Review: efficacy of alginate supplementation in relation to appetite regulation and metabolic risk factors: evidence from animal and human studies

Abstract

This review provides a critical update on human and animal studies investigating the effect of alginate supplementation on appetite regulation, glycaemic and insulinemic responses, and lipid metabolism with discussion of the evidence on potential mechanisms, efficacy and tolerability. Dependent on vehicle applied for alginate supplementation, the majority of animal and human studies suggest that alginate consumption does suppress satiety and to some extent energy intake. Only one long-term intervention trial found effects on weight loss. In addition, alginates seem to exhibit beneficial influence on postprandial glucose absorption and insulin response in animals and humans. However, alginate supplementation was only found to have cholesterol-lowering properties in animals. Several mechanisms have been suggested for the positive effect observed, which involve delayed gastric emptying, increased viscosity of digesta and slowed nutrient absorption in the small intestine upon alginate gel formation. Despite reasonable efficacy and tolerability from the acute or short-term studies, we still realize there is a critical need for development of optimal alginate types and vehicles as well as studies on further long-term investigation on alginate supplementation in humans before inferring that it could be useful in the management of obesity and the metabolic syndrome.

Sodium alginate prevents progression of non-alcoholic steatohepatitis and liver carcinogenesis in obese and diabetic mice

“…SA is expected to have beneficial effects on postprandial insulinemia because of its high viscosity and gelling properties [ 30 ]. Reduction in food intake and suppression of body weight gain after administration of high-viscosity SA, compared to low-viscosity SA, were observed in a previous study [ 40 , 41 ]. In rats fed a diet supplemented with cholesterol and bile acids, high-viscosity SA administration reduced cholesterol levels, whereas low-viscosity SA did not [ 41 ].…”

Seaweed Supplements Normalise Metabolic, Cardiovascular and Liver Responses in High-Carbohydrate, High-Fat Fed Rats

“…Based on body surface area, conversion of the seaweed intake in the current study in rats to humans [ 25 ] would provide a fibre intake of between 5.8 and 15.6 g/day, lower than the recommendations, but sufficient to double current intake in the USA. The physicochemical properties of seaweed fibre, such as the ability to absorb and hold water, ion exchange capacity and viscosity, will slow down absorption of compounds in the gut [ 26 , 27 ]. We suggest that the high soluble fibre content of UO could increase gastrointestinal viscosity and therefore inhibit intestinal absorption of fatty acids more effectively than DT, leading to the decreased total body fat mass with UO but not DT.…”

Functional foods as potential therapeutic options for metabolic syndrome

“…The viscous dietary fibre from linseed given either as a drink or a tablet suppressed appetite and energy intake in young healthy subjects of normal weight . A further option could be dietary supplementation with alginates from marine brown algae as a long‐term intervention to control body fat mass; alginates may decrease postprandial glucose absorption, delay gastric emptying, increase the viscosity of gastric contents and slow down nutrient absorption in the small intestine after gel formation . Plant‐derived appetite suppressants need further investigation for the treatment of obesity, both alone and in combination with other functional foods and nutraceuticals.…”