People who smoke while drinking alcohol may be at greater risk of suffering a hangover the next morning, according to a study in the Journal of Studies on Alcohol and Drugs.
Most people who have ever had too much to drink are familiar with that day-after combination of headache, nausea and fatigue. A new study suggests that smoking could boost the odds of developing the dreaded hangover.
Researchers found that college students were more likely to report hangover symptoms after a heavy drinking episode if they smoked heavily on the day they consumed alcohol - and it wasn't simply because they smoked more when they drank more.
"At the same number of drinks, people who smoke more that day are more likely to have a hangover and have more intense hangovers," said researcher Damaris J. Rohsenow, of the Centre for Alcohol and Addiction Studies at Brown University in the United States.
Her team controlled for some other factors as well, such as whether students reported drug use in the past year. And smoking, itself, was linked to an increased risk of hangover compared with not smoking at all.
That raises the likelihood that there is some direct effect of tobacco smoking on hangovers, Rohsenow said.
It is not entirely clear why people who smoke suffer more severe hangovers. But other research has shown that nicotine receptors in the brain are involved in our subjective response to drinking, Rohsenow said. For example, smoking and drinking at the same time boosts the release of dopamine, a "feel-good" brain chemical.
The fact that nicotine and alcohol are connected in the brain may explain why smoking is tied to hangover.
The findings are based on a survey of 113 college students who recorded their drinking and smoking habits, and any hangover symptoms, every day for eight weeks. Overall, when students drank heavily - the equivalent of five or six cans of beer in about an hour - those who'd smoked more on that same day had higher odds of suffering a hangover the next morning and suffered more when they did.
Furthermore there is evidence that a hangover affects your attention and reaction time in the short term, Rohsenow said. So it could be unwise to drive or work in safety sensitive occupations with a hangover, for instance. No one is sure yet whether hangovers may signal some type of damage to the brain, but smoking is already known from other studies to aggravate the ill effects on the brain caused by years of heavy drinking.