E-cigs and DNA – Bad Science Strikes Again
It probably won’t surprise anyone to hear that another study on the dangers of vapor products is starting to make waves on the wild seas of the internet. It’s already been picked up by some science-themed websites and online news sources like the Huffington Post, and most likely it’s only a matter of time before the mainstream media glom onto it too. This is unfortunate because, as usual, it’s based on some very dubious science.
The latest attack on vaping comes from the University of Connecticut, where a team of researchers has used a new technique to analyze how much damage e-cig vapor does to the DNA in human cells. This isn’t exactly a new angle; there have been at least two previous studies into the effect of vapor in DNA before, and they gave contradictory results.
First came a study from the University of California, San Diego. This was published in January 2016 and, considering it came from the relentlessly negative UC system, its results were about what you’d expect. So was its methodology. After an initial surge of attention caused by lead researcher Jessica Wang-Rodruiguez’s wild claims – she told the media the experiment had shown vaping was no safer than smoking – the paper was systematically taken to pieces by more objective scientists.
It turned out that Wang-Rodriguez and her colleagues had exposed cultures of human cells to e-cig vapor extract for eight weeks; at the end of the period around 5% of them had died. What wasn’t mentioned anywhere in the publicity was that the control sample of cells, which had been exposed to cigarette smoke, all died in one day. The media, cued by Wang-Rodriguez, had been making claims that the research simply didn’t support. This was, at best, incompetent media management; at worst it was blatant dishonesty.
Spot The Difference
Then, last December, another study appeared. This one used a highly realistic 3D model of a human airway to compare the effects of both vapor and tobacco smoke on cells. The researchers found that after 48 hours exposure to cigarette smoke a total of 1,078 genes showed changes. With e-cig vapor the number was just four – and none of them showed double-strand DNA breaks of the type which can lead to cancer. This experiment showed that using an e-cigarette instead of combustible tobacco eliminated almost all the excess risk. Mysteriously, it didn’t get very much publicity.
Actually the reason for the media’s relative silence isn’t really all that mysterious. The research was funded by British American Tobacco, so in the eyes of health journalists it’s fatally tainted. This is convenient because it meant they could simply ignore it, and didn’t have to look for weaknesses in the research itself.
In fact the research strictly followed accepted methods of testing for damage caused by cigarette smoke, and six months after it was published nobody has found any criticism of the science. That’s more than can be said for Wang-Rodriguez’s “science”, which had no resemblance to real-life use and, despite the negative spin she put on it, found little or no harmful effect on DNA.
Making A Mess Of It
So, finally, that brings us to the latest study. Like the Wang-Rodriguez one, it claims to show that vaping is “at least” as bad for DNA as smoking unfiltered cigarettes. The first interesting thing about this study is that lead researcher Karteek Kadimisetty isn’t a scientist; he’s just a Research Assistant. RAs are people who have a science degree but haven’t gone on to do a PhD. They don’t do independent research; they help actual scientists by growing cell cultures, taking notes and running the lab equipment.
So either Kadimisetty was allowed to run his little experiment because he was at a loose end and his research leader thought he looked bored, or he’s a front for someone else. I wouldn’t like to speculate on who he might be a front for, although he does use Stanton Glantz as a source of figures, but it doesn’t really matter.
What does matter is that the experimental design was predictably terrible. Like Wang-Rodriguez, they didn’t even try to realistically model the human body; this time they just used a small 3D-printed array of chambers which each contained human enzymes and DNA. If the enzymes could turn the vapor extract into something dangerous to DNA, it lit up and was detected by a camera.
One point that interested me is that the array was spray-painted with Krylon ColorMaster acrylic paint. According to its OSHA safety data sheet this is corrosive to skin and a Category 2 carcinogen. I’m not saying the paint might have caused the DNA damage, of course, but it does make you think…
Anything To Worry About?
Anyway, obviously this test isn’t very relevant to the real world and the test equipment might cause cancer, but it gets even worse. By now all competent researchers know that conventional smoking machines don’t work with e-cigarettes, but Kadimisetty didn’t even do that well; he used a syringe to collect the vapor. When the e-cig stopped producing as much vapor after around 20 puffs they used more vacuum.
It’s pretty obvious what was happening; they were inducing dry puffs. Real-world vapers don’t inhale dry puffs; in fact we try very, very hard to avoid them. Sadly this doesn’t stop over-zealous but under-informed researchers making the same mistake time after time. If you dry-puff an e-cigarette the level of formaldehyde in the vapor spikes dramatically – and formaldehyde kills cells.
Summing up, this was a study carried out by someone with pretty minimal scientific qualifications who used a collection method with known problems and painted their experimental equipment with toxic paint. Is it worth looking at this issue again just in case the BAT study missed something? Of course. Is this particular study worth worrying about? Absolutely not.
Right now the best evidence available says e-cig vapor doesn’t cause DNA damage. This paper changes nothing. Do not worry about its alarmist claims, because they almost certainly aren’t true.