Bias, Confusion and Consequences: How Misleading Vape Studies are Undermining Public Health
Biased studies, growing misinformation, and political pressure are reshaping global perceptions of vaping, threatening progress in tobacco harm reduction and risking smokers’ lives.
Over the past decade, vaping has been one of the most significant public health breakthroughs in reducing smoking-related harm. Millions of smokers in the UK, Europe, Australia, and North America have switched completely or partially to safer nicotine products. The UK in particular became one of the main global leaders in pragmatic, evidence-based harm reduction. Yet today, that same country, along with several others, appears to be moving in the opposite direction. Public confidence in vaping is falling, policymakers are shifting toward precautionary prohibition, and questionable research is increasingly guiding debate.
A pattern has emerged across multiple new studies and policy reports: evidence is being framed in a way that magnifies hypothetical risks while overshadowing the overwhelming real-world data showing the dramatic risk reduction associated with vaping compared to smoking. What once looked like a public health success story is now being rewritten through the lens of fear.
Failing to differentiate between unrealistic testing and real-life settings
One of the clearest examples of this trend appeared in a review published in Toxicology Letters (2025). The authors argued that heating standard e-liquid ingredients — propylene glycol and vegetable glycerin — can release harmful chemicals like formaldehyde and acetaldehyde. While this is chemically possible under extreme temperatures, the methods used in many of the cited studies bear little resemblance to how real consumers vape.
Harm reduction scientists quickly noted that the studies relied on dry-burning devices, overriding airflow, and generating temperatures far higher than any human could physically inhale without immediate discomfort. Under normal, human-controlled usage, emissions of these chemicals remain at trace levels, if they appear at all.
Researchers call this research pattern “harm-searching science”: recycling old laboratory artefacts under unrealistic conditions to produce alarming headlines. Notably, there is still no evidence of meaningful respiratory or systemic harm from PG or VG, both ingredients that have been used safely for decades in foods, inhaled medicines, and stage fog. A 2018 human exposure study in Inhalation Toxicology even found negligible respiratory effects at levels far exceeding typical vaping exposure.
Despite this, the review’s conclusions circulated widely as “proof” that vaping may be as dangerous as smoking — a narrative completely at odds with real-world toxicological measurements and human biomarker studies.
Twisting data to fit a narrative, instead of shaping a narrative on accurate data
A similar issue has unfolded in Australia, where a recent report on illicit tobacco and vaping markets has been heavily criticized by economists, criminologists, and harm reduction experts. Released just before a major Police Ministers’ Conference, the paper appeared to support a predetermined narrative that current prohibition-leaning policies are effective.
The study’s analysis understated the scale of Australia’s illicit tobacco trade, despite years of warnings from economists and criminologists that punitive taxes and restrictive nicotine regulations would drive consumers toward unregulated products. Instead of acknowledging the surge in black-market activity, counterfeit cigarettes, and dangerous illicit vapes, the study relied on citations from a close circle of aligned sources, including dated reports, government summaries, and even a newspaper article quoting a tobacco executive.
Reviewers argued that this narrow evidence base created an echo chamber of self-reinforcing claims, giving the appearance of academic rigor while omitting real-world data and dissenting perspectives. But, the deeper concern raised by critics is not limited to one review or one policy paper. It reflects a broader shift in public health research, where politically favourable conclusions are increasingly prioritised over methodological rigor.
When evidence is filtered to support a predetermined agenda, the public begins to perceive manipulation rather than transparency. This erosion of trust has long-term consequences: smokers become reluctant to switch to safer alternatives, vapers fear they may have made the wrong choice, and policymakers adopt rules based on distorted science rather than balanced assessment.
Implying causation from mere correlations
Another telling case comes from a University of Georgia analysis that recently made headlines for suggesting vaping may increase the risk of prediabetes or diabetes. While headlines portrayed the findings as evidence that vaping causes metabolic disease, the study was based entirely on correlational survey data and cannot establish causation.
The dataset, drawn from over 1.2 million BRFSS responses, simply maps associations without tracking biological mechanisms or controlling for major confounders such as income, diet, body weight, stress, or pre-existing health conditions. Not surprisingly, the strongest predictors of metabolic disease in the dataset were well-established risk factors like high BMI and low income.
Dual users (people who both smoke and vape) showed higher prevalence of prediabetes, but this group also carries the heaviest burden of underlying health problems. Vapers who never smoked were too small a subset to draw strong conclusions from, and the 7% statistical difference reported is likely attributable to confounding variables rather than vaping itself. Yet the title and framing of the study presented vaping and smoking within a similar risk narrative, misleading both the media and the public.
The cost of misinformation: ineffective policies and lost lives
All three cases — the emissions review, the Australian market paper, and the diabetes analysis — share a common theme: the amplification of risk in the absence of evidence, and the omission of context that would remind readers that smoking remains exponentially more harmful. This scientific climate has real consequences.
Every misleading study, political report, or sensationalised headline chips away at harm reduction by blurring the stark contrast between smoking and vaping. Smoking kills half of its long-term users. Vaping on the other hand, according to global leading independent reviews, carries only a small fraction of that risk. Yet the public is increasingly taught to view both as comparable a message that benefits only one industry: the cigarettes one.
For harm reduction to survive, policymakers and researchers must return to a principle once central to effective tobacco control: the difference between risk and relative risk matters. When that distinction is lost, smokers, especially disadvantaged smokers, pay the price.
Inside the anti-tobacco harm reduction movement
The future of tobacco harm reduction will depend on whether evidence can reassert itself over fear, ideology, and misinformation. If it cannot, the world risks undoing decades of progress in the fight against smoking, not because safer products failed, but because public health communication did.
Taken together, these studies illustrate how flawed or overstated science can influence perception and policy. When public health messaging exaggerates potential vaping risks while failing to contextualize them against the extremely high risks of smoking, the result is confusion — and that confusion has a cost. Smokers who might otherwise have switched to vaping delay or avoid doing so. Some who already switched may return to combustible cigarettes, believing that vaping is “just as bad.” Policymakers, reacting to alarming headlines, impose restrictive rules that limit access to safer alternatives while unintentionally strengthening criminal markets.
The consequences of misinformation ripple widely. Countries that once championed harm reduction, like the UK, now face declining public confidence in vaping and proposals that echo failed prohibitionist approaches. Australia’s strict policies have already created a thriving illicit vape market, undermining both safety and enforcement. When scientific studies are used to justify predetermined narratives, rather than to inform policy objectively, institutions lose credibility and public health loses effectiveness.
Reversing progress
Harm reduction has never claimed that vaping is risk-free. Instead, it recognizes that adult smokers deserve access to far safer alternatives and accurate information about those alternatives. The overwhelming evidence, from toxicology, epidemiology, biomarker studies, and population data, shows that vaping dramatically reduces exposure to the deadly toxins found in combustible tobacco. Ignoring this evidence in favour of speculative or poorly constructed studies threatens to roll back years of progress.
As misinformation grows louder, the responsibility to defend evidence-based harm reduction becomes more urgent. Researchers, advocates, and consumers must push for transparency, demand rigorous scientific standards, and challenge narratives built on selective or unrealistic data. The future of tobacco harm reduction depends on separating ideological bias from empirical evidence. Whether progress continues, or is reversed by fear, confusion, and politicized science, will shape public health for years to come.