The Global Incident Gastrointestinal Cancers Attributable to Suboptimal Diets From 1990 to 2018

The contribution of suboptimal diets to gastrointestinal (GI) cancer incidence globally remains unquantified, and we aimed to evaluate it.

Comprehensive meta-analyses and rigorous evidence-grading assessment identified the associations between suboptimal diets and 6 GI cancers and their subtypes. A comparative risk assessment model was used to estimate the proportional attributable burden and attributable rate of GI cancers to suboptimal diets by using the corroborative association estimates. In addition, correlation assessments with the Sociodemographic Index were carried out.

In 2018, 21.5% (95% uncertainty interval, 19.1%-24.5%) of incident GI cancer cases globally were attributable to suboptimal diets, maintaining a relatively stable proportion since 1990 (22.4%; 19.7%-25.6%), whereas the absolute diet-attributable cases doubled from 580,862 (510,658-664,076) in 1990 to 1,039,877 (923,482-1,187,244) in 2018. Excessive processed meat consumption (5.9%; 4.2%-7.9%), insufficient fruit intake (4.8%; 3.8%-5.9%), and insufficient whole grain intake (3.6%; 2.8%-5.1%) were the most significant dietary risk factors in 2018, a shift from 1990 when the third major concern was insufficient nonstarchy vegetable intake. In addition, Central and Eastern Europe and Central Asia experienced the highest attributable burden across regions in both 1990 (31.6%; 27.0%-37.4%) and 2018 (31.6%; 27.3%-36.5%), and a positive correlation (P < .001) between the Sociodemographic Index and the attributable GI cancer incidence was observed.

Although the proportional attributable GI incidence remains relatively stable, the doubling of absolute cases from 1990 to 2018, along with the discrepancies among urbanicity and countries/regions, informs dietary priorities and more targeted preventive measures.