By Shereen Jegtvig
NEW YORK (Reuters Health) - College students who consume energy drinks tend to drink more alcohol and having both in the same day may lead to more negative consequences, a new study says.
Combining heavily caffeinated energy drinks and alcohol is a trend, especially among college students. In fact, about half of energy drink users admit to combining them with alcohol while partying.
Mixing alcohol and energy drinks is a serious public health concern when compared to drinking alcohol alone. The FDA banned the sale of premixed alcoholic energy drinks such as Four Loco, saying they're unsafe, but it's easy for college kids to just mix their own.
"We were interested in how using energy drinks affects alcohol use and alcohol-related consequences," Megan Patrick told Reuters Health by email.
Patrick is a research assistant professor at the Institute for Social Research at the University of Michigan. She is co-author of the new study, which was published in the Journal of Adolescent Health.
"We wanted to compare days college students used both energy drinks and alcohol to days they used only alcohol," Patrick said.
Specifically, the researchers wanted to learn more about the level of alcohol use, whether or not the students thought they were drunk and what consequences occurred on the days when energy drinks and alcohol were both consumed.
The researchers used information from the University Life Study that took place at Penn State University.
Starting with the first semester of college, 744 university students completed surveys for each of seven semesters, plus daily surveys. Data on alcohol and energy drink use was available from spring of the students' sophomore year (spring 2009) to fall of their senior year (fall 2010).
Students were asked about energy drink consumption with and without alcohol. They were asked the number of alcoholic drinks they drank the day before, what time they started drinking, when they stopped and if they got drunk.
The researchers also used gender, body weight and length of drinking time to calculate blood alcohol levels.
The consequences of alcohol use were determined by yes or no responses to each of 10 negative consequences, including such things as having a hangover or getting into trouble.
Just over 80 percent of students drank alcohol, and 51 percent consumed at least one energy drink during the study. Thirty percent admitted to using energy drinks and alcohol on the same day at least one time.
Men consumed a greater number of drinks but also spent more hours drinking than women. Students who consumed more energy drinks also consumed a greater number of alcoholic drinks, and had a trend toward spending more time drinking.
They also reached higher peak blood alcohol levels when they combined alcohol and energy drinks compared with days they only drank alcohol.
Students were also more likely to report getting drunk and having more negative consequences on the days they also consumed energy drinks.
The researchers also wanted to see if energy drinks were related to negative consequences independent of the amount of alcohol consumed. When they adjusted for blood alcohol levels, they found that energy drink use was no longer associated with students' feeling of being drunk, but it was still linked to a greater number of negative consequences.
"We found that college students tended to drink more heavily, become more intoxicated, and have more negative drinking consequences on days they used both energy drinks and alcohol, compared to days they only used alcohol," Patrick said.
"It's important for consumers to be aware the mixing energy drinks with alcohol, even on the same day, may lead to more serious alcohol-related consequences," Patrick said.
People who consume energy drinks and alcohol are combining the stimulant effects of caffeine and the depressant effects of alcohol, which can make them feel less drunk, when they are actually just as impaired, Patrick said
"This can have serious potential health impacts, for example if people don't realize how intoxicated they actually are and decide to drive home," she said.
The study doesn't prove that drinking caffeinated beverages causes young adults to drink more alcohol and suffer more consequences. It's possible that people who consume more energy drinks are bigger risk takers.
"It appears that the consumption of caffeinated alcoholic beverages has a direct effect on increasing risk by masking intoxication and making it easier for youth to consume more alcohol. It also appears that consumption of alcohol with caffeine may itself be a marker for youth who engage in riskier behavior," Dr. Michael Siegel told Reuters Health in an email.
Siegel is a professor in the Department of Community Health Sciences at the Boston University School of Public Health. He was not involved in the new study, but he published a similar study last month in the journal Addictive Behavior.
Siegel's team also found that drinking caffeinated alcoholic beverages was associated with a riskier drinking profile and a higher probability of negative alcohol-related consequences.
"More research is needed to help elucidate the mechanisms by which the consumption of caffeinated alcoholic beverages lead to increased risk of adverse consequences. But based on the current evidence, it seems prudent for parents to warn their teenagers about the risks of consuming alcohol mixed with caffeinated beverages," he said.
SOURCE: http://bit.ly/1e5U4iJ Journal of Adolescent Health, online December 3, 2013.