Irish algal extracts can lower glycaemic response and could be used in functional foods for diabetics, claims research published in the journal Food Chemistry.
According to the study by researchers at the Teagasc Food Research Centre and the Irish Seaweed Research Group, seaweed extracts inhibit two enzymes which lower postprandial hyperglycaemia - a-amylase and a-glucosidase.
“Due to their availability and strong inhibitory properties, these algal extracts have potential for use in functional food applications aimed at lowering glycaemic response,” said the study.
“The observed effects were associated with the phenolic content and antioxidant activity of the extracts, and the concentrations used were below cytotoxic levels.”
Two species most effective
The researchers screened 15 different seaweed extracts and selected five brown seaweed species for their tests.
They found two extracts, Fucus vesiculosus and Pelvetia canaliculata, particularly effective at inhibiting the enzymes involved in hyperglycaemia.
“Overall, our findings suggest that brown seaweed extracts may limit the release of simple sugars from the gut and thereby alleviate postprandial hyperglycaemia,” said the researchers.
The study was conducted as part of the Sea Change Strategy, an Irish government backed project to develop marine resources in Ireland.
Previous research has touted two marine algae - Gelidiella acerosa (red seaweed) and Sargassum wightii (brown seaweed) – for use in nutritional supplements, due to their high fibre, vitamin and protein content.
Other research has suggested prebiotic potential for seaweed compounds.
The HYFFI (Hydrocolloid Derivatives as Functional Food Ingredients) project, a consortium includes Irish firms Cyber Colloids and Marigot, Scottish company Hebridean Seaweed, Spanish-based Industrias Roko and the Universities of Reading and Ulster, found in lab tests that seaweed fibre increased bacteria and bifidobacterial populations that could be beneficial to human health.
However, a later human trial involving 60 volunteers found that positive changes in microflora were insufficient to demonstrate prebiotic activity. See HERE .
Food Chemistry 141 (2013) 2170–2176
‘The α-amylase and α-glucosidase inhibitory effects of Irish seaweed extracts’
Authors: Sinéad Lordan, Thomas J. Smyth, Anna Soler-Vila, Catherine Stanton, R. Paul Ross