We are all made very aware that cigarettes are bad, thanks to all the PSA that keeps on reminding us every chance they get. Just easily, we can recite the harmful and negative effects of smoking on our health, such as heart disease, stroke, and lung cancer. But, did you know that smoking cigarette is as addictive and affects the brain as heroin?
Nicotine addiction is hard to beat because it changes the brain as it develops extra nicotine receptors to accommodate the large doses of nicotine from tobacco. When the brain stops getting the nicotine it’s used to, the result is nicotine withdrawal causing you to feel anxious, irritable, and have strong cravings for nicotine.
New research shows that smoking cigarettes trigger the release of addictive "feel-good" brain chemicals, just like it does with heroin and morphine. The study’s findings show that smoking cigarettes stimulate the brain's production of chemicals called opioids. The opioids are known to play a role in soothing pain, increasing positive emotions, and creating a sense of reward. Both morphine and heroin trigger this same chemical flow.
The new study also confirms previous findings — from animal studies — that smoking cigarette affects the flow of another feel-good brain chemical called dopamine. Researchers are now investigating the interaction between the two chemicals in the brains of smokers and nonsmokers. It appears that smokers have an altered opioid flow all the time, when compared with non-smokers, and that smoking a cigarette further alters that flow by 20 to 30 per cent in regions of the brain important to emotions and craving.
Smoking Cigarettes During Brain Scans
The research team spent several years testing a way of using PET imaging (positive emission tomography) to study the opioid system in the brain. The scans don't show the flow of opioids directly, but they do show opioid receptor activity in the brain. The researchers have also created a system that allows someone to smoke cigarettes while lying in the PET scanner having his or her brain scanned.
This new study involving six healthy men who smoked one pack per day, refrained the smokers from smoking cigarettes for at least 10 hours before the study began. During their brain scans, each first smoked a cigarette almost devoid of nicotine, and then smoked a regular cigarette. Researchers also asked the men to rate their feelings at various times during the study, including before and after smoking cigarettes.
Significant differences in the flow of opioids were seen when the smoker smoked low-nicotine versus high-nicotine cigarettes. The men who smoked low-nicotine cigarettes, their brains started to show changes in opioid flow. But as soon as they smoked regular cigarettes, opioid levels increased significantly in the brain area involved in emotion and emotion-memory processing. However, other brain regions were 20% to 30% less active — the areas involved in memory, emotion, and pleasure.
The findings matched the men's feelings at the time, where they reported feeling more relaxed, less alert, less nervous, and having fewer cravings than before smoking cigarettes. This meant that far more "feel good" chemicals were being released. The researchers aren't sure why these other areas of the brain respond differently. But this decreased activity allows other chemicals — like nicotine — to affect these areas. This suggests that nicotine binds to the opioid receptors, causing these brain areas to activate "feel good" hormones.