Starting tobacco products, including e-cigarettes, before the age of 18 is a major risk factor for people to become daily cigarette smokers, suggests a new study. Reporting in the online edition of Pediatrics, researchers found that in 2014 people age 12 to 24 who used e-cigarettes were three times as likely to become daily cigarette smokers in the future. Daily cigarette smoking nearly doubled between 18 to 21-year-olds (12 per cent) and 25 to 28-year-olds (21 per cent). 'The start product has changed from cigarettes to e-cigarettes, but the end product has stayed the same. When users become dependent on nicotine, they are converting to cigarette smoking,' said the lead researcher.