Veteran country star Willie Nelson has swapped smoking joints for puffing on a vaporiser to preserve his lungs and his singing voice.

The 81 year old is a proud pot smoker and has never hidden his love of weed, but he now uses a hi-tech device to super-heat his stash so he can get high without inhaling smoke.

He tells Uncut magazine, "I enjoy smoking. But I use a vaporiser these days; they're better for your voice and lungs. There's no smoke and heat on it. Even though marijuana smoke is not as bad as cigarette smoke, any time you put any kind of smoke in your lungs it takes a toll of some kind."