Why is the FDA still pushing e-cigs as lower risk based on ancient evidence?

Today (April 16, 2024) the FDA released a new web page on The Relative Risks of Tobacco Products that irresponsibly promotes e-cigarettes as a lower risk alternative to cigarettes. This recommendation is based on the 2018 National Academy of Sciences, Engineering and Medicine report on e-cigarettes that concluded that e-cigarettes reduce exposure to some toxic chemicals.

The problem is that, in the science of e-cigarettes, 2018 is ancient history.

The NASEM report was a reasonable summary of the evidence on the harms of e-cigarettes as of August 2017, when the literature search it is based on was conducted. As of mid-2017, there were about 2000 peer reviewed papers on e-cigarettes. Today, there are nearly 10,000.

In particular, as of mid-2017 there were only 5 studies of the association of e-cigarettes with actual disease. (The NASEM report cites 3 of them, all dealing with asthma in youth.) So, back then, the only thing that one could do was draw conclusions about exposure to toxicants in e-cig aerosol compared to cigarette smoke.

That’s not the case today. As of October 1, 2023, there were 107 population studies of e-cigarettes and disease. Our meta-analysis of those papers showed that for cardiovascular disease, stroke and metabolic dysfunction e-cigarette risks were indistinguishable from cigarette risks. For respiratory and oral disease, e-cigarette risks were lower than for smoking, but not a lot lower. Dual use was always worse than just smoking.

As we concluded at the end of our meta-analysis:

Even without considering the millions of youth who initiate nicotine use with e-cigarettes, these results suggest a need for a careful reassessment of the assumption that e-cigarettes are a substantially less harmful alternative to cigarettes, particularly given the fact that, as consumer products, e-cigarettes are not associated with increased smoking cessation and,
over the long run, are associated with less cessation and increased odds of becoming a dual user. [citations dropped]

Another important problem with the FDA’s approach is that it assumes e-cigarettes produce a subset of cigarette smoke toxicants, so, if there are lower levels of some toxicants the overall risk will be lower. That was the view in 2017, when scientists did not appreciate the fact that e-cigarettes also expose users to thousands of toxicants, many of which are different from cigarette smoke. We now know that e-cigarettes expose users to a different toxicant mix than cigarettes, so the fact that there are lower levels of some toxicants that are present in cigarette smoke does not necessarily mean that, overall, e-cigarettes pose less disease risk.

The same day the new FDA web page was released FDA Center for Tobacco Products Director Brian King wrote in a commentary, “it is important for such messaging to be evidence based.” I agree, and urge the FDA to immediately start making its recommendations based on the currently available evidence on disease risks not the ancient history of 2017/2018.

On the same web page, FDA also announced that it was seeking people to submit grants on “Public Health Communication Messaging about the Continuum of Risk for Tobacco Products.” Is FDA expecting that messaging to also be based on ancient history? I doubt that many applicants are going to want to buck current 2017/2018 FDA dogma on the relative risks of e-cigarettes.

Our meta-analysis paper, published in NEJM Evidence is available open access here. A one page plain-language summary of the paper is available here.