According to Robert Lee (Bruce's brother), Bruce's father, Lee Hoi Chuen was a heavy opium cum cigarette smoker since young. His health deteriorated when he was old due to heavy smoking, thus, at the advice of the doctor, he quitted smoking and took up Tai Chi Chuan (Taiji boxing)to improve his health. Bruce picked up Taiji from his father at the age of 7 and witnessed the improvement in health of his father.
Bruce also saw many male Chinese in HK, like his father, became sick and unhealthy due to heavy smoking (regardless of opium or cigarette). That was the reason, he did not really smoke (the smoking scenes in "The Orphan" and other Cantonese movie were just purely acting) and he always disliked the smell of smoking. He told his family and friends that he would rather put his time in practising Kung Fu rather than killing himself with puff of cigarttes in their mouth.
This was also why the 1972's Winston's Cigarette TV commercial had only Bolo, Chieh Yuan and another guy in it. Bruce would not allow himself engage in this kind of commercial that would spoil his health and image.