Last updated March 28, 2018 at 4:19 pm
From toxic ingredients to encouraging young adults to smoke – e-cigarettes are no silver bullet.
Three separate research papers have been published this week raising questions about the health claims of e-cigarettes.
Seen by some as the silver bullet to the problems of tobacco cigarettes, the new papers reveal toxic ingredients in vaping liquids, being receptive to e-cigarette ads increasing the chance of smoking tobacco in the next 12 months, and raised questions that need further study about whether they do assist people to quit tobacco.
Research published in the last month has also revealed that promotion of e-cigarettes could increase the health burden on a population level, by encouraging younger people into tobacco smoking.
Are e-cigarettes a gateway drug?
Backing up that previous finding is a new study in JAMA Pediatrics, which found that 12- to 21-year-olds who have never smoked, but find e-cigarette advertising interesting, would be significantly more likely to smoke tobacco cigarettes within the next year.
Using real examples of advertising shown to over 10,000 people who had never smoked before, those who did show some interest and recall of the e-cigarette advertising were 60% more likely to smoke tobacco within the next year, compared to those who weren’t receptive of e-cigarette advertising.
The study, conducted by the University of California San Diego, found that the link was specific to e-cigarette advertising, and not the advertising of tobacco products.
The participants in the study were classified as being the lowest risk for picking up smoking, having indicated they had no interested in trying any smoking products in the next year. However, over the course of the year, the advertising appears to have swayed their behaviour towards e-cigarettes and tobacco smoking.
“This is the most comprehensive assessment to date of young people’s receptivity to tobacco industry advertising,” said John Pierce from UCSD, the lead author on the study.
“There is a growing body of evidence that adolescents who start with an e-cigarette may transition to cigarettes. This study provides the first evidence that e-cigarette advertising is one of the risk factors for those who are underage to become cigarette smokers.”
“Years ago, when we took away marketing of Joe Camel and similar ads, we saw a major decline in cigarette use among youth,” said Pierce.
“Today, these results suggest that it may be possible for the tobacco industry to use e-cigarette advertising as a way around the public health restrictions on cigarette advertising. E-cigarette advertising is allowed on television and we now have evidence that these ads not only are an influence on committed never users to try an e-cigarette, but also an influence on never users under the age of 21 to start smoking cigarettes.
“There is an urgent need for more research to confirm this finding and determine why e-cigarette advertisements appear so effective at promoting cigarette smoking.”
Do they really help people quit?
A second paper released this week in the Annals of Internal Medicine has raised questions over how e-cigarettes are used in assisting people to quit smoking tobacco, and sparked calls for further studies to work out how to gain the biggest benefit from them.
Researchers from Massachusetts General Hospital studied 1,357 recently admitted adult smokers who planned on quitting following discharge.
The randomised clinical trial compared two approaches – usual care, which involved recommendations regarding smoking cessation medications and support services, or providing participants with their choice of free FDA-approved smoking cessation medications for up to three months and automated phone calls providing advice and encouragement. People in either group were allowed to use e-cigarettes to assist.
Six months following discharge, the researchers used surveys and lab tests to determine who had quit smoking regular cigarettes.
Unexpectedly, people who used an e-cigarette in addition to the treatment strategy dictated by the study, were less likely to have stopped smoking tobacco 6 months later than smokers who did not use e-cigarettes.
However, the data showed that the people who used e-cigarettes generally used them infrequently and not every day. This pattern may not be an effective way to use them for quitting smoking, and they may need to be used regularly to provide the greatest benefit.
Nancy Rigotti, from the Tobacco Research and Treatment Center at Massachusetts General Hospital and leader of the study pointed out that the study “does not prove that e-cigarettes could not be of benefit if a smoker switches completely from tobacco cigarettes and uses them regularly, in the same way that FDA-approved nicotine replacement products are intended to be used.”
The researchers have called for greater study into e-cigarettes as a quitting tool to find the most effective strategy for their use.
“These results indicate the urgent need for randomized, controlled trials to investigate whether e-cigarettes can help smokers to quit, which have been difficult to do in the U.S. because of regulatory challenges,” Rigotti says.
“In the meantime, I would tell smokers who want to quit or cut down to use one of the FDA-approved smoking cessation medications, which are known to be safe and effective, as a first choice.
“If they do choose to try e-cigarettes, they should switch completely from tobacco cigarettes and use e-cigarettes daily, something the American Cancer Society has recently recommended.”
Concerns over toxicity of vaping liquid
One of the major worries of e-cigarettes is the contents of the e-liquid itself, with the health effects of vaping still unclear for the majority of the commercially available e-liquids.
A team of researchers from the University of North Carolina have developed a new screening technique to investigate the different toxicity levels of more than 7,700 types of e-liquids available to consumers.
The two main ingredients of e-liquids, propylene glycol and vegetable glycerin, have been considered non-toxic when consumed orally. However, e-cigarette vapours are inhaled, which could change their effect.
The UNC scientists found that even without nicotine or flavouring chemicals, small doses of these two organic compounds significantly reduced the growth of the test cells, thus indicating high toxicity.
The scientists also found that flavouring ingredients varied tremendously across the e-liquid products tested, with some of the chemicals more toxic than nicotine itself. Overall, more ingredients meant greater toxicity.
The researchers tested a range of human cells including lung and upper airway cells, and found the toxicity results remained largely the same across all cell types. Toxicity results were also the same when the researchers exposed the cells to vaporous puffs of e-liquids rather than applying the liquid directly.
“We found that e-liquid ingredients are extremely diverse, and some of them are more toxic than nicotine alone and more toxic than just the standard base ingredients in e-cigarettes – propylene glycol and vegetable glycerin,” said Robert Tarran, who was the senior author of the study.
The new test is based on a standard toxicity screening test, using fast growing human cells. The amount that chemicals added to the cells slow or stop the growth of their cells indicates the chemical’s toxicity. The researchers now want to use the test to analyse more chemicals contained in e-liquids to discover their toxicity.
“There are more than 7,700 e-liquid products out there, and regulators as well as the general public should know more about the ingredients they contain and how toxic they might be,” said M. Flori Sassano, who lead the research.
The research was published in PLoS Biology.
In total, the thee papers show that much more research is required into e-cigarettes in the future to address these questions and give them a clean (or otherwise) bill of health.