My friend is an occasional smoker and drinker actually three years before he was addicted to it but right he has reduced it much. Yesterday he went to hospital with his friend who was afraid of having lung cancer and finally doctor told that his friend is having cancer symptoms. Right now my friend is afraid Abt he getting affected. He doesn't have any symptoms but I want to prevent it rather than curing it. If there are any home remedies available to get rid of this before getting ill due to disease. Please suggest me those remedies.