It is unfortunate that ‘negative’ media stories about vaping garner a lot more clicks and shares than ones which tend to be more balanced and accurately reported. One thing most casual readers would hope however, is that what is contained in the press release which gets sent out to journalists does indeed reflect the study findings, and that the data and its implications have been communicated honestly and accurately.
So it certainly disappointing that a study which came to light on Tuesday has elicited some highly alarmist headlines. Although the research was conducted in November, its release this week seems to perfectly coincide with the exact time of year that many smokers will perhaps be thinking of looking for an alternative as part of their new resolutions.
‘Scientists warn e-cigarettes could cause cancer’
‘E-cigarettes may be ‘no better’ than smoking regular cigarettes, warn scientists’
‘E-cigarettes are not safe! They can cause cancer too’
‘E-cigarettes are ‘no better’ than traditional cigarettes, say scientists’
So what lies behind the headlines, what was the study looking at, and was the media frenzy warranted?
According to the press release,
…a lab team at the Veterans Affairs San Diego Healthcare System tested two products and found they damaged cells in ways that could lead to cancer. The damage occurred even with nicotine-free versions of the products.
“Our study strongly suggests that electronic cigarettes are not as safe as their marketing makes them appear to the public,” wrote the researchers, who published their findings in the journal Oral Oncology.
…created an extract from the vapor of two popular brands of e-cigarettes and used it to treat human cells in Petri dishes. Compared with untreated cells, the treated cells were more likely to show DNA damage and die.
Dr. Jessica Wang-Rodriquez, one of the lead researchers concludes:
“Based on the evidence to date,” she says, “I believe they are no better than smoking regular cigarettes.”
The study tells us that ”E-cigarette vapor was pulled through media using negative pressure, and the resulting extract was filter-sterilized with a 0.2µm pore-size filter before treating cell cultures.”
However, as Tom Pruen, Chief Scientific Officer for ECITA points out:
Here’s what is not described in the method:
- Hardware – No mention is made of what hardware was used to generate the vapour. No mention of what design the hardware was, its resistance, or how much power was supplied to it.
- Topography – How long were the puffs? How long between puffs? How many puffs were taken per cartomiser/tank? Was the number of puffs plausible for the design?
- Were the emissions generated in a sensible, realistic way, or was there dry burning (leading to huge emissions of carcinogens – an effect described in the literature back in 2013)? This could have been easily established by conducting an analysis of the vapour condensate for carbonyls, but this was not done.
Effectively, this leaves us with no information at all on the sampling methods, making this research incomplete and unrepeatable. That is not how science is supposed to be conducted.
As regards the fact that this particular type of cell was used, there has been some criticism of the use of cell studies to look at whether results can be directly translated into similar effects in humans. Dr Farsalinos from the Onassis Cardiac Surgery Centre in Athens said when looking at a different study that: ”In the majority of cases, the protocols and experimental procedures are irrelevant to human effects.”
So in comparing the effects of tobacco smoke and e-cigarette vapour, were the two protocols of exposure to the cell cultures comparable, so that an accurate comparison between the amount or rate of cell death observed could be made?
Not at all.
From the study itself:
“Treatment media was replaced every three days with 1% e-cigarette extract. Because of the high toxicity of cigarette smoke extract, cigarette-treated samples of each cell line could only be treated for 24 h.”
Tom Pruen looks at this more closely:
So the cells were being constantly exposed to the vapour condensate for periods of multiple days, with the solution refreshed every 3 days, but only for 24 hours to cigarette smoke condensate because it was too toxic.
Despite the massive difference in exposure, the cigarette smoke extract scored as high or higher on most of the measured outcomes:
This is reported as:
“Cigarette smoke extract led to the highest number of DSBs in HaCaT and HN30 cell lines, but were not significantly higher than V2 nic 1%.”
Except, of course that the exposures were completely different!
Paul Barnes, in his blog notes ”…the cell cultures were specifically chosen to “represent e-cig smokers that already have HNSCC (head and neck squamous cell carcinoma)” In other words, the cell strains specifically chosen for this study were already cancerous.
However, it’s hard to see if this would have mattered, given that, as quite succinctly put here, by clinical researcher and medical statistician Adam Jacobs:
All it tells us is that cigarettes do far more damage to cell cultures than e-cigarette vapour does. Because, and I can’t emphasise this point enough, THEY COULDN’T DO THE STUDY WITH EQUIVALENT DOSES OF CIGARETTE SMOKE BECAUSE IT KILLED ALL THE CELLS.
Since first posting, Dr Farsalinos has added this comment on the methodological error of the experiment itself:
…when you want to look for effects such as inflammation or DNA beaks you need to have cells which have survived the exposure to the medium. In the case of tobacco cigarette smoke, it is so toxic that cells die so you cannot measure any effect. However, what you SHOULD DO is dilute the smoke extract to levels that are not cytotoxic (so that cells survive). Then, you should do the same with the e-cigarette aerosol extract. The problem (for the researchers) was that if they had done that they would see almost no adverse effect from e-cigarette aerosol exposure.
(This appears in full with more context on Clive Bates’ blog, here)
What has been missing from a lot of the reporting are these few statements that should have alerted any journalist to dig deeper and beyond the PR to find out if such salacious headlines were in fact factually accurate, or the scenario even possible:
She notes that cells in the lab are not completely comparable to cells within a living person.
The cells lines that scientists work with have been “immortalized because of certain cell changes,” she says. So it could be that e-cigarette vapor has different effects than those seen in the lab.
Also, her team didn’t seek to mimic the actual dose of vapor that an e-cigarette user would get.
“In this particular study, it was similar to someone smoking continuously for hours on end, so it’s a higher amount than would normally be delivered
For a scientist to outline the above, and then come to the conclusion that “based on the evidence to date, I believe they are no better than smoking regular cigarettes.” is nothing short of bizarre.
The press release suggests that ”the over arching question” is whether vaping products are any safer that tobacco cigarettes.
We would suggest that the more pertinent question might be the real life consequences of such bad science, should smokers be turned off moving to a less harmful alternative, or a vaper goes back to smoking.
The study and the manner in which the story was reported on the media has gained quite a lot of criticism. Below is just a sample of that opinion expressed on social media yesterday from those working in tobacco control, and public health.
— Robert West (@robertjwest) December 30, 2015
— Clive Bates (@Clive_Bates) December 30, 2015
There seems to be a palpable sense of frustration among some of the tweets and exchanges that we have seen. Perhaps because they understand more than most that in order to keep people who are still smoking fully informed of all the options open to them, research and reporting like this isn’t useful. Those who still choose to smoke should be informed that the health risks involved in continuing to smoke are higher than the small amount of risk involved in using a vaping product.
Public Health England re-iterated the importance of balanced risk communication so that smokers are not put off trying vaping:
…provide the public with clear and accurate information on the relative harm of nicotine, e-cigarettes and smoked tobacco. Nearly half the population don’t realise e-cigarettes are safer than smoking, and studies have shown that some smokers have avoided switching in the belief that e-cigarettes are too dangerous.
As did this study looking at how the perceived relative risk of vaping can affect smokers and would-be switchers, which followed respondents over two years. When they found that the portion of people who accurately thought that vaping was safer than smoking had decreased, the authors speculated:
…that this may be due to a predominance of reports and discussions focusing on the risks of e-cigarettes without comparison to the much greater risks posed by cigarettes.
Among a cohort of smokers and ex-smokers, accurately perceiving e-cigarettes as less harmful than smoking predicted subsequent e-cigarette use in never-users; this perception declined over time. Clear and balanced information on the relative harm of e-cigarettes and cigarettes is needed.
The IVVA stands by the position that more research on vaping products is needed and welcomed. But we are also going to publicly call for research to be conducted in a proper manner and that the science be communicated by the media in a way that responsibly informs the public, the industry and policy makers.
For now, we’re going to leave the final words to Dr Michael Siegel:
“not only is this conclusion baseless, but it is damaging to the public’s health. It undermines decades of public education about the severe hazards of cigarette smoking. To declare that smoking is no more hazardous than using e-cigarettes, a non-tobacco-containing product is a false and irresponsible claim.” One of Siegel’s chief concerns about the misrepresentation of e-cigarettes is many ex-smokers who took up vaping may switch back to regular cigarettes if they believe there is no difference between the two. “This will cause actual human health damage, not merely damage to some cells in a laboratory culture.”
and Professor Robert West:
Further reading on this topic: