Micronutrient antioxidants and smoking.

Cigarette smoking is a major risk factor in such human diseases as cardiovascular disease (especially atherosclerosis), lung cancer (the leading world-wide cancer killer), and chronic obstructive pulmonary disease (COPD). An avalanche of studies has suggested that a diet rich in fruit and vegetables is associated with decreased risk for atherosclerosis and cancer. However, the dietary intake of fruits and vegetables, as well as antioxidant micronutrients, is decreased in smokers. This, along with evidence of increased utilization of ascorbic acid and alpha-tocopherol, possibly on the basis of increased oxidative stress, contributes to the low plasma antioxidant concentrations seen in many smokers. This review addresses selected mechanistic considerations of this relationship.