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-coloured 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.
Brain impaired by hangover
"The most important thing for people to realise 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 Centre for Alcohol and Addiction Studies at Brown University in the US.
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 Alcoholism: Clinical and Experimental Research.
Red wine vs white wine
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.
Effects of alcohol
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.
"What's clearly emerged is that it's the alcohol content that is the most salient factor in terms of damage and long-term damage and addiction," he said. "It's the actual amount of alcohol that counts. Nonetheless, we see emerging some interesting issues in terms of which congeners go along with which alcohol. For example, in terms of what produces more hangover."
"So research like this points to the fact that there are other peripheral issues which have some import and are worth exploring," he acknowledged.
To avoid a hangover, the National Institutes of Health (NIH) suggests drinking slowly, on a full stomach, with water and in moderation. For women, the National Institute on Alcohol Abuse and Alcoholism recommends no more than one 12-ounce drink per day. For men, no more than two drinks per day.
For those who are already saddled with a morning-after head-pounding, the NIH recommends plenty of rest - noting that hangovers usually dissipate within 24 hours - while consuming food and liquids containing salt, potassium, and fructose, which is found in fruit juice and honey. - (Alan Mozes/HealthDay News, December 2009)