Table 1.
Study population | Study design | Algae | Method of administration | Intervention | Duration | Study outcomes (Glucose and Satiety) | References |
---|---|---|---|---|---|---|---|
Healthy volunteers, 19–56 years, M/F, n = 38 | Double-blinded, randomized 3-way crossover trial |
F. vesiculosus (brown seaweed) |
Capsules | Intervention 1: 500 mg F. vesiculosus Intervention 2: 2000 mg F. vesiculosus Control: 2000 mg cellulose placebo Study meal of 50 g available carbohydrate (white bread) |
Acute postprandial study (2 h post-meal) | No effects on glucose or insulin. Asian participants had consistently ↑ insulin responses. | Murray et al. (126) |
Healthy volunteers, 19–59 years, M/F, n = 23 | Double-blinded, randomized 2-way crossover trial |
A. nodosum and F. vesiculosus (brown seaweed) |
Capsules | Intervention: 500 mg algae blend 1-week washout Control: 500 mg placebo Study meal of 50 g available carbohydrate (white bread) |
Acute postprandial study (3 h post-meal) | ↓ insulin and ↑ insulin sensitivity. No differences in glucose. | Paradis et al. (127) |
Healthy volunteers, 20–50 years, M/F, n = 20 | Blinded, randomized 3-way crossover trial |
L. digitata (LD) and U. pinnatifida (UP) (brown seaweed) |
Whole seaweed salads | 5,000 mg of LD or UP or an energy-adjusted control meal containing pea protein. | Acute postprandial study (3 h post-meal) | ↓ glucose, insulin, and C-peptide following LD and UP intake in participants <63 kg, after adjustment for body weight. LD and UP ↓ hunger and ↑ satiety but did not affect subsequent food intake. |
Zaharudin et al. (128) |
Overweight, otherwise healthy volunteers, 18–65 years, M, n = 12 | Single-blinded, 2-way crossover trial | A. nodosum (brown seaweed) | Algae-enriched bread | Intervention: 100 g toasted bread enriched with 4% A. nodosum Control: 100 g toasted standard whole meal bread (0% A. nodosum) Both meals were consumed with scrambled eggs |
Acute postprandial study (4 h post-meal) | ↓ subsequent food intake. No changes in glucose. | Hall et al. (129) |
Healthy volunteers, 18–45 years, M/F, n = 28 | Double-blinded, prospective, randomized, 2-way crossover, pilot study |
A. nodosum (brown seaweed) |
Capsules | Intervention: Capsules containing 1,000 mg Garcinia cambogia (G. cambogia), 400 mg A. nodosum and 40 mg L-carnitine in total for 1 week 1-week washout Control: Placebo capsules similar in weight, color, and size to intervention for 1 week |
2 weeks (excluding 1-week washout) | ↓ hunger and satiety; ↑ fullness and preference for sweet foods. | Mayer et al. (130) |
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 weeks | ↓ fasting glucose and 2-h postprandial glucose. No changes in HbA1c. | Kim et al. (82) |
Participants with at least 1 symptom of the metabolic syndrome, men (47.4 ± 9.9 years), women (45.6 ± 12.2 years), M/F, n = 27 | Double-blinded, 2-way crossover study |
U. pinnatifida (brown seaweed) |
Capsules | Group 1: 1 month of maltodextrose placebo followed by 1 month of 4,000 mg/day algae Group 2: 1 month of 4,000 mg/day algae followed by 1 month of 6,000 mg/day algae |
8 weeks | No changes in glucose, insulin, or HOMA-IR. | Teas et al. (131) |
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 | ↓ glucose. No significant changes in insulin and HOMA-IR. | Ebrahimi-Mameghani et al. (132, 133) |
Hypercholesterolemia patients, 20–60 years, M/F, n = 103 | Double-blinded, randomized, controlled and parallel-group comparison trial |
P. palmata (red seaweed) |
Capsules | Intervention: 2000 mg/day P. palmata Control: Placebo capsules |
8 weeks | No differences in glucose, glycated albumin, insulin, or HOMA-IR. |
Takase et al. (134) |
Type 2 diabetes mellitus patients, 20–65 years, M/F, n = 84 | Double-blinded, randomized controlled trial |
C. vulgaris (green microalgae) |
Capsules | Intervention: 1,500 mg/day C. vulgaris Control: 1,500 mg/day placebo |
8 weeks | No changes in glucose, insulin, HbA1c or HOMA-IR. | Hosseini et al. (135) |
Intervention: Non-insulin dependent diabetes mellitus (NIDDM) patients, mean age: 47.8 years, M/F, n = 15 Control: Healthy volunteers, Mean age: 53.4 years, M/F, n = 7 |
Controlled clinical trial | Spirulina (blue-green algae; species not specified) |
Tablets | Intervention: 2000 mg/day Spirulina Control: Not supplemented with Spirulina |
8 weeks | ↓ glucose | Mani et al. (136) |
At-risk group: Volunteers with high risk of diabetes or hyperlipidemia, > 20 years, M, n = 17 Healthy group: Healthy volunteers, > 20 years, M, n = 16 |
Clinical trial |
C. pyrenoidosa (green microalgae) |
Tablets | Both groups took 8,000 mg/day of Sun Chlorella A | 12 weeks (excluding 4-weeks follow-up) | ↓ glucose; no changes in insulin. | Mizoguchi et al. (137) |
NAFLD patients, 35–70 years, M/F, n = 54 | Randomized open-label clinical trial |
C. vulgaris (green microalgae) |
Tablets | Intervention: 1,200 mg/day C. vulgaris + 750 mg/day metformin +200 mg/day Vitamin E Control: 1,250 mg/day metformin +200 mg/day Vitamin E |
12 weeks | ↓ HbA1c and HOMA-IR in intervention group. ↓ glucose in control group. | Panahi et al. (138) |
Pre-diabetic volunteers, 20–60 years, M/F, n = 80 | Double-blinded, randomized, clinical trial | Ecklonia cava (brown seaweed; referred hereafter as E. cava) | Tablets | Intervention: 1,500 mg/day dieckol-rich extract from E. cava Control: 1,500 mg/day placebo |
12 weeks | ↓ glucose | Lee et al. (139) |
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 | No effect on glucose; ↓ C-peptide at 120 min-OGTT. | Vodouhè et al. (140) |