KEY INTERVIEW: Brown Seaweed Polyphenols Accessible to Humans, Research Proves

26 Feb 2016 --- New research published in the British Journal of Nutrition has demonstrated the bioavailabilty of phlortannins from brown seaweed. Sarah Hotchkiss, Projects Manager of CyberColloids Ltd and one of the authors of the study explains to NutritionInsight about how these beneficial compounds are absorbed and metabolised in the human gut.

Polyphenols are ubiquitously found in plants and comprise a major part of a daily human diet. Brown seaweeds such as Ascophyllum nodosum are a rich source of phlorotannins (oligomers and polymers of phloroglucinol units), a class of polyphenols that are unique to Phaeophyceae. 

At present, there has been no information on the bioavailability of seaweed polyphenols, and limited evidence on their bioactivity in vivo. Therefore, researchers from the Universities of Reading and Ulster working with CyberColloids Ltd investigated the gastrointestinal modifications in vitro of seaweed phlorotannins from A. nodosum and their bioavailability and effect on inflammatory markers in healthy participants. 

“Our study is the first to demonstrate that phlorotannins from brown seaweed are bioavailable to humans,” says Hotchkiss, who overviewed the preparation of seaweed materials, extracts and capsules. “We have shown that they can be metabolized and absorbed.”

The research highlights the variances and complexities of phlorotannins:  “It appears that most activity has occurred in the large intestine which explains the differences seen between different volunteers, but also poses a lot of very interesting questions about the effect of important factors such as molecular weight and structure on bioavailability.”

“Phlorotannins are an extremely diverse group of compounds, and extracts or seaweed ingredients that contain phlorotannins will vary tremendously between different species and with season, location of harvest and method of production. 

What does this mean for the future? “We are extremely pleased with the outcome of our study as a basis for further research, but there is still a lot to understand about the fate of seaweed derived phlorotannins in the human digestive tract.”

“The use of seaweed and seaweed derived ingredients in various products for human (and animal) health and nutrition has risen significantly in recent years. Seaweed is generally accepted to be ‘good for you’ but studies like ours are really needed to support this belief.” 
 
Hotchkiss concludes: “Ascopyllum nodosum is an important commercial species for most North Atlantic seaweed fisheries, consequently there has been a lot of interest in recent years to find higher value uses for this seaweed.”

by Kerina Tull