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E-cigs far safer than smoking, shows long-term research

Lower carcinogen levels after 6 months in people who swapped cigarettes for e-cigs or NRT

Louise Prime

Tuesday, 07 February 2017

People who swapped their conventional cigarettes for nicotine replacement therapy (NRT) or e-cigarettes had lower levels of carcinogens in their bodies after 6 months than those who continued to smoke cigarettes, research published in Annals of Internal Medicine has shown. Experts from Cancer Research UK, which funded the study*, said the findings showed that e-cigarettes could help people quit smoking safely, cutting tobacco-related deaths in the process, as they deliver similar amounts of nicotine to cigarettes with minimal long-term effects on their health.

Researchers led from University College London (UCL) pointed out that previous research into the safety of e-cigarettes had focused on assessing the concentrations of potentially harmful chemicals within the products themselves, or the vapour they produce, rather than the levels found in the bodies of users.

To rectify this, they designed a new study in which they compared levels of metabolites of well-established smoking-related toxic and carcinogenic substances – such as tobacco-specific nitrosamines (TSNAs) and volatile organic compounds (VOCs) – in the saliva and urine of people who had swapped conventional cigarettes for e-cigarettes or NRT, with levels in those who continued to smoke. They found that compared with people still smoking, ex-smokers who had switched to e-cigarettes or NRT for at least six months both had significantly lower levels of TSNA and VOC metabolites in their bodies. However, it became clear that a complete switch from cigarettes was needed to attain these benefits – people who still smoked cigarettes as well as using NRT or e-cigarettes failed to see such a marked improvement in levels of toxins and carcinogens.
Lead author of the study, senior lecturer in the department of epidemiology and public health at UCL Dr Lion Shahab, said: “Our study adds to existing evidence showing that e-cigarettes and NRT are far safer than smoking, and suggests that there is a very low risk associated with their long-term use.

“We’ve shown that the levels of toxic chemicals in the body from e-cigarettes are considerably lower than suggested in previous studies using simulated experiments. This means some doubts about the safety of e-cigarettes may be wrong.

“Our results also suggest that while e-cigarettes are not only safer, the amount of nicotine they provide is not noticeably different to conventional cigarettes. This can help people to stop smoking altogether by dealing with their cravings in a safer way.”

Cancer Research UK said the results of its study could help cut UK smoking death. The charity’s director of cancer prevention, Alison Cox, said: “Around a third of tobacco-caused deaths are due to cancer, so we want to see many more of the UK’s 10 million smokers break their addiction.

“This study adds to growing evidence that e-cigarettes are a much safer alternative to tobacco, and suggests the long-term effects of these products will be minimal.

“Understanding and communicating the benefits of nicotine replacements, such as e-cigarettes, is an important step towards reducing the number of tobacco-related deaths here in the UK.”

* Shahab L, Goniewicz ML, Blount BC, et al. Nicotine, carcinogen, and toxin exposure in long-term e-cigarette and nicotine replacement therapy users: a cross-sectional study. Annals of Internal Medicine 2017; doi:10.7326/M16-1107.

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