Forget the hair of the dog or a greasy fry-up, a coffee-and-aspirin combo has been scientifically proven to be the best cure for a hangover.
Researchers at the Thomas Jefferson University in Philadelphia set out to discover exactly what causes a hangover and the best way to deal with it.
In the body, alcohol is metabolised to acetaldehyde, and then acetate and "the dogma has always been that acetaldehyde causes the headache because it's poisonous," researcher Dr Michael L Oshinsky told MNSBC.
"But there's been no direct evidence to demonstrate that."
In the study, lab rats that were prone to having migraines were given a small amount of ethanol, the equivalent of one shot of alcohol for humans, as low doses of alcohol are known to bring on migraines in sufferers, New Scientist reported.
The researchers then analysed different steps of the alcohol-metabolism process to see which was the cause of the morning-after headache.
They found that the rats remained headache-free until they were given acetate the final step in the breakdown of alcohol in the body. The researchers used sensory tests to determine if the rats had a headache.
"Sure enough, they got a headache," Dr Oshinsky told MNSBC. "Then we gave them a higher dose and they got more of [a] headache for a longer amount of time."
Dr Oshinsky said the research disproves commonly held belief that hangovers were caused by dehydration or cogeners.
Once the source of the headache was discovered, Dr Oshinky and his colleagues set about finding a cure. And what they discovered was the combination of caffeine and over-the-counter inflammatory drugs (such as aspirin and ibuprofen) were best at blocking the effects of the acetate. But you have to act quickly.
"If you drink a small amount of alcohol, three or four hours later, drink some coffee," he said. "Or take caffeine in some form, like an Excedrin that has caffeine in it. If you take the caffeine at the same time as you drink, it will be gone when the acetate levels are high."
The study was published in the online journal, PLoS One .
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