Is vaping less harmful than smoking, and does it help people quit?

From the article:

While we can’t say that vaping carries zero risk, the evidence clearly indicates that it is much less harmful than smoking.

This should not be surprising: tobacco is extremely bad for health. It not only increases the risk of lung cancer — American men who smoke are around 21 times more likely to die from lung cancer — but a range of other diseases too, including strokes, heart disease, and several other cancers. In the UK, smoking is the leading risk factor for early death, ahead of obesity, high blood pressure, cholesterol, and other behavioral and environmental factors. If you’re a smoker who wants to improve your health, quitting is probably the single best thing you can do.

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People often note that we have less data on the long-term health impacts of vaping. This is certainly true compared to cigarettes. However, vapes’ earliest adopters have been using them for two decades — they were first commercialized in the early 2000s. If there were significant long-term health impacts, we’d expect to see signs of those by now, especially if they were anywhere close to those of tobacco. And while we don’t have very long-term epidemiological data, we do have a good understanding of the ingredients, the levels of exposure, and how these are likely to affect the human body.

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Research suggests that e-cigarettes are the most effective quitting tool.

Periodically, researchers publish “Cochrane Reviews” on the effectiveness of vapes as a way to stop smoking. Cochrane Reviews are independent assessments that attempt to answer important medical questions by examining the scientific literature as a whole.

Their latest review — published in 2025 — found “high certainty evidence” that people who used vapes were more likely to stop smoking than those using other nicotine replacement therapies, like patches or gums. This confidence level is rare for these Cochrane assessments.

They also judged that there is moderate evidence that vapes that contained nicotine were more effective as a quitting tool than those without.

The changes in the last decade are consistent with this finding. If we look at success rates for stopping tobacco smoking in Britain, we see a gradual increase over the last decade or so, both among adults and young people.

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More than half of British smokers who quit in the last five years say they used e-cigarettes in their final, successful attempt. That amounts to 2.4 million people. 60% of those ex-smokers still use vapes, but 32% have since quit vaping too. E-cigarettes have not been the only factor in more people quitting, but they have likely played some role.

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If vapes are an effective and less harmful tool that helps people quit cigarettes, then current smokers need to know this. Survey data suggests that they do not.

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If vaping were a widespread reason for young people to start smoking tobacco, then we would expect to see more youngsters using cigarettes over time. Vaping rates have increased quite dramatically among young people, and with almost 20% of 15-year-olds regularly using them, have reached a level where we would expect to see an effect in the smoking data.

In England, we don’t see such an effect: smoking rates continue to fall (or hold constant at their lowest levels in decades). [...] Only a few per cent of 15-year-olds smoke regularly, which is a huge drop from the 1980s, when it was over 20%. The share of pupils (aged 11 to 15) who have ever smoked has also fallen dramatically, from 50% to 12% since the 1990s. The same is true for other nations in Great Britain.