A Prospective Analysis of Red and Processed Meat Consumption and Risk of Colorectal Cancer in Women

Background: Red and processed meats have been implicated as risk factors in the development of colorectal cancer in U.S. women, but associations with cooking practices are less well established. Methods: Data are from the Sister Study, a cohort of women ages 35 to 74 years from the United States and Puerto Rico who have a sister diagnosed with breast cancer. Red and processed meat consumption, meat cooking practices, and intake of common meat products were collected at baseline using self-administered questionnaires (N = 48,704). Multivariable HRs (HRadj) and 95% confidence intervals (95% CI) were estimated. Results: During a median 8.7 years' follow-up (range <1-12.7 years), 216 colorectal cancer cases were diagnosed. In categorical analyses, an increased risk of colorectal cancer was seen in the highest quartile of processed meat consumption compared with the lowest [HRadj = 1.52 (95% CI, 1.01-2.30); P-trend = 0.02], and for specific meat products, including breakfast sausages [HRadj = 1.85 (95% CI, 1.30-2.64)] and bacon [HRadj = 1.46 (95% CI, 1.012.11)]. The HRadj for the highest quartile of red meat consumption was 1.04 (95% CI, 0.68-1.60), and little evidence of association was observed for cooking practices or doneness of red meat. We observed positive associations with specific red meat products when cooking methods were considered, for example, grilled/barbequed steaks [HRadj = 2.23 (95% CI, 1.20-4.14)] and hamburgers [HRadj = 1.98 (95% CI, 1.00-3.91)]. Conclusions: Higher reported daily intake of processed meats and consumption of barbecued/grilled red meat products were associated with increased risk of colorectal cancer in women. Impact: Variability in colorectal risk risk by meat type and cooking method should be considered when evaluating meat consumption.