Table 1.
Table of included meta-analyses for summarizing possible health effects linked to the intake of antioxidant and phytochemicals. The meta-analyses are reported based on outcome measures as given by the authors.
| Study | Study design (number of studies) | Intervention | Population characteristics | Outcome measures | Results given as SMD/WMD (95% CI)a | Evidence for heterogeneityb | Comments |
|---|---|---|---|---|---|---|---|
|
* Zeraattalab-Motlagh et al. (2021), Am J Clin Nutr (43) |
RCT (n = 28 RCT from 11 meta-analysis) | Resveratrol (8–3,000 mg/d) Duration: 4–48 w |
1,476 participants with T2D (ranging from 77 to 789 for reported variables) |
T2D 29 variables, 9 variables with moderate-certainty evidence are reported |
Reduction in: SBP –1.23 (–1.96, –0.49), DBP –0.85 (–1.56, –0.13), MAP –4.21 (–7.35, –1.07), PP –6.52 (–11.20, –1.84), HOMA-IR –0.46 (–0.74, –0.11), FGC –0.33 (–0.57, –0.09) Increase in: GGT 2.01 (0.70, 3.32, AST 1.23 (0.29, 2.16), adiponectin 1.37 (0.15, 2.60) No effect: ALT, TG, BMI, and WC |
Significant: SBP, DBP | Only results related to T2D are given. Certainty of evidence (GRADE) for the other studied variables (9 of totally 29) was evaluated as low. |
|
* Zeraattalab-Motlagh et al. (2021), Am J Clin Nutr (43) |
RCT (n = 15 RCT from 9 meta-analyses) | Resveratrol (100–3,000 mg/d) Duration: 4–24 w |
727 participants with MetS (407 participants for the reported variable) |
MetS 24 variables, 1 variable with moderate-certainty evidence is reported |
No effect: HDL | Not significant for reported variable | Only results related to MetS are given. Certainty of evidence (GRADE) for the other studied variables (23 of totally 24) was evaluated as low. |
|
* Zeraattalab-Motlagh et al. (2021), Am J Clin Nutr (43) |
RCT (n = 6 RCT from 10 meta-analyses) | Resveratrol (150–3,000 mg/d) Duration: 8-24 w |
271 participants with NAFLD (ranging from 156 to 216 for reported variables) |
NAFLD 24 variables, 6 variables with moderate-certainty evidence are reported |
Reduction in: BW –0.67 (–1.26, -0.08), BMI –0.25 (–0.45, -0.04), DBP –0.40 (–0.79, -0.02). No effect: TG, MAP, or WC |
Not significant for reported variables | Only results related to NAFLD are given. Certainty of evidence (GRADE) for the other studied variables (18 of totally 24) was evaluated as low. |
| Mousavi et al. (2019), Obesity Reviews (44) | RCT (n = 28) | Resveratrol (8–3,000 mg/d) Duration: 4–52 w |
1,514 subjects with BMI in the range from 23 to 35.1 kg/m2 |
Obesity 4 variables |
Reduction in: BW –0.51 (-0.94, -0.09), BMI –0.17 (-0.32, –0.03), WC –0.79 (–1.39, -0.2) No effect: FM |
Significant: BW | Subgroup analysis: Reduction in BW and BMI in trials with doses <500 mg/d, duration >3 months and performed on participants with obesity |
| Akbari et al. (2019), High Blood Pressure & Cardiovascular Prevention (45) | RCT (n = 28) | Resveratrol (40–3,000 mg/d) Duration: 1–48 w |
1,748 participants with MetS or related disorders |
BP 3 variables |
Increase in: FMD 1.77 (0.25, 3.29) No effect: SBP or DBP |
Significant: FMD, SBP, and DBP due to duration and type of disease | Subgroup analyses: SBP and DBP decreased in trials with T2D compared to other diseases |
| Gorabi et al. (2021), Phytotherapy Research (46) | RCT (n = 35) | Resveratrol (8–3,000 mg/d) Duration: 4–48 w |
1,128 participants with MetS, CVD, CAD, stable angina, overweight, T2D, older, postmenopausal women, hypertension, RA, or PCOS |
Inflammation 2 variables |
Reduction in: hs-CRP –0.40 (–0.70 to –0.09), CRP -0.47 (–0.69, –0.25) |
Significant: hs-CRP | Subgroup analysis: hs-CRP and CRP decreased in trials of longer duration (≥10 w) and with doses ≥500 mg/d (CRP) |
| Koushki et al. (2018), Clinical Therapeutics (47) | RCT (n = 17) | Resveratrol (6–800 mg/d) Duration: 4–52 w |
736 participants with CVD, T2D, NAFLD, healthy normal weighted, obese, or angina pectoris |
Inflammation 3 variables |
Reduction in: TNFα –0.44 (–0.71, –0.164), hs-CRP –0.27 (–0.5, –0.02) No effect: IL-6 |
Significant: hs-CRP, IL-6, and TNFα. | Significant heterogeneity was observed for the type of sample in IL-6 and study duration for IL-6, TNF-α, and hs-CRP. |
|
Mohammadi-Sartang et al. (2017), Pharmacological Research (49) |
RCT (n = 9) | Resveratrol (16–3,000 mg/d) Duration: 4–48 w |
590 participants with obesity, T2D, NAFLD, CVD, postmenopausal women, or healthy elderly |
Adipokines 2 variables |
Increase in: Adiponectin 1.10 (0.88, 1.33) No effect: Leptin |
Not significant for reported variables | Subgroup analysis: Greater adiponectin-reducing effect in trials with doses >100 mg/d Compared to doses <100 mg/d |
|
Koushki et al. (2020), Postgraduate Medical Journal (48) |
RCT (n = 12) | Resveratrol (40–3,000 mg/d) Duration: 4–26 w |
575 participants with T2D, healthy normal weighted or obese, NAFLD, chronic kidney disease, nephropathy, hypercholesterolemic or ulcerative colitis |
Oxidative stress 4 variables |
Increase in: TAC 0.52 (–0.02, 1.07) No effect: SOD, CAT, and GPx |
Significant: TAC, SOD, CAT, and GPx | Subgroup analysis: Resveratrol in doses between 500 and 800 mg/d and treatment >60 d changed the oxidative stress markers |
|
Li et al. (2021), BMC Complementary Medicine and Therapies (50) |
RCT (n = 10) | Resveratrol (8–1,500 mg/d) Duration: 4–52 w |
698 participants with T2D, NAFLD, obesity, healthy elderly, or postmenopausal women |
Bone quality 9 variables |
No effect: BMD, hip BMD, whole body BMD, bone serum markers (ALP, BAP, OCN, PINP, CTX, and PTH) | Not significant for reported variables | Subgroup analysis: BMD and serum bone markers were not affected by dose, intervention duration, and pathology of participants |
Significant results are given as standardized mean differences (SMD) or weighted mean differences (WMD) with 95% CI compared to placebo and are indicated in bold.
Significant heterogeneity if I2 > 50% or p > 0.05.
SMD: standardized mean differences; RCT: randomized controlled trials; BP: blood pressure; SBP: systolic BP; DBP: diastolic BP; FMD: flow-mediated dilatation; MAP: mean arterial pressure; TC: total cholesterol; TG: trigycerides; HDL: high density lipoprotein; LDL: low density lipoprotein; Apo-A: apoplipoprotein A; Apo-B: apoplipoprotein B; HOMA-IR: homeostatic model assessment-insulin resistance; FGC: Fasting glucose concentration; ALT: aminotransferase; ASDT: aspartate aminotransferase; GGT: γ-glutamyl transferase; ALP: alkaline phosphatase; IL-6: interleukin-6; NAFLD: non-alcoholic fatty liver disease; BMD: bone mineral density; PCOS: polycystic ovary syndrome; BW: body weight; BMI: body mass index; WC: weight circumferences; T2D: Type 2 diabetes mellitus; MetS: Metabolic syndrome; NAFLD: non-alcoholic fatty liver disease.
This study reported outcomes related to T2D, MetS, and NAFLD.