Just one cigarette a day significantly raises heart disease risk. A new study conducted at the Cancer Institute of University College London and published in the British Medical Journal reviewed all credible health studies from 1946 regarding how many cigarettes people smoked and what happened to them – and the results were shocking. The study concluded that women who smoke just one cigarette a day have a 57 percent greater risk of heart disease than that of a non-smoker. To put that in perspective, smoking 20 cigarettes a day almost triples that risk. The main message is that quitting is the only option to substantially minimize your risk. Most credible sources have also found little evidence that e-cigarettes (and the very new “heat-not-burn” cigarettes) lower health risks, except in cases when transitioning to them helps people eventually quit smoking altogether.