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Thursday, March 31, 2011

Misusing science: the Four Loko ban

Last November, the FDA banned Four Loko and similar alcoholic energy drinks because of the supposedly devastating impact they were levying on young drinkers. Proponents of the ban claimed that the stimulants in the beverages mask the depressant effects of alcohol, making it more likely that those who consume them will engage in risky behaviors that they otherwise would not. In response, manufacturers of the drinks removed the caffeine and other stimulants that caused the panic.

But that's not good enough. Some state legislators are now pushing for a more comprehensive ban that would prohibit the sale of drinks like Four Loko - now just fruity malt beverages - in every retail outlet except liquor stores.

There's a lot of hype behind the efforts to ban these "alcopops," but is there any science? Nope. And there never was. Supporters of the heavy handed regulations cite two studies that supposedly demonstrate the elevated risk posed by consuming caffeinated malt beverages. But the research often touted in support of the ban actually suggests that a much more modest policy would be appropriate.

For example, one study conducted by Wake Forest University researchers in 2007 surveyed 4, 271 college students from ten universities about drinking and its associated risks. 697 of those surveyed reported trying the drinks. The study found that consuming alcohol mixed with caffeine was associated with a “significantly higher prevalence of alcohol-related consequences,” including riding with an intoxicated driver and engaging in risky sexual activity.

What was usually not reported in the reactionary news stories, however, is that the study did not demonstrate a causal relationship between consuming the drinks and increased risk taking. While it is certainly possible that caffeinated alcohol is to blame for increased risk taking, the data may also be explained by the fact that “sensation seeking individuals may be drawn to energy drinks, heavy alcohol consumption, and risky behaviors,” according to the researchers. Essentially,  the association could be backwards; it is impossible to know from the study.

Not only do advocates of the ban assume causation where there is only correlation, but the data for the study were obtained by self-report. That means the students surveyed could have easily overestimated how much alcohol they consumed and the consequences that resulted from their drinking.

The Wake Forest study is not the only one plagued by such serious limitations. In 2008, scientists at the University of Florida conducted a similar survey of over 800 college-aged bar patrons as they left seven bars near the university. Participants completed self-administered questionnaires that asked about their drinking history and intention to drive that night, and researchers tested participants’ breath-alcohol concentration levels.

Of all the students surveyed, 6.5 percent reported mixing alcohol and caffeine and were three times as likely to be intoxicated as students who consumed only alcohol. The average breath-alcohol concentration reading for those who mixed alcohol and energy drinks was 0.109, much higher than the 0.08 legal limit. There's just one major problem. The researchers did not determine how much caffeine the study participants consumed. As a result, they write that their “...findings provide no information about the extent to which potentially dangerous antagonist effects were produced in the patron sample.” How is it possible to know if people who consume caffeinated-alcohol are in harm's way if you do not know how much they consume?

Given the limitations of these studies, the authors of both suggested that the beverages carry labels indicating their caffeine content and a warning that the stimulant will not counteract the effects of alcohol, not an outright ban.

Beyond the very limited research available, there is no way to tell if Four Loko is more harmful than "regular" alcohol. Jacob Sullum at Reason Magazine points out that "[t]he National Highway Traffic Safety Administration counted 13,800 alcohol-related fatalities in 2008. It did not place crashes involving Four Loko drinkers in a special category."

 Furthermore, college students were drinking too much long before the introduction of alcoholic energy drinks. Sullum says, citing data from the federal government, that "more than 100,000 18-to-20-year-olds make alcohol-related visits to American emergency rooms every year."

As usual, it's just hype generated by overzealous health nannies. Remember that the next time, and there always is a next time, a politician or consumer advocacy group wants to ban something.


Citations:

O’Brien, M.C., et al., Caffeinated Cocktails: Get wired, Get drunk, Get injured, annual meeting of the American Public Health Association (2007), Abstract # 166629


Thombs, D.L., et al., Event-level analyses of energy drink consumption and alcohol intoxication in bar patrons, Addictive Behaviors (2009), doi:10.1016/j.addbeh.2009.11.004