass of wine.

In cells called hepatocytes, enzymes convert ethanol initially into a poisonous substance called acetaldehyde, which leads to a queasy feeling and throbbing head, then into relatively harmless acetic acid. This is drained from the liver, via the kidneys, to the bladder.

Scientists at the National Laboratory of Forensic Toxicology in Linkšping, Sweden, found that when the liver gets around to clearing out the methanol, which is processed about ten times more slowly, the by-products are extremely toxic formaldehyde, (used in embalming fluid), and formic acid, which causes the most severe hangover symptoms.

The Swedish research goes some way to justify the hair-of-the-dog remedy -- a drop more booze eases a hangover by making the liver revert to the less gut-wrenching ethanol processing, stopping the build-up of formic acid. Relief is temporary, however, because methanol breakdown resumes later.

In addition free radicals, unstable compounds generated by the metabolism of alcohol, build up in the liver. Free radicals are usually mopped up by the enzyme glutathione, but after heavy drinking, reserves run low.

Glutathione is made up of cysteine, a sulphur-rich amino acid which is found in eggs. This gives a clue to the success of some age-old hangover cures, such as prairie oysters, omelettes and the English fried breakfast. So maybe Pliny knew a thing or two about the Òmorning-after.Ó TodayÕs hellraisers can buy N-acetyl-cysteine (NAC), an amino acid supplement sold in health food stores.

Elsewhere around the bodyÕs battered battleground the alcohol breaks down reserves of energy-rich blood sugar -- glycogen -- into glucose, leading to hypoglycaemia -- and the weak and wobbly effect of a hangover. 

One of the worst symptoms of the hangover is caused by dehydration. Ethanol is a diuretic. It acts on the brainÕs pituitary gland and blocks production of the hormone vasopressin, which directs the kidneys to reabsorb water that would otherwise end up in the bladder. Once this hormonal hydrostat is switched off, the line outside the restroom just gets longer and longer.

The body then suffers electrolyte loss: essential ions, sodium, potassium, calcium and magnesium -- key to the way nerves and muscles work -- are washed out of the body, causing headaches, nausea and fatigue.

Faced with drought, the body borrows water from other parts, including the brain, which shrinks temporarily. Though the brain cannot sense pain, its protective membrane, the dura, shrivels, stretching pain-sensitive filaments connecting it to the skull and causing pounding headaches. So drink plenty of water before bed.

As if this is not enough, alcohol also upsets the flow of electrolyte ions through the gamma-aminobutyric acid (GABA) receptors in the brain cells, dulling the senses and giving that ÒfoggyÓ morning-after feeling.

Why, oh why, do we do it to ourselves?
/ENDS

Sources: BMJ, BMA, GrayÕs Anatomy, Scientific American, New Scientist