Lowering the amount of nicotine in cigarettes to non-addictive levels may reduce smoking without worsening mental health in smokers with mood or anxiety disorders, according to Penn State College of Medicine and Harvard Medical School researchers.
They said reducing nicotine content in cigarettes could also lessen addiction, lower exposure to toxicants and increase a smoker’s chances of quitting.
Tobacco remains the leading preventable cause of premature death and disease in the United States. Recent proposals by the U.S. Food and Drug Administration and the New Zealand government seek to limit the amount of nicotine in cigarettes to minimally addictive levels.
Prior research indicates that reducing nicotine content could help smokers quit, but there is little evidence to demonstrate if these policies could adversely affect smokers with current or prior affective disorders like depression and anxiety disorders — which affect an estimated 38% of U.S. cigarette smokers.
According to Jonathan Foulds, professor of public health sciences and of psychiatry and behavioral health, smokers with mental health conditions are more likely to have severe nicotine withdrawal symptoms and less success at quitting.
He also said there is speculation that lessening nicotine content to very low levels could worsen psychiatric symptoms in smokers with mental health conditions and lead to heavier smoking and increased exposure to toxicants, or harmful chemicals.
The researchers studied 188 smokers with a history of or who had a current mood or anxiety disorder and had no plans to quit.
Volunteer participants were randomly assigned to a group that received either research cigarettes containing the usual amount of nicotine (11.6 mg nicotine/cigarette) or a progressively reduced amount of nicotine for an additional 18-week period (the final amount was 0.2 mg nicotine/cigarette).
At the beginning and conclusion of the study, the researchers measured levels of cotinine, a metabolite of nicotine, levels of harmful chemicals, cigarette dependence indexes and various mental health measures.
The team used the Kessler Psychological Distress Scale, a six-item self-report assessment where participants reported on a 5-point scale the degree to which they experienced feelings or emotions like “nervous,” “hopeless” or “so depressed that nothing could cheer them up.” Scores are developed by summing points for the six experiences.
Participants in the reduced nicotine content group scored an average of 5.3 at the beginning of the study and finished at an average score of 4.6, while participants in the usual nicotine content group scored 6.1 at the beginning of the study and finished around 4.9.
“These findings are important because we want to understand the effect these policies would have on smokers with anxiety or depressive disorders,” said Foulds, a Penn State Cancer Institute researcher.
“Our data showed that there wasn’t a significant difference in mental health measures between the groups, suggesting reduced nicotine cigarettes might not have adverse psychological effects on this population.”
Similar to what prior studies reported, Foulds and team found that groups in the reduced nicotine content group were absorbing lower amounts of nicotine and ingesting lower levels of harmful carcinogens such as the biomarker 4-(methylnitrosamino)-1-(3-pryidyl)-1-butanol), more commonly known as NNAL. That group also smoked fewer cigarettes and reported lower levels of nicotine addiction by the end of the randomized phase of the trial.
The results were published in PLOS ONE today, Nov. 2.
Unique to this study, participants in both groups were also given the choice to “choose their treatment,” after the 18-week period. They could go back to using their own cigarettes, continue smoking the research cigarettes or attempt to quit.
Of the 188 participants in the study, those randomized to reduced nicotine content cigarettes were more likely to have quit smoking 12 weeks later (18.1%), compared to those in the control (usual nicotine content) group (4.3%).
“We believe this is the first randomized trial to find that smokers who used very low nicotine cigarettes were significantly more likely to have quit smoking (with biochemical verification), three months after the end of the trial,” Foulds said.
“Our results suggest that these policies will likely result in reduced nicotine absorption from cigarettes without worsening the mental health of smokers with mood or anxiety disorders,” said Dr. Eden Evins, Cox Family Professor of Psychiatry at Harvard Medical School. “They also suggest that with proper support and resources, smokers with mood and anxiety disorders could quit successfully as a result of these policies.”
For more information on nicotine, smoking and health studies at the Penn State Center for Research on Tobacco and Health, visit https://research.med.psu.edu/smoking/#participants.
Is smoking tobacco really addictive?
Addiction is marked by the repeated, compulsive seeking or use of a substance despite its harmful effects and unwanted consequences. Addiction is mental or emotional dependence on a substance. Nicotine is the known addictive substance in tobacco. Regular use of tobacco products leads to addiction in many users. Nicotine is a drug that occurs naturally in tobacco and it’s thought to be as addictive as heroin or cocaine.
How nicotine affects you
- Nicotine and other chemicals in tobacco smoke are easily absorbed into the blood through the lungs. From there, nicotine quickly spreads throughout the body.
- When taken in small amounts, nicotine causes pleasant feelings and distracts the user from unpleasant feelings. This makes the tobacco user want to use more. It acts on the chemistry of the brain and central nervous system, affecting mood. Nicotine works very much like other addicting drugs, by flooding the brain’s reward circuits with a chemical called dopamine. Nicotine also gives a little bit of an adrenaline rush – not enough to notice, but enough to speed up the heart and raise blood pressure.
- Nicotine reaches the brain within seconds after taking a puff, and its effects start to wear off within a few minutes. The user may start to feel irritated and edgy. Usually it doesn’t reach the point of serious withdrawal symptoms, but the person using the product gets more uncomfortable over time. This is what most often leads the person to light up again. At some point, the person uses tobacco, the unpleasant feelings go away, and the cycle continues. If the person doesn’t smoke again soon, withdrawal symptoms get worse over time.
- As the body adapts to nicotine, people who use it tend to increase the amount of tobacco they use. This raises the amount of nicotine in their blood, and more tobacco is needed to get the same effect. This is called tolerance. Over time, a certain nicotine level is reached and the person will need to keep up the usage to keep the level of nicotine within a comfortable range.
- People who smoke can quickly become dependent on nicotine and suffer physical and emotional (mental or psychological) withdrawal symptoms when they stop smoking. These symptoms include irritability, nervousness, headaches, and trouble sleeping. The true mark of addiction, though, is that people still smoke even though they know smoking is bad for them – affecting their lives, their health, and their families in unhealthy ways. In fact, most people who smoke want to quit.
Researchers are also looking at other chemicals in tobacco that make it hard to quit. In the brains of animals, tobacco smoke causes chemical changes that are not fully explained by the effects of nicotine.
The average amount of nicotine in one regular cigarette is about 1 to 2 milligrams (mg). The amount you actually take in depends on how you smoke, how many puffs you take, how deeply you inhale, and other factors.
How powerful is nicotine addiction?
About 2 out of 3 of people who smoke say they want to quit and about half try to quit each year, but few succeed without help. This is because they not only become physically dependent on nicotine. There’s also a strong emotional (psychological) dependence. Nicotine affects behavior, mood, and emotions. If a person uses tobacco to help manage unpleasant feelings and emotions, it can become a problem for some when they try to quit. Someone who smokes may link smoking with social activities and many other activities, too. All of these factors make smoking a hard habit to break.
In fact, it may be harder to quit smoking than to stop using cocaine or opiates like heroin. In 2012, researchers reviewed 28 different studies of people who were trying to quit using the substance they were addicted to. They found that about 18% were able to quit drinking, and more than 40% were able to quit opiates or cocaine, but only 8% were able to quit smoking.
What about nicotine in other tobacco products?
Nicotine in cigars
People who inhale cigar smoke absorb nicotine through their lungs as quickly as people who smoke cigarettes. For those who don’t inhale, the nicotine is absorbed more slowly through the lining of the mouth. This means people who smoke cigars can get the desired dose of nicotine without inhaling the smoke directly into their lungs.
Most full-size cigars have as much nicotine as several cigarettes. Cigarettes contain an average of about 8 milligrams (mg) of nicotine, but only deliver about 1 to 2 mg of nicotine. Many popular brands of larger cigars have between 100 and 200 mg, or even as many as 444 mg of nicotine. The amount of nicotine a cigar delivers to a person who smokes can vary a great deal, even among people smoking the same type of cigar. How much nicotine is taken in depends on things like:
- How long the person smokes the cigar
- How many puffs are taken
- Whether the smoke is inhaled
Given these factors and the large range of cigar sizes, it’s almost impossible to make good estimates of the amounts of nicotine larger cigars deliver.
Small cigars that are the size and shape of cigarettes have about the same amount of nicotine as a cigarette. If these are smoked like cigarettes (inhaled), they would be expected to deliver a similar amount of nicotine – 1 to 2 mg.
Nicotine in smokeless tobacco
Smokeless tobacco delivers a high dose of nicotine. Nicotine enters the bloodstream from the mouth or nose and is carried to every part of your body.
Nicotine in smokeless tobacco is measured in milligrams (mg) of nicotine per gram (g) of tobacco. It’s been found to vary greatly, for instance as much as 4 to 25 mg/g for moist snuff, 11 to 25 mg/g for dry snuff, and 3 to 40 mg/g for chew tobacco. Other factors that affect the amount of nicotine a person gets include things like:
- Brand of tobacco
- Product pH level (how acidic it is)
- Amount chewed
- Cut of tobacco
Still, blood levels of nicotine have been shown to be much the same when comparing people who smoke cigarettes to those who use smokeless tobacco.
Nicotine in non-combusted products
Non-combusted tobacco products come in various forms and are used in different ways. Non-combusted products contain nicotine and can lead to nicotine addiction.
- Non-combusted (heat-not-burn) cigarettes have a heating source and tobacco. The tobacco is heated to a lower temperature than a regular (combustible) cigarette. The heat creates an aerosol that is inhaled by the user.
- Dissolvable tobacco products are edible. They can be lozenges, strips, gummies, or sticks. They can be easily hidden and can look like candy.
- Nicotine gels are tobacco products that are rubbed on, and absorbed by, the skin.
Nicotine in e-cigarettes
The e-liquid in most e-cigarettes (vapes) contains nicotine. However, nicotine levels are not the same in all types of e-cigarettes, and sometimes product labels do not list the true nicotine content.
There are some e-cigarette brands that claim to be nicotine-free but have been found to contain nicotine.
Why is it so hard to quit tobacco?
Stopping or cutting back on tobacco causes symptoms of nicotine withdrawal. Withdrawal is both physical and mental. Physically, your body is reacting to the absence of nicotine. Mentally, you are faced with giving up a habit, which calls for a major change in behavior. Emotionally, you might feel like as if you’ve lost your best friend. Studies have shown that smokeless tobacco users have as much trouble giving up tobacco as people who want to quit smoking cigarettes.
People who have used tobacco regularly for a few weeks or longer will have withdrawal symptoms if they suddenly stop or greatly reduce the amount they use. There’s no danger in nicotine withdrawal, but the symptoms can be uncomfortable. They usually start within a few hours and peak about 2 to 3 days later when most of the nicotine and its by-products are out of the body. Withdrawal symptoms can last a few days to up to several weeks. They get better every day that a person stays tobacco-free.
Nicotine withdrawal symptoms can include any of the following:
- Dizziness (which may last a day or 2 after quitting)
- Feelings of frustration, impatience, and anger
- Trouble sleeping, including trouble falling asleep and staying asleep, and having bad dreams or even nightmares
- Trouble concentrating
- Restlessness or boredom
- Increased appetite
- Weight gain
- Slower heart rate
- Constipation and gas
- Cough, dry mouth, sore throat, and nasal drip
- Chest tightness
These symptoms can lead a person to start using tobacco again to boost blood levels of nicotine and stop symptoms.
Original Research: Open access.
“The effects of reduced nicotine content cigarettes on biomarkers of nicotine and toxicant exposure, smoking behavior and psychiatric symptoms in smokers with mood or anxiety disorders: A double-blind randomized trial” by Jonathan Foulds et al. PLOS ONE