Energy drinks and alcohol: research supported by industry may be downplaying harms.

Concern is growing about the harms that may arise from heavy drinkers mixing alcohol with so called energy drinks to enable them to drink for longer and achieve higher levels of intoxication. On Friday and Saturday evenings, about 40% of people on Australian city streets are heavily intoxicated (breath alcohol concentrations (BAC) greater than 0.087mg alcohol/100 ml) and nearly a quarter of these drinkers will have consumed more than two energy drinks. Data are lacking on energy drink use by alcohol drinkers in other countries but in samples, 73% of US college students and 85% of Italian college students reported consuming energy drinks mixed with alcohol in the past month. Epidemiological studies show that drinkers who consume energy drinks are more likely to record a higher breath alcohol concentration than those who do not. 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. The role that energy drinks may play in facilitating intoxication is under-researched. Because of ethical concerns about people getting too drunk and drinking too many energy drinks, much of the research in laboratory settings has studied only the effects of combining low levels of alcohol intoxication (BAC less than 0.1 mg alcohol/100 ml) with a single energy drink (equivalent to a strong cup of coffee). Some researchers doing these studies have concluded that we should not be concerned about the risks of combining alcohol and energy drinks. But evidence from these studies does not convincingly refute the hypothesis that more energy drinks consumed with more alcohol facilitates intoxication and increases the risk of alcohol related injuries and assaults. Many of the researchers who draw reassuring conclusions from this research have been funded by a major producer of energy drinks, Red Bull. These researchers have presented their findings at special sessions on alcohol and energy drinks at international conferences where, because of limited disclosure requirements, audiences may not be aware of the extent of their industry sponsorship. Many conferences have no requirements that authors declare specific potential conflicts of interest, although several have recently introduced general requests, which rely on authors’ perceptions and have been found inadequate for journal articles, leading to comprehensive requirements. At a 2012 Australasian Professional Society on Alcohol and Drugs conference, for example, four out of five researchers who presented research on alcohol and energy drinks had received financial support from Red Bull (for example, funds to attend international conferences or for research). The four presenters who had received such support all concluded that no evidence showed that the combination of energy drinks and alcohol increased drinking or harm. The non-industry funded researcher also reported no significant difference between alcohol and alcohol with energy drink sessions, but went on to highlight that there is simply not enough evidence to answer the key questions yet. 13 I am not implying a causal relation here, simply an association. Only the presenters, who were the first authors of each paper, supplied declarations of competing interests. These researchers were all critical of the epidemiological evidence to the contrary. 4 Yet they drew strong conclusions about their own studies despite substantial limitations, most notably the lack of research into the effects of real world levels of alcohol intoxication (greater than 0.1 mg alcohol/100 ml blood) and consuming typical amounts of energy drinks (2-5 drinks).Only the presenter who did not declare industry funding argued that we needed more research to assess the associations between energy drinks and harmful alcohol use in epidemiological studies.