TABLE 2.
Controlled feeding intervention studies that compared the effects of different amounts of plant- and animal-based protein1
| Relative contribution of animal vs. plant protein |
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| Diet (reference) | Study design | Duration of diet periods, wk | Study population, n | Intervention diet(s) | Total protein,% kcal | Plant-based, % total protein | Animal-based, % total protein | Control and/or comparator diet(s) | Effect of intervention diet 2 |
| DASH (50, 51, 54) | Parallel | 8 | Adults with SBP < 160 mm Hg and DBP 80 – 95 mm Hg [n = 436 for (50)][n = 459 for (51)] | Increased fruits, vegetables, low-fat dairy | 15 | 37 | 63 | Average American diet control | BP reduction: 5.5/3 mm Hg |
| Reduced SFA and total fat | Fruits and Vegetables Diet comparator | ↓ TC by 13.7 mg/dL | |||||||
| ↓ LDL-C by 10.7 mg/dL | |||||||||
| ↓ HDL-C by 3.7 mg/dL | |||||||||
| ↔ TG | |||||||||
| OmniHeart (52) | Crossover | 6 | Adults with prehypertension and hypertension (n = 164) | High-protein DASH diet variation replaced 10% of CHO with protein, emphasizing protein from plant sources | 25 | 47 | 54 | Carbohydrate-rich DASH diet control | SBP reduction: 1.4 mm Hg |
| Unsaturated-fat DASH diet variation (10% CHO replaced by unsaturated fat) | ↓ LDL-C by 3.3 mg/dL | ||||||||
| ↓ HDL-C by 1.3 mg/dL | |||||||||
| ↓ TG by 15.7 mg/dL | |||||||||
| BOLD (53, 55) | Crossover | 5 | Normotensive adults (n = 36) | BOLD, modified-DASH diet rich in animal protein, particularly lean beef | 19 | 13 | 87 | HAD control | BOLD ↓ AI by 4.1% |
| BOLD+, moderate protein diet rich in animal protein | 27 | 19 | 80 | M-DASH | BOLD+ ↓ SBP | ||||
| M-DASH, BOLD, and BOLD+ similarly ↓ TC, LDL-C, HDL-C, and non-HDL-C | |||||||||
1
AI, augmentation index; BOLD, Beef in an Optimal Lean Diet; BP, blood pressure; CHO, carbohydrate; DASH, Dietary Approaches to Stop Hypertension; DBP, diastolic blood pressure; HAD, Healthy American Diet; HDL-C, HDL-cholesterol; LDL-C, LDL-cholesterol; M-DASH, DASH-like diet comparator; SBP, systolic blood pressure; TC, total cholesterol.
2
Results reported for DASH and BOLD studies are relative to control diet; results from OmniHeart Study represent changes relative to the standard DASH diet (i.e., additional reductions beyond those achieved with the carbohydrate-rich DASH diet control).