Why it’s wrong to say vaping is as bad for you as smoking

Summary

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More or Less – "Why it’s wrong to say vaping is as bad for you as smoking"

BBC Radio 4 | Host: Charlotte MacDonald | Air Date: May 9, 2026

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Episode Overview

This episode of More or Less, hosted by Charlotte MacDonald, investigates whether vaping is as harmful as smoking. The impetus is a recent sensational news headline claiming a major study has shown vaping to be just as bad for you as smoking, particularly regarding cancer risk. The episode, featuring input from reporter Tom Coles and Professor Leon Shahab (UCL), dissects the statistics and scientific evidence underpinning these claims—clarifying what the research actually says and untangling public confusion.

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Key Discussion Points & Insights

The Public Health Context ([01:41])

• Smoking: WHO estimates 7 million deaths/year globally.
• Smoking is acknowledged as “one of the world’s leading causes of preventable death,” linked directly to cancer, heart disease, and stroke.

What Makes Smoking and Vaping Different ([03:08])

• Tom Coles explains the fundamental difference:
  • Smoking: “You’re setting chemically treated tobacco on fire and inhaling the smoke, coating your lungs with toxic tar...” ([03:08])
  • Vaping: “Works by heating a liquid containing nicotine and flavourings with an electric coil to produce an aerosol…that you inhale.”
• Professor Leon Shahab:

  “It’s quite clear that E cigarettes are not as harmful, because there’s no combustion going on and there’s no tobacco involved.” ([03:41])

Dissecting the “Major Study” and Its Limitations ([04:05])

• The article referenced is based on an Australian qualitative risk assessment summarizing existing research—not new data.
  • Prof. Shahab:

    “This is not presenting any new information...the authors of this study didn’t undertake any new research themselves.” ([04:23])

  • The review identifies 'potential' cancer mechanisms, not proven risk.

Vaping, Cancer, and the Evidence Puzzle ([04:54])

• Key point: Cancer develops over decades; widespread vaping is only recent, so population-level data is lacking.
• The paper examined:
  • DNA damage, inflammation, oxidative stress—“potentially linked with cancer, but also potentially not.” ([05:13])
  • Animal studies (notably, extreme-exposure studies in mice) are hard to interpret for humans:
    • “The level of nicotine they were exposed to was massively higher than for human vapers...” ([05:41])
    • Even after these studies, scientists qualify their claims:

      “Electronic cigarettes may or may not pose a danger to humans.” ([06:04])

Context of Chemical Risks & Dose ([06:45])

• Prof. Shahab:

  “The dose makes the poison. We are exposed to things that are considered to be carcinogenic in every day...but because of the levels being very, very low, it is unlikely that these trace amounts would actually lead to cancer in any large number.” ([06:47])

Actual Exposure Levels ([07:13])

• The referenced study compared carcinogen exposure for smokers, vapers, and non-users:
  • For one known carcinogen (NNK):
    • Vapers: 400% above non-users.
    • Smokers: 22,000% above non-users.
• Another risk assessment (New Zealand):
  • Vapers may inhale slightly more formaldehyde than smokers—but this depends heavily on “the voltage of your vape and how hot it makes the liquid...some producing none at all.” ([07:54])
  • Even so, total carcinogen exposure is “much lower than for smokers.”

Is Vaping “Not Safer” Than Smoking? ([08:23])

• Cancer risk specifically:
  • The Australian study says e-cigarettes may be carcinogenic but doesn’t (and cannot) quantify risk.
  • The New Zealand research: “Cancer risk from vaping is likely lower than the cancer risk from smoking.” ([08:35])
• Other health risks:
  • Some meta-analyses suggest elevated risk for vaping of strokes, heart disease, and asthma.
  • These risks are smaller than with smoking and not always statistically significant.

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Notable Quotes & Memorable Moments

• Prof. Leon Shahab:

  “It’s quite clear that E cigarettes are not as harmful, because there’s no combustion going on and there’s no tobacco involved.” ([03:41])

  “The dose makes the poison...these trace amounts would actually [rarely] lead to cancer in any large number later in life.” ([06:47])

• Tom Coles:

  “Just because you’ve identified a chemical that can potentially cause cancer in mice under extreme conditions, that doesn’t mean that it’ll do the same in people who vape, does it?” ([06:35])

• On the headline’s conclusion:

  “It also looks to me like smoking is almost certainly worse for you than vaping. Just how much worse is still up for debate. But if you’re a smoker, it seems to make sense to switch if you can’t stop by other means.” ([09:48])

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Important Segment Timestamps

• [01:41] – Introduction: Smoking statistics and health context
• [03:08] – Mechanisms: How smoking vs. vaping work
• [03:41] – Prof. Shahab’s first expert insight
• [04:05–06:24] – Meaning and limitations of the ‘major study’; animal studies
• [06:45] – “Dose makes the poison” explanation for carcinogen risk
• [07:13] – Comparative exposure to carcinogens: smokers vs. vapers
• [08:23] – Why vaping is not “just as bad” as smoking (and why some reports claim otherwise)
• [09:48] – Final recap: “Smoking is almost certainly worse for you than vaping”

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Conclusion

Charlotte MacDonald and guests conclusively demonstrate that current evidence does not support the claim that vaping is as harmful as smoking—especially in terms of cancer risk.

• While vaping isn’t risk-free and may carry non-cancer health risks, all evidence suggests its dangers are still markedly lower than those posed by traditional smoking.
• For smokers unable to quit entirely, switching to vaping is a “rational choice,” though for non-users, abstaining from both remains healthiest due to the addictive potential of nicotine.

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Further Information

If you come across numbers or statistics you think More or Less should investigate, email [e-mail].

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Transcript

[A]

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[C]

Hello and thanks for downloading the More or less podcast. We're the programme that looks at the numbers in the news and in life and in nicotine. I'm Charlotte MacDonald. According to the World Health Organization, smoking kills some 7 million people every year. It's one of the world's leading causes of preventable death. Because smoking causes lung cancer and other awful health conditions, many smokers switch to vaping using nicotine based e cigarettes. But the World Health Organization is also concerned about vaping. Last year they said 100 million people around the world are now using e cigarettes, including millions of children, and warned that they were fuelling a new wave of nicotine addiction. But how do the health risks of these two means of getting nicotine into your bloodstream compare? According to a recent article in the Daily Mail, they're basically the same. Here's the headline. Vaping is linked to lung and mouth

[D]

cancer in major study as experts warn it is not safer than smoking.

[C]

But is that true? Is vaping Just as bad for you as smoking. Tom Coles has been taking a look at this. Hi, Tom.

[D]

Hello, Charlotte.

[C]

So we know, or more or less, that smoking is one of the clearest examples of something that is unambiguously bad for you. We know that it causes cancer, heart disease, strokes, you name it, right?

[D]

And we know why that is. Because you're setting chemically treated tobacco on fire and inhaling the smoke, coating your lungs with toxic tar in the process. At the same time, we also know that vaping does not involve those things. E cigarettes work by heating a liquid containing nicotine and flavourings with an electric coil to produce an aerosol or mist that you inhale before filling the street

[C]

with a sickly sweet smell.

[D]

Indeed, here's Professor Leon Shahab, co Director of the UCL Tobacco and Alcohol Research Group at University College London.

[E]

So, based on that very simple description of the process in which nicotine gets into the body, it's quite clear that E cigarettes are not as harmful because there's no combustion going on and there's no tobacco involved.

[C]

Now, the headline in the Mail seems to be saying two things. First, that a major new study has found that vaping is linked to cancer, and second, that this means that it's not safer than smoking. Is that right?

[D]

Not really and no. Let's start with the first part. The study in question comes from researchers in Australia who did something called a qualitative risk assessment on the carcinogenicity, that is the cancer causing potential of vaping. By looking at existing research, as Leon

[E]

says, it's very important to make clear that this is not presenting any new information. So this is a review. The authors of this study didn't undertake any new research themselves.

[D]

It wasn't a systematic review where you have clear selection criteria and a method for establishing how to weigh different studies. They just looked at recent research on E cigarettes in general and identified aspects of vaping that had cancer causing potential. At this point, we don't know whether those potential risks are actual risks.

[C]

Why not?

[D]

Well, because cancer takes a long time to develop, years or even decades. Vapes have only been in widespread use since the 2010s, and not enough time has passed to get a clear statistical idea of the cancer risk from actual cancer cases, if there is a risk.

[C]

So what evidence did they look at in the paper?

[D]

All kinds of stuff. They looked at biological mechanisms that have a potential cancer risk, things like DNA damage, inflammation and oxidative stress. All of these are potentially linked with cancer, but are also potentially not.

[E]

E cigarettes increase oxidative stress. That is true. However, oxidative stress is also increased when you exercise or is part of normal aging. All of these things individually aren't a smoking gun that suggests they cause cancer.

[D]

They also looked at evidence from animal studies, one of which is the topic of considerable scientific debate. This study put mice in vape filled cages for four hours a day, five days a week for about a year. The level of nicotine they were exposed to was massively higher than for human vapours. Once you take their size into account and they were exposed over their whole body, which, being furry animals they constantly lick, vapours don't tend to do that. Nine out of the 40 mice in the E Cig group developed lung cancer, compared to one out of 40 in the control groups. But the scientists who did the research specifically state that despite the results, electronic cigarettes may or may not pose a danger to humans.

[C]

That doesn't sound very convincing.

[D]

No, but the authors of the Australian paper told me that these kind of experiments have helped to identify carcinogens in the past.

[C]

Okay, but just because you've identified a chemical that can potentially cause cancer in mice under extreme conditions, that doesn't mean that it'll do the same in people who vape, does it?

[D]

No, and that's exactly Leon's argument.

[E]

The term I would use there is that the dose makes the poison. We are exposed to things that are considered to be carcinogenic in every day. For instance, we have low levels of benzene in soft drinks, or if you eat rice, they can contain inorganic arsenic. But because of the levels being very, very low, it is unlikely that it will actually. These trace amounts would actually lead to cancer in any large number later in life.

[D]

In terms of the actual dose, the paper in question includes a table that lists the quantities of known carcinogens that vapours are exposed to comp to smokers and people who do neither. For most of them, smokers are exposed to much higher quantities than vapers. For one well known carcinogen known as NNK, the levels were up by 400% in vapers compared to people who don't vape or smoke, but by 22,000% in smokers. But even this question is really difficult to pin down. Another risk assessment, this time from New Zealand, argued that people who vape were potentially exposed to another carcinogen, formaldehyde, at slightly higher levels levels than smokers. But when you look at the underlying research, you find that the formaldehyde levels are massively dependent on the voltage of your vape and how Hot, it makes the liquid with hugely variable levels and some producing none at all. That paper found that the overall amount of carcinogens inhaled by E CIG users was much lower than for smokers. And they didn't even include some of the worst carcinogens from smoking, including in their assessment.

[C]

Which brings us to the second part of the headline, the idea that vaping is not safer than smoking. From what you've said, I'm not clear how you draw that conclusion if we're talking about the cancer risk.

[D]

Me neither. And if we're talking about cancer, they don't actually say that in the Australian paper. All they say is that nicotine e cigarettes are likely to be carcinogenic. They don't talk about the size of the potential risk nor the amount of vaping you would have to do in order to be exposed to it. That means they can't actually say how it compares to the massive and known cancer risk from smoking. The New Zealand researchers I just mentioned agreed that there are potential carcinogens in E cigarette vapour, but they were explicit that the cancer risk from vaping is likely lower than the cancer risk from smoking.

[C]

Okay, so why do they say that vaping is not safer than smoking?

[D]

Yeah, it's an odd one. They throw that in as the final line of the Australian paper and it's talking about the non cancer risks. It cites a Meta analysis from 2024 which found sizeable health risks from vaping around things like strokes, cardiovascular disease and asthma. Although the risks appear to be lower than for smokers, the difference wasn't statistically significant for some of them.

[C]

Ok, but if we're not including cancer risk, doesn't that make the overall comparison meaningless?

[D]

Well, that is how it looks to me. It also looks to me like smoking is almost certainly worse for you than vaping. Just how much worse is still up for debate. But if you're a smoker, it seems to make sense to switch if you can't stop by other means. To repeat, vaping has to be really bad to get anywhere near the dangers of smoking. But if you don't smoke or vape and you want to live a healthy life, then probably don't start vaping. It's not good for you. And nicotine is highly addictive.

[C]

Got it. Thanks tomorrow and thanks to Professor Leon Shahab. If you've seen a number or stat in the news, you think we should take a look at email more or [e-mail] that's it for this week. Goodbye.

[F]

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