Degreasing engines & killing cells

Although cell studies for e-cigarettes have some value, presenting them with press statements making ridiculous claims about supposed findings and interpretations makes the whole issue look more like a joke. A wise comment from Dr Farsalinos from May 2015, however these “studies” keep getting churned out some with, and some without scary press releases. But as it is that time of year when folk are more likely to make a quit attempt either due to someone buying them a starter kit for Christmas, or they’ve made a resolution to “kick the habit” at the start of the year; you wouldn’t be surprised to see the useful idiots trumpeting all kinds of daft claims about “the dangers of e-cigarettes”.

Picked up via the Eureka Alert site, the headline of “Cell harm seen in lab tests of e-cigarettes” is one of those types of headlines that will get translated into something more sensationalised by the slathering copy & paste press “journalists”. Especially when you have a line in the press release that says:

Adding to growing evidence on the possible health risks of electronic cigarettes

Which will of course be interpreted as “more evidence that e-cigs cause harm” by journo hacks. You know how it works. So what exactly did this intrepid team of researchers do, and what did they find out?

  • Cells in an artificial environment (in vitro)
  • Two e-cig brands V2 and VaporFi (supposedly two of the most popular currently on the market)

These budding scientists sought to assess the contribution of e-cigs to the pathogenesis and progression of head and neck squamous cell carcinoma (HNSCC), a disease for which traditional cigarette smoking is a well-established risk factor yet the potential role of e-cigs has remained entirely unexplored. In other words, are e-cigs likely to cause cancer of the head or neck to the same degree that cigarette smoking is “well-known” for.

So, stick some cells in a petri dish so they swim about in e-liquid “extract” and see if the cells “die”. In the words of the press release:

Her team 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.

Plus there’s this little nugget, which will no doubt create some scary headlines (emphasis mine):

The exposed cells showed several forms of damage, including DNA strand breaks. The familiar double helix that makes up DNA has two long strands of molecules that intertwine. When one or both of these strands break apart and the cellular repair process doesn’t work right, the stage is set for cancer.

Oh right, so if you drown your cells in e-liquid it’s going to cause irreparable damage to the double-helix setting the stage for cancer. Really? Oh, by the way I almost forgot to mention that the cells were swimming in the solution for up to eight weeks with the treatment media being replaced every three days. That’s 24 hours a day for up to eight weeks. But, as the lead author states:

her team didn’t seek to mimic the actual dose of vapor that an e-cigarette user would get.

So nothing to do with real world usage then. Let us also remember that these budding scientists exposed the same cell lines to tobacco smoke, but it wasn’t for the same duration – Because of the high toxicity of cigarette smoke extract, cigarette-treated samples of each cell line could only be treated for 24 h. – 24 hours. That’s how long they exposed these cells to tobacco smoke, as opposed to up to eight weeks with regular treatment media replacement every three days.

See, here’s the thing. The method used in this study is not the only method for studying cell death. Which makes me wonder why these researchers decided on the method they used.

I doubt that this snippet will see the light of day:

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.

Bit of a shortcoming there when combined with the lack of real world usage. It’s like bathing rat cells in liquid nicotine and extrapolating that effect to human cells. It doesn’t translate all that well.

“Based on the evidence to date,” she says, “I believe they are no better than smoking regular cigarettes.”

Cue the grandiose headlines claiming that e-cigs are no better than smokes! Bravo! Now here’s more grant money to find out more.

What I did take away from reading this paper was that even though they did look at cigarette smoke, they didn’t always report the results and when they did it was only for comparison. Not to mention the cell cultures were specifically chosen to “represent e-cig smokers that already have HNSCC (head and neck squamous cell carcinoma)” Interestingly, the rate of “cell death” doesn’t vary that much between the two brands with or without nicotine.

Percentage of Cell Death
Percentages of Cell Death of the cell cultures

The “healthy” cell line (HaCat) shows consistently low “cell death” with an upper percentage of ~7-8%, even when exposed to cigarette smoke or to nicotine. Remember, the other two cultures (UMSCC10B and HN30) were deliberately chosen from head and neck squamous cell carcinoma cell lines. If you ignore the fact that cancerous cell lines were chosen, the graph can look pretty scary. The reality is, we know that vaping may carry some risk compared with cigarette smoking, and it’s a risk we are prepared to take, just as we did with smoking. All this study is highlighting is the fact that exposing already cancerous cells to cigarette smoke, nicotine or vapour may accelerate cell death, but of course only if you swim in it.

So, the science is pretty clear if a little weird. After all, the first rule of toxicology is “the dose makes the poison” so drowning near-human cells in anything will have an effect, but you cannot specifically claim that it is “cancer causing” that is pure propaganda, not science. So the researchers writing statements like:

“Our study strongly suggests that electronic cigarettes are not as safe as their marketing makes them appear to the public”

Or like:

For now, we were able to at least identify that e-cigarettes on the whole have something to do with increased cell death

And finally:

I believe they are no better than smoking regular cigarettes

Diminishes what little value this research has, after all no credible researcher anywhere believes that, simply because it’s patently and inherently wrong. What we have here is yet another demonstration of science being distorted by personal bias and the results being mis-reported by so-called science journalists.