By Wan Manan Muda and Jomo Kwame Sundaram
KUALA LUMPUR, Malaysia, Sep 10 2019 – Smoking-related diseases are the major causes of premature death worldwide. Every year, six million smoking-related deaths are reported worldwide. If current smoking trends persist, 8 million deaths can be expected by 2030, of which four-fifths will occur in lower- and middle-income countries.
Start them young
Many studies show that smoking is typically learned and started during adolescence. Owing to nicotine addiction, the earlier someone starts to smoke, the higher the likelihood he or she will continue the habit into adulthood, and the smaller the likelihood of stopping smoking.
Early smoking initiation is associated with greater risk of developing lung cancer. The younger the age of smoking initiation, the greater the harm it causes. Early initiation is associated with subsequent heavier smoking, higher dependency, less chance of stopping smoking, and higher mortality.
The first Global Youth Tobacco Survey (GYTS) in 2003 found that 20.2% of 13-15 year-old school-based adolescents were already smoking. Prevalence was much higher among males (36.3%) compared to females (4.2%). Subsequently, the 2009 GYTS reported reduced prevalence (18.2%) of current cigarette smoking among adolescents, mainly due to less male smokers (30.9%) while female smokers increased (5.3%).
Electronic cigarettes new threat
Many studies have reported increasing e-cigarette usage worldwide. E-cigarettes were touted as a means to help smokers stop smoking. However, studies suggest no difference between e-cigarette users and non-users in rates of successfully quitting.
As the vaping epidemic spreads, health risks associated with nicotine rise dangerously. Young people are vaping in record numbers in many parts of the world. “Adolescents don’t think they will get addicted to nicotine, but when they do want to stop, they find it’s very difficult,” notes Yale neuroscientist Marina Picciotto.
Despite many research reports highlighting its dangers and marketing tactics to hook teenagers and young adults, the number of vaping users continues to climb. And while it is possible to buy liquid or pod refills without nicotine, it is much harder to find them.
Many observers, including policymakers, overlook or underestimate the role of nicotine, a key ingredient in the vapours inhaled. Most teens do not realize that nicotine is deeply addictive. Studies show that young people who vape are much more likely to move on to cigarettes, which cause a broad range of diseases.
Why nicotine is so dangerous for youth
Nicotine is dangerous to health at any stage in life, but is especially dangerous before the brain is fully developed, around age 25. Studies show that nicotine can physically change the teenage brain. Adolescents do not think they will get addicted to nicotine, but find it very difficult to stop as “the adolescent brain is more sensitive to rewards”, according to Picciotto, who has studied nicotine addiction for decades.
The mesolimbic dopamine ‘reward’ system is a more primitive part of the brain which positively reinforces behaviour needed to survive, such as eating. As the mechanism is etched into the brain, it is hard to resist. When a teen inhales vapour with nicotine, the drug is quickly absorbed through blood vessels lining the lungs, reaching the brain in about 10 seconds. There, nicotine particles fit ‘well’ into receptors on nerve cells (neurons) throughout the brain.
Why nicotine cravings persist
“Nicotine, alcohol, heroin, or any drug of abuse works by hijacking the brain’s reward system”, according to Yale addiction neurobiologist, Nii Addy. The reward system was never meant for drugs, but evolved, enabling nicotine to biochemically interact well with natural neurotransmitters which activate the muscles in our body.
Once nicotine binds to the receptor, it signals the brain to release dopamine, a well-known neurotransmitter which generates a ‘feel-good’ feeling. Dopamine is part of the brain feedback system signalling that “whatever just happened felt good”, training the brain to repeat the action.
Unlike other drugs such as alcohol, nicotine quickly leaves the body once it is broken down by the liver. And once it is gone, the brain craves nicotine again. Craving, due to the drug that causes the dopamine rush, makes it difficult for addicted youth to quit nicotine.
Recent research, including human brain imaging studies, shows that “environmental cues, especially those associated with drug use, can change dopamine concentrations in the brain”. Simply seeing a person one vapes with, or visiting a school toilet where teens vape during the school day, can unleash intense cravings, making it difficult not to relapse.
Physical changes caused by nicotine
Nicotine also causes physical changes to the brain, some temporary, while others could be long-lasting. Cigarette smoking research has long shown that acetylcholine receptors in the brain increase with continuous exposure to nicotine, intensifying cravings.
But the receptors decrease after the brain is no longer exposed to nicotine, implying that such changes are reversible. Animal studies also show nicotine adversely affecting brain functions, relating to focus, memory and learning, which may be long-lasting.
According to Picciotto, nicotine can cause a developing brain to increase connections among cells in the cerebral cortex region in animals, which would cause cognitive function and attention problems, if also true for humans.
Vaping vs regular cigarettes
Comparing the pros and cons of vaping versus smoking is complicated. On the one hand, unlike regular combustible cigarettes, e-cigarettes probably do not produce 7,000 chemicals, some of which cause cancer. However, aerosol from vaping devices contains lead and volatile organic compounds, some of which are linked to cancer, while the long-term health effects of vaping are still unresearched.
E-cigarettes have not been approved by the US Food and Drug Administration (FDA) as smoking cessation devices. But according to the US Centers for Disease Control and Prevention (CDC), e-cigarettes may be better for adult smokers if they completely replace smoking.
The ‘pod mod’ is a newer, popular vape device outcompeting many other e-cigarettes. The nicotine in these pods is two to ten times more concentrated than most ‘free-base’ nicotine in other vape liquids. A single pod from one vape manufacturer contains 0.7 mL of nicotine, about the same as 20 regular cigarettes.
Despite its highly addictive nature, people can successfully quit nicotine, particularly with personalized approaches under the guidance of suitably trained physicians. For young people, early intervention could significantly improve the quality of the rest of their lives.
To learn more, visit yalemedicine.org
Professor Wan Manan Muda was professor of nutrition and public health at Universiti Sains Malaysia. Jomo Kwame Sundaram was an economics professor and United Nations official.