Vegan Diets and Risk Markers of Cardiovascular Disease: An Umbrella Meta analysis

Background: The popularity of vegan diets (strictly vegetarian) has increased globally. However, the evidence regarding their impact on cardiovascular disease (CVD) risk remains inconclusive. The aim of this study was to conduct an umbrella meta-analysis that synthesizes the available meta-analyses on the effect of vegan diets on cardiovascular health markers. Methods: A comprehensive search of PubMed and Scopus identified meta-analyses evaluating the association between vegan diets and cardiovascular risk factors. Inclusion criteria mandated a clear focus on vegan diets and inclusion of a control group comprising omnivorous or mixed dietary patterns. A random-effects model was applied, and heterogeneity was assessed using the I ² and Cochran’s Q-statistic. Publication bias was evaluated using funnel plots and Egger’s regression test. Results: Nine eligible meta-analyses used both observational studies and clinical trials encompassing diverse hard (i.e., CVD events) and soft (i.e., risk markers) endpoints were included. A vegan diet was inversely associated with body mass index (pooled β = −1.67 kg/m 2 , P < 0.01, I 2 = 0.00%), waist circumference (pooled β = −4.90 cm, P < 0.01, I 2 = 45.64%), fasting glucose (−0.30 mg/dL, P < 0.01, I 2 = 21.75%), glycated hemoglobin (pooled β = −0.20%, P = 0.01, I 2 = 80.16%), both systolic (pooled β = −1.65 mmHg, P = 0.05, I 2 = 77.00%) and diastolic blood pressure (pooled β = −1.25 mmHg, P = 0.01, I 2 = 68.40%), and also C-reactive protein (pooled β = −0.54 mg/L, P < 0.01, I 2 = 0.00%). No significant associations were found with total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels. Substantial publication bias and heterogeneity were noted in several outcomes. Conclusions: Vegan diets appear to be favorably associated with surrogate markers of cardiovascular health, such as adiposity, glycemia, blood pressure, and inflammatory status.