Table 3.
Impact of dietary interventions (olive oil) on primary and secondary outcomes.
| Study | Outcome Measures in Study | Attrition/Dropout | Primary Outcomes | Secondary Outcomes |
|---|---|---|---|---|
| Properzi 2018, Australia [30] | HS (MRS-PDFF), LSM [TE FibroScan™ (Echocens, Paris, France)], HepaScore, ALT, cardiometabolics, anthropometry, and QoL | Intervention: 2/26, 7.7% Control: 1/25, 4.0% |
↓ HS and ↓ ALT (both) HS RR: −32.4% ± 25.5% vs. −255.0% ± 25.3% (intervention vs. control) |
↓ gGT, HbA1c, TC, TG and FRS (intervention) ↓ WC and ↑ QoL (both) ↓ BW (both) BW: −2.3% vs. −2.1% (intervention vs. control) |
| Rezaei 2019, Iran [9] | HS (US), ALT, AST, cardiometabolics, anthropometry and diet record diaries |
Intervention: 6/32, 18.8% Control: 6/34, 17.6% |
↓ HS (both) ↓ ALT (control) ↓ HS (intervention vs. control) |
↓ AST (both) ↓ TG (intervention) ↓ BW, WC, and systolic/diastolic BP (both) BW: −4.1% vs. −2.9% (intervention vs. control) |
| Nigam 2014, India [28] | LF (US), AST, ALT, anthropometry, cardiometabolics, and food questionnaire | Intervention: 0/30, 0% Intervention: 0/30, 0% Control: 3/33, 9.1% |
↓ LF (intervention) ↓ ALT (intervention) |
↓ AST, TC, TG (intervention) ↑ HDL-C (intervention) ↓ FBG (intervention vs. control) ↓ FBG (olive oil vs. canola oil) ↓ BW (olive vs. control) |
| Scorletti 2014, United Kingdom [29] | HS (MRS), diet questionnaire, ALT, AST, cardiometabolics, and anthropometry | Intervention: 4/51, 7.8% Control: 4/52, 7.7% |
↓ ALT (control) | ↓ HS and TG (intervention) ↓ AST (control) ↓ HDL-C (intervention) |
| Kruse 2020, Germany [27] | HS (H-MRS), ALT, AST, anthropometry, cardiometabolics, and diet record diaries | Intervention: 0/11, 0% Control: 1/16, 6.3% |
↓ ALT (both) ↑ IHL (intervention vs. control) |
↓ LDL, AST (intervention) ↑ HDL (intervention) No changes BW, TG (both) |
| Tobin 2018, United States [31] | LF (MRI-PDFF), ALT, AST, anthropometry, and cardiometabolics | Intervention: 6/87, 6.9% Control: 3/89, 3.4% |
↓ ALT (control) | ↓AST and gGT (control) ↓ WC (control) ↓ in LF percentage (both) ↓ TG 18% vs. 7% (intervention vs. control) |
| Shidfar 2018, Iran [32] | HS (US), ALT, AST, anthropometry, and diet questionnaire |
Intervention: 4/25, 16.0% Control: 3/25, 12.0% |
↓ ALT (both) ↓ ALT and HS (intervention vs. control) |
↓ AST (intervention) ↓ WC (both) ↓ BW (both) BW: −4.3% vs.−3.5% (intervention vs. control) |
AST: aspartate aminotransferase, ALT: alanine transaminase, BW: body weight, WC: waist circumference, HS: hepatic steatosis, US: ultrasound, MRS: magnetic resonance spectroscopy, H-MRS: proton magnetic resonance spectroscopy, MRS-PDFF: magnetic resonance spectroscopy–measured proton density fat fraction, MRI-PDFF: magnetic resonance imaging–measured proton density fat fraction, IHL: intrahepatic lipid content, HDL-C: high-density lipoprotein cholesterol, gGT: gamma-glutamyl transferase, FBG: fasting blood glucose, TG: triglyceride, TC: total cholesterol, LDL: low-density lipoprotein, LF: liver fat, BP: blood pressure, LSM: liver stiffness measurement, FRS: Framingham risk score, QoL: quality of life, TE: transient elastography, ↓ Decreased, ↑ Increased.