E-cigarettes and vaping may only have been around for a decade or so but it's estimated more than 35 million people globally have taken it up. Marnie Chesterton heads to a vape show to discover why these gadgets are proving so popular, and hears from one expert who warns they could be damaging lung immune cells. She examines the research behind claims that e-cigarettes can help smokers quit, and finds conflicting evidence about how good they are at giving people the nicotine hit they crave. It's a research field that's in its infancy and with vaping technology constantly changing, it's little wonder some scientists say it's a struggle to keep up.

Presenter: Marnie Chesterton

Presenter: Marijke Peters

(Photo: A woman smoking an e-cigarette. Credit: Getty Images)