Researchers say vaping instead of smoking can add years to the lives of 6 million smokers. Other experts say e-cigarettes are still unhealthy.

Millions of smokers could live longer, healthier lives by switching to e-cigarettes.

How much longer?

According to a new study from the Georgetown Lombardi Comprehensive Cancer Center, an estimated 6.6 million smokers that kick traditional cigarettes to the curb could live a combined 86 million more years than those who don’t.

That research, published today in the journal Tobacco Control, is the first to model prospective health outcomes based on a hypothetical situation in which cigarette use is largely replaced by e-cigarettes over a 10-year period.

The study authors based their predictions on two separate models: one “optimistic” and one “pessimistic.”

In the optimistic model, researchers used data from current e-cigarette use patterns and published evaluations for potential harm reduction — that is, the ability of e-cigarettes to help smokers quit.

It’s in this model that researchers discovered the large lifesaving potential of making the switch for millions of smokers.

In the pessimistic model, researchers used a “worst case” scenario, where e-cigarettes are more harmful than currently believed and less likely to help with smoking cessation.

Even in this model, researchers found beneficial results.

Under this scenario, an estimated 1.6 million premature deaths would be averted and 20 million fewer years of life lost.

“I did go into the study confident of the ability to save lives under the optimistic scenario, which I believe is consistent with the data that we have so far,” David Levy, PhD, professor of oncology at the Lombardi Comprehensive Cancer Center at Georgetown University and the study’s lead author, told Healthline.

“I did not expect that under the worst-case scenario, where we assumed all of the negative claims that we have found about e-cigarettes, that we would still find substantial public health gains in terms of lives saved,” he said.

While the lifesaving potential of e-cigarettes hypothesized in the study is promising, it’ll hardly be the last word in an ongoing and ever growing debate about the benefits or harms of e-cigarettes.

The American Lung Association declined to comment on this research. But they’ve previously affirmed to Healthline that they don’t support the premise that e-cigarettes are any safer than traditional cigarettes at this time.

At the end of the day, e-cigarettes aren’t considered safe from a health perspective. They’re still nicotine products.

However, for many researchers and advocates, they’re safer. And, when it comes to getting smokers to stop, safer most likely has to suffice.

Smoking cigarettes remains one of the largest preventable health risks.

For long-term smokers, 2 out of 3 will likely die prematurely due to ailments from smoking.

As tobacco control experts move into what they’ve dubbed “endgame,” or eliminating tobacco consumption entirely, the focus still remains on stubbing traditional cigarette smoking above all else.

That’s why some argue that e-cigarettes are generally a good thing, if it means less cigarettes (again, safer, not safe).

“The best studies to date indicate that the most popular forms of e-cigarettes have a small fraction of the cancer-causing and other toxic chemicals that are ingested with cigarettes,” said Levy.

Equally important as the emphasis on the “healthiness” of e-cigarettes are two key public health factors.

Does it help people quit and does it encourage young people to take up smoking?

Anti-smoking advocates, including the American Lung Association, have been particularly critical of e-cigarettes as a gateway for kids and teens to take up nicotine.

The major sticking point is flavorings.

Advocates say that e-liquids, taking on all different flavors from fruits to candy, are enticing to youth.

The U.S. Food and Drug Administration (FDA) previously cracked down on flavored tobacco products in 2009, when it banned the sale of flavored cigarettes.

The lung association has since argued that the FDA should have the ability to do the same thing with e-cigarettes.

Levy says the debate over flavorings is more complicated than that.

“Not only youth are attracted to the flavorings, but so are smokers, and they appear to encourage cessation from cigarettes,” he said. “As we learn more about which flavors encourage cessation and which flavors encourage initiation, I think that the FDA will be in a better position to determine which should be banned.”

Nonetheless, going back to Levy’s two scenarios, it’s important to remember: Even in the pessimistic scenario, in which all the evils of e-cigarettes argued by the lung association and others are true, they still appear to save lives.

In an optimistic scenario, the benefits are significantly more robust.

As far as smoking is concerned, e-cigarettes may simply represent the lesser of two evils.