Data extraction table: characteristics of interventional studies (RCTs & crossover trials, n = 8).
| Authors (Year)Country | Study designDuration | Population (n, M/F/MSC, age) | Intervention (nut type, duration) | Control group | Primary outcomes/Results |
|---|---|---|---|---|---|
| Oliver-Pons et al. (2024);Spain [19] | Randomized controlled2 Years | n = 352, healthy MSC, 63–79 y | Walnut ~15% of total energy (30–60 g) daily | No walnuts and maintain usual diet | No effect on BMD at spine P = 0.632, femoral neck P = 0.653, bone turnover biomarker |
| Kamoun et al. (2024);North Africa [25] | Randomized controlled6 Weeks | n = 20, physically active healthy M, 65 y | Three training sessions per week: concurrent training + ad libitum diet w/ walnut (15 g/d for 6 weeks) | Three training sessions per week: concurrent training + ad libitum diet | Concurrent training, w/ or w/out daily walnut, improved knee strength, support leg standing & sleep quality. Memory & balance improved only in walnut group |
| Bulló et al. (2009);Spain [20] | Parallel RCT 12 Months | n = 202, MSC, 55–80 y | Mediterranean diet + mixed nuts (walnuts (15 g/d), hazelnuts (7.5 g/d), and almonds (7.5 g/d)), Mediterranean + virgin olive oil (15 L for 3 months) | Low-fat diet | Mediterranean diet + mixed nuts ↑ PTH levels in elderly subjects (P = 0.02). No effect on bone biomarkers |
| Nieman et al. (2014);United States [17] | 2 × 2 Crossover randomized controlled2 Weeks | n = 19, physically active healthy M, 27–49 y | Pistachio nut, 3 oz w/ water (1.5 oz) before and (1.5 oz after 1 h) during exercise2-Week washout | Water only 2-Week washout | Pistachio group had 4.8% slower performance (2.84 ± 0.11 & 2.71 ± 0.07 h, P = 0.034) & ↑ oxidative stress markers |
| Philpott et al. (2023); United Kingdom and United States [18] | 3 × 3 Crossover randomized controlled2 Weeks | n = 18, physically active healthy M, 23.1 ± 1.2 y | Pistachio nut: either standard dose (42.5 g/d) or higher dose (85.0 g/d)3-Week washout | No pistachio3-Week washout | Mean quadriceps soreness (non-dominant leg) during exercise recovery ↓ (P < 0.05) in high dose vs. control (mean difference 13 mm; 95% CI: 1–25). No effect on muscle function following modest muscle damage |
| Rayo et al. (2022);United States [26] | 3 × 3 Crossover randomized controlled2 Weeks | n = 27, M athletes, 18–35 y | Pistachio nut: either high dose (3 oz/d) or low dose (1.5 oz/d)3–4-Week washout | No pistachio or other nuts throughout study3–4-Week washout | High dose: lower pain ratings post 72 h recovery & decrease in force production at 120 ◦/s of knee flexion; force was diminished in the other trials |
| Siegel et al. (2024);United Kingdom and United States [27] | 2 × 2 Crossover randomized controlled8 Weeks | n = 25, MSC, 35.1 ± 4.7 y | Raw whole almonds (57 g/d)3-Week washout | Unsalted pretzels, isocaloric amount (86 g/d)3-Week washout | Muscle soreness measured during vertical jump reduced by ~24% (P < 0.05) & improved jump performance in almond vs. control. No effect on leg extension/flexion or blood markers |
| Rayo et al. (2024);United States [28] | 2 × 2 Crossover randomized controlled8 Weeks | n = 26, MSC, 37 ± 6 y | Raw almonds (2 oz/d)4-Week washout | Unsalted pretzels, isocaloric amount4-Week washout | CK reduced post 72 h in almond group (Δ – 50% from peak; P < 0.05), flexion greater, pain lower vs. control. No effect on jump force or other blood markers |
↑: higher or increased; ↓: lower(ed) or reduced; BMD: bone mass density; CK: creatine kinase; MSC: mixed-sex cohort; PTH: parathyroid hormone; RCTs: randomized controlled trials; P < 0.05, statistical significance.