Table 1.
Characteristics of the included studies.
| First Author, Year | Study Name (Country) | N of Participants | N of Cases (Absolute Rate of Stroke, %) | Age, Years, Mean (SD) | Female (%) | BMI, Mean (SD) | Ethanol Intake, g/day, Mean (SD) | Incidence of DM | Incidence of HTN | Average Follow-Up Length, Years (Date) | Dietary Assessment | Definition of Vegetarian/non-Vegetarians | Stroke Assessment | Covariate Adjustment Set | Risk Estimates, HR (95% CI) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Baden et al., 2021 [14] | NHS (US) | 473 of vegetarians/65,987 of non-vegetarians | 29 in vegetarians (6.1)/3575 in non-vegetarians | 69 (7) | 100 | 24.9 (5.2) | 2.3 (7.2) | 7% | 42% | 31.4 (1984–2016) | 110-item FFQ, updated every 2–4 years | Lacto-ovo-vegetarians (meat and/or fish intakes were 0 or <1 serving per month)/meat and/or fish intakes were ≥1 serving per month | Hospital-based records | Age, race, smoking, alcohol intake, physical activity, total energy intake, DM, HTN, dyslipidemia, BMI, medication use | 1.07 (0.74–1.55) |
| Baden et al., 2021 [14] | NHS II (US) | 978 of vegetarians/90,539 of non-vegetarians | 6 in vegetarians (0.6)/734 in non-vegetarians | 48 (5) | 100 | 24.8 (5.2) | 3.1 (7.3) | 2% | 14% | 25.8 (1991–2017) | 110-item FFQ, updated every 2–4 years | Lacto-ovo-vegetarians (meat and/or fish intakes were 0 or <1 serving per month)/meat and/or fish intakes were ≥1 serving per month | Hospital-based records | Age, race, smoking, alcohol intake, physical activity, total energy intake, DM, HTN, hypercholesterolemia, BMI, medication use | 0.75 (0.33–1.67) |
| Baden et al., 2021 [14] | HPFS (US) | 320 of vegetarians/37,095 of non-vegetarians | 16 in vegetarians (5)/1881 in non-vegetarians | 68 (9) | 0 | 25.0 (4.7) | 4.5 (10.8) | 8% | 36% | 26.0 (1986–2012) | 110-item FFQ, updated every 2–4 years | Lacto-ovo-vegetarians (meat and/or fish intakes were 0 or <1 serving per month)/meat and/or fish intakes were ≥1 serving per month | Hospital-based records | Age, race, smoking, alcohol intake, physical activity, total energy intake, DM, HTN, hypercholesterolemia, BMI, medication use | 0.98 (0.60–1.62) |
| Chiu et al., 2020 [15] | TCHS (Taiwan) | 1424 of vegetarians/3626 of non-vegetarians | 10 in vegetarians (0.7)/44 in non-vegetarians | 53.8 (9.0) | 59 | 23.0 (3.1) | 8.1% ever drink alcohol | 4.6% | 14.2% | 6.1 (2007–2014) | 64-item FFQ, baseline | Lacto-ovo-vegetarians (consuming no meat and fish)/any consumption of meat or fish | ICD 9: 430–438 | Age, sex, smoking, alcohol intake, betel nut, physical activity, education, DM, HTN, dyslipidemia, ischemic heart disease, and BMI | 0.51 (0.25–1.06) |
| Chiu et al., 2020 [15] | TCVS (Taiwan) | 2719 of vegetarians/5583 of non-vegetarians | 24 in vegetarians (0.9)/97 in non-vegetarians | 50.1 (9.3) | 64 | NA | 11% ever drink alcohol | 11.8% | 9.4% | 9.3 (2005–2014) | 57-item FFQ, baseline | Lacto-ovo-vegetarians (consuming no meat and fish)/any consumption of meat or fish | ICD 9: 430–438 | Age, sex, smoking, alcohol intake, betel nut, physical activity, education, DM, HTN, dyslipidemia, and ischemic heart disease | 0.52 (0.33–0.82) |
| Petermann-Rocha et al., 2021 [16] | UK Biobank (UK) | 7537 of vegetarians/415,304 of non-vegetarians | 65 in vegetarians (0.9)/5881 in non-vegetarians | 53.1 (7.9) | 55 | 25.6 (4.6) | 77.9% ever drink alcohol | NA | NA | 8.5 (2006–2020) | 24-hr recall questionnaire via Oxford WebQ, baseline | Lacto-ovo-vegetarians excluding vegans (consuming cheese and/or milk but not fish, poultry, or red meat)/meat-eaters (consumption of cheese, milk, fish, poultry, and red meat) | ICD 10: I60, I61, I63, I64 | Age, sex, deprivation, race, smoking, alcohol intake, physical activity, and BMI | 0.84 (0.66–1.07) |
| Tong et al., 2019 [24] | EPIC-Oxford (UK) | 16,254 of vegetarians/31,934 of non-vegetarians | 258 in vegetarians/814 in non-vegetarians | 39.4 (13.1) | 77 | 23 | 9.3 (12.8) | 0.6% | 5.8% | 14 (1993–2016) | 130-item FFQ, baseline and a follow-up 2010 | Lacto-ovo-vegetarians including vegans (consuming no meat and fish)/meat-eaters (consumption of meat and fish) | ICD-9: 430–431, 433–434, 436ICD-10: I60–I61, I63–I64 | Age, sex, smoking, alcohol intake, region, education, deprivation, physical activity, medication use | 1.20 (1.02–1.40) |
Abbreviation: BMI, body mass index; DM, diabetes mellitus; EPIC, European Prospective Investigation Into Cancer; FFQ, food frequency questionnaire; HR, hazard ratio; HPFS, Health Professionals Follow-Up Study; HTN, hypertension; ICD, International Classification of Disease; N, number; NA, not applicable; NHS, Nurses’ Health Study; SD, standard deviation; TCHS, Tzu Chi Health Study; TCVS, Tzu Chi Vegetarian Study; UK, United Kingdom; US, United States.