Published on: May 5, 2020
by Women’s Brain Health Initiative:
Use of vaping devices has grown rapidly in the past decade. While initially promoted as a smoking cessation aid for adults addicted to conventional cigarettes, vaping devices have become incredibly popular among young people, many of whom are attracted to their enticing flavours, alluring advertisements, and the belief that they are safer than cigarettes.
In a recent study, for example, researchers found that the number of Canadian participants aged 16 to 19 who reported vaping in the previous month increased by 74% in just one year (rising from 8.4% in 2017 to 14.6% in 2018). That same study – conducted by Dr. David Hammond and colleagues and published in 2019 in BMJ – found that 37% of Canadians aged 16 to 19 reported having tried vaping in 2018, compared to 29.3% in 2017.
This trend is of great public health concern because it is becoming increasingly clear that vaping is not harmless.
What is Vaping?
Vaping is the act of inhaling and exhaling an aerosol that is created when a liquid is heated up inside an e-cigarette or similar device. These devices come in varying shapes and designs, and include vape pens, vapes, mods, tanks, and other electronic nicotine delivery systems (ENDS). Recently, the e-cigarette brand JUUL has become so widespread among youth that “JUULing” is also used as a common verb for all e-cigarette use. Disposable devices (such as Puff Bars and Bidi Sticks) have also become very popular.
Typically, each device has a power source, a heating element, and a reservoir for the liquid. Yet, there are vastly differing appearances across devices. For example, some devices look similar to a conventional cigarette or a pen, while others look like a USB flash drive or a unique contraption, unlike any other everyday object.
The contents of vape liquids also vary substantially, but most contain a base of some kind – propylene glycol or glycerin – along with nicotine in different doses and flavourings. The liquids can also contain colourings, sweeteners, and other chemicals, some of which are considered toxic. Some e-liquids contain THC (tetrahydrocannabinol), the component of the cannabis plant responsible for its psychoactive effects (i.e. the “high”). This article focuses on the vaping of nicotine-containing products.
While e-liquids themselves have been found to contain over 60 chemical compounds, the aerosol created once the liquid is heated contains even more.
“Heating liquids in these vaping devices causes thermal decomposition and changes the e-liquid chemicals that some have said ‘pose limited danger’ into known toxicants,” explained Dr. Ilona Jaspers, an inhalation toxicologist and Professor at University of North Carolina at Chapel Hill.
Studies have found that vape aerosol can contain various carcinogens, known respiratory irritants, and volatile organic compounds (such as benzene, which is found in car exhaust fumes), as well as heavy metals such as cadmium, lead, nickel, tin, and copper.
“Because what chemicals and how much of them can be added to e-liquids is not regulated, it is impossible to clearly establish what people are actually inhaling. Furthermore, it’s important to realize that just because something isn’t in the base liquid doesn’t mean that your lungs will not eventually be exposed to it,” emphasized Dr. Jaspers.
What do we know about the health impacts of vaping?
Since vaping is a relatively new phenomenon, there is currently limited research on the direct and long-term health effects of inhaling propylene glycol or other ingredients in e-cigarettes, as well as the potential health consequences from second-hand exposure. However, a recent outbreak of “e-cigarette or vaping product use-associated lung injury” or “EVALI” demonstrates the negative impact of this habit on respiratory health. Researchers have found that these lung injuries resemble those seen after exposure to toxic chemical fumes, poisonous gases, and toxic agents.
As of November 2019, more than 2,000cases of vaping-associated lung illness had been reported to the U.S. Centers for Disease Control and Prevention, including 39 confirmed deaths.
The number of cases of otherwise healthy young people who have been hospitalized and, in some cases, died from vaping-associated lung injury is alarming.
Vaping has also been found in some studies to be associated with cardiovascular disease, oral disease, and increased carcinogenic potential. In addition, more than 100 seizures and other neurological problems linked to vaping have been reported to the U.S. Food and Drug Administration in the past decade.
How does nicotine affect the brain?
Almost all vaping liquids contain nicotine, and the impact of nicotine on the brain has been studied quite extensively. Nicotine increases the release of acetylcholine neurotransmitters that suppress appetite, enhance pleasure, and help with relaxation. Low doses of nicotine have been found to temporarily boost cognitive function, including some aspects of attention and memory. These are some of the effects of nicotine consumption that may contribute to its initial appeal.
However, high doses of nicotine are associated with impaired memory consolidation, and nicotine abstinence after habitual use seems to impair cognitive function temporarily (i.e. when regular users stop using nicotine, they will experience short-term negative impacts on cognition during withdrawal).
It is important to note that chronic smoking of combustible cigarettes has been linked with decreased cognitive performance in middle age, as well as increased risk of cognitive decline and dementia in older age. These effects may be the result of exposure to nicotine and/or other components of regular cigarette smoke. At this point in time, though, it is unknown what the long-term effects of vaping are on cognitive function and dementia risk.
Young people are particularly vulnerable to the negative effects of nicotine on their brains.
After reviewing the available research, the U.S. Surgeon General issued an advisory on e-cigarette use among youth in 2018, warning that “nicotine exposure during adolescence can harm the developing brain,” negatively impacting learning, memory, and attention. Other risks from exposing developing brains to nicotine include addiction, mood disorders, and lower impulse control.
While nicotine is a highly addictive substance for everyone, young individuals are particularly susceptible to developing an addiction to nicotine because of its effect on key receptors in their developing brains. (The brain continues to grow and develop until approximately the age of 25.) It also appears that nicotine can prime the adolescent brain for future addiction to other drugs.
Is vaping safer than cigarette smoking?
Because e-cigarettes do not expose users to the combustible “smoke” of regular cigarettes, it has been suggested that vaping might be safer than cigarette smoking. However, e-cigarette aerosol exposes users to different substances – some of which may be as bad (or even worse) than what is contained in regular cigarette “smoke.”
Even though regular cigarettes and e-cigarettes do have some similarities – e.g. both are products one inhales and they commonly contain nicotine – they are very different in many ways and should not be compared, according to Dr. Jaspers. “E-cigarettes expose users to different chemicals, in a fundamentally different way,” she explained. “With cigarettes, one inhales a mixture created by combusting tobacco plants and other chemicals within. Whereas, with e-cigarettes, one inhales an aerosol created from a liquid. By definition, these are very different exposures. Just as we would not compare smoking cigarettes to smoking crack, even though both involve inhaling, we should not compare vaping with smoking cigarettes.”
Research to date suggests that vaping poses unique health harms, so comparisons with regular cigarette smoking may be irrelevant.
The latest generations of e-cigarettes, including JUUL, use a specific type of nicotine called “nicotine salts” in their e-liquids. This newer form of nicotine allows for much higher concentrations of nicotine to be inhaled with less irritation to the throat. In essence, these newer products have figured out a way to increase nicotine levels in a palatable way.
“The recent outbreak of vaping-associated lung injuries proves the point that vaping is having a uniquely negative impact on health,” said Dr. Jaspers. “The symptoms doctors saw in these patients are not something that would ever be seen in someone who had been smoking cigarettes or marijuana for just a few months. Since doctors are seeing these severe diseases in vapers after relatively short exposures, does that make vaping more harmful than cigarettes? Are these effects truly linked to a single compound like Vitamin E acetate contained in bootlegged products, as some have suggested? More research is needed to answer these questions.”
Amount of nicotine in vaping products
How much nicotine one is exposed to from vaping can vary widely depending on many factors, including how much nicotine is in the liquid, the type of nicotine, the type of device used and whether that device has been modified, and the intensity of inhaling. The amount of nicotine in e-cigarettes can reach or exceed that found in regular cigarettes.
It is also important to know that mislabeling of the nicotine content in e-liquid is common. Although some brands of vape products offer a zero-nicotine liquid option, many brands do not – including some of the most widely-used brands like JUUL.
What’s the impact of second-hand exposure?
Although some e-cigarette manufacturers and retailers have claimed that what a person exhales after using an e-cigarette is “water-only vapor” that is harmless to others, there is actually more than just water being released into the air.
Some of the components that are contained in the aerosol as it is inhaled by the user can linger once it is exhaled, potentially exposing bystanders to nicotine, as well as the respiratory irritants, heavy metals, volatile organic compounds, and various cancer-causing chemicals. Exposure to second-hand vaping aerosol should be avoided, especially by vulnerable populations such as pregnant women and children.
Vaping may be more harmful than we know
There is still so much that is unknown about the health impacts of vaping, including its long-term effects. “It’s likely that vaping has dangers that could take years for scientists to even know about,” warned Dr. Jaspers.
It took decades for epidemiologists to discover that cigarette smoking caused lung cancer, for example, so we should be careful not to assume that e-cigarettes don’t have hidden dangers that might take years to manifest too.
Research on vaping is challenging, in part because the devices and liquids keep evolving quite quickly. As scientists continue to study the health effects of vaping, it is important to remember that the absence of evidence of harm is not the same as absence of harm. There is a lot that we do know already about the negative health impacts of vaping, so it would be wise to err on the side of caution and think twice about vaping, particularly if you are under the age of 25.
Source: MIND OVER MATTER V10
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