The relationship between animal fat intake, cigarette smoking, and lung cancer.

An international ecologic study on the relationship between fat intake, cigarette consumption, and age-specific lung cancer mortality rates was conducted using data obtained from 29 countries. The 1969-71 and 1984-86 mortality rates for lung cancer were related to smoking habits and to levels of animal fat intake. Highly significant independent positive correlations for lung cancer with both cigarette smoking and animal fat consumption were seen. No significant independent relationship was found between lung cancer mortality and vegetable fat consumption. In a multiple regression analysis linking lung cancer mortality to dietary intake of animal fat, cigarette smoking, and the interaction term between cigarette smoking and animal fat intake, only the latter term was significant (P less than 0.001) pointing towards a role for animal fat as a promoter of lung cancer.