Abstract
OBJECTIVE: A systematic analysis was conducted to determine the relationship between a plant-based diet and all-cause mortality. METHODS: The PubMed, Embase and Web of Science databases were searched. Two authors selected English documents from the database. Then the other two authors extracted the data and evaluated the Newcastle-Ottawa Scale (NOS). This study adhered to the guidelines of the Preferred Reporting Project (PRISMA) and the PROSPERO Registry protocols. A mixed-effects model combined maximum adjusted estimates, with heterogeneity measured using the I(2) statistic. The sensitivity analysis validated the analysis's robustness, while publication bias was assessed. RESULTS: The results of the meta-analysis of 14 articles revealed that a plant-based diet (PDI) can reduce cancer mortality (RR = 0.88, [95% CI 0.79-0.98], τ(2): 0.02, I(2): 84.71%), cardiovascular disease (CVD) mortality (RR = 0.81, [95% CI 0.76-0.86], τ(2): 0.00, I(2): 49.25%) and mortality (RR = 0.84, [95% CI 0.79-0.89], τ(2): 0.01, I(2): 81.99%) risk. Adherence to a healthy plant-based diet (hPDI) was negatively correlated with cancer mortality (RR = 0.91, [95% CI 0.83-0.99], τ(2):0.01, I(2):85.61%), CVD mortality (RR = 0.85, [95% CI 0.77-0.94], τ(2): 0.02, I(2): 85.13%) and mortality (RR = 0.85, [95% CI 0.80-0.90], τ(2): 0.01, I(2): 89.83%). An unhealthy plant-based diet (uPDI) was positively correlated with CVD mortality (RR = 1.19, [95% CI 1.07-1.32], τ(2): 0.02, I(2): 80.03%) and mortality (RR = 1.18, [95% CI 1.09-1.27], τ(2): 0.01, I(2): 89.97%) and had a certain correlation with cancer mortality (RR = 1.10, [95% CI 0.97-1.26], τ(2): 0.03, I(2): 93.11%). Sensitivity analysis showed no contradictory results. CONCLUSION: The hPDI was negatively associated with all-cause mortality, and the uPDI was positively associated with all-cause mortality. SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/PROSPERO/#loginpage.