Table 6.
Randomised Controlled Trials of Plant-Based Diets and Inflammatory Biomarkers.
| Reference | Country | Population (n) | Sex | Age (Years) | Intervention (n) | Study Length (Design) | Outcomes | * Results | Significance |
|---|---|---|---|---|---|---|---|---|---|
| Acharya et al. [42] | USA | Overweight/obese (143) | M/F | LOV-D: 45.2; STD-D: 43.5 | LOV-D (64) vs. STD-D (79) | 6 months (parallel) | Adiponectin (µg/mL) | Changes from baseline (%): LOV-D: +9.4; STD-D: +7.2 (difference: +2.2) | ns (p = 0.45) difference between groups |
| Barnard et al. [30] | USA | T2DM (99) | M/F | LFVG: 56.7; ADA: 54.6 | LFVG (49) vs. ADA-recommended diet (50) | 74 weeks (parallel) | CRP (mg/L) | ITT analysis: −5.0 | ns (p = 0.65) difference between groups |
| Dinu et al. [54] | Italy | Healthy (118) | M/F | LOV: 50.5; MD: 52 | LOV (54) vs. MD (53) | 3 months | Leptin (ng/mL), adiponectin (µg/mL), LAR, resistin (ng/mL) | LOV: leptin: −0.58, adiponectin: +0.49, LAR: −0.12, resistin: −0.12; MD: leptin: −1.35 (difference: +0.77), adiponectin: +0.45 (difference: +0.04), LAR: −0.17 (difference +0.05), resistin: +0.04 (difference: −0.16) | ns (p > 0.05) difference between groups for all outcomes |
| Djekic et al. [46] | Sweden | Overweight (31) | M/F | LOV: 67.0; NVD: 68.0 | Isocaloric LOV (16) vs. NVD (15) [both adhering to Nordic Recommendations] | 12 weeks: 4 weeks × 2 (crossover) with a 4-week washout in between | hsCRP (mg/L) | Difference: −0.09 | ns (p = 0.6) difference between groups |
| Elkan et al. [35] | Sweden | Rheumatoid arthritis (66) | M/F | VG: 50.0; NVD: 50.8 | VG gluten-free (38) vs. NVD (28) | 12 months (parallel) | CRP (mg/L) | VG: −8; NVD: −10 (difference: +2) | no significance test reported for difference between diet groups |
| Hall et al. [37] | USA | Overweight (20) | M/F | All: 29.9 | LFPBD vs. ABKD | 4 weeks: 2 weeks × 2 (crossover) | hsCRP (mg/L) | LFPBD: −0.9; ABKD: 0 (difference: −0.9) | p = 0.003 |
| Jenkins et al. [39] | Canada | Overweight with hyperlipidaemia (44) | M/F | LCPBD: 56.1; LFLOV: 57.8 | LCPBD (22) vs. LFLOV (22) | 1-month parallel, metabolically controlled study | hsCRP (mg/L) | LCPBD: −0.89; LFLOV: −0.69 (difference: −0.2) | ns (p = 0.66) difference between groups |
| Jenkins et al. [40] | Canada | Overweight with hyperlipidaemia (39) | M/F | LCPBD: 57.6; LFLOV: 55.3 | LCPBD (20) vs. LFLOV (19) | 6 months (parallel) | hsCRP (mg/dL) | LCPBD: −0.4; LFLOV: −0.2 (difference: −0.2) | ns (p = 0.082) difference between groups |
| Lederer et al. [52] | Germany | Healthy (53) | M/F | VG: 33.2; OD: 29.9 | VG (26) vs. meat-rich diet (27) | 4 weeks (w/ pre-treatment controlled mixed diet for 1 week) | Leukocytes (thousands/μL), monocytes (thousands/μL), hsCRP (mg/dL), lymphocytes (thousands/μL) | VG: hsCRP: −0.2, leukocytes: −0.6, lymphocytes: −35.7, monocytes: −0.03; Meat-rich diet: CRP: +0.2 (difference: −0.04), leukocytes: 0 (difference: −0.06), lymphocytes: +0.8 (difference: −35.78), monocytes: +0.03 (difference: −0.06) | Leukocytes (p = 0.003), monocytes (p = 0.032); ns (p > 0.05) differences for all other outcomes |
| Shah et al. [33] | USA | Coronary artery disease (100) | M/F | VG: 63.0; AHA: 59.5 | VG (50) vs. AHA-recommended diet (50) | 8 weeks (parallel) | hsCRP (mg/L), WBC count (K/μL), NLR | Adjusted β for VG vs. AHA-recommended diet (as reference): hsCRP: 0.67, WBC count: 1.06, NLR: 1.20 | hsCRP (p = 0.02); ns (p > 0.05) differences for all other outcomes |
| Sofi et al. [43] | Italy | Overweight or obesity with elevated TC or LDL-C or TGs or glucose (118) | M/F | LCLOV: 49.5; LCMD: 52.0 | Isocaloric hypocaloric LCLOV vs. LCMD | 6 months: 3 months × 2 (crossover) | WBC count (× 10³/mm³), IL-6 (pg/mL), TNF-α (pg/mL) | LOV: WBC count: +0.16, IL-6: +0.07, TNF-α: +0.45; MD: WBC count: −0.09 (difference: +0.25), IL-6: −0.09 (difference: +0.16), TNF-α: −0.34 (difference: +0.79) | ns (p > 0.05) differences for all outcomes |
| Wells et al. [53] | USA | Healthy (21) | M | 59 to 78 | LOV (10) vs beef-containing diet (11) | 12 weeks (w/ pre-treatment vegetarian diet for 2 weeks) | WBC count (10⁹/L) | LOV: −0.2; Beef-containing diet: +0.5 (difference: −0.7) | no significance test reported for difference between diet groups |
Abbreviations: ABKD: animal-based ketogenic diet; ADA: American Diabetes Association; AHA: American Heart Association; CRP: C-reactive protein; F: female; hsCRP: high-sensitivity C-reactive protein; IL-6: interleukin 6; ITT: intention to treat; LAR: leptin-to-adiponectin ratio; LCLOV: low-calorie lacto-ovo-vegetarian diet; LCMD: low-calorie Mediterranean diet; LCPBD: low-carbohydrate plant-based diet; LDL-C: low-density lipoprotein cholesterol; LFLOV: low-fat lacto-ovo-vegetarian diet; LFPBD: low-fat plant-based diet; LFVG: low-fat vegan diet; LOV-D: calorie- and fat-restricted lacto-ovo-vegetarian diet; LOV: lacto-ovo-vegetarian diet; M: male; MD: Mediterranean diet; NLR: neutrophil-to-lymphocyte ratio; NVD: non-vegetarian diet; ns: non-significant; PBD: plant-based diet; STD-D: standard calorie- and fat-restricted diet; T2DM: type 2 diabetes mellitus; TC: total cholesterol; TGs: triglycerides; TNF-α: tumour necrosis factor alpha; VG: vegan diet; WBCs: white blood cells. * Results are presented for each intervention (i.e., PBD; comparison), and then the difference between interventions (PBD vs. comparison), where possible. Age is reported as mean, median, or range.