By Alan Mozes
FRIDAY, Dec. 18 (HealthDay News) -- As the holidays approach, booze is a common indulgence -- and nasty hangovers a common consequence. But if those who tend to overdo it stick to lighter-colored beverages, they might feel a little better the next day.
New research reveals that darker liquors like bourbon contain more toxic properties that provoke more painful hangovers than lighter choices such as vodka.
This is probably because the materials used in the alcohol fermenting process -- grains and wood casks -- produce small amounts of toxic byproducts, the researchers say.
Known as "congeners," these complex organic molecules include acetone, fusel oil and tannins, and are present in much higher quantities among darker liquors than lighter ones. Bourbon has 37 times as many congeners as vodka, for example.
"The most important thing for people to realize is that if you're feeling hungover, you're probably impaired in terms of performing tasks that require vigilance and making quick decisions, " cautioned study author Damaris J. Rohsenow, associate director of the Center for Alcohol and Addiction Studies at Brown University in Providence, R.I.
If they drink to inebriation, "people are going to feel sicker after drinking an alcohol -- such as bourbon -- which is among the darker liquors, and therefore has a lot more naturally toxic poisons in it," Rohsenow added. "Of course, they'll still get hungover just from vodka or white wine. But it will just be a little less painful than if they drink a darker liquor."
Rohsenow and her colleagues will publish their findings in the March issue of Alcoholism: Clinical and Experimental Research.
The authors did not specifically explore how red wine vs. white wine consumption might affect a hangover. However, Rohsenow noted that, as with other darker liquors, red wines contain more troublesome congeners than white wines. It would be logical to conclude that drinking red wine to intoxication would provoke a harsher hangover that drinking a similar amount of white wine, she suggested.
Nonetheless, the current effort focused solely on the comparative impact of drinking bourbon vs. drinking vodka.
The research team monitored 95 healthy heavy drinkers between the ages of 21 and 33 (male and female) residing in the greater Boston region.
None had ever been treated for alcohol-related problems, and none had experienced any form of sleep disorder prior to the study.
Over the course of two overnight sessions, the participants consumed either vodka (100 proof Absolut, the low-congener alcohol) or bourbon (101 proof Wild Turkey, the high congener alcohol) on one night, and a placebo beverage (caffeine-free soda, containing no alcohol) the second.
The researchers repeatedly measured breath alcohol concentration (BrAC) levels among all the participants until everyone had obtained a reading reflective of inebriation.
The following morning participants were asked to rate their hangover in terms of severity, ranging from little or no impact to incapacitating. Neuropsychological tests were conducted to assess speed, vigilance and concentration skills during the hangover. Sleep quality over prior evening was also assessed.
Rohsenow and her team found that drinking to inebriation resulted in cognitive impairment the following morning.
Furthermore, higher congener levels appeared to increase the intensity of the hangover, as bourbon drinkers had a worse experience than vodka drinkers.
However, higher congener levels did not cause people to perform worse on cognitive tasks. Nor did higher congener levels have any impact on sleep the night before.
"Certainly a lot of the effects of a hangover are just due to alcohol itself," stressed Rohsenow. "So, most performance impairment during a hangover is directly due to alcohol affects. But certainly we can see that there is the potential for an added pain factor that will make the experience worse, and that can be attributed to the toxins in darker alcohol."
Dr. Marc Galanter , a professor of psychiatry at New York University School of Medicine in New York City, agrees that drinking too much period is the root cause of a hangover, regardless of the alcoholic weapon of choice.