A prospective study of meat, cooking methods, meat mutagens, heme iron, and lung cancer risks.

BACKGROUND

Red and processed meat consumption may play a role in lung cancer pathogenesis because of these meats' fat and carcinogen content.

OBJECTIVE

We prospectively investigated whether meat type, cooking method, doneness level, and intake of specific meat mutagens and heme iron are associated with lung carcinoma.

DESIGN

Men (n = 278,380) and women (n = 189,596) from the National Institutes of Health-AARP Diet and Health Study with no history of cancer at baseline were monitored for 8 y. Diet was assessed with a 124-item food-frequency questionnaire. A meat-cooking module was used to estimate the intake of individual heterocyclic amines, benzo(a)pyrene, and heme iron. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% CIs.

RESULTS

In a comparison of quintiles 5 with 1 (Q5vsQ1), a high intake of red meat was associated with an increased risk of lung carcinoma in both men (HR(Q5vsQ1): 1.22; 95% CI: 1.09, 1.38; P for trend = 0.005) and women (HR(Q5vsQ1): 1.13; 95% CI: 0.97, 1.32; P for trend = 0.05). A high intake of processed meat increased the risk only in men (HR(Q5vsQ1): 1.23; 95% CI: 1.10, 1.37; P for trend = 0.003). In an analysis stratified by smoking status, we observed a tendency for an increased risk with red meat intake in never smoking men and women; however, the risks were not statistically significant. In a comparison of tertiles 3 and 1 (T3vsT1), the risk of lung carcinoma was associated with intake of well-/very-well-done meat (HR(T3vsT1): 1.20; 95% CI: 1.07, 1.35; P for trend = 0.002) and the intake of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (HR(Q5vsQ1): 1.20; 95% CI: 1.04, 1.38; P for trend = 0.04) in men. Heme iron intake increased the risk of lung carcinoma in both men (HR(Q5vsQ1): 1.25; 95% CI: 1.07, 1.45; P for trend = 0.02) and women (HR(Q5vsQ1): 1.18; 95% CI: 0.99, 1.42; P for trend = 0.002).

CONCLUSION

We observed a moderate association between meat consumption and lung carcinoma, which might be explained by heme iron intake, high-temperature cooking, and associated mutagens.