Drinks canned (image:Joe Raedle/Getty)

College students know it as the “blackout in a can”: Four Loko contains as much alcohol as five beers and the caffeine equivalent of a cup of coffee. Now the US Food and Drug Administration (FDA) is cracking down on such “alcoholic energy drinks”, arguing that they create a state of wide-awake drunkenness that puts imbibers at risk.

On 17 November, the FDA wrote to four manufacturers, warning them that caffeine is an “unsafe food additive” in strong beers, and giving them 15 days to withdraw the drinks from sale.

Anticipating the letter, industry leader Phusion Projects in Chicago, which makes Four Loko, had already announced that it was removing caffeine and other stimulants from its drinks.


In its letters, the FDA cited research including a study conducted in the bar district near the University of Florida in Gainesville, which showed that patrons who had consumed alcohol mixed with energy drinks were three times as likely as other drinkers to be highly intoxicated, and four times as likely to say they intended to drive.

Hooked on alcohol

While it came too late to be considered in the FDA’s safety review, a new paper suggests that consuming energy drinks also has long-term consequences. The risk of alcohol dependence increases for these drinkers, even taking into account factors such as depression and a family history of alcohol abuse.

Amelia Arria of the University of Maryland in College Park, who led the research, suspects that this is might be because people drink more alcohol when they mix it with energy drinks.

In another study, researchers led by Sean Barrett of Dalhousie University in Halifax, Canada, found that students consumed an average of 8.6 alcoholic drinks per session when mixing it with energy drinks, compared to 4.7 when they consumed alcohol alone.

The FDA can regulate pre-mixed drinks, but cannot control the use of products that are sold separately. Still, Arria believes the agency’s action may make bar owners wary of serving energy drinks mixed with alcohol, for fear of being sued if drinkers hurt themselves or others. “This should send a clear and an unequivocal message that mixing energy drinks with alcohol is not safe,” she says.

Mixing energy drinks with alcohol is also popular in Europe – where authorities seem less concerned about the risks. In 2003, the European Commission’s Scientific Committee on Food came to the conclusion that caffeine should not exacerbate the adverse effects of alcohol. “There is currently no evidence to indicate a need for a review,” a spokesman for the UK Food Standards Agency told New Scientist.

Journal references:

Addictive Behaviors, vol 35, p 325

Alcoholism: Clinical and Experimental Research, DOI: 10.1111/j.1530-0277.2010.01352.x

Drug and Alcohol Review, vol 29, p 331