Table 3.
Summary of human trials on effects of algae consumption on other health-promoting properties.
| Study population | Study design | Algae | Method of administration | Intervention | Duration | Study outcomes (Other Health-Promoting Properties) | References |
|---|---|---|---|---|---|---|---|
| Volunteers with infrequent bowel movements (3-5x weekly), 20–65 years, M/F, n = 38 | Double-blinded, randomized clinical trial |
M. nitidum (green seaweed) |
Capsules | Intervention: 100 mg of RS (Rhamnox), a sulfated polysaccharide from M. nitidum Control: Placebo |
2 weeks | ↑ excretion frequency, ↑ excretion days. In intervention group: ↑ excretion frequency in those with ↑ BMI, weight, or gut microbiota diversity. ↑ excretion days in those with ↑ BMI. | Shimada et al. (156) |
| Healthy volunteers, 18–75 years, M/F, n = 40 | Randomized clinical trial |
L. japonica (brown seaweed) |
L. japonica – tablet Duolac7S – capsule Duolac7S is a probiotic mixture of lactic acid bacteria |
Intervention: L. japonica (1,250 mg/day) with Duolac7S Control: L. japonica (1,250 mg/day) with corn starch placebo |
4 weeks (excluding 2-week follow-up) | ↑ in 4 intestinal microbiota species. No changes in gastrointestinal symptoms or bowel functions. | Ko et al. (157) |
| Healthy volunteers, 18–65 years, M/F, n = 35 | Double-blinded, randomized clinical trial |
P. palmata (red seaweed) |
Algae-enriched bread | Intervention: 5,000 mg/day P. palmata incorporated into bread Control: Bread of the same composition as intervention bread but without P. palmata. |
4 weeks | ↑ C-reactive protein | Allsopp et al. (158) |
| Type 2 diabetes mellitus patients, 40–70 years, M/F, n = 20 | Randomized controlled trial | Sea mustard (also known as wakame or U. pinnatifida, a brown seaweed) and sea tangle | Pills | Intervention: 48 g algae/day Control: No supplementation |
4-week intervention | ↓ TBARS; ↑ catalase and GSH-Px. | Kim et al. (82) |
| Postmenopausal volunteers, 47–54 years, F, n = 21 | Clinical trial | Klamath algae (A. flos-aquae) (blue-green algae) |
Tablets | 1,600 mg algae extract/day | 8 weeks | ↓ lipid peroxidation; ↑ carotenoids, tocopherols, and retinol. | Scoglio et al. (159) |
| NAFLD patients, 20–50 years, M/F, n = 55 | Double-blinded, randomized, controlled clinical trial |
C. vulgaris (green microalgae) |
Tablets | Intervention: 1,200 mg/day C. vulgaris + 400 mg/day Vitamin E Control: Placebo tablets +400 mg/day Vitamin E |
8 weeks | ↓ hs-CRP | Ebrahimi-Mameghani et al. (132) |
| Overweight or obese prediabetic volunteers, 18–70 years, M/F, n = 56 | Double-blinded, randomized, parallel clinical trial |
A. nodosum and F. vesiculosus (brown seaweed) | Capsules | Intervention: 500 mg/day brown algae extract Control: 500 mg/day placebo Both groups also received individualized nutritional advice for moderate weight loss |
12 weeks | Inhibited ↑ in IL-6. No changes in hs-CRP and F2-isoprostane. | Vodouhè et al. (140) |
| Study 1: Overweight or obese volunteers (BMI 25-40 kg/m2), ≥ 18 years, M/F, n = 64 Study 2 Overweight volunteers (BMI 25-29 kg/m2), ≥ 18 years, M/F, n = 64 |
Study 1: Double-blinded, randomized, controlled trial Study 2: Double-blinded, randomized, 2-way crossover trial |
Ulva sp. 84 (green seaweed) |
Capsules | Study 1: Intervention 1: 2000 mg/day SXRG84 Intervention 2: 4,000 mg/day SXRG84 Study 2: Intervention 1: 2000 mg/day SXRG84 for 6 weeks Control: Placebo for 6 weeks |
Study 1: 6 weeks Study 2: 12 weeks (no washout period) |
Study 1: ↓ CRP with 4,000 mg/day dose in overweight participants. Gut flora shifts in pooled 2000 and 4,000 mg/day SXRG84 compared to placebo. No changes in F2-isoprostanes. Study 2: ↓ pro- inflammatory and anti-inflammatory cytokines. No differences in gut microbiota. |
Roach et al. (154) |
| Overweight and obese volunteers BMI ≥ 25 kg/m2, 30–65 years, M/F, n = 78 | Double-blinded, randomized, 2-way crossover trial |
A. nodosum (brown seaweed) |
Capsules | Intervention: 400 mg/day capsule containing 100 mg algae (poly)phenol and 300 mg maltodextrin for 8 weeks 8-week washout Control: 400 mg/day maltodextrin placebo capsule for 8 weeks |
16 weeks (excluding 8-week washout) | ↓ basal DNA damage in obese participants and in men; ↓ peroxide in women. No other changes in CRP, antioxidant status or inflammatory cytokines. |
Baldrick et al. (160) |