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In this blog, Jamie Hartmann-Boyce from the Cochrane Tobacco Addiction Group and Martin Dockrell from the Office of Health Improvement and Disparities share 7 things you need to know about e-cigarettes and quitting smoking, with evidence from the Cochrane Living Review of E-cigarettes and Smoking Cessation

Close-up of smoke against black background © Pexels

Blog authors: Associate Professor, Dr Jamie Hartmann-Boyce and Martin Dockrell from the Office for Health Improvement and Disparities


One of the most common things we hear about e-cigarettes and health is “we just don’t know yet” but the evidence, especially on their contribution to quitting smoking, is continuing to build.

The Cochrane living review of e-cigarettes for smoking cessation brings together the best available research evidence to examine the effectiveness, tolerability, and safety of using electronic cigarettes (ECs) to help people who smoke tobacco achieve long‐term smoking abstinence (1). The evidence is gathered monthly and systematically reviewed with emphasis on quality control to improve knowledge and to feed into healthcare decisions.


  1. Quitting cigarettes even for a few days can benefit your health
  • Within days your heart rate will drop and carbon monoxide and oxygen levels in your blood will return to normal levels.(1)
  • After 1 to 9 months any coughing and shortness of breath will decrease.(1)
  • After 1 year your risk of heart attack will have halved compared to someone who smokes.(1)

2.      Will power is important, but it is rarely enough

  • In England today there are twice as many ex-smokers as current smokers but that does not mean that quitting is always easy. (2)
  • Most smokers have to make repeated attempts and there is no one way that works for every one first time.
  • “Will power alone” provides the baseline on which better interventions can build.

3.      Combine different types of support for the best quit rates

  • People are more likely to successfully quit if they use an evidence-based stop smoking treatment, such as behavioural counselling, stop-smoking medication, and/or e-cigarettes with nicotine. Using both behavioural support and stop-smoking medication increases quit rates more than using either alone (3, 4, 5).

4.      E-cigarettes are an effective tool to help people stop smoking

  • Evidence shows that, head to head, e-cigarettes with nicotine are more effective than nicotine replacement therapy or than e-cigarettes without nicotine in helping people quit smoking. (3)
  • In England e-cigarettes are more popular than nicotine replacement therapy (patches and gum) as a quitting tool. (6)
  • NICE (National Institute for Health and Care Excellence) guidelines advise people who provide stop smoking support to offer advice on using nicotine-containing products on general sale, including over-the-counter nicotine replacement therapy and nicotine-containing e-cigarettes. (4)
  • People who use e-cigarettes to quit smoking may use them longer than if they were to use other treatments, like nicotine patches. This may be one reason that they are more effective. Approximately half of people using e-cigarettes to stop smoking are still using e-cigarettes at 6 months. Among people successfully using e-cigarettes to stop smoking 70% continued to use e-cigarettes at 6 months. (7)

5.      People who switch from smoking to vaping are likely to improve their health

  • Switching from combustible cigarettes to e-cigarettes reduces levels of toxicants in the blood and breath. (8)
  • E-cigarettes do not burn tobacco and do not produce tar or carbon monoxide, two of the most damaging constituents of tobacco smoke. (1)
  • E-cigarettes heat a liquid that usually contains nicotine, propylene glycol and/or vegetable glycerine and flavourings. (1)
  • We still need data on the long-term use of e-cigarettes, however, expert consensus is that, though not risk-free, e-cigarettes are considerably safer than combustible cigarettes. (3)

6.       Misplaced fears about EC safety may be putting smokers off switching

  • Despite a growing body of evidence suggesting e-cigarettes are less harmful than smoking, risk perceptions are going in the opposite direction. (11)
  • A rare but serious lung condition associated with vaping (EVALI) received a lot of media attention. This led people to be more concerned about the risks of using e-cigarettes (Tatton Birch paper on EVALI and EC risk perception) (9).  However, this condition was later linked to vitamin e acetate, an additive found in non-regulated e-cigarettes containing THC (the active ingredient in marijuana) in North America. Vitamin e acetate is banned from e-cigarettes in the UK and Europe, and there have been no cases of EVALI in the UK.
  • Smokers from less advantaged backgrounds may be more likely to have misperceptions of the relative harm (12). People from less advantaged backgrounds are more likely to smoke and more likely to find it harder to quit (12), so are some of the people who would benefit most from trying to use e-cigarettes to quit smoking.

7.       Combustible cigarette use is reducing across the world. The UK is one of the countries aiming to become smoke free

  • Across the world, prevalence of combustible cigarette smoking is 17.5%. This has dropped from 23% 15 years ago. (10)(WHO, 2021). In the UK the prevalence of combustible cigarette smoking is 14%. (2) More than half of people in the UK who currently smoke said they would like to quit. (2)
  • Many countries are moving towards smoke free goals. The UK aims to be smoke free by 2030. (13)



  1. NHS: ; [Accessed 19.5.22.]
  2. ONS Office for National Statistics, Adult smoking habits in the UK: 2019.  [Accessed 19.05.22.]
  3. Hartmann-Boyce J, Lindson N, Butler AR, McRobbie H, Bullen C, Begh R, Theodoulou A, Notley C, Rigotti NA, Turner T, Fanshawe TR, Hajek P. Electronic cigarettes for smoking cessation. Cochrane Database of Systematic Reviews 2022, Issue 11; DOI 10.1002/14651858.CD010216 .pub7
  4. NICE guidelines NG209, 30th Nov 2021, updated 4 August 2022,
  5. Hartmann-Boyce J, Livingstone-Banks J, Ordóñez-Mena JM, Fanshawe TR, Lindson N, Freeman SC, Sutton AJ, Theodoulou A, Aveyard P, Behavioural interventions for smoking cessation: an overview and network meta‐analysis, Cochrane Database of Systematic Reviews 2021, DOI: 10.1002/14651858.CD013229.pub2
  6. McNeill A, Simonavičius E, Brose LS, Taylor E, East K, Zuikova E et al. Nicotine vaping in England: an evidence updateincluding health risks and perceptions. A report commissioned by the Office for Health Improvement and Disparities.London: Office for Health Improvement and Disparities. 29 Sept 2022.
  7. Butler AR, Lindson N, Fanshawe TR, Theodoulou A, Begh R, Hajek P, et al. Longer-term use of electronic cigarettes when provided as a stop smoking aid: systematic review with meta-analyses. Preventive Medicine 2022;EPub. [PubMed: 35933001; DOI: 10.1016/j.ypmed.2022.107182]
  8. Hartmann-Boyce J, Butler AR, Theodoulou A, Onakpoya IJ, Hajek P, Bullen C, et al. Biomarkers of potential harm in people switching from smoking tobacco to exclusive e-cigarette use, dual use, or abstinence: secondary analysis of Cochrane systematic review of trials of e-cigarettes for smoking cessation. Addiction 2022. [DOI: 10.1111/add.16063]
  10. WHO Eighth WHO report on the global tobacco epidemic, WHO Report on the Global Tobacco Epidemic, 2021 Addressing new and emerging products, ISBN: 978 92 4 003209 5
  11. ASH (Action on Smoking and Health) Use of e-cigarettes among adults in Great Britain, August 2022.
  12. ASH (Action on Smoking and Health), Health inequalities and smoking, briefing document Sept 2019,
  13. OHID, Office Health Improvement and Disparities. Guidance Smoking and tobacco: applying All Our Health. Updated 2022,

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