Burden and projections of diet related early onset gastrointestinal cancers in young adults

The global burden of early-onset gastrointestinal cancers, including colorectal cancer and gastric cancer, among individuals aged 15-49 years has risen substantially over the past three decades. Among modifiable risk factors, dietary patterns have emerged as key contributors to this increase. Using GBD 2021 data, we estimated age-standardized DALYs for EO-CRC and EOGC attributable to low fiber, high processed meat, and high sodium from 1990-2021, stratified by sex, country, and SDI. ARIMA models projected trends to 2050 (95% UIs). In 2021, dietary-attributable DALYs were 1,248.6/100,000 for EO-CRC and 238.1/100,000 for EOGC, with higher burdens in males (male-to-female ratio: 1.16 and 1.64). Taiwan (China) had the highest EO-CRC burden (237.7/100,000), Mongolia the highest EOGC burden (30.7/100,000). Middle- and high-SDI countries bore disproportionately high EO-CRC burdens (57.96/100,000), and socioeconomic inequalities widened over time. By 2050, EO-CRC DALYs are projected to increase by 31.6% (1,642.6/100,000), with South Asia most affected, while EOGC DALYs are expected to decline by 18.7%. EO-GIC burdens are rising in young populations, driven by low fiber, high processed meat, and high sodium intake, with marked sex, regional, and socioeconomic disparities. Targeted dietary interventions are urgently needed, particularly in high-risk and rapidly westernizing regions.