Effects of non-soy legume protein on lipid profile in hypercholesterolemic adults: a systematic review and meta-analysis of randomized controlled trials

Cardiovascular disease (CVD) continues to rank as the foremost cause of death globally, with dyslipidemia representing a major contributing risk factor. While soy legumes have been extensively studied for their lipid-lowering effects, the extent to which non-soy legume protein influences lipid profiles in hypercholesterolemic adults warrants investigation. Databases including PubMed, Scopus, and Web of Science were comprehensively searched through September 23, 2025. Randomized controlled trials (RCTs) examining the impact of non-soy legume protein intake on lipid profiles in adults were included. The primary outcomes encompassed alterations in total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). Weighted mean differences (WMD) alongside 95% confidence intervals (CIs) were derived using random- or fixed-effects models contingent on heterogeneity assessment. Subgroup analyses were stratified by age, body mass index (BMI), and intervention duration. Moreover, the certainty of evidence for each outcome was assessed using the GRADE approach. Six RCTs comprising 297 hypercholesterolemic adults and eight treatment arms were included. Overall, non-soy legume protein intake yielded no statistically significant changes in lipid parameters (TG: 0.895 mg/dL; 95% CI: -1.980 to 3.769; TC: -2.251 mg/dL; 95% CI: -4.693 to 0.192; LDL-C: -1.533 mg/dL; 95% CI: -3.575 to 0.509; HDL-C: 0.187 mg/dL; 95% CI: -0.614 to 0.988). However, subgroup analyses disclosed a statistically significant TC reduction in participants older than 50 years (-8.27 mg/dL; 95% CI: -16.41 to -0.12) and those with a BMI below 28 kg/m² (-5.18 mg/dL; 95% CI: -9.28 to -1.08). Similarly, LDL-C was significantly associated with a reduction in participants with BMI < 28 kg/m² (-2.94 mg/dL; 95% CI: -5.87 to -0.01). The certainty of evidence for all outcomes was rated as very low according to the GRADE approach. While non-soy legume protein consumption did not significantly impact overall lipid profiles, modest reductions in TC and LDL-C were observed in certain subgroups; however, these findings are based on a limited number of studies and should be interpreted cautiously as exploratory. These results indicate that the cholesterol-modulating capacity of non-soy legume proteins may be shaped by individual characteristics and warrant further investigation to identify optimal consumption parameters and mechanisms of action. The study protocol was prospectively registered in the International Prospective Register of Systematic Reviews (PROSPERO) and is accessible at: https://www.crd.york.ac.uk/prospero/ . The registration ID is CRD420251045801.