Partial substitution of red or processed meat with plant-based foods and colorectal cancer risk

Abstract

Abstract Background Consumption of plant-based foods, particularly whole grains, may decrease colorectal cancer (CRC) risk, while red and processed meat consumption increases it. Moreover, shifting to more plant-based diets promotes sustainable food systems. Yet, few studies have examined the impact of dietary shifts towards more plant-based diets on CRC risk. We modelled a partial substitution of red or processed meat with whole grains, vegetables or fruits in relation to CRC risk in Finnish adults. Methods Our data comprised 43 788 participants (79% men) aged ≥25 years from five Finnish cohorts. The median follow-up was 29 years, during which 1124 CRC cases were diagnosed. Diet was assessed by a validated food frequency questionnaire. We modelled substitutions of 100g/week of red meat or 50g/week of processed meat with an equivalent amount of plant-based foods. In a two-stage meta-analysis, cohort-specific hazard ratios (HR) were calculated using Cox proportional hazards model and pooled together. We adjusted the analyses for sex and other relevant confounders. Results We observed a small decrease in CRC risk when red or processed meat was partially substituted with vegetables (red meat: HR 0.97, 95% CI 0.94-0.99, P = 0.008; processed meat: 0.99, 0.98-1.00, P = 0.029) or fruits (red meat: 0.97, 0.94-0.99, P = 0.007; processed meat: 0.99, 0.98-1.00, P = 0.036). No association occurred between the partial substitution of red or processed meat with whole grains and CRC risk. Conclusions Our results suggested that already small and easily implemented substitutions of red or processed meat with vegetables or fruits could reduce CRC risk in Finnish adults. The findings highlight the need for effective nutrition policy actions to promote the shift towards more plant-based diets that would benefit both public health and sustainable food systems. Further research on similar substitutions in relation to CRC risk is required in different populations and real-life settings. Key messages • Already small and easily implemented substitutions of 100g/week of red meat or 50g/week of processed meat with vegetables or fruits could reduce colorectal cancer risk in Finnish adults. • The findings highlight the need for effective nutrition policy actions to promote the shift towards more plant-based diets that would benefit both public health and the sustainability of food systems.