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E-cigarettes are in the news again. This time with headlines that they may cause cancer.
But the study that the stories are based on, published in the journal PNAS, doesn’t show this.
What did the study do?
Researchers from New York University School of Medicine looked at how e-cigarette vapour affected the DNA of mice, and human cells in a dish.
They didn’t look at how it affected people. And they didn’t directly compare it to smoking.
The researchers focused on how components of e-cig vapour damage cells’ DNA. And DNA damage increases the risk of cancer.
But they didn’t look directly at whether e-cigs caused cancer, either in mice or in people.
What did the study show?
They found that e-cig vapour raised levels of DNA damage in the lungs, bladders and hearts of mice.
They also found that the molecular machinery cells use to repair this DNA damage was less effective in the lungs of mice exposed to e-cig vapour.
Then they looked at how nicotine, the chemical that e-cigs vaporise, affects human lung and bladder cells grown in a lab dish. Nicotine is what makes cigarettes addictive, but isn’t what causes the damage from smoking. Both e-cigarettes and conventional cigarettes contain nicotine, but e-cigs have much lower levels of the harmful components of tobacco smoke.
The researchers found that nicotine damages the DNA inside those lab-grown human lung and bladder cells. And they found that these cells were less able to repair this damage. These cells were then more susceptible to further genetic faults that could give them properties like those of cancer cells.
What do the results mean?
The researchers described their results with an interesting line:
“It is therefore possible that e-cigarette smoke may contribute to lung and bladder cancer, as well as heart disease, in humans.”
While this is technically possible, the study didn’t look at humans, and so didn’t show any effect on the health of humans.
Different e-cigs devices deliver different amounts of vapour, and people use them in different ways. So the levels of e-cig vapour and nicotine used in the study might not match the levels that people are exposed to through normal use.
And other research didn’t show a link between nicotine products and cancer.
Finally and crucially, the study didn’t compare vaping to tobacco smoke.
The evidence so far shows that e-cigarettes are far less harmful than smoking.
And for some people they’re a helpful aide to stop smoking.
Up to two-thirds of long term smokers will die because of their addiction. E-cigarettes don’t contain tobacco, which is the biggest cause of preventable death worldwide.
E-cigs are a relatively new technology and so we can’t be certain about any long-term effects the devices might cause to health – they haven’t been around long enough for this to be completely worked out. But compared to smoking, the evidence so far shows they are less harmful.
Studies like this are important for building up the evidence around vaping, and how e-cig vapour might damage cells in controlled conditions. It’s a small piece in the puzzle, and must be viewed alongside other studies. Large, long-term studies are also needed to definitively answer health questions, because those conclusions can’t be made from lab-grown cells and mice alone.
The popularity of e-cigs continues to grow, but figures show that most people using these devices are now ex-smokers, and people mainly use them to quit smoking or cut down.
So conclusions around the health effects of vaping must be viewed alongside the damage that smoking has wreaked for decades. Only then can smokers make a call that could have a big impact on their health.
If you want to quit smoking you can find support to help you here, and find out about your local Stop Smoking Services here.
Thomas July 30, 2018
it might be helpful to mention when using mice they give exorbitant amounts of the substance. much more concentrated than would enter human lungs at any given time.
Philippe Dodier July 2, 2018
Thanks a lot for sharing the news.
Dayle June 25, 2018
l think i wanna marry you
Blaine D. June 7, 2018
I’ve used a JUUL now for about 5 weeks. I intended to cut one in every 4 cigs by using it. I’ve been a 2-3 pack a day smoker for 10 years and a 1-2 pack a day for almost 20 years before that. I haven’t touched a cig at all in 3 weeks.
I went to the local track yesterday to see if my lungs have improved. Last year at this time after 30 days training I could run 1.5miles and with no training or preparation I ran 2.25miles yesterday. My smokers cough has pretty much gone away completely and I barely use my inhalers that I used to need 3-5x per day. I’ll take my chances with my JUUL.
Previously I’ve used other vape machines and e-cigs and had results that varied, including residue build up in my mouth and more trouble breathing than when smoking.
I believe that the type of vape/e-cig and liquid makes a huge difference and should be studied or factored in.
JEO June 3, 2018
I’m an ex-smoker…since vaping was invented. E-cigarettes have definitely saved my life. My sincerest thanks to this tech!
Jordan May 9, 2018
You’ve claimed that the study didn’t show that vaping can contribute to cancer risk in animal models…. But it does show that. Rather directly, in fact. Mice are 85% identical to humans when it comes to coding regions in their genome. Because of this, they’re a viable model for studying some human disease processes.
Speaking Truth April 18, 2018
I’ve poisoned myself for 25 years by smoking on the coffin nails and can tell you first hand when I started vaping 6 years ago it was God sent! I could see/smell/taste/breathe/feel much better within the first 2 weeks of switching to vaping. Its ridiculous how the big tobacco greedy companies haven’t had enough money made by contribution to human skulls and skeletons and continue paying off some “unknown lobbyists” to publish all the scare tactics of articles to deter people from longevity and quality of life just so they can make all the $$ and make us people sick and pass us on to the big pharma to continue making $$ by radiation/so called treatments and finally pass us in to the grave (population control). Guess what? Go screw yourselves big pharma and tobacco! People are getting wiser and you’re losing the war!
Ben March 29, 2018
Thank you for writing this article. I am personally doing a research on vaping and your post is helpful. I look forward to reading more of your posts. Cheers!
Mawsley February 12, 2018
Aryeh Greenberg’s link is precisely the kind of ridiculous, pseudo-research that places the lives of a billion smokers at risk. Place cultured cells in a dish in contact with any substance and they will die – which, of course, is just the response the researchers sought. It is shameful that the media gives wide coverage to junk science like this and ignores proper studies. Greenberg clearly doesn’t value harm reduction for smokers – fortunately for us in Britain our NHS and medical bodies do.
Aryeh Greenberg February 7, 2018
Not when you read this paper:
Trisha February 5, 2018
I’ve been using ecig for around 6-7 months now, and feel so much better for it. I try to keep up to date with all the research and studies, though this one doesn’t seem as reliable as most. I’m in the process of cutting out nicotine (in stages, almost there…) as I believe the chemical is harmful as well as addictive, which this study also seems to suggest, however a nicotine free ecig study alongside the standard nicotine levels being studied on the mice and human tissue would make an interesting and maybe more informative read.
B February 4, 2018
This doesn’t tell us anything. I thought it was half of smokers not 2/3.
Faiz February 2, 2018
I tell you smoking is danger cause cancer but vaping is not danger because is liquid just for wrap ok
Steven February 1, 2018
Cancer research UK helped me switch to vaping in February 2017 After reading their first research paper. I was smoking for 23 years. After 7 months I stopped vaping and stopped smoking altogether. Even whilst i was vaping I felt a lot better then when i smoked tabacco products. now I am a proud non smoker.
anthonyb February 1, 2018
As Oliver on an earlier comment has already mentioned, changing of the coil in the Njoy. It was one of the first things that was picked up on the forum, no mention in the method of how often the coil was changed, or, how they detected when the coil was in need of changing.
As most if not all ecig users know, even changing a coil, at a regular timed interval, does not insure that any given coil is ok to use for that time interval. The reason being, that even two coils from the manufacturing batch, will not necessarily perform the same. One might last only a couple of days, the other a couple of weeks.
If it is the case, that these “scientists” have a coil that will last 12 weeks, then they have cracked it, as very ecig user on the planet would like to buy some please.
I would like to ask as well. How many mice actually survived the 12 week gassing from a burnt out coil ?
Sophie shimman February 1, 2018
Vaper is water. Water on your lung cause pneumonia. Pneumonia no cure??? Know ppl who just use vape instead fags. 3 ppl i know still vape 2 years on .
Fingerspete February 1, 2018
E-cig are not as taking in a thousand chemicals that are dangous nicotine is addicti9ve yes but from what I’ve read and seen no more harmful then tea or coffee
Ralph Concialdi February 1, 2018
I think big tobacco will do or say anything about vaping to be harmful or more harmful than cigarettes just to kept you hooked. Vaping got me off a very bad habit I started at age 12, I’m now 64 and have smoked all this time, what a waste of money. Tried patches and was still smoking with them, waste of money. Tobacco companies should be paying for this not ME, they got me hooked, and our own government could care less as long as they got their fair share of revenue ! Vaping got me off cigs the day I tried it. I think vaping is much safer than what the drug companies are making you take to quit, the side effects alone scare the hell out of me. Just like big oil paying for studies on global warming saying it’s not real, so will tobacco and drug companies will try to discourage vaping.
Oliver February 1, 2018
As others have stated, the study seems pretty flawed. Misusing the e-cigarettes in the study (failing to read the recommended use of the Njoy vape pen) and exposing mice to the extremes of vaping (puff regime consisting of 35-mL puff volumes of 4-s duration at 30-s intervals) stand out to me the most. Are the scientists changing the coils of the e-cigarettes? Do scientists have data on the average amount of use people are getting out of e-cigarettes to give us relevant data (because everything in large quantities is going to present some harmful side-effects)? Are scientists aware of the fact that certain compounds are harmful or even toxic to one species and go completely unnoticed by another? Hopefully this article from cancer research uk will spread so that people aren’t deterred from trying to swap from a life threatening habit to something less harmful by what consistently feels like propaganda and flawed research.
MarcK February 1, 2018
I had been a pack-a-day (20-25), full strength (16mg) smoker for 25 years. I have lost count of the number of times I tried to quit. I started vaping late Jan 2017. By mid Feb, I was down to 6 per day. By June, I had stopped the cigs completely. My sense of smell has come back. I feel and (apparently) look better. I am saving heaps of money. I don’t smell like an ashtray any more. I can no longer tolerate the taste of tobacco (the smell, I can live with).
Switching to vapes is probably the single best decision I have ever made.
Plus, it tastes nice…
John February 1, 2018
Big Tobbaco. You’re dying and us vapers are all clapping.
N woodward January 31, 2018
I have smoked for over 30 years and found it impossible to give up. I spent thousands over the years on acupuncture hypnotherapy and anything else I thought would help. Got myself a vape. Chose a day and I have not picked up a cigarette since! I do however admit to using lozenges on occasion too if the urge got too much. I promised myself I wouldnt ever smoke again. I do worry about the effects as they haven’t been around long enough for any proper analysis on their dangers BUT they can’t be any worse than smoking!
Adam Williams January 31, 2018
It’s about time these junk scientists were brought to court. If one smoker dies because they didn’t switch, then I’d have the for manslaughter! Well done CRUK for your response.
RAED January 31, 2018
I am a smoker , but I think the publication of this study is mainly intended for more advertising.
Matthew January 31, 2018
Another liberal based test that shows nothing of the effects on a living person