Four Loko, one of 2010’s most popular alcoholic energy drinks may be without caffeine now, but people can still make vodka Red Bull, Jager bombs (Jagermeister and Red bull), and Crunk Juice (cognac and Red Bull), among other things. In a recent editorial in BMJ, Peter Miller, a professor of psychology, writes that research into the health effects of these drinks hasn’t done enough to consider the “real world levels of consumption,” and that the effects could be downplayed because of industry-funded studies.

Are Energy Drink Companies Downplaying Health Effects?

“Epidemiological studies show that drinkers who consume energy drinks are more likely to record a higher breath alcohol concentration than those who do not,” Miller wrote in the article. “They are also more likely to report drinking more alcohol, engaging in aggressive acts, being injured; symptoms of alcohol dependence; having driven while drunk or been a passenger in a car with an alcohol impaired driver; and having taken sexual advantage of, or having been taken advantage of by another person.”

Energy drinks, alone, have been shown to disturb heart rhythm and increase blood pressure. When consumed with alcohol, it’s believed that drinkers are less likely to feel drunk, and therefore, they will continue to drink. However, most studies on the subject focus more on the aftereffects and less on the actual effects on the person as they drink.

One 2011 study asked participants, who were split into four groups — energy drink, energy/alcohol drink, alcohol drink, and placebo drink — to rate how they felt with regards to stimulation, sedation, impairment, and levels of intoxication, found that energy drinks altered the participants’ reactions to the alcohol, when compared to those who had only alcohol. The participants were also measured on how quickly they were able to suppress and execute actions after drinking.

“A consumer of alcohol, with or without the energy drink, acts impulsively compared to when they had not consumed alcohol,” Cecile Marczinski, assistant professor of psychology at Northern Kentucky University and author of the study said in a statement. “However, the consumer of the alcohol/energy drink felt more stimulated compared to an alcohol-alone consumer. Therefore, consumption of an energy drink combined with alcohol sets up a risky scenario for the drinker due to this enhanced feeling of stimulation and high impulsivity levels.”

Marczinski’s study, however, is one of the few that concludes that alcohol and energy drinks are a dangerous combination. Many researchers who have researched the health effects of alcoholic energy drinks were funded by energy drink makers, such as Red Bull, Miller says. And when they report at conferences, they aren’t always required to disclose conflicts of interest, leading to a biased report.

At the 2012 Australian Professional Society on Alcohol and Drugs Conference, four of the five researchers that reported on the correlation between alcohol and energy drinks said there was no evidence to suggest that both drinks together caused more drinking or harm. They were also the four sponsored by Red Bull. The sole researcher who didn’t have a conflict of interest, although agreeing that there wasn’t a significant difference in using the two together, also admitted that there just wasn’t enough evidence to conclusively answer the key questions yet.

Miller says that all of the researchers’ most notable study limitations were that none of them had a substantial amount of research into the effects of real world levels of alcohol intoxication — about 0.1mg of alcohol per 100ml of blood — when consumed with energy drinks (about two to five drinks).

“It is critical that the public can be confident in the findings of research on these products,” Miller concluded. “Conference organizers and journal editors should require researchers working on energy drinks to declare whether they have received research funding [or other conflicts of interest].”

A Brief History of Alcoholic Energy Drink Products

The alcoholic energy drink market has been scrutinized in recent years. Four Loko, a caffeinated, 23.5 ounce, 12 percent alcohol by volume malt beverage was especially popular among the youth in 2010, but after several alcohol-related illnesses — 17 at just one college party — colleges across the nation banned the drink. Increasing opposition from state governments and citizens, and a threat of action from the Food and Drug Administration (FDA), forced Four Loko’s maker, Phusion Products, to pull caffeine from the drink or risk lost revenue, The Week reported. MillerCoors, the maker of Sparks alcoholic energy drink, also pulled caffeine from its drinks in 2008.

According to the National Institutes of Health, 37 percent of all traffic deaths are among those between 16 and 20 years old. About one in five teens are considered problem drinkers, and 51 percent of adults, ages 18 older are considered to be regular drinkers by the Centers for Disease Control and Prevention (CDC).

Source: Miller P. Energy drinks and alcohol: research supported by industry may be downplaying harms. BMJ. 2013.