Table 5
Effects of Increased Fiber Intake on Serum Lipids Levels
| Meta-analysis Authors, Year | No. of Studies in Meta-analysis | No. of Participants in Meta-analysis | Fiber Type (Average Amount per Day) | Mean Duration (wk) | Main Findings of Meta-analysis | Q Test P Value | I2 Statistic | Egger or Begg Test P Value | Quality Assessment and Outcome |
|---|---|---|---|---|---|---|---|---|---|
| Brown et al, 199932 | 66 | 2975 | Dietary fiber (9.5 g) | 7 | TC ↓ 10.4 mg/dL, P < .05 LDL ↓ 10.8 mg/dL, P < .05 HDL ↓ 0.8 mg/dL, NS Trigs 0.9 mg/dL, NS | P < .001 P < .001 P < .001 P < .001 | |||
| Hartley et al, 201633 | 17 | 1067 | Dietary fiber (NR) | 12 | TC ↓ 7.7 mg/dL, P = .005 LDL ↓ 5.4 mg/dL, P = .001 HDL ↓ 1.2 mg/dL, NS Trigs 0.0 mg/dL, NS | P < .05 NS NS NS | 46% 36% 0% 32% | Cochrane 10/17 | |
| Ripsin et al, 199234 | 12 | 1603 | β-Glucan (4 g) | 6 | TC ↓ 5.1 mg/dL, P < .05 LDL NR HDL NR Trigs NR | NS | |||
| Talati et al, 200935 | 8 | 391 | β-Glucan (6.5 g) | 5 | TC ↓ 13.4 mg/dL, P < .05 LDL ↓ 10.0 mg/dL, P < .05 HDL 1.0 mg/dL, NS Trigs ↓ 11.8 mg/dL, P < .05 | NS NS NS NS | 0% 0% 0% 0% | P = .02 NS NS NS | |
| AbuMweis et al, 201036 | 11 | 329 | β-Glucan (6 g) | 5 | TC ↓ 11.6 mg/dL, P < .000 LDL ↓ 10.4 mg/dL, P < .000 HDL 0.0 mg/dL, NS Trigs ↓ 4.4 mg/dL, NS | NS NS NS NS | 16% 0% 30% 41% | P < .05 P < .05 NR NR | Yes, 1 study excluded |
| Tiwari and Cummins, 201137 | 11 | 516 | β-Glucan (5 g) | 6 | TC ↓ 23.2 mg/dL, P < .05 LDL ↓ 25.5 mg/dL, P < .05 HDL 1.2 mg/dL, NS Trigs ↓ 3.5 mg/dL, NS | P < .000 P < .000 NS NS | 77% 84% 0% 0% | NS NS NS NS | |
| Whitehead et al, 201438 | 28 | 2519 | β-Glucan (5.5 g) | 6 | TC ↓ 11.2 mg/dL, P < .05 LDL ↓ 11.2 mg/dL, P < .05 HDL 1.1 mg/dL, NS Trigs ↓ 2.0 mg/dL, NS | NS NS P < .001 NS | 28% 22% 81% 0% | P < .05 NS NR NR | Yes NR |
| Zhu et al, 201539 | 17 | 916 | β-Glucan (5.5 g) | 7 | TC ↓ 10.1 mg/dL, P < .000 LDL ↓ 8.1 mg/dL, P < .000 HDL ↓ 0.8 mg/dL, NS Trigs ↓ 1.8 mg/dL, NS | NS NS NS NS | 0% 0% 0% 0% | NS NS NS NS | Jadad Scale 11/17 high quality |
| Hou et al, 201540 | 7 | 453 | β-Glucan (NR) | NR | TC ↓ 18.9 mg/dL, P < .05 LDL ↓ 11.2 mg/dL, P < .05 HDL ↓ 1.9 mg/dL, NS Trigs ↓ 14.2 mg/dL, NS | P = .016 NS NS NS | 62% 21% 0% 10% | NOS scale 4/7 high quality | |
| Ho et al, 201641 | 14 | 723 | β-Glucan from barley (6 g) | 5 | TC NR LDL ↓ 9.7 mg/dL, P < .000 HDL NR Trigs NR | NS | 0% | NS | MQS 7/14 high quality |
| Ho et al, 201642 | 56 | 3745 | β-Glucan from oats (4 g) | 6 | TC NR LDL ↓ 7.3 mg/dL, P < .000 HDL NR Trigs NR | P < .000 | 79% | NS | MQS 9/56 high quality |
| Olson et al, 199743 | 12 | 404 | Psyllium (9 g) | 6 | TC ↓ 12.0 mg/dL, P < .000 LDL ↓ 13.5 mg/dL, P < .000 HDL 0.0 mg/dL, NS Trigs NR | ||||
| Anderson et al, 200044,a | 8 | 656 | Psyllium (10 g) | 10 | TC ↓ 9.3 mg/dL, P < .000 LDL ↓ 10.8 mg/dL, P < .000 HDL ↓ 0.4 mg/dL, NS Trigs ↓ 5.3 mg/dL, NS | ||||
| Wei et al, 200945 | 21 | 1717 | Psyllium (10 g) | 8 | TC ↓ 14.7 mg/dL, P < .05 LDL ↓ 10.8 mg/dL, P < .05 HDL ↓ 1.2 mg/dL, NS Trigs 0.9 mg/dL, NS | P < .000 NS NS NS | NS P = .04 NR NR | ||
| Brighenti, 200746 | 16 | 290 | Fructans (14 g) | 5 | TC NR LDL NR HDL NR Trigs ↓ 15.1 mg/dL, P = .04 | NS | 0% | NS | |
| Liu et al, 201647 | 19 | 585 | Fructans (13 g) | 5 | TC ↓ 1.5 mg/dL, NS LDL ↓ 5.8 mg/dL, P = .03 HDL 1.2 mg/dL, NS Trigs ↓ 1.8 mg/dL, NS | NS P = .04 NS NS | 2% 40% 0% 0% | NS NS NS NS | Cochrane 6/19 high quality |
| Baker et al, 200948 | 6 | 416 | Chitosan (2.4 g) | 9 | TC ↓ 11.6 mg/dL, P = .02 LDL ↓ 3.7 mg/dL, NS HDL 1.0 mg/dL, NS Trigs ↓ 4.3 mg/dL, NS | P < .05 NS NS NS | 70% 0% 26% 0% | P < .05 P < .05 P < .05 P < .05 | |
HDL, high-density cholesterol lipoproteins; LDL, low-density lipoproteins; MQS, methodological quality score; NR, not reported; NS, not significant; TC, total cholesterol; Trigs, triglycerides.
aLow-quality score on the Critical Appraisal Checklist for Systematic Reviews.