Vaping may raise cancer and heart disease risk, study suggests

Nicotine in e-cigarettes may convert into DNA-damaging chemicals, mouse trial indicates, but critics say results are irrelevant to humans

Vaping may raise the risk of certain cancers and heart disease, according to a team of scientists who studied the effects of e-cigarette smoke on healthy mice and human cells.

Researchers found evidence that nicotine inhaled from e-cigarettes could be converted into chemicals that damage DNA in the heart, lungs and bladder, and dampen down the body's genetic repair mechanisms.