The higher the level of certain vitamins and minerals in the bloodstream, the better a person' s lung function, as measured by the amount of air the person can expel in one second  The lung function of smokers is significantly worse, on average, than that of nonsmokers
Clearly, ttherefore, one way for smokers to improve their lung function is for them to increase their intake of foods that are rich in these helpful vitamins and minerals
Smokers are less likely than nonsmokers to have diets that are rich in vitamins and minerals.