Evidence of a vegan diet for health benefits and risks – an umbrella review of meta-analyses of observational and clinical studies

To summarize and evaluate the evidence on health impact of a vegan diet, we conducted an umbrella review systematic reviews meta-analyses. PubMed, Cochrane Library, Web Science Epistemonikos were searched up to September 2021. Meta-analyses recalculated by using random effects model. The certainty (CoE) was evaluated GRADE approach. For general healthy population, diet effective for reducing body weight [MD (95% CI): ?2.52 kg (?3.06, ?1.98), n = 8 RCTs; moderate CoE] associated with further benefits (with low CoE), including lower risk cancer incidence [SRR 0.84 (0.75, 0.95), 2] trend all-cause mortality 0.87 1.01), 2], as well ApoB levels ?0.19 µmol/L (?0.23, ?0.15), 7 RCTs). findings suggested adverse associations fractures 1.46 (1.03, 2.07), 3; CoE]. persons diabetes or at high CVD risk, reduced measures adiposity, total cholesterol, LDL improved glycemic control (CoE low). A may have potential prevention cardiometabolic health, but it also impair bone health. More well-conducted primary studies are warranted.