E-cigarettes, often advertised as an aid for smoking cessation, may actually encourage young adults to take up smoking, new research suggests.

E-cigarettes are growing in popularity, both in the US and UK, with vaping shops opening on every other street corner. E-cigarettes provide the same smoking experience as traditional cigarettes, but with fewer toxins. First introduced in the US in 2007, it was hoped they would help many of the country’s 40 million smokers quit. However, they have become clouded in controversy, as scientists haven’t been able to determine their benefits and drawbacks when used on a large scale.

The new research, conducted by the Norris Cotton Cancer Centre in America’s Dartmouth University, alongside many other partners, uses the most up-to-date evidence to quantify the scientific grounding of the benefits and drawbacks of large scale e-cigarette use.

The scientists found that, based on 2014 data, e-cigarettes did more harm than good on the whole population level. Dr. Samir Soneji, the study’s principal investigator from the Dartmouth Institute for Health Policy and Clinical Practice said: “Although the tobacco industry markets e-cigarettes as a tool to help adult smokers quit smoking [they] only marginally increase the number of adult cigarette smokers who are able to successfully quit”. He added: “E-cigarettes may facilitate cigarette smoking initiation and confer substantial harm to adolescents and young adults once they are introduced to nicotine.”

Researchers used census counts, national health tobacco-use surveys, and published literature to create a model estimating the number of years of life expectancy lost by adolescents who had never smoked, and who used e-cigarettes before eventually becoming daily cigarette smokers by the age of around 35-39. The scientists specifically compared the additional number of people who quit thanks to e-cigarettes against those who quit without, with successful quitting defined as constant abstinence for seven years.

The current 2014 data show that 3,490,000 current smokers used e-cigarettes to quit, whilst 3,640,000 young adults started using e-cigarettes despite previously not smoking. The model estimated that, in 2015, an additional 2,070 individuals would quit smoking using e-cigarettes compared to those who did not use them. In contrast, it predicted that 168,000 young adults who did not smoke in 2014 would begin smoking by the next year, eventually becoming full-time smokers by the age of 35 compared to those who never used e-cigarettes. Alarmingly, the model also estimated that e-cigarette usage in 2014 caused about 1.5 million years of life to be lost by adolescents who had never before smoked.

The researchers warn that more needs to be done on a national and local scale to make e-cigarette beneficial on the large scale. Soneji argued: “E-cigarettes will likely cause more public health harm…unless ways can be found to substantially decrease the number of adolescents and young adults who vape and increase the number of smokers who use e-cigarettes to successfully quit smoking”