Table 1.
Summary of clinical trials included in this review (n = 10).
| Authors | Subjects | Substance | Dosage | Study Design | Study Duration | Dependent Variables | Results |
|---|---|---|---|---|---|---|---|
| Paradis et al., (2011) [49] | 23 healthy subjects (11 men,12 women), aged 18–60 years (mean age: 39 ± 12.7 years; mean BMI: 24.9 ± 3.2 kg/m2) | Ascophyllum nodosum and Fucus vesiculosus (a) | Two 250 mg seaweed capsules 30 min prior to the consumption of 50 g of carbohydrates from bread | Double-blind, randomized, placebo-controlled crossover study | 3 h after the ingestion of the capsules | Plasma glucose and insulin concentrations | Compared with placebo, consumption of seaweed was significantly associated with a 12.1% reduction in the insulin incremental area under the curve and a 7.9% increase in the Cederholm index of insulin sensitivity. The single ingestion of brown seaweed had no significant effect on the glucose response |
| Hall et al., (2012) [50] | 12 overweight or obese men, aged 18 and 65 years (mean age: 40.1 ± 12.5 years; mean BMI: 30.8 ± 4.4 kg/m2) | Ascophyllum nodosum (b) | 100 g of bread containing Ascophyllum nodosum (4%) | Single blind crossover study | 4 h after administration of Ascophyllum nodosum | Energy intake, appetite, plasma glucose and insulin | Significantly reduced energy intake at a test meal 4 h following administration of Ascophyllum nodosum bread. No changes in plasma glucose and cholesterol levels |
| Iacoviello et al., (2013) [51] | 43 healthy subjects (19 men, 24 women), aged 21–63 years (mean age: 45.75 ± 9.51 years; mean BMI: 28.2 ± 4.8 kg/m2) | Ascophyllum nodosum and iodine (a) | Two capsules of algae, each containing 900 mg algae and 175 μg iodine | Randomised, placebo-controlled, double-blind trial, following a crossover design | 14 weeks (6-week A. nodosum or placebo, 2 weeks of washout, additional 6-week with other treatment) | Anthropometric indexes and biomarkers of metabolic risk for cardiovascular disease | Significant decrease in both body weight and BMI, with no difference between the treatment and placebo groups. Compared to placebo group, Triglyceride levels were significantly lowered by 5% in treatment group after 6 weeks of active treatment. A non-significant trend to decreased total cholesterol and low-density lipoprotein and to increased high-density lipoprotein was observed in both supplementation groups. TNF-⍺ was significantly increased in the placebo group, but not in the active group, while adiponectin was significantly increased in both groups, with no difference between them |
| Mayer et al., (2014) [52] | 28 healthy subjects (7 men, 21 women), aged 18–45 years (mean age: 31 ± 5 years; mean BMI: 22.6 ± 1.7 kg/m2) | Ascophyllum nodosum, Garcinia cambogia and L-carnitine (a) | Two capsules a day, each containing 200 mg Ascophyllum nodosum, 500 mg Garcinia cambogia and 20 mg l-carnitine | Double-blind, prospective, randomized, cross-over, placebo-controlled pilot study | 1 week | Satiety sensations and food preferences | No differences in energy intake between study groups. Active treatment significantly reduced subjective hunger sensations and significantly increased satiety and fullness ratings |
| Murray et al. (2018) [53] | 38 healthy subjects (9 men, 29 women), aged 19–56 years (median 23 years), BMI18.9 to 28.3 kg/m2 (median 21.9 kg/m2) | Fucus vesiculosus (a) | Each participant consumed a low dose (500 mg) Fucus vesiculosus, a high dose (2000 mg) Fucus vesiculosus and placebo (2000 mg cellulose) 30 min prior to 50 g of available carbohydrate form white bread | Double-blind, placebo-controlled, randomised cross-over study |
2 h following carbohydrate consumption | Postprandial blood glucose and plasma insulin concentrations | No lowering effect on postprandial glucose or insulin responses. Different insulin sensitivity in Asian subjects |
| Baldrick et al. (2018) [54] | 80 overweight/obese adults (39 men, 41 women), aged 30–65 years (mean age: 42.7 ± 7.1 years; mean BMI: 30.2 ± 3.9 kg/m2) | Ascophyllum nodosum (a) | A 400 mg capsule containing 100 mg Ascophyllum nodosum and 300 mg maltodextrin | Randomized, double-blind, placebo-controlled crossover study | 8-week | DNA damage, plasma oxidant capacity, C-reactive protein (CRP) and inflammatory cytokines | Modest decrease in DNA damage but only in a subset of the total population who were obese. There were no significant changes in CRP, antioxidant status, or inflammatory cytokines |
| De Martin et al., (2018) [36] | 50 patients (18 men, 32 women), aged 18–60 years (mean age: 54 ± 12 years) | Ascophyllum nodosum, Fucus vesiculosus and chromium picolinate (a) | Three capsules a day, each containing 237.5 Ascophyllum nodosum, 12.5 mg Fucus vesiculosus and 7.5 μg chromium picolinate | Observational study | 6-months | Waist circumference, fasting blood glucose, HOMA index and insulin levels | Waist circumference decreased significantly after 6 months of treatment. Both blood glucose and insulin levels were significantly reduced after 6 months of treatment. HOMA index decreased significantly, suggesting an improvement of insulin sensitivity status |
| Derosa et al., (2019) [55] | 65 dysglycemic patients (33 men, 32 women), aged ≥ 18 years (mean BMI: 28.9 ± 2.7 kg/m2) | Ascophyllum nodosum, Fucus vesiculosus and chromium picolinate (a) | Three capsules a day, each containing 237.5 Ascophyllum nodosum, 12.5 mg Fucus vesiculosus and 7.5 μg chromium picolinate | Double-blind, randomized, placebo-controlled study | 6-months | Body Weight, Body Mass Index, Waist Circumference, Hip Circumference, Fasting plasma glucose (FPG), postprandial plasma glucose (PPG), HbA1c, fasting plasma insulin, HOMA index, high sensitivity C-reactive protein, tumour necrosis factor-α and adhesion molecules | FPG, PPG, HbA1c, HOMA-IR, CRP and TNF- α reduced significantly compared to placebo after 6 months. No significant changes were observed in anthropometric indexes |
| Murray et al., (2019) [56] | 18 normotensive subjects (12 females, 6 males), aged 18–65 years (mean age: 25.5 ± 19 years; mean BMI 23.8 ± 2.6 kg/m2) | Fucus vesiculosus (a) | 2000 mg powdered extract from Fucus vesiculosus containing 560 mg polyphenols and 1340 mg fucoidan | Double-blind, placebo-controlled, randomized crossover trial | 3 h after ingestion of Fucus vesiculosus | Post prandial blood glucose levels | No effect on postprandial glycaemia. Only in females, peak blood glucose concentration was reduced after the polyphenol-rich extract |
| Derosa et al., (2019) [57] | 175 Caucasian patients with type 2 diabetes (85 men, 90 women), aged 18 years and over (mean BMI: 27.5 ± 2.3 kg/m2) | Ascophyllum nodosum, Fucus vesiculosus and chromium picolinate (a) | Three capsules a day, each containing 237.5 Ascophyllum nodosum, 12.5 mg Fucus vesiculosus and 7.5 μg chromium picolinate | Multicentre, 6 months, double-blind, randomized, controlled, clinical trial | 6-months | Anthropometric parameters (body weight, BMI, abdominal circumference), glyco-metabolic control (FPG, PPG, HbA1c) and lipid profile (Total cholesterol, TC; low-density lipoprotein-cholesterol, LDL-C; high-density lipoprotein-cholesterol, HDL-C and Triglycerides, TG) | No variation of body weight and BMI were recorded. A significant reduction of waist circumference was recorded in the nutraceutical group but not in placebo group. HbA1c, FPG and PPG were significantly reduced by the nutraceutical combination, but not by placebo. No variations of TC, LDL-C, HDL-C and TG were recorded compared to baseline. |
The form of test substance administered in the clinical trials: (a) capsular form (b) powder incorporated into a meal.