The Center for Disease Control and Prevention estimates that 34% of young adults (18-24 year olds) regularly consume "energy drinks" - infusions designed to boost pep through a tasty mixture high in sugar and caffeine. After some inventive youths showed how energy drinks could juice up depressed spirits, by, for example, giving ho-hum whisky a shot of Red Bull, caffeinated alcoholic beverages have become an increasingly popular drink among young adults. Beginning in 2002, beverage manufacturers tried to capitalise on this trend by producing ready-made "alcohol energy drinks" (AEDs). The undertaking has been a remarkable success for the producers of the almost 30 brands of AEDs which subsequently flooded local Circle Ks and 7-Elevens. The US beer market: impact databank review and forecast (2009) reported a six-year 67-fold increase in AED sales.
To coax youths into replacing their Monsters or Jägerbombs (1 shot of Jägermeister and Red Bull) with the pre-made AEDs, manufacturers have had to use marketing, product design and pricing strategies. Like their sober brethren, AEDs are packaged with psychedelic patterns whose dancing neon lizards give a trippy effect before one sip has been swallowed; they have more alcohol content per ounce than your average beer but a sweet smooth taste thanks to the addition of sugar, guarana, glucuronolactone, taurine and wormwood. Although sold in similarly large 24 oz portions, they are cheaper than dry energy drinks.
All of these enterprising efforts were paying off for manufacturers Charge Beverages Corp., New Century Brewing Co., LLC, Phusion Projects, LLC, and United Brands Company Inc. until last week when the US Food and Drug Administration (FDA) delivered the warning that the production and sale of caffeinated beverages was in violation of the Federal Food, Drug, and Cosmetic Act (FFDCA). The companies were given 15 days to respond and were told that, under the FFDCA, continued sale of products like Moonshot and Four Loko could result in product seizure by the FDA who deems caffeine an "unsafe food additive" when combined with malt liquor. Five US states (Mass, Michigan, Utah, Oklahoma, Washington) have already responded by banning sales of the infringing products.
The FDA's denunciatory verdict on AEDs comes after a year-long review of the scientific literature and discussions with expert panels about the health hazards associated with caffeine-infused alcohol. From the information gathered, the administration reached two conclusions: 1) compared to other popular alcoholic beverages, AEDs are associated with an increased rate of binge drinking (5 or more drinks per occasion for males) and consequent health risks, including mortality, and 2) the increased risk is due to the action of the stimulant caffeine which masks the physiomotor impairments induced by alcohol.
Though this announcement has now been well-circulated through the news cycle most reports have missed the most remarkable side of the story. Risks resulting from human behavior are invariably difficult to study. Consider the long slog to show the link between tobacco consumption and lung cancer. Despite the compelling 1950 JAMA report of Ernst Wynder and Evarts Graham, frankly entitled "Tobacco Smoking as a Possible Etiologic Factor in Bronchiogenic Carcinoma: A Study of 684 Proven Cases", it took numerous confirmatory human and animal trials over 14 years before the first Surgeon General's damning report against smoking appeared.
Put in this context, the swiftness and definitiveness of the FDA's verdict on caffeine is truly remarkable. In fact, the speed with which this consensus was reached would only seem possible for evidence based on a randomized trial since the selection bias in an observational study would have difficulty excluding the possibility that excessive drinkers simply have a preference for AEDs. In fact, the O'Brien survey (2008) of North Carolina undergraduates found that, compared to alcohol drinkers who did not mix their spirits with energy drinks, AED drinkers were more likely to be male and a member of a fraternity, a profile not incommensurate with intemperance.
Would a randomised study to address the binge-drinking risk of AED use be possible? And, even supposing that there were no ethical concerns about randomly assigning young adults toad libitum drinking of alcohol, how could such a study isolate the role of caffeine apart from sugar and other additives? How could a laboratory mimic the naturalistic setting of a frat party? What strategy could investigators use to assure an unbiased sample? Recruitment fliers seeking "STUDENTS WILLING TO DRINK FOR RESEARCH" would simply not do.
The study of Ferreira and colleagues (2006) came as close to an ideal experimental design of AED and binge drinking as is ethically conceivable. The researchers recruited 26 young males with no history of substance abuse or excessive use of energy drinks. On three separate occasions they were given a mixture vodka, Red Bull, or vodka combined with Red Bull. The volume and taste per kilogram body weight was fixed with the addition of water and a diet fruit juice. The sample was divided into a low and high dose alcohol condition. Before and after each session, alcohol intoxication was evaluated with a measure of breath alcohol concentration, subjective assessment of somatic states and objective measures of motor coordination. The researchers found that the concentration of alcohol in the breath during the period before and for 2.5 hours after ingestion was not changed with the addition of energy drink. Also, motor function and visual reaction time was similarly impaired 30 minutes after consumption, both the alcohol only (AO) and alcohol + energy (AE) subjects took a comparably longer time on average to place 25 pegs in a pegboard (motor coordination) and to respond to the presentation of a yellow square on a computer screen (visual reaction time) than at baseline. All of this evidence suggests that the addition of a sugary, caffeinated beverage does not impact the physiological effects of alcohol.
But what about the risk of a binge? The researchers did not allow subjects to drink to their limit so binging could not be directly observed. Instead, Ferreira and colleagues measured the perception of drunkenness, which would enable them to infer whether AEDs created a binge-inducing state by diminishing the perception of drunkenness. Of 18 subjective assessments of somatic states measured 30 minutes after alcohol ingestion, the AE group differed from the AO group only in reported alterations of sight. On a visual analog scale from 0 to 100, with 0 being no impairment and 100 maximum impairment, AEs reported an average of 8 and AOs an average of 12. Although the difference was significant based on an analysis of variance, which took into account the three treatment groups, two dose levels, and repeated measures, there was no adjustment for multiple testing. With a type I error rate of 5% for the statistical tests made with each questionnaire item there was a 60% chance that at least one significant finding would be incorrectly found among the 18 items which makes the single difference found hardly surprising.
Despite the high quality of its design, the Ferreiara experimental study did not make a strong case that AED diminishes the perception of intoxication. Perhaps with a more sensitive questionnaire of somatic states more differences between the AOs and AEs would have emerged. Still, even with this improvement, an alternative design would be needed to determine whether the stimulating effects of caffeine alone encourage higher consumption or if one of the other additives of energy drinks is the causal factor. If youths are consuming more alcohol as AEDs because these products are tastier than standard beer or spirits, the FDA's censure of caffeine is unlikely to be an effective prevention strategy.
No comments:
Post a Comment