Vaping can cause cancer, say researchers but still isn't as damaging as smoking cigarettes. More than 5.5 million Britons currently use e cigarettes, which have long been viewed as a safer alternative Secondhand smoke and secondhand aerosol Strongest evidence yet that vaping likely causes cancer Modern Sciences E cigarettes are not a healthier alternative to cigarettes. They contain nicotine and many harmful ingredients that can cause cancer and heart disease. Since these products are relatively new, we don't know all