Article written by Charles P. Vega, MD, Brande Nicole Martin, Fran Lowry, and Laurie E. Scudder, DNP, NP
Consumption of highly caffeinated energy drinks may be associated with risks of heavy drinking and alcohol dependence, new research suggests.
These heavily caffeinated drinks are increasingly popular with college students, who use them to help stay awake at night while they cram for exams, said Amelia M. Arria, PhD, director of the Center on Young Adult Health and Development at the University of Maryland School of Public Health in College Park.
Also growing in popularity is the trend of using energy drinks together with alcohol.
"These drinks are being heavily marketed to youngsters. You can tell by the colorful packaging and type of ads that are on TV. But we don't know yet if there are possible adverse effects from caffeine intoxication or from the high caloric content from sugars in these drinks. And using them together with alcohol may be a very dangerous mix," she said in an interview with Medscape Medical News.
The study is published online November 12 in Alcoholism: Clinical & Experimental Research.
Prompted by prior research that highlighted the dangers of combining energy drinks with alcohol, Dr. Arria and colleagues investigated the extent to which energy drink use might pose additional risk for alcohol dependence over and above that from known risk factors.
They collected data from personal interviews with 1,097 fourth-year college students (46% male, 73% white, aged 20 – 23 years) from a large public university and measured alcohol dependence according to Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) criteria.
They found that 51.3% of the students were "low frequency" energy drink users, who drank from 1 to 51 days in the past year, and 10.1% were "high-frequency" users, who drank more than 52 days. They also found that high-frequency users drank alcohol more frequently (141.6 vs 103.1 days) and in higher quantities (6.15 vs 4.64 drinks per typical drinking day) than low-frequency energy drink users.
Red Bull was the most popular of the energy drinks, consumed by 82% of the users.
The study found that high-frequency energy drink users were at a significantly greater risk for alcohol dependence compared with nonusers (adjusted odds ratio [AOR], 2.40; 95% confidence interval [CI], 1.27 – 4.56; P = .007) and with low-frequency users (AOR, 1.86; 95% CI, 1.10 – 3.14; P = .020).
The association held after adjusting for race, socioeconomic status, depressive symptoms, parental history of alcohol or drug problems, and childhood conduct problems.
The investigators also found that low-frequency energy drink users did not differ from nonusers on their risk for alcohol dependence.
The study is an associational study and not a prospective one and therefore cannot attribute energy drink consumption as a cause of alcohol dependence, Dr. Arria said.
"But it does not close out the possibility that there is some causal association that we need to look into further. Energy drinks could make alcohol more reinforcing, so that you drink more, and then you have more problems, and then you have more craving for alcohol.
"There are a lot of mechanisms between the use of energy drinks and the possibility of alcohol dependence, and we're not completely clear of those mechanisms yet. That's another study. We are trying to get federal funding to do the prospective analyses to see whether or not the frequent consumption of energy drinks comes beforehand."
The results of the study also give clinicians one more thing to be vigilant about with their teen and young adult patients.
"It's important for clinicians to recognize that energy drinks are now part of a mix of substances that are routinely consumed by adolescent and young adult populations, so they should have a greater awareness and vigilance that these drinks may be contributing to some symptoms, such as palpitations and anxiety, that they may be seeing in this age group," she said.
Important Questions Remain
Weighing in with his opinion, Itai Danovitch, MD, director of the Addiction Psychiatry Clinical Service at Cedars-Sinai Medical Center in Los Angeles, California, said that the study "shows very nicely that there is an association between caffeine consumption in the context of energy drinks and alcohol dependence" mostly in a cohort of white college seniors.
"What it doesn't reveal is an answer to the question, 'Is there a causal relationship?' Does exposure to energy drinks and to caffeine increase the risk of alcohol dependence? Or is this due to a common set of risk factors which might drive people to experiment and use more energy drinks and binge?" Dr. Danovitch said.
Another limitation of the study is that it does not differentiate between use of energy drinks by themselves and the use of energy drinks used as mixers with alcohol.
"There's a trend now for kids to use energy drinks as the mixer with alcohol. They have vodkas and Red Bulls. And if that's the context in which kids who drink a lot are also consuming a lot of energy drinks, then there's a bit of a confound," he said.
"The caffeine counteracts the sedating effects of the alcohol so you can stay up longer and drink harder. If you know that you are going to binge and you don't want to be out by 10:30 pm, then it makes sense to mix with a caffeinated beverage. That's a really important thing to sort out."
Dr. Danovitch agrees that more studies are needed to clarify the association and develop more evidence of causality between the two.
He added that more research is needed on the health effects of high-dose caffeine exposure on young people.
"We know that youth have different vulnerabilities than adults and that studies of exposure to medication in adults do not always apply to kids whose brains aren't mature. So we need to know, given that kids are now getting exposed to doses of hundreds of milligrams of caffeine in coffee and energy drinks, if that has any deleterious effects."
Finally, people who consume energy drinks and alcohol together need to be aware of the risks.
"Particularly if caffeine exposure allows people to continue to be drunk while having lost their subjective perception of being intoxicated and increase their bad judgment and risky behavior, then they need to be aware of that. Proper labeling and education about risks is really key," Dr. Danovitch said.