UncategorizedMay 27, 2020
It's no secret that people who smoke are more likely to abuse alcohol. In fact, the two unhealthy habits could be said to go hand in hand.
Now, a new study has found why. The study, conducted by The Scripps Research Institute (TSRI) shows that, in rat models, nicotine exposure actually promotes alcohol dependence.
“It’s a vicious cycle,” said TSRI biologist Oliver George, a senior author of the new study. “Nicotine makes individuals crave alcohol to ‘reward’ the brain and reduce stress.”
In conducting the new research, the team first tested whether nicotine exposure could affect alcohol-drinking behavior in rat models. They started with two groups of male rats. Both groups were given access to alcohol to establish the baseline of how much they would drink. The rats drank a little bit, perhaps the equivalent of one or two beers for a human, but they stopped before showing signs of drunkenness.
After this baseline test, the researchers used alcohol vapor to induce alcohol dependence in one group of rats. Dependence developed in about two months. These rats consumed the equivalent of a six-pack of beer and had blood alcohol levels close to three times the legal limit for humans.
The second group of rats were exposed to both nicotine and alcohol vapor. These rats developed alcohol dependence much faster—and they began drinking the equivalent of a six-pack in just three weeks.
“We had never seen such a rapid escalation of alcohol drinking before,” said George.
The study suggests that alcohol works with nicotine to activate the brain’s reward system and dampen the stress of nicotine exposure. Interestingly, the combination of neurons activated by nicotine and alcohol together is different from the neurons activated by each substance on its own. This interaction may explain why it is difficult for smokers to quit drinking, and vice versa.
“Now we can try to find compounds that will specifically inactivate those neurons,” said George.