E-cigarettes are less toxic and safer to use compared to conventional cigarettes, according to UK research. Cancer Research UK-funded scientists found that people who swapped smoking regular cigarettes for e-cigarettes or nicotine replacement therapy (NRT) for at least six months, had much lower levels of toxic and cancer causing substances in their body than people who continued to use conventional cigarettes.
For the first time, researchers analysed the saliva and urine of long-term e-cigarette and NRT users, as well as smokers, and compared body-level exposure to key chemicals. Ex-smokers who switched to e-cigarettes or NRT had significantly lower levels of toxic chemicals and carcinogens in their body compared to people who continued to smoke tobacco cigarettes. But, those who used e-cigarettes or NRT while continuing to smoke, did not show the same marked differences, highlighting that a complete switch is needed to reduce exposure to toxins.
Dr Lion Shahab, senior lecturer in the department of epidemiology and public health at University College London, and lead author of the publication, 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."
Alison Cox, Cancer Research UK's director of cancer prevention, said: "Around a third of tobacco-caused deaths are due to cancer, so we want to see many more of the UK's 10m 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."
Abstract
Background: Given the rapid increase in the popularity of e-cigarettes and the paucity of associated longitudinal health-related data, the need to assess the potential risks of long-term use is essential.
Objective: To compare exposure to nicotine, tobacco-related carcinogens, and toxins among smokers of combustible cigarettes only, former smokers with long-term e-cigarette use only, former smokers with long-term nicotine replacement therapy (NRT) use only, long-term dual users of both combustible cigarettes and e-cigarettes, and long-term users of both combustible cigarettes and NRT.
Design: Cross-sectional study.
Setting: United Kingdom.
Participants: The following 5 groups were purposively recruited: combustible cigarette–only users, former smokers with long-term (≥6 months) e-cigarette–only or NRT-only use, and long-term dual combustible cigarette–e-cigarette or combustible cigarette–NRT users (n = 36 to 37 per group; total n = 181).
Measurements: Sociodemographic and smoking characteristics were assessed. Participants provided urine and saliva samples and were analyzed for biomarkers of nicotine, tobacco-specific N-nitrosamines (TSNAs), and volatile organic compounds (VOCs).
Results: After confounders were controlled for, no clear between-group differences in salivary or urinary biomarkers of nicotine intake were found. The e-cigarette–only and NRT-only users had significantly lower metabolite levels for TSNAs (including the carcinogenic metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol [NNAL]) and VOCs (including metabolites of the toxins acrolein; acrylamide; acrylonitrile; 1,3-butadiene; and ethylene oxide) than combustible cigarette–only, dual combustible cigarette–e-cigarette, or dual combustible cigarette–NRT users. The e-cigarette–only users had significantly lower NNAL levels than all other groups. Combustible cigarette–only, dual combustible cigarette–NRT, and dual combustible cigarette–e-cigarette users had largely similar levels of TSNA and VOC metabolites.
Limitation: Cross-sectional design with self-selected sample.
Conclusion: Former smokers with long-term e-cigarette–only or NRT-only use may obtain roughly similar levels of nicotine compared with smokers of combustible cigarettes only, but results varied. Long-term NRT-only and e-cigarette–only use, but not dual use of NRTs or e-cigarettes with combustible cigarettes, is associated with substantially reduced levels of measured carcinogens and toxins relative to smoking only combustible cigarettes.
Authors
Lion Shahab, Maciej L Goniewicz, Benjamin C Blount, Jamie Brown, Ann McNeill, K Udeni Alwis, June Feng, Lanqing Wang, Robert West
[link url="https://www.sciencedaily.com/releases/2017/02/170207104358.htm"]University College London material[/link]
[link url="http://annals.org/aim/article/2599869/nicotine-carcinogen-toxin-exposure-long-term-e-cigarette-nicotine-replacement"]Annals of Internal Medicine abstract[/link]