Pulses and Cancer Outcomes: A Scoping Review of Human Studies on Risk Reduction

Background/Objectives: Pulses are nutrient-dense, low-glycaemic legumes rich in fibre and bioactive compounds that may modulate carcinogenesis through effects on diet quality, metabolism, and the gut microbiome. This scoping review mapped human evidence on pulses in relation to cancer risk reduction and related mechanistic and survivorship-relevant outcomes. Methods: Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) and Joanna Briggs Institute (JBI) Population, Concept and Context (PCC) guidance, we searched CENTRAL, Scopus and PubMed (2014-31 December 2025), supplemented by backward and forward citation tracking, for English-language human studies in which pulses were a defined exposure or intervention and cancer-specific clinical outcomes or biomarkers were reported. Exposures are described using the original 'legume' terminology, with pulse-specific interpretation restricted to FAO-defined pulses or clearly dry pulse forms and to pulse-dominant legume intake where the constituent items were predominantly pulses but preparation was not specified. Results: After screening 1244 records, 15 studies met the inclusion criteria, comprising five case-control studies, five 4-week randomised controlled trials (RCTs), one 8-week randomised crossover trial, one controlled feeding study, two prospective cohort studies, and one other prospective study. Observational data from a single pooled case-control study suggest that higher pulse-dominant legume intake is compatible with modestly lower colorectal cancer risk, although the findings are mixed and often attenuate after adjustment for lifestyle and dietary confounders. Evidence for breast and oesophageal cancer and all-cancer mortality is limited, frequently subgroup-specific or highly sensitive to confounder control, and survivorship endpoints are represented mainly by short-term mechanistic and feasibility trials in colorectal cancer survivors rather than by long-term clinical outcomes. Notably, five of these navy bean interventions were conducted by a single research group using similar protocols, which constrains the independence of replication. Conclusions: Pulses can be considered practical components of cancer-protective dietary patterns, especially for colorectal cancer, but the heterogeneity of study designs, short-term interventions, limited sample sizes, and lack of preparation-specific exposure data preclude firm causal inferences; longer-term, rigorously designed trials and detailed observational work are needed to refine pulse-based recommendations for cancer risk reduction and to clarify any role in survivorship care.