It has been shown in a large number of in vitro studies that seaweed extracts act as potent inhibitors of enzymes of carbohydrate digestion suggesting their potential to modulate postprandial glycaemic response and prevent the damaging effects of hyperglycaemic state. However, the results from human trials are limited and inconsistent.~The investigators confirmed that the in vitro inhibitory effects of seaweed extracts depend on the type, level and ratio of bioactive compounds, and optimised the composition of the extract to obtain the most potent one, to be tested in the proposed study.~The present study will determine whether the seaweed extract added to a carbohydrate-rich meal, can lower blood glucose levels after its consumption, and hence lower its glycaemic index, and if this effect is mediated through effects on insulin or determined by the individual levels of digestive enzymes.~Healthy volunteers will be asked to consume three different meals: (1) white bread; (2) white bread with the lower dose (LD) of the extract; (3) white bread with the higher dose (HD) of the extract~The levels of glucose and insulin will be measured in plasma isolated from blood samples obtained before and up to 3 hours after the consumption of each meal.~Additional measurements taken at the screening will include blood pressure values and blood lipids levels. All participants will be characterized for the activity of salivary a-amylase.
The study is designed to determine whether seaweed extract added to a carbohydrate-rich meal, can lower blood glucose levels after its consumption, and hence lower its glycaemic index, and if this effect is mediated through effects on insulin. It is designed as an acute, randomised, cross-over, controlled, three-arm dietary intervention trial in healthy subjects. Participants will be asked to consume either white bread, white bread with lower dose of seaweed extract or white bread with higher dose of seaweed extract.The effects on plasma glucose levels and levels of insulin will be determined over 3 hours after the consumption.