It's no secret that smoking is bad for you, or that one of the best things a person can do to improve their health is to quit smoking. Of course, quitting smoking is easier said than done, and so the common wisdom is that even cutting down is a good thing, and it absolutely is.
However, according to a study published in Lancet Respiratory Medicine, even smoking as few as five cigarettes a day can do almost as much damage to the lungs as smoking a whole pack.