Global Burden and 2050 Projections of Colorectal Cancer Attributable to Dietary Risk Factors: Insights From the GBD 2021 Study

Background Colorectal cancer (CRC) remains a major cause of cancer‐related mortality worldwide. Diet is among the few modifiable determinants of CRC risk, yet the global contribution of specific dietary factors over time, and their projected impact, is not fully understood. Assessing both historical patterns and future trends is essential for guiding prevention strategies. Methods We used estimates from the Global Burden of Disease (GBD) 2021 study to quantify CRC mortality, disability‐adjusted life years (DALYs), and age‐standardized rates (ASRs) attributable to six dietary risk factors across 204 countries and territories from 1990 to 2021. Analyses were stratified by sex, age, sociodemographic index (SDI), and region. We applied decomposition analysis to separate demographic from epidemiological drivers and a Bayesian age–period–cohort (BAPC) model to project ASRs through 2050. Results Between 1990 and 2021, global ASRs for diet‐related CRC declined, yet the absolute number of cases rose. In 2021, low whole grain intake (28.38%), low milk intake (24.01%), and high red meat consumption (23.31%) were the leading dietary risks for CRC mortality, with comparable rankings for DALYs. Men, older adults, and high‐SDI populations experienced the heaviest burden, while the highest ASRs linked to low calcium intake occurred in low‐SDI regions, particularly in Southeast Asia, Africa, the Caribbean, and Oceania. Modelled projections suggest continued global declines in ASRs through 2050, but with slower reductions in high‐SDI settings and relatively larger gains in some low‐ and middle‐SDI regions; disparities are unlikely to close. Conclusion Although diet‐attributable CRC rates have declined, the global burden remains substantial and heterogeneous across SDI strata. Projections to 2050 indicate the need for SDI‐tailored prevention strategies, prioritizing reductions in red and processed meat in high‐SDI settings and improvements in calcium‐related intake in low‐SDI regions, supported by context‐appropriate dietary guidelines and public health programmes.