Numerous stories breathlessly claimed e-cigarettes may be no better than smoking regular cigarettes.

This, the stories inaccurately stated, was what the researchers from the VA San Diego Healthcare System and UC San Diego concluded in their study.

Looking at the factual wreckage spread by slipshod journalism, medical statistician Adam Jacobs picked a story from the Daily Telegraph as the “most dangerous, irresponsible, and ill-informed piece of health journalism of 2015.”

“E-cigarettes are no safer than smoking tobacco, scientists warn,” the Daily Telegraph headline stated.

Scientists didn’t say this in the study. One scientist, Jessica Wang-Rodriguez, said that was her belief. She didn’t claim to speak for all the researchers. And she said it in a press release. File that fact away, I’ll return to it later.

I’m writing not just as a science reporter, but as a San Diegan who is literally and figuratively closer to the research than most reporters. And when, after being occupied by other stories, I got around to writing about this study, the sensational accounts bore little resemblance to what I had read in the study and heard from the researchers.

Everyone makes errors — journalists and scientists alike. But failure to correct errors once pointed out, as happened here, is just wrong. And that so many reporters got it so wrong reflects a systemic problem. Copy and pasting press releases is more popular than actual thinking about the underlying claim.

The botched stories even acquired a Twitter hashtag, #SanDiegoGate, actually a resurrected hashtag previously used for a purely San Diego scandal.

What, then, did the study say?

The study found that in cell cultures, heavy exposure to e-cigarette vapor extract damages DNA, causing genetic instability that could lead to cancer. That’s certainly suggestive of possible harm in people, but doesn’t prove it. Further research is needed to investigate that possibility.

“E-cigarette vapor, both with and without nicotine, is cytotoxic to epithelial cell lines and is a DNA strand break-inducing agent…” the study stated. “Further research is needed to definitively determine the long-term effects of e-cig usage, as well as whether the DNA damage shown in our study as a result of e-cig exposure will lead to mutations that ultimately result in cancer.”

The study also used a high concentration of e-cigarette vapor, intended to simulate what might happen to those most heavily using e-cigarettes. Wang-Rodriguez noted in the press release that this would imply vaping for hours on end.

I can understand the logic to that. If you’re looking for potential harm and want quick results, test the heaviest conceivable dose and scale down from there. If the cell culture model is valid, there might be a point below which e-cigarette smoking shows no evidence of harm. This would be valuable information to vapers. Testing from the lowest dose upward would take far longer to find a harmful effect, if it is proven to exist.

You just have to keep in mind that the studies are looking for evidence of potential harm, and can’t as of yet provide definitive proof one way or the other. For that, a long-term epidemiological study might be needed, perhaps consisting of current smokers, ex-smokers who took up vaping, ex-smokers who don’t vape, and non-smokers.

People don’t like such uncertainty, though, and waiting for the scientific method to do its work taxes their patience. And the stakes are high. If e-cigarettes are indeed safer and provide a reliable pathway to quitting smoking, they would provide a tremendous public health boon. If they prove to be most popular with non-smokers, not so much.

Back to the study. Contrary to the widespread misreporting, the study didn’t conclude that e-cigarette vaping is as harmful as cigarette smoking. Cigarette smoke extract is far more toxic to human cell cultures than e-cigarette vapor extract, the study found.

While cells could be cultured in solutions containing 1 percent e-cigarette vapor for up to eight weeks, cells cultured with cigarette smoke extract could only be treated for 24 hours, due to its high toxicity, the study stated.

And to place the study in context, most of the evidence to date indicates that vaping, while not entirely safe, is a safer alternative than smoking cigarettes. This study is consistent with that evidence.

How did the reporters get it so wrong?

In most cases, they appear to have based their stories on the press release, and misconstrued the personal opinion of one researcher as representing the study itself. Many reporters didn’t cite study findings not included in the press release, so it’s unclear whether they actually consulted the study before writing their stories.

Press releases are supposed to reflect the study’s main conclusions, of course. But they are not a substitute for actually reading the study itself, and ideally, getting help from one or more knowledgeable scientists. And if there’s an online link to the study itself, providing it is a service to readers.

Most tellingly of all, reporters freely used the press release quotes without attribution, as if they had conducted their own interview. So the reporters may not have only failed to read the study, they may never have even talked with the researcher whose quotes they copied.

(To see if quotes were likely taken from a press release, Google a brief excerpt. You’ll often seem the exact same quotes in numerous articles).

The Daily Telegraph article quotes one health expert as saying, “What this research doesn’t do is compare the impact of electronic cigarette vapor with that of tobacco smoke, which we know is far more toxic to cells than vapor.”

Actually, it does. From the study:

“For comparison, cells were also treated with conventional cigarette smoke or with 0.5 mM nicotine, with both nicotine concentrations equivalent to that of the treatment media for nicotine-containing e-cigs.”

And to conclude its parade of errors, the Daily Telegraph article gives an incorrect title for the journal where the study was published. The journal is Oral Oncology, not the Journal of Oncology.

As of Sunday afternoon, the Daily Telegraph has not corrected the reference.

(This article originally appeared here.)