Table 2.

Study characteristics of included systematic reviews examining the relationship between vegetarian and vegan diets and cardiovascular risk and disease outcomes.

Author, Year	Population (Health Status, Age)	Diet (Vegetarian, Vegan) Diet Duration	Study Designs Included	Years of Primary Studies	Diet Adherence Assessment Reported	Outcomes of Interest Reported	Meta-Analysis	RoB Assessment	Certainty of Evidence Grading	Overall Confidence in Results from AMSTAR2
Bakaloudi et al. 2021 [28]	No limits on health status or age	Vegan Duration: NA-11.7 years	Cross-sectional, cohort	NR	Yes	BMI	No	Newcastle-Ottawa and modified Newcastle-Ottawa Scale	No	Low
Benatar et al. 2018 [29]	No significant comorbidities ≥18 years	Vegan Duration: ≥1 year	Cross-sectional, cohort	1960–2018	Yes	•BMI •BP •LDL-C •TGs	Yes	Newcastle-Ottawa Scale	No	Critically Low
Craddock et al. 2019 [30]	No limits on health status or age	Vegetarian Duration: ≥4 weeks for interventions, ≥1 year for observational	Cross-sectional, RCTs	NA-2017	No	CRP	Yes	Modified Newcastle-Ottawa Scale	GRADE	Critically Low
Dybvik et al. 2022 [31]	Presumably healthy general population No limits on age	Vegetarian, Vegan Duration: 5.14–28.3 years	Prospective Cohort Studies	NA-2021	No	•CVD Incidence •CVD Mortality •IHD Incidence •IHD Mortality •Stroke Incidence •Stroke Mortality	Yes	Modified ROBINS-I	World Cancer Research Fund grading criteria	Low
Elliot et al. 2022 [32]	No limits on health status ≥18 years	Vegetarian, Vegan Duration: 3 months- 3.75 years	RCT, prospective cohort, cross-sectional	NA-2022	No	•LDL-C •TGs •CRP/ hsCRP	No	No	No	Critically Low
Gibbs et al. 2021 [33]	No limits on health status ≥18 years	Vegetarian, Vegan Duration: 1.4–204 weeks (median 12 weeks)	Controlled trials	1961–2019	No	BP	Yes	RoB2	GRADE	Low
Glenn et al. 2019 [34]	With or without diabetes Median age range: 33–58 years	Vegetarian Duration: ≥1 year	Prospective cohort	NA-2018	Yes	•CHD Incidence •CHD Mortality •CVD Mortality •Stroke Mortality	Yes	Newcastle-Ottawa	GRADE	Critically Low
Ivanova et al. 2021 [35]	No limits on health status ≥18 years	Vegetarian, Vegan Duration: 30 days-2 years	Controlled trials, prospective cohort studies	NA-2021	No	•BMI •LDL-C	No	Newcastle-Ottawa Scale	No	Critically Low
Jabri et al. 2021 [36]	No limits on health status or age	Vegetarian Duration: Mean of 10.68 years	Prospective Cohort Studies	NA-2019	No	•CHD Mortality •CBVD Mortality	Yes	ROBINS-I	GRADE	Critically Low
Jafari et al. 2021 [37]	No limit on health status ≥18 years	Vegetarian, Vegan Duration: 4–25 years	Prospective Cohort Studies	1988–2020	Yes	•CVD Mortality •CBVD Mortality •CHD Mortality	Yes	Newcastle-Ottawa	GRADE	Low
Kaiser et al. 2021 [38]	No limits on health status or age	Vegan Duration 8 weeks-18.1 years	RCTs, Prospective Cohort, Cross-sectional	NR-2020	Yes	•Stroke Incidence •Myocardial Infarction Incidence •CHD Incidence •CHD Incidence •CVD Mortality •CBVD Mortality	No	Cochrane Collaboration Tool and Newcastle-Ottawa	Agency for Healthcare Research and Quality	Low
Koch et al. 2023 [47]	No limit on health status ≥18 years	Vegetarian, Vegan	RCTs	1980–2022	No	LDL-C TGs	Yes	RoB 2	No	Critically Low
Lee et al. 2020 [39]	No limits on health status or age	Vegetarian, Vegan Duration: ≥ 2 weeks	RCTs	NA-2020	No	BP	Yes	RoB	GRADE	Critically Low
Lopez et al. 2019 [40]	No limit on health status ≥18 years	Vegan Duration: ≥3 weeks	RCTs	NA-2018	No	BP	Yes	NR	GRADE	Low
Lu et al. 2021 [41]	No history of stroke No limits on age	Vegetarian Duration: 6–26 years	Prospective Cohort Studies	NA-2021	Yes	Stroke Incidence	Yes	Newcastle-Ottawa	Nutrigrade	High
Menzel et al. 2020 [42]	No limit on health status ≥18 years	Vegetarian, Vegan Duration: 1–25 years	Cross-sectional	NA-2020	No	CRP	Yes	Newcastle-Ottawa Quality Assessment Scale adapted for cross-sectional studies	No	Low
Pollakova et al. 2021 [43]	Healthy ≥18 years	Vegan Duration: 6–74 weeks	RCTs	NR-2020	No	BMI	No	Cochrane Risk of Bias tool	No	Critically Low
Quek et al. 2021 [44]	No limit on health status 38–67 years	Vegetarian Duration: NR	Prospective Cohort Studies	NA-2021	Yes	•CVD Incidence •CVD Mortality •Stroke Incidence	Yes	Newcastle-Ottawa	No	Critically Low
Rees et al. 2021 [45]	General Population or with CVD Risk	Vegan Duration: 8–39 weeks	RCTs	1900–2020	No	•CVD Events •CVD Mortality •LDL-C •TGs •BP •BMI	Yes	RoB2	GRADE (for some outcomes)	High
Remde et al. 2022 [46]	No limit on health status Adult	Vegetarian, Vegan Duration: ≥4 weeks	RCTs and Quasi-experimental studies	NR-2020	No	•BMI •BP •LDL-C •TGs	No	Cochrane RoB	No	Low
Wang et al. 2023 [48]	No limit on health status ≥18 years	Vegetarian Duration: 2–36 years	Prospective cohort studies, case-cohort studies, or nested case-control studies	NR- 2023	Yes	•CVD Incidence •T2DM Incidence	Yes	Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies	No	Critically Low

Abbreviations: AMSTAR2= A MeaSurement Tool to Assess systematic Reviews version 2, BMI= body mass index, BP= blood pressure, CBVD= cerebrovascular disease, CRP= C-reactive protein, CHD= coronary heart disease, CVD= cardiovascular disease, GRADE= Grading of Recommendations, Assessment, Development, and Evaluations, IHD= ischemic heart disease, hsCRP= high-sensitivity c-reactive protein, LDL-C= low-density lipoprotein cholesterol, NA= not applicable, NR= not reported, RCT= randomized controlled trial, ROB= risk of bias, RoB2= Version 2 of the Cochrane risk-of-bias tool for randomized trials, ROBINS-I= Risk Of Bias In Non-Randomized Studies - of Interventions; TGs= triglycerides.