Going to work or school with a bad hangover is a painful experience. And new research suggests that alcohol may affect your cognitive performance long after it has left your system.
In a new analysis, researchers at the University of Bath in the UK analyzed previous studies on people who had a blood alcohol content of zero or close to zero after a night of heavy drinking. They found that during a hangover, people still showed impairments in attention, short- and long-term memory, coordination, and reaction time.
"These results have quite significant implications for things like workplace performance or activities like driving," Sally Adams, the senior author of the study and assistant professor at the University of Bath, told BuzzFeed News. "You might still be impaired even after most of the alcohol has left your system."
Alcohol acts as a depressant on the brain and nervous system. It can cause slurred speech, impaired concentration, and poor coordination — aka being drunk.
Typically, alcohol is completely out of your system by about 12 hours after your last drink, Adams said. But hangover symptoms, such as fatigue and headaches, peak when your alcohol level reaches zero, and can continue for up to 24 hours, according to the National Institute on Alcohol Abuse and Alcoholism.
The new research suggests that one night of heavy drinking may continue to impair your brain function for a day or more.
One possible reason for this is the way our body metabolizes booze, Adams says, which involves enzymes breaking down the alcohol into toxic byproducts. "One of these metabolites is called acetaldehyde, and some neurological studies have shown early indications that acetaldehyde might mimic the effects of alcohol on the brain and subsequent cognition," Adams said.
Another reason is that drinking impacts sleep quality, said Adams. So even after passing out for eight hours you may still feel fatigued and sleep-deprived the next day. Alcohol can also lead to dehydration, tissue inflammation, and stomach irritation — producing distracting symptoms like a headache or nausea.
"You get the double whammy of malaise from a toxic event and the effects of an acute mini withdrawal that comes from even one night of drinking," Aaron White, senior scientific adviser to the director of the NIAAA, told BuzzFeed News. "These two things make it hard to concentrate and execute fine motor skills."
"Alcohol can increase the likelihood of deleterious outcomes even when there's no alcohol left in your body," White said. "There's a plethora of evidence that we remain cognitively impaired during hangovers."
The economic impact of alcohol is also well known, Adams noted, and hangovers can cost billions of dollars in lost productivity because workers don't show up or can't perform their duties after a night of drinking.
The new research suggests that skipping work after a night of heavy drinking may not be the worst idea — especially if your job requires you to drive, operate machinery, perform surgery, or concentrate for a long period of time.
"The results suggest we might still be impaired in key cognitive processes required to be productive but also to be safe during activities like driving," Adams said.
Unfortunately, there is no magical cure for hangovers. Once it hits, you pretty much just have to wait it out and manage the symptoms. "You are really recovering from a toxic event," White said.
Last week, a study published in the Lancet found that there is "no safe level" of alcohol consumption. (Though some critics have noted that the risk of harm for light and moderate drinking is very small.)
The only way to completely avoid a hangover is to not drink any alcohol. If you are drinking, you may be able to reduce the severity of symptoms the next day by keeping it in moderation, eating first, and drinking lots of water.
In the meantime, maybe think twice about going out to drink if you have to do something that requires a lot of brainpower the next morning.