Caffeinated coffee and tea intake and its relationship to cigarette smoking: an analysis of the Second National Health and Nutrition Examination Survey (NHANES II).

Recent studies have shown that smokers' intake of caffeine is higher than nonsmokers. This investigation evaluated the relationships between smoking status and self-reported caffeine intake from both coffee and tea. Subjects were adults who participated in the Second National Health and Nutrition Examination Survey (NHANES II). Results indicated that subjects who ingested caffeine from tea were more likely to be female, less educated, younger, non-Caucasian, and lighter drinkers. In contrast, those who ingested caffeine from coffee were more likely to be older, Caucasian, heavier drinkers, and have higher incomes. Smokers were not more likely to drink caffeinated tea. In contrast, smokers were much more likely to drink caffeinated coffee, and a dose-response relationship between caffeine from coffee and smoking intake was observed. These results clarify the relationship between smoking and caffeine intake. Implications for intervention efforts are discussed.