The key role alginates play in health

The role of alginates, widely utilised gelling agents in pharmaceutical and food applications, in human health has broadened recently with the recognition that they have a number of potentially beneficial physiological effects in the gastrointestinal tract. These include an effect on intestinal absorption and colonic health. Importantly, alginates have also been shown to moderate human appetite and energy intake. It has been proposed that, following ingestion, ionic gelation of alginate in stomach acid can modulate feeding behaviour through slowed gastric clearance, stimulation of gastric stretch receptors and attenuated nutrient uptake. It should be recognised however that these alginate formulations utilise gastric acid as the ‘trigger mechanism’ for gelation which can be unreliable because a number of factors may reduce gastric acidity. To address this concern, we have developed an alginate:calcium carbonate powder mix that when reconstituted with water and ingested, does not rely on stomach acid to ‘trigger’ ionic gelation. The formulation development process and a series of randomised, controlled trials to assess whether the novel alginate beverage could modulate feeding behaviour are discussed. The findings suggest a role for appropriately designed alginate formulations in the management of overweight and obesity.