Dietary fat and risk of lung cancer in a pooled analysis of prospective studies.

Lung cancer rates are highest in countries with the greatest fat intakes. In several case-control studies, positive associations have been observed between lung cancer and intakes of total and saturated fat, particularly among nonsmokers. We analyzed the association between fat and cholesterol intakes and lung cancer risk in eight prospective cohort studies that met predefined criteria. Among the 280,419 female and 149,862 male participants who were followed for up to 6-16 years, 3,188 lung cancer cases were documented. Using the Cox proportional hazards model, we calculated study-specific relative risks that were adjusted for smoking history and other potential risk factors. Pooled relative risks were computed using a random effects model. Fat intake was not associated with lung cancer risk. For an increment of 5% of energy from fat, the pooled multivariate relative risks were 1.01 [95% confidence interval (CI), 0.98-1.05] for total, 1.03 (95% CI, 0.96-1.11) for saturated, 1.01 (95% CI, 0.93-1.10) for monounsaturated, and 0.99 (95% CI, 0.90-1.10) for polyunsaturated fat. No associations were observed between intakes of total or specific types of fat and lung cancer risk among never, past, or current smokers. Dietary cholesterol was not associated with lung cancer incidence [for a 100-mg/day increment, the pooled multivariate relative risk was 1.01 (95% CI, 0.97-1.05)]. There was no statistically significant heterogeneity among studies or by sex. These data do not support an important relation between fat or cholesterol intakes and lung cancer risk. The means to prevent this important disease remains avoidance of smoking.