FRIDAY, Nov. 19, 2004 (HealthDayNews) -- It's no secret a night of heavy drinking can leave you with a parched mouth, a ferocious headache and an unsteady stomach the next morning.
But it can also make it tough to learn new information or recall things you already know, a new study says.
Researchers from Northern Ireland say they've shown that hangovers contribute to memory problems and delayed reaction time, even many hours after last call.
The findings may sound obvious, and indeed they "confirm what a lot of people observe about how they function after a night out drinking," said Dr. Robert Cloninger, a professor of psychiatry at Washington University Medical School who studies the effects of alcohol.
What's different about the new findings is that the bodies of most of the study participants had processed all the booze from the night before. Even after their blood-alcohol levels had returned to zero, they still had trouble with basic tasks.
"That's significant because it suggests that if you went out drinking and allowed enough time so that your blood-alcohol concentration was at zero by the time you went to class the next day, you could still have difficulty learning new information," said alcohol researcher Aaron White, an assistant research professor of psychology at Duke University. "These findings suggest that alcohol can affect your ability to learn long after the effects of the drug have worn off."
The researchers enlisted 33 women and 15 men, all "social drinkers," to take part in their study. The subjects underwent memory and coordination testing the mornings after either abstaining or drinking their usual amount of alcohol between 10 p.m. and 2 a.m.
The participants were hardly light drinkers. The women, on average, drank 10.6 "units" per evening when they were allowed to drink; the average for men was 10.5. A "unit" was defined as a glass of wine, a half-pint of beer or a "measure" of liquor.
The findings appear in the November/December issue of Alcohol and Alcoholism.
The morning after drinking, the subjects performed worse on some tests of memory and reaction time than those who didn't drink, although being hung over didn't hurt the performance of the drinkers in all the tests.
As expected, the drinkers didn't feel great, either.
"Participants reported hangover effects as measured in terms of fatigue, physical discomfort and emotional disturbance," said study co-author Adele McKinney, a research assistant at the University of Ulster.
The study didn't speculate about how hangovers contribute to lower performance on mental tasks. However, Duke University's White said hangovers have a lot to do with the fact that alcohol simply isn't good for the body.
"People feel sick the next day primarily because they've poisoned their bodies the night before with alcohol," White said. "It's a poison, and it just so happens to be a poison that gives us a nice buzz. But you pay for it. The body must devote energy to processing and removing it."
Even when no alcohol is left in the body, people are still plagued by aftereffects such as fatigue, nausea and dehydration, he said. "All of that is going to make it harder for you to pay attention, to feel like learning and stay awake," he added. "Those things are going to impair your function."
What to do? Of course, you could decide not to drink or at least not drink too much. Downing a glass of water or another non-alcoholic beverage between drinks will slow drunkenness and combat dehydration, White suggested.
But if you do drink too much, the best thing to do the next morning is to take an aspirin, White said. And simply wait for time to pass.
For more about alcohol abuse, visit the National Institute on Alcohol Abuse and Alcoholism.