Isocaloric substitution of animal protein with plant protein and its impact on all-cause, cardiovascular, and cancer mortality: A systematic review and meta-analysis

BACKGROUND AND AIMS: Epidemiological evidence indicates that isocaloric substitution of animal-protein sources with plant-protein sources may reduce all-cause mortality (ACM), cardiovascular mortality (CVM), and cancer mortality (CM). However, the impact of substituting different proportions of animal-protein with plant-protein remains unclear. This systematic review and meta-analysis aimed to evaluate the effects of isocaloric substitution of animal-protein with plant-protein at two levels-3% and 5% of total caloric value (TCV)-on ACM, CVM and CM, and to assess whether these effects differ between substitution levels. METHODS: ., Statistical analysis was performed using Review Manager 5.4. RESULTS: = 8%), with a significant subgroup difference (p = 0.008). CONCLUSIONS: Isocaloric substitution of animal-protein with plant-protein is associated with lower ACM, CVM and CM, with stronger cardiovascular benefits observed at the 5% substitution level. These findings support the potential role of increased plant-protein intake in dietary strategies aimed at reducing mortality risk. REGISTRATION: PROSPERO, CRD42024614889.