How Does Smoking Prime the Brain for Alcohol Abuse?
Substance abuse and addiction specialists and public health officials have known for a long time that people who smoke cigarettes substantially increase their risks for eventually abusing alcohol. However, researchers and doctors have never fully understood why the strong connection between smoking and problematic alcohol use exists. According to the results of a study published in 2013 in the journal Neuron, the answer apparently lies in nicotine’s ability to change the way the brain responds to the pleasure-producing effects of alcohol intake.
Alcohol Use and Smoking
Alcohol use and smoking have a highly interdependent relationship as recreational activities. In the U.S., the average smoker consumes alcohol substantially more often than the average nonsmoker; conversely, the average drinker smokes cigarettes substantially more often than the average nondrinker. Among alcohol-dependent individuals (alcoholics), smoking plays a prominent role in producing declining health, triggering such conditions as heart and blood vessel disease, throat cancer, mouth cancer and several serious lung ailments. Combined alcohol and cigarette use take a particularly heavy toll on mouth and throat health, the National Institute on Alcohol Abuse and Alcoholism explains. Roughly 80 percent of all throat and mouth cancers among U.S. men stem from combined exposure to alcohol and nicotine. Among women, this combined exposure accounts for roughly 65 percent of all throat and mouth cancers.
The impact of smoking among alcoholics is so pervasive that alcohol-dependent people may actually die from smoking-related health complications at a higher rate than they die from alcohol-related health complications. Generally speaking, men combine alcohol use and smoking more often than women. In addition, young adults tend to smoke and drink more often than the members of other age groups.
Previously Established Factors
Doctors and researchers have already identified some of the factors that seem to connect smoking with alcohol intake. Some of these factors are environmental, while others are biological. Examples of the relevant environmental factors include the settings where both drinking and smoking commonly take place (bars, clubs, etc.) and the ready availability of alcohol and cigarettes. Examples of the relevant biological factors include preexisting genetic susceptibilities to the effects of both alcohol and nicotine, the ability of both alcohol and nicotine to activate the brain’s pleasure centers, and the ability of alcohol to increase the pleasure derived from nicotine intake. Previous efforts to understand the true impact of these and other factors have been hampered by such things as age-related variations in people’s responses to nicotine and alcohol intake, and gender-related variations in people’s responses to nicotine and alcohol intake.
In the study published in Neuron, researchers from Baylor College of Medicine used laboratory experiments with rats to help pinpoint the reasons alcohol use and smoking so often occur together. They began their experiments by exposing a group of rats to nicotine and then giving those rats access to alcohol. Compared to another group of rats not exposed to nicotine, the exposed animals sought out alcohol intake substantially more often. Next, the researchers tested the nicotine-exposed rats’ ability to experience the pleasure-inducing brain changes normally associated with alcohol consumption. After completing this test, they concluded that nicotine exposure diminished the rats’ ability to derive pleasure from alcohol intake. In order to compensate for a decline in their sensitivity to alcohol’s effects, the rats consumed more alcohol. Through a series of additional experiments, the researchers found that the effects of emotional and environmental stress apparently begin the chain of events inside the brain that leads to diminished alcohol sensitivity.
Significance and Considerations
The authors of the study published in Neuron note that even a single exposure to nicotine can produce the drop in alcohol sensitivity that promotes increased alcohol consumption. Especially in teenagers, who frequently experiment with smoking at one time or another, this immediate impact on the brain can potentially set the stage for an excessive pattern of drinking and the eventual onset of medically serious alcohol abuse. In line with their findings, the authors urge public health officials to increase their efforts to reduce the initiation of cigarette smoking in adolescent populations. They also note the importance of their discovery of stress’ role in triggering the alcohol-related brain changes that support increased alcohol intake. In the future, doctors may be able to target the body’s stress-generating chemicals in their efforts to either treat alcohol abuse or prevent alcohol abuse from occurring in the first place.