What to know about the controversial tobacco scientist who wants to ban e-cigarettes

Stanton Glantz's crusade against vaping has some critics—and former allies—questioning his research.
Vintage no tobacco cigarette ad with gladiators
No-To-Bac contained licorice, gentian violet, guaiac, and ammonium chloride salt in a chewing gum base designed to substitute for the act of smoking cigarettes, pipes, and cigars. U.S. Food and Drug Administration

Marc Gunther is a veteran reporter whose interests include philanthropy, psychedelics, animal rights, and tobacco. This story originally featured on Undark.

Not many scientists have fought harder against smoking than Stanton Glantz. As a professor of medicine at the University of California, San Francisco and founding director of its Center for Tobacco Control Research and Education, Glantz led campaigns to ban smoking in public places, exposed secret tobacco industry documents, and wrote or co-wrote five books and nearly 400 papers, most documenting the harm done by tobacco.

The cigarette companies despised him, and the feeling was mutual.

“I’d like to just destroy the tobacco industry,” Glantz once said. “It is an industry that kills 5 million people a year. It has no business existing. Make them go do something useful.”

In recent years, however, as a contentious debate over electronic cigarettes has fractured the community of tobacco researchers, many of Glantz’s former allies have turned on the 75-year-old scientist. His critics accuse him of exaggerating the dangers of e-cigarettes and downplaying their benefits. They say that his research into vaping has been driven by politics, not science. Some are even revisiting doubts about his earlier work, saying that his contempt for the cigarette manufacturers—and his activism against them—tainted his influential research into the dangers of secondhand smoke.

In the unkindest cut of all, these critics say that Glantz has become an unwitting ally of the tobacco industry. He has become one of “Big Tobacco’s little helpers,” as David Sweanor, a longtime anti-smoking activist, says.

How can that be? It stems from the belief held by many tobacco researchers, but not by Glantz, that e-cigarettes are safer than combustible tobacco. (Scientists do disagree about how much safer.) Many respected researchers—but again, not Glantz—also believe that e-cigarettes help smokers quit by delivering regular doses of nicotine in a way that won’t end up killing them.

Glantz and his powerful allies in the anti-tobacco movement—nonprofit advocacy organizations the Campaign for Tobacco-Free Kids and the Truth Initiative, as well as the American Lung Association, the American Heart Association, and the American Cancer Society—have mounted a campaign against e-cigarettes funded with $160 million from Bloomberg Philanthropies. Instead of inviting smokers to switch to vaping, Glantz and the nonprofits have promoted more traditional quitting strategies, including those involving the use of FDA-approved medications, while simultaneously working to ban e-cigarettes, tax them, prohibit the sale of flavored e-cigarettes, outlaw their use in smoke-free zones, and generally do whatever they can to stop both adults and children from vaping.

Glantz has made a variety of claims about e-cigarettes—that they are a gateway into smoking, that they don’t help smokers to quit, and that they raise the risk of heart attacks. All have been challenged, and one influential study has been retracted. But as Glantz’s work has been amplified by the nonprofits, they’ve helped turn public opinion against e-cigarettes. His critics say this bad science is driving bad public policy.

“They’ve convinced most of the public, including a majority of smokers, that vaping is as dangerous or more dangerous than smoking,” says Kenneth Warner, a founding board member of the Truth Initiative and former dean of the University of Michigan School of Public Health. “That’s crazy.”

“Stan has always been an advocate and ideologue willing to twist the science,” says David Abrams, a New York University professor and veteran tobacco researcher. He says that some scientists ignored flaws in his work when Glantz focused on combustible tobacco because they, too, strongly opposed smoking. “Frankly, none of us cared if he was a little bit sloppy with his research because the ends justified the means,” Abrams says.

Over his long career, Stanton Glantz embraced his reputation as a rabble rouser, wearing a T-shirt given to him by colleagues that read “Here Comes Trouble.” In retirement, he plans to “keep fighting the tobacco industry,” he wrote to colleagues. Photo: “Tobacco War,” by Stanton Glantz and Edith D. Balbach

Glantz denies that his research has been distorted by his activism. “That’s just bullshit,” he says. “It’s actually the other way around. The activism follows from the science.” He says the scientists favoring harm reduction—the claim, in the case of e-cigarettes, that vaping can reduce the damage of smoking—fail to grasp the dangers of vaping.

While Glantz retired from USCF last year, he remains the go-to scientist for the anti-tobacco movement and an honored figure on campus. “His research contributions in tobacco control are legendary,” said Pam Ling, who succeeded Glantz as head of USCF’s Center for Tobacco Control Research and Education, at a campus event earlier this year. Supporters and critics alike agree that his work has had an enormous impact on public policy.

For four decades, and especially during the early days of the US anti-smoking movement, Glantz was the “preeminent translator of the science of tobacco and disease into the public discourse of tobacco control,” wrote Michael Pertschuk, the former chairman of the Federal Trade Commission, in his 2001 book, “Smoke in Their Eyes.” The feisty academic became a “master of the sound bite” and a “tactical treasure,” according to Pertschuk’s account. Methodological questions aside, Glantz’s papers have been widely cited and publicized, and his relentless advocacy on behalf of smoke-free environments helped to curb smoking, save lives, and reduce the toll of disease. “He truly has been a hero in this global effort to fight the smoking epidemic,” says Clifford Douglas, director of the University of Michigan Tobacco Research Network.

And the impact of his work on e-cigarettes? That is decidedly more complicated.

On April 14, 1994, the CEOs of America’s seven largest tobacco companies stood before a congressional committee and a bevy of television cameras and swore under oath that they did not believe that cigarettes were addictive.

Less than a month later, a Federal Express package containing 4,000 pages of confidential tobacco industry documents arrived at Glantz’s office at UCSF. The return address: Mr. Butts, the name of a character in the comic strip “Doonesbury” who encouraged kids to smoke.

The four-foot-tall stack of papers showed that the tobacco CEOs had lied. “Nicotine is addictive,” said a 1963 memo from a vice president at Brown & Williamson, admitting the company was in the business of selling an addictive drug. The papers were rich with other insights; a letter from movie star Sylvester Stallone to Brown & Williamson promised to use its cigarettes in five movies, in exchange for $500,000.

Working with colleagues at UCSF, Glantz shared the papers with regulators, litigators, and reporters, published research to expose industry tactics, arranged to have the documents digitized, and over time raised millions of dollars to build a vast and valuable archive of materials created by the food, drug, and chemical industries, as well as the tobacco companies. Today, the tobacco archive alone contains more than 14 million items.

“The documents really transformed the whole tobacco issue,” Glantz says.

In an April 1994 congressional hearing, CEOs of the seven largest tobacco companies testified to Congress that they believed nicotine was not addictive. Numerous documents dating back to the 1960s, sent anonymously to Glantz, showed that they were lying. Screenshot: C-SPAN

Big Tobacco and its allies hit back, hard. Brown & Williamson sued UCSF, claiming the documents were stolen. Californians for Scientific Integrity, an industry-funded group, sued the university system, accusing Glantz of scientific misconduct in connection with a study about the impact of smoking bans on the restaurant industry. Congressional allies of the tobacco industry tried unsuccessfully to terminate a National Cancer Institute grant to Glantz, and pro-smoking forces petitioned to cancel his consulting contract with the U.S. Occupational Safety and Health Administration.

In a letter to OSHA asking the agency to sever its ties with Glantz, the National Smokers Alliance called him “an avowed anti-smoking activist.” That was one charge that Glantz couldn’t deny.

Glantz was an anti-smoking activist even before embarking on his career as a tobacco researcher—and often in his career, he has played both roles simultaneously. In 1978, he volunteered to work on a statewide initiative to restrict smoking in public places in California that was defeated by the tobacco industry. “I just got sucked into the campaign leadership,” he says. He was a founder of Californians for Nonsmokers’ Rights, a nonprofit that incorporated in 1981 and grew into Americans for Nonsmokers’ Rights five years later. He helped to lead the 1983 campaign that made San Francisco one of the first major cities in the US to restrict smoking in public, a milestone that made national and international news.

Activism aside, Glantz has an unusual pedigree for a tobacco scientist. Most are physicians, epidemiologists, economists, lawyers, or psychologists. Glantz has a bachelor’s degree in aerospace engineering from the University of Cincinnati—he worked briefly at NASA—and a master’s and doctorate in applied mechanics from Stanford University. His Ph.D. thesis, a study of cardiovascular function, was titled “A mathematical approach to cardiac muscle physiology.”

His understanding of heart mechanics led him into tobacco research in the early 1980s. He found the tobacco work more rewarding, in every sense. Grants from the National Institutes of Health were available to study the effects of smoking, and funding for tobacco research would only grow. In 2009, Congress mandated that tobacco companies start paying annual user fees to finance regulation by the Food and Drug Administration and academic research overseen by the NIH. (The companies paid more than $700 million in 2020.) Private funders including the Robert Wood Johnson Foundation and the Truth Initiative also supported Glantz’s work, which has attracted well over $75 million to UCSF.

More importantly, tobacco research aligned with Glantz’s lifelong commitment to social change. His very first publication, which appeared in Science when he was a graduate student at Stanford, examined the influence of U.S. Department of Defense contracts on research at the university. He embraced his reputation as a rabble rouser, wearing a T-shirt given to him by colleagues that said, “Here Comes Trouble.”

He says his work to achieve a smoke-free society was especially satisfying. It’s easy to forget today that people used to smoke everywhere—at work, in restaurants, on airplanes, even in hospital waiting rooms. In his book, Tobacco War, Glantz recalled: “The executive director of the California division of the American Lung Association was a chain-smoker, and the American Heart Association distributed ashtrays and packs of cigarettes at its board meetings.”

With Glantz’s full-throated support, Americans for Nonsmokers’ Rights took the battle to towns and cities across the country. There, unlike in Washington, grassroots activists could defeat the tobacco industry. More than 400 localities passed laws restricting smoking.

The second-hand smoke issue transformed the politics of tobacco. No longer could the industry defend smoking as a matter of individual choice. Smoking was recast as indoor air pollution and a threat to the health of others. In a 1987 editorial in the journal Circulation, Glantz wrote: “The issue should be framed in the rhetoric of the environment, toxic chemicals, and public health, rather than the rhetoric of saving smokers from themselves or the cigarette companies.”

“Unquestionably, Stan was one of the major warriors in the fight against secondhand smoke,” says James Repace, a former official with the Environmental Protection Agency and one of the first scientists to analyze the health impacts of secondhand smoke.

The cigarette companies recognized the threat early on. In a 1978 report to the Tobacco Institute, the industry’s lobbying arm, a public opinion research group sounded the alarm: “This we see as the most dangerous development to the viability of the tobacco industry that has yet occurred.”

But how dangerous, really, was secondhand smoke? While experts agree that the risks of sustained exposure are high, especially for children, they may not be as high as many advocates claim. Despite lingering uncertainties, opponents of tobacco distilled the science into three words: Secondhand smoke kills. The Surgeon General said in 1986 “there is no risk-free level of exposure to secondhand smoke.” In an anti-smoking bus poster from 1997 depicting an elegantly dressed couple, the man asked: “Mind if I smoke?” The woman replied: “Care if I die?”

In December 2002, after a hard-fought battle, New York City’s then-mayor Michael Bloomberg signed a law that all but eliminated smoking in restaurants and bars. A few months later, Glantz presented the eye-popping findings of his latest study at a meeting of the American College of Cardiology: The rate of heart attacks in Helena, Montana, had fallen by nearly 60 percent after a six-month smoking ban in the small city.

“This striking finding,” he said at the time, “suggests that protecting people from the toxins in secondhand smoke not only makes life more pleasant; it immediately starts saving lives.” Glantz and two local physicians who worked with him on the study also reported that heart attacks returned to their historic levels when the ban was suspended because of a legal challenge.

The Helena miracle, as the study became known, generated global press coverage, including a New York Times op-ed. It was widely touted by anti-smoking groups. But it defied common sense. California had banned smoking in workplaces and bars, with no discernible impact on heart attacks. In other big cities with smoking bans, no one had noticed drops in heart attacks. The small sample size in Helena—four cases per month during the ban, compared to seven beforehand—should have raised red flags; random fluctuations could have explained the drop in hospital admissions.

When the study, which was funded by the National Cancer Institute, was published in the BMJ, the decline in heart attacks was revised downward to 40 percent—still an extraordinary outcome. Detractors pushed back. “I am truly amazed that a study of such poor quality was not only accepted for publication in a journal with the reputation of the BMJ but was accorded widespread coverage in the lay press,” wrote Henry Mizgala, an emeritus professor of medicine at the University of British Columbia, in a response to the journal. “This is, in my opinion, gross misrepresentation designed to provide maximal public impact in furthering the biased and unscientific opinions of these authors.” (Mizgala noted in a disclosure that he had “submitted affidavits on behalf of defendants in the tobacco litigation.”) Glantz’s former student, Michael Siegel of Boston University, was one of a few anti-smoking advocates to challenge the findings. In his own response to the BMJ, he wrote: “I am afraid that the credibility of tobacco control scientists and practitioners may be threatened if scientific claims are made that are not adequately justified.”

The Helena miracle generated global press coverage and was widely touted by anti-smoking groups. But it defied common sense.

Subsequent research with larger sample sizes contradicted Glantz’s findings. England and New Zealand, both of which imposed national bans on smoking in public places, found much smaller impacts—a 2 percent reduction in heart attacks in England, no significant effects in New Zealand. A study by researchers at the Rand Corporation and elsewhere found that the reductions in Helena—which seemed to be confirmed by studies in other small cities, including Pueblo and Greeley, Colorado—were likely a result of their small sample sizes. The authors concluded: “We find no evidence that legislated US smoking bans were associated with short-term reductions in hospital admissions for acute myocardial infarction or other diseases in the elderly, children or working age adults.”

Glantz stands by his findings. (They’re cited in his current biography.) He points out the study found that at the 95 percent confidence interval the effect was real, but ranged from 1 percent to 79 percent, meaning that the reduction in heart attacks could have been much bigger or smaller. However, the caveat was never mentioned by those who cited the study to argue for smoking bans.

For their part, both the Institute of Medicine, now known as the National Academy of Medicine, and the Surgeon General have concluded that there is a causal link between smoking bans and a reduction in coronary events, including heart attacks—though the precise magnitude of the effect remains unclear.

The published version of the Helena study acknowledged its limits, noting the city’s small size. “There is always the chance,” the authors wrote, “that the change we observed was due to some unobserved confounding variable or systemic bias.” They concluded by making the modest claim that smoking bans “may be associated with an effect on morbidity from heart disease.”

When describing the study, though, Glantz showed no such restraint. In the original UCSF press release announcing the results, Glantz was quoted as saying: “Smoke-free laws save lives, and they do it quickly.”

This was the beginning of a pattern. Clive Bates, the former director of the London-based anti-tobacco organization Action on Smoking and Health, says Glantz habitually makes claims to the media or on his blog that go well beyond what his research says.

“We didn’t bother too much about it when he was doing things that we thought were good,” Bates said.

That changed with the arrival of the e-cigarette.

Glantz plays a cameo role in the origin story of vaping. To develop the device that became JUUL, the leading e-cigarette brand in the U.S., two Stanford graduate students dug deep into UCSF’s tobacco industry archives, studying earlier efforts by tobacco companies R.J. Reynolds and Philip Morris to design electronic cigarettes. The students approached Glantz, seeking his support for what they pitched as a tobacco cessation tool. He declined, warning that vaping would appeal to kids.

On that point, he was right. By 2018, after JUUL blitzed young people with marketing on Instagram, in magazines, and on billboards, one in five high school students had used e-cigarettes. The U.S. Surgeon General at the time decried what he called an “epidemic of youth e-cigarette use.” Then again, fewer young people than ever were smoking cigarettes. Some experts described vaping as a disruptive technology that was helping to drive smoking’s long-term decline.

The debate that ensued polarized the tobacco science community. In a commentary in Nicotine and Tobacco Research, nine early-career researchers led by Dana Mowls Carroll of the University of Minnesota expressed concern that “the continued promotion of select, polarized stances on e-cigarettes will threaten the integrity of research.” In a speech at a 2020 conference on e-cigarettes and public health, Steven Schroeder, the former president of the Robert Wood Johnson Foundation and a professor of medicine at UCSF, accused researchers on both sides of engaging in “strident discourse” and “troublesome activities.” He reserved his sharpest criticisms for the opponents of e-cigarettes. “In their anti-vaping advocacy, some have gone beyond the science, stretched the results, cherry picked the analyses, and skated around standard methodological practices,” Schroeder said.

Glantz staked out his position early, and he has stuck to it. In a background paper prepared for the World Health Organization in 2013—before the so-called epidemic of vaping began—Glantz and two UCSF colleagues called for an array of policies, including flavor bans, to curb e-cigarette use. Glantz has been in the thick of the debate ever since, producing several dozen scholarly papers on e-cigarettes, most in collaboration with others, some widely cited. His work has addressed the most important questions about e-cigarettes. He makes three broad claims, all of them sharply contested.

The first claim is that e-cigarettes encourage young people to smoke cigarettes. Glantz’s 2014 article in JAMA Pediatrics was the first national study to show that e-cigarettes were a “gateway to nicotine addiction for US teens,” according to a UCSF press release. His 2018 study in Pediatrics also claimed that e-cigarette usage encourages more young people to smoke. “I don’t know anybody credible who doesn’t accept the gateway,” Glantz says.

Vaping pens in a lab in a rack
Electronic cigarettes, or vaping pens, are lauded by some as a cigarette cessation tool. But from the get-go, Glantz opposed the device, concerned that vaping would appeal to kids. Photo: Centers for Disease Control and Prevention/Unsplash

But neither study proved the existence of a gateway effect. The 2014 JAMA Pediatrics paper found associations between vaping and smoking, but there’s no way to know from the data whether young people first vaped and then smoked, first smoked and then vaped, or had a predilection for both. The 2018 Pediatrics paper claimed a gateway effect, but the alleged link between vaping and smoking disappeared when other teen behaviors, such as using marijuana, were taken into account.

The claims made in JAMA Pediatrics were publicly rejected by scientists at the American Cancer Society and the Truth Initiative, anti-smoking groups that for a brief time in the mid-2000s were open to the idea that e-cigarettes could reduce the harm from smoking. (Both now strongly oppose e-cigarettes.) “The data in this study do not allow many of the broad conclusions that it draws,” Thomas Glynn, a researcher who at the time was at the American Cancer Society, told The New York Times. The Journal of the American Medical Association, the parent publication of JAMA Pediatrics, published a critique of the study written by Glynn, Abrams, and Raymond Niaura, a colleague of Abrams at NYU and another longtime tobacco researcher. Bates, the British anti-smoking activist and persistent Glantz critic, called the study’s conclusions “false, misleading, and damaging” in an open letter.

The 2018 Pediatrics paper was also sharply criticized. Population studies provide the most compelling reason to reject claims of a gateway hypothesis, says Niaura—who, along with Abrams, was previously an unpaid member of the Scientific Technical Advisory Council for the Foundation for a Smoke-Free World, funded by Philip Morris International. “Cigarette smoking among kids is going down and down and down,” he adds. “If e-cigarette use was driving cigarette use, smoking would be going up.” (Glantz contends that e-cigarettes have slowed the decline.)

The second contested Glantz claim is that e-cigarettes, when sold as consumer products, don’t help smokers quit. Glantz made this case in two meta-analyses—studies that collect and combine data from other studies—one in The Lancet Respiratory Medicine in 2016, another in the American Journal of Public Health in 2020. “The irony is that quitting smoking is one of the main reasons both adults and kids use e-cigarettes, but the overall effect is less, not more, quitting,” Glantz said in a press release announcing the 2016 findings.

Meta-analyses can be problematic, particularly when they mix and match different kinds of research. They depend entirely on the quality of the underlying studies, and the Lancet research fell short in that regard, critics say.

In a submission to the FDA, scientists with the Truth Initiative (then known as the American Legacy Foundation) said the Lancet paper included studies that were “uninformative and marred by poor measurement.” They continued: “Quantitatively synthesizing heterogeneous studies is scientifically inappropriate and the findings of such meta-analyses are therefore invalid.”

Scientists in the United Kingdom, where health authorities promote vaping as a safer alternative to smoking, blasted the study as “grossly misleading,” “not scientific,” and a “major failure of the peer review system.” Ann McNeil, a professor of tobacco addiction at King’s College London, issued a response to the Lancet paper, saying that it included information about two studies that she co-authored that was “either inaccurate or misleading” and that in one instance Glantz and his co-author, Sara Kalkhoran, then a physician at UCSF, were told before publication “that they were misreporting the findings.” (Glantz says he doesn’t recall the specific details but that he and Kalkhoran would not have ignored such a warning.)

Plenty of countervailing evidence has surfaced since then. In 2015, Kalkhoran left UCSF for Harvard University where she and colleagues studied US adult cigarette smokers for two years. Using data from 8,000 adult smokers, Kalkhoran and her co-authors concluded that “daily e-cigarette use, compared to no e-cigarette use, was associated with a 77 percent increased odds of prolonged cigarette smoking abstinence.” (Kalkhoran did not respond to requests for comment.) Cochrane, an independent network of researchers, examined randomized control trials of e-cigarettes for smoking cessation and wrote: “We are moderately confident that nicotine e‐cigarettes help more people to stop smoking than nicotine replacement therapy or nicotine‐free e‐cigarettes.” In the UK, an estimated 3.6 million people use e-cigarettes, and nearly two-thirds are ex-smokers, according to Action on Smoking and Health.

None of that will end the debate over whether e-cigarettes can help smokers quit. But even Glantz and his co-authors, in their 2020 meta-analysis for the American Journal of Public Health, ceded some ground. “Daily e-cigarette use was associated with more quitting,” albeit under limited circumstances, they wrote. But Glantz continues to oppose vaping because, he says, the health risks are too great.

The third and final Glantz claim has attracted the most pushback: That e-cigarettes increase the risk of heart attack. In the space of less than a year, Glantz and colleagues produced two studies that led him to push this idea. In August 2018, he described the results from the first study in the American Journal of Preventive Medicine on his UCSF blog under the headline: “Risk of heart attacks is double for daily e-cigarette users.” Ten months later, when describing the second study, published in 2019 in the Journal of the American Heart Association, Glantz said it provided “more evidence that e-cigs cause heart attacks.”

“E‐cigarettes,” he asserted, “should not be promoted or prescribed as a less risky alternative to combustible cigarettes.”

This work was wildly influential with anti-vaping advocates and government health authorities. The American Journal of Preventive Medicine paper was cited by the WHO chief and the U.S. Surgeon General and covered in nearly 200 news stories. A New York Times article read: “Compared with people who never used e-cigarettes, daily users almost doubled their risk for heart attack.”

Critics pounced on what they called glaring flaws in the analyses. Some of the e-cigarette users had previously smoked, for example, muddying the correlation. Brad Rodu, a University of Louisville professor who has numerous and longstanding connections to the tobacco industry, dug into the raw data and found that at least 11 of the 38 heart-attack victims cited in the Journal of the American Heart Association study had suffered their heart attacks before they started vaping—some as many as 10 years before. Glantz was made aware of the temporality problem before publication because it was raised by a peer reviewer, the journal’s editor subsequently realized.

Sixteen tobacco researchers wrote to the journal editor asking for a retraction, and the Journal of the American Heart Association ultimately did just that—something it has done only a handful of times in its history. Its editor, though, was careful to state in a letter to Glantz that “the retraction notice is intentionally absent of any language suggesting scientific misconduct.”

The 2019 American Journal of Preventive Medicine paper came under pressure as well. Twenty-two tobacco scientists asked for a retraction, noting, among other things, that the association between vaping and heart attacks could be due to heavy smokers at risk of heart disease switching to e-cigarettes, or smokers who suffered heart problems then trying to quit with e-cigarettes. To assert or imply causation from the study is irresponsible, they wrote.

“It’s bad science,” says Niaura.

Matthew Boulton, the journal’s editor-in-chief, declined to retract the paper. But, in a letter to the 22 scientists earlier this year, he acknowledged that the paper suffered from “serious methodological issues,” including the fact that the database used by the researchers “makes it impossible to make causal claims.” The journal has asked new researchers to reexamine the issue in a paper that will be presented to readers as a cautionary tale to highlight how data can be misinterpreted.

Glantz remains unrepentant. On his blog, he blamed the Journal of the American Heart Association retraction on “pressure from e-cig interests,” naming Rodu. None of the other scientists who signed the letters seeking retractions appear to have financial ties to the industry. Abrams from NYU once contributed an op-ed to Filter, a publication owned by The Influence Foundation, which has received support from tobacco companies. (Abrams says he was not paid.)

Andrew Gelman, a professor of statistics at Columbia University who followed the controversy on his blog, was unimpressed with Glantz’s response to the retraction, calling it “anti-scientific.” He wrote: “If someone points out an error in your work, you should correct the error and thank the person. Not attack and try to salvage your position with procedural arguments.”

Last summer, Glantz retired from UCSF, where he had worked for 45 years. “I’m confident,” he wrote to colleagues, “that there will be more ways that I can keep contributing to fighting the tobacco industry and promoting public health.”

His last years at UCSF brought difficulties besides the controversies over his research. Three women filed complaints of sexual harassment against him and sued both Glantz and the Regents of the University of California, who fought the charges in court; the cases were eventually settled without an admission of guilt.

Meanwhile, there were worrisome signs that the campaign against e-cigarettes led by the Campaign for Tobacco-Free Kids and the Truth Initiative—which by this time had switched its stance on e-cigarettes—was having unintended consequences.

Minnesota enacted a steep tax on e-cigarettes that led to “increased adult smoking and reduced smoking cessation,” a study by researchers with the National Bureau of Economic Research found. In a story headlined “Smoking’s Long Decline is Over,” The Wall Street Journal reported that some e-cigarette users may have returned to combustible cigarettes “because of increased e-cigarette taxes, bans on flavored vaping products, and confusion about the health effects of vaping.” Public opinion polls showed that most people believed, wrongly, that vaping is as dangerous or more dangerous than smoking.

About the timing of his retirement, Glantz says he’d been planning for years to step away from UCSF. He’ll continue to produce academic research and engage in activism, he adds, speaking out on his blog and elsewhere. He says he is proud of having mentored dozens of researchers over the years: “It’s important to give opportunities to others.”

Siegel, one of those mentored by Glantz, has mixed feelings about his mentor. “I love him,” Siegel says. “He’s accomplished great things.” But Siegel says he no longer trusts Glantz and the anti-tobacco nonprofits. “The science is not driving the anti-smoking agenda,” he says. “Rather, the anti-smoking agenda appears to be driving the interpretation of the science.”

For his part, though, Glantz argues that the increasingly popular perception of e-cigarettes as dangerous is a positive development—and one backed by the science. “None of the people who are e-cigarette enthusiasts,“ Glantz says, “know anything about biology.”

Update August 6, 2021: A previous version of this article neglected to disclose that both David Abrams and Raymond Niaura of New York University were previously unpaid advisors for a smoking cessation organization funded by Philip Morris International. It also neglected to note that both the U.S. Surgeon General and the National Academy of Medicine (formerly the Institute of Medicine) have concluded that smoking bans do reduce coronary events, although the precise size and timing of such an effect is a matter of debate. The story has been updated to include these points.