According to statistics from a national study into teenage tobacco trends, the main initiation age of vaping is between 17 and 18, whilst smoking is most commonly taken up three years earlier.
Cigarette smoking initiation peaks around 14 to 15, whilst e-cigarette use is much closer to 18, according to Yan Wang, PhD, from the University of Florida in Gainesville and his colleagues.
The study, now available online on the American Journal of Preventive Medicine, examined data on 20,680 adolescents from the National Youth Tobacco Survey in 2014.
Participants, all aged between 11 and 19, were 50.6% male and 43.3% white, and were asked what age they were when they started using the products.
The study shows that teenagers are more likely to take up smoking at a younger age.
Vaping is widely considered the best method of quitting smoking, and reputable health body Public Health England recognises that e-cigarettes are around 95% safer than regular cigarettes.
A recent study found that young vapers believe that e-cigarette use does not increase the likelihood of adopting smoking.
According to statistics, there are still more smokers than vapers in the US.