Partial substitution of red meat or processed meat with plant-based foods and the risk of colorectal cancer
Rilla Tammi, Niina E. Kaartinen, Kennet Harald, Mirkka Maukonen, Heli Tapanainen, Stephanie A. Smith‐Warner, Demetrius Albanes, Johan G. Eriksson, Pekka Jousilahti, Seppo Koskinen, Maarit A. Laaksonen, Sanna Heikkinen, Janne Pitkäniemi, Anne‐Maria Pajari, Satu Männistö
Abstract
Abstract Objectives Shifting from animal-based to plant-based diets could reduce colorectal cancer (CRC) incidence. Currently, the impacts of these dietary shifts on CRC risk are ill-defined. Therefore, we examined partial substitutions of red or processed meat with whole grains, vegetables, fruits or a combination of these in relation to CRC risk in Finnish adults. Methods We pooled five Finnish cohorts, resulting in 43 788 participants aged ≥ 25 years (79% men). Diet was assessed by validated food frequency questionnaires at study enrolment. We modelled partial substitutions of red (100 g/week) or processed meat (50 g/week) with corresponding amounts of plant-based foods. Cohort-specific hazard ratios (HR) for CRC were calculated using Cox proportional hazards models and pooled together using random-effects models. Adjustments included age, sex, energy intake and other relevant confounders. Results During the median follow-up of 28.8 years, 1124 CRCs were diagnosed. We observed small risk reductions when red meat was substituted with vegetables (HR 0.97, 95% CI 0.95 − 0.99), fruits (0.97, 0.94 − 0.99), or whole grains, vegetables and fruits combined (0.97, 0.95 − 0.99). For processed meat, these substitutions yielded 1% risk reductions. Substituting red or processed meat with whole grains was associated with a decreased CRC risk only in participants with < median whole grain intake (0.92, 0.86 − 0.98; 0.96, 0.93 − 0.99, respectively; p interaction =0.001). Conclusions Even small, easily implemented substitutions of red or processed meat with whole grains, vegetables or fruits could lower CRC risk in a population with high meat consumption. These findings broaden our insight into dietary modifications that could foster CRC primary prevention.