–It is enormously important to keep tobacco consumption down in society, there are many gains to be made, says Louise Adermark, associate professor at the Department of Neuroscience and Physiology at the University of Gothenburg, who researches how nicotine affects the brain.
The addictive nature of nicotine is due to the nicotine receptors. They are the body's "reception centers" for nicotine and are found in many places in the body. Repeated exposure to nicotine through, for example, smoking or snuff leads to an increase in the number of nicotine receptors, which can affect many functions in the body.
Nicotine affects the body's reward system by releasing dopamine, a neurotransmitter that makes us feel good and awake, happy and present.
“The reward system is important for survival. In addition to making us feel good, it is needed for memory and learning,” says Louise Adermark.
But dopamine is also a brain-rebuilding molecule. Nicotine changes communication in the brain and affects how the tobacco user acts and thinks in the long term.
– Since almost all cells in the brain's reward system have nicotine receptors, this system changes with repeated nicotine use. This in turn makes it easy to become addicted. Not only to nicotine, but also to other substances, such as alcohol, she says.
Increases worry and anxiety
Nicotine also affects feelings such as anxiety and worry. Initially, nicotine makes you feel better, but over time, feelings of anxiety and worry are reinforced.
–There is a high proportion of smokers among people with psychiatric diagnoses. Previously, cigarettes were considered a kind of self-medication, but new research suggests that nicotine can increase the risk of developing a diagnosis. Human research is supported by studies conducted on animals. These show that nicotine slowly “rebuilds” the brain, which leads to changes in how the animals behave, even when they do not have nicotine in their bodies, says Louise Adermark.
It is also no coincidence that cigarettes and alcohol are linked. Smokers consume twice as much alcohol as non-smokers. Most alcoholics are smokers. Louise Adermark talks about animal experiments where animals were given the choice between drinking water and alcohol.
“When the animals were given nicotine, all the animals started drinking more alcohol,” she says, explaining that there is a connection between age of first smoking and abuse of alcohol and other drugs later in life.
Another thing that has been shown through animal experiments is that nicotine can have effects that extend across generations.
– Genetic studies conducted on rats and mice indicate that nicotine changes genetics and behavior in several generations. This may include an increased risk of asthma, increased intake of addictive substances, hyperactivity, and more. The results apply regardless of whether it is the male or female that has been exposed to nicotine, says Louise Adermark.
Read more:
Alcohol & Drugs No. 2/2016: Research on snus and alcohol
Science Translational Medicine, November 2011: Epigenetics of Nicotine: Another Nail in the Coughing
