Global burden of gastric cancer attributed to high-salt diets: spatiotemporal trends and socio-demographic inequalities from 1990 to 2021

Background: Gastric cancer (GC) remains a major global health burden. High-salt diets are a key modifiable risk factor, promoting mucosal damage, chronic inflammation, and increased susceptibility to Helicobacter pylori infection. This study aimed to quantify the global, regional, and national GC burden attributable to high-salt diets and assess spatiotemporal trends and socio-demographic disparities from 1990 to 2021. Methods: This study used data from the Global Burden of Disease (GBD) 2021 to assess the burden of GC attributable to high sodium intake. Mortality and disability-adjusted life years (DALYs) were estimated across 204 countries and territories from 1990 to 2021. Age-standardized mortality rate (ASMR) and age-standardized DALY rate (ASDR) were stratified by Socio-demographic Index (SDI) quintile and GBD region. Temporal trends were assessed using estimated annual percentage change (EAPC). Decomposition and inequality analyses were conducted to explore drivers of DALY changes and disparities across SDI levels. Results: The global ASMR and ASDR for GC due to high salt intake decreased by 48.9% and 53.3%, respectively, from 1990 to 2021. In high-SDI regions, the ASMR decreased from 1.24 to 0.54 per 100,000 EAPC =-2.72, 95% confidence interval (CI): -2.75, -2.70. In contrast, in low-SDI regions, the ASMR and ASDR decreased by only 29.4% and 34.6%, respectively, with EAPCs of -1.14 (95% CI: -1.20, -1.08) and -1.41 (95% CI: -1.47, -1.36). East Asia showed the most notable decline, with the ASMR decreasing from 3.77 to 1.76 per 100,000 (EAPC =-2.54, 95% CI: -2.75, -2.33), and the ASDR dropping from 96.58 to 41.09 per 100,000 (EAPC =-2.88, 95% CI: -3.07, -2.69). while Sub-Saharan Africa exhibited limited progress. Conclusions: While global efforts to reduce salt intake have yielded positive results, significant disparities were observed across regions, with high-SDI countries experiencing greater reductions compared to low-SDI regions. Therefore, future interventions should focus on salt reduction policies, improved dietary patterns, and enhanced screening programs, particularly in resource-limited settings.