This week the National Academies of Sciences, Engineering, and Medicine (NASEM) weighed in on the question of whether e-cigarettes are a public health menace or a public health boon. The answer is yes, according to a NASEM report published on Tuesday.

The report, which was sponsored by the Food and Drug Administration (FDA), concludes that "e-cigarettes cannot be simply categorized as either beneficial or harmful to health." While that is true in principle, the report gives too much weight to scenarios in which these products could be harmful, even while confirming that they dramatically reduce exposure to toxins and carcinogens for smokers who switch to them.

NASEM's advice is important because it will guide the FDA as the agency decides how to regulate the vaping industry, which last year got a four-year reprieve from rules that threatened to drive the vast majority of companies out of business. The demands that the FDA ultimately imposes on manufacturers of vaping equipment and liquids will affect the options available to consumers and their knowledge of them, which in turn will determine the extent to which they take advantage of products that could save their lives.

The NASEM report, which is the work of a committee chaired by University of Washington toxicologist David Eaton, acknowledges the harm-reducing potential of e-cigarettes. "E-cigarette aerosol contains fewer numbers and lower levels of most toxicants than smoke from combustible tobacco cigarettes does," Eaton et al. say. "Laboratory tests of e-cigarette ingredients, in vitro toxicological tests, and short-term human studies suggest that e-cigarettes are likely to be far less harmful than combustible tobacco cigarettes."

When people who otherwise would be smoking use e-cigarettes instead, that represents an unambiguous gain from a public health perspective, which seeks to minimize disease and preventable death. "If e-cigarette use by adult smokers leads to long-term abstinence from combustible tobacco cigarettes," the report says, "the benefit to public health could be considerable."

But Eaton and his colleagues worry that e-cigarettes also could increase tobacco-related morbidity and mortality if they encourage teenagers to smoke. Depending on how big that effect is, they say, it might even outweigh the benefit from smoking cessation among adults.

That concern seems wildly implausible in light of current trends. Cigarette smoking by teenagers has continued to fall despite a surge in experimentation with vaping, and last year it reached the lowest level ever recorded by the Monitoring the Future Study, which began surveying high school students in 1975.

Two other factors make it unlikely that significant numbers of teenagers become smokers after getting hooked on nicotine in e-cigarettes. The vast majority of nonsmoking teenagers who vape do so only occasionally, and most of them use nicotine-free e-liquids.

Against these facts, the NASEM report cites studies that find teenagers who try vaping are more likely than those who don't to subsequently try smoking. According to Eaton et al., these studies amount to "substantial evidence that e-cigarette use increases risk of ever using combustible tobacco cigarettes among youth and young adults."

As the report acknowledges, however, these observational studies do not distinguish between correlation and causation. They may simply show that teenagers who are inclined to try vaping are also inclined to try smoking. Such research cannot tell us how many of these teenagers become regular smokers or whether they would have experimented with tobacco even if e-cigarettes did not exist.

Under the collectivist calculus prescribed by the Family Smoking Prevention and Tobacco Control Act, Eaton et al. note, it is not enough to show that e-cigarettes are much less hazardous than the conventional kind and therefore offer a big benefit to smokers who might want to switch. The FDA also must be persuaded that the product, on balance, benefits "the population as a whole."

I think e-cigarettes easily pass this test. I also think it is the wrong test for a free society that respects individual choices and the markets that respond to them.

© Copyright 2018 by Creators Syndicate Inc.