That’s because of the “congeners,” or impurities in alcohol that provide much of the aroma and color in different beverages. These organic molecules, which include acetone, fusel oil and tannins, come about as a result of the fermenting process, whether they’re from, say, the grains used to make corn whiskey or the wood casks in which the alcohol is aged. But congeners also exacerbate the effects of hangover, including headaches, nausea and tiredness. Vodka, a clear spirit, has an extremely low level of congeners. Bourbon, on the other hand, is a darker liquor, with 37 times the level of congeners that vodka has.
To see if these particles had an effect on hangovers, researchers Damaris J. Rohsenow and Jonathan Howland had young adults between age 21 and 33 drink bourbon, vodka or a caffeine-free cola. They had the drinkers reach a blood alcohol content level of 0.10% (the legal limit is 0.08%), and monitored them overnight. Once their blood alcohol content had gone back down to zero, they measured participants’ state as well as their performance. The results, published in the March 2010 issue of Alcoholism: Clinical and Experimental Research: Those who downed bourbon reported feeling worse than vodka drinkers the next morning, though they performed about the same on tests the next day.
Those tests gauged participants’ ability to react quickly and maintain concentration – both of which are needed for tasks such as driving. The study found that hung over drivers — whatever they had imbibed — performed 2% worse than their cola-drinking counterparts. Might not sound like much, Dr. Damaris J. Rohsenow at Brown University said in an interview, but “if you’re 2% slower and in a traffic situation where you might have to make split second decisions, that [difference] might get you into a bit of trouble.”
That’s also true of jobs requiring quick reactions and sustained attention, she added. “Think of air traffic control, think of flying a plane.”
Even scarier? Those hung over subjects did not perceive their performance to be impaired, Rohsenow said – which is why those still feeling the effects of last night’s carousing should stay away from cars and heavy equipment.
“People aren’t always good judges of their own performance,” Rohsenow said, adding, “maybe it’s because it always impairs their awareness and their ability to judge. That’s why it’s important for the news to get out.”Think a little hair of the dog will cure that nasty headache? Think again. Here, Max Pittler and colleagues provide a comprehensive list of folksy cures – aspirin, dialysis, pizza, Sob'r-K HangoverStopper – and concluded in a 2005 BMJ paper, “The most effective way to avoid the symptoms of alcohol induced hangover is thus to practise abstinence or moderation.”
-- Amina Khan
Photo credit: Andrea Adleman