Adding extracts from brown seaweed to a meal may reduce blood sugar spikes by about 14% and offer benefits from people at risk of type-2 diabetes, suggests a new study.
A drink formulated with alginates from seaweed was also found to reduce the overall increase in blood sugar levels after a meal by over 50%, according to findings of a randomized, single-blinded, controlled, parallel trial.
“There is evidence to suggest alginate ingestion results in ‘gel lump’ formation, which alters nutrient transport to the small intestine,” reported researchers in the Journal of Functional Foods .
“In this study the glycaemic response to a test-lunch of mixed composition following the [sodium alginate] drink was consistently lower throughout the investigation, thus it seems likely that nutrients were captured within the gel matrix to some degree.”
The potential health benefits of alginate gels have been studied by several groups, with the focus predominantly on enhancing satiety and benefiting weight management. In 2007 researchers from the University of Buffalo in collaboration with McNeil Nutritionals reported on the potential of an alginate-pectin product to reduce energy intake between lunch and dinner (Am. J. Clin. Nutr., Vol. 86, pp. 1595-1602).
Scientists from the University of Sheffield and Sheffield Hallam University have also reported the potential of a novel beverage containing sodium alginate to slow the emptying of the stomach and prolong the feeling of fullness (Appetite, Vol. 51, pp. 713-719; Nutrition Research, Vol 28, pp. 501-505).
At the start of 2012, Danish researchers reported that five or ten grams of alginates consumed as a ready-to-drink beverage reduced subsequent energy intake by 10% (Food Chemistry, Vol. 132, pp. 823-829).
The new study builds on the obesity work, but considering that obesity people are at a higher risk of developing diabetes, and curbing blood sugar increases may offer an avenue for reducing this diabetic risk.
Led by Bernard Corfe, PhD, from the University of Sheffield in England, the researchers recruited 40 healthy men with an average age of 30 and BMIs ranging from 18.6 to 39.4 kg/m2.
Participants were randomly assigned to receive one of two drinks before a meal – one group received an ionic-gelling alginate drink containing 1.5 g sodium alginate (Protanal, FMC BioPolymer) and 0.7 g calcium carbonate, and the other group received an acidic-gelling control.
Results showed that the alginate drink reduced the increase in peak blood sugar levels by 14%, and the overall levels by 52%, compared with the other drink.
“The difference between these responses can most probably be attributed to the addition of calcium carbonate in the [sodium alginate] formulation,” explained Dr Corfe and his co-workers.
“The acid-soluble calcium salt was expected to facilitate intra-gastric ionic gelation of the drink.”
“The benefits of optimizing glycaemic control through the use of ionic-gelling sodium alginate products in patients with morbidity related to body fatness (including type 2 diabetic and metabolic syndrome patients) warrant further investigation,” they concluded.
The study was funded by Technostics Ltd., UK, and the alginate beverage was formulated in accordance with Patent Number WO2007039294.
Source: Journal of Functional Foods
Volume 4, Issue 1, Pages 122–128, doi: 10.1016/j.jff.2011.09.002
“An ionic-gelling alginate drink attenuates postprandial glycaemia in males”
Authors: C.J. Harden, J. C. Richardson, P.W. Dettmar, B.M. Corfe, J.R. Paxman