(CNN) -- For 15 years, e-cigarettes have been billed as a safer alternative to traditional cigarettes. But a study found e-cigs can make it harder to quit smoking, and in most cases -- people end up vaping and smoking.
The study also found daily e-cig use can double the risk of heart attack.
If you are a dual user, that is vaping and smoking cigarettes every day, the combined risk for heart attack goes up five times.
E-cigs have lower levels of carcinogens than cigarettes, but researchers say the electronic versions have other toxins that can have detrimental effects, like increased cardiovascular and lung disease risks.
If you are a smoker, here is something you can do now: stop. Scientists say stopping smoking immediately drops your risk for heart attack.