A cup of coffee has been thought to ‘sober you up’ after a couple drinks, but an ongoing study proves otherwise.

A study in December’s issue of Behavioral Neuroscience, published by the American Psychological Association, revealed that a combination of alcohol and caffeine tested in mice did not prevent decision-making problems associated with alcohol consumption, though it did make animals more alert and less anxious.

Thomas Gould, author of the study and associate professor of psychology at Temple University, and his former colleague Danielle Gulick of Dartmouth College measured the behavior of groups of young mice that were given doses of only alcohol, doses of only caffeine, none of either substance or doses of both alcohol and caffeine.

‘It is well known that alcohol will produce cognitive decline, and we wanted to physically test if caffeine would reduce alcohol-induced learning deficits,’ Gould said.

Although the human brain is more complex than a mouse’s brain, mice metabolize alcohol in a similar fashion to humans, he said.

Gould and his fellow researchers concluded that when humans combine alcohol and caffeine they are prone to drinking more or putting themselves in a dangerous situation. The mixture makes them more alert and confident in their actions and decreases their awareness of how intoxicated they really are, Gould said.

‘The combination affects the prefrontal cortex of the brain, or the area that is involved in decision making. People aren’t as sedated so they are able to stay out later and drink more. This can lead to hostile decisions,’ he said.

The mice were given alcohol doses equivalent to a blood alcohol content, or a measurement of the concentration of alcohol in a person’s blood, in the range of 0.05 and 0.09. Caffeine doses ranged from the equivalent of one cup of coffee to six to eight cups, Gould said. The animals were then placed in a maze that they had never been through before. The maze was fashioned with areas of bright lights or sudden sounds to disorientate the rats.

The mice that received doses both of alcohol and caffeine continued to display impaired judgment similar to the behavior of the mice that were given doses of only alcohol, Gould said.

Although the mice given both substances appeared more relaxed and moved around the maze with greater ease, their ability to learn which areas of the maze to avoid was still impaired, Gould said.

‘Mice naturally don’t like loud noise or bright lights, but the animals that were drunk with caffeine would keep returning to those dangerous environments,’ Gould said. While students may think drinking coffee will cure a hangover, that is not true either, he said.

‘Caffeine may nap some symptoms of a hangover. For some individuals, it can help with a headache, but it is not going to make the hangover go away. A hangover is really due to clearing the toxins out of the system and drinking coffee will not aid in that process,’ Gould said.

Caffeine and alcohol both dehydrate the body, so someone will experience worse symptoms if they drink coffee because a hangover results from dehydration, said Aesoon Park, an assistant professor of psychology at Syracuse University.

Gould cited another study that preceded his that also explored the dangerous effects associated with consuming mixtures of caffeine and alcohol. The study, published in 2008 by the Wake Forest University School of Medicine, was based off responses to an Internet survey from a sample group of college students from 10 universities in North Carolina.

The students who had reported drinking alcohol mixed with an energy drink in the last 30 days had higher episodes of ‘alcohol-related consequences including being taken advantage of sexually, taking advantage of another sexually, riding with an intoxicated driver, being physically hurt or injured, and requiring medical attention,’ according to the study.

‘It may sound surprising to the college student who believes that consuming caffeine will allow them to drink more and have an all-nighter, but drinking caffeine does not affect the way our bodies metabolize alcohol,’ Park said.

Kate Carey, an SU psychology professor who studies the prevention and treatment of alcohol-use disorders, explained that the term ‘drunk’ can be interpreted in two ways: how impaired you feel and your blood alcohol content level.

Caffeine wears off quicker than alcohol does and it will only make you more alert for a short period of time, Carey said.

‘If I’m feeling alert even though my BAC is over .08, I may feel that it’s perfectly safe to drive home or have another couple rounds,’ she said. ‘You will continue to build your BAC, so the intoxication may hit you real fast as the caffeine is wearing off.’

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Published on December 18, 2009 at 12:00 pm