If the results of this small pilot study can be repeated in larger human trials, it may see alginate establish itself as a health ingredient against metabolic syndrome, a condition that affects an estimated 15 per cent of adult Europeans, and a staggering 32 per cent of American adults.
"We have therefore demonstrated the potential of alginate to offset preclinical metabolic syndrome symptoms including insulin resistance, to treat type 2 diabetes mellitus, to treat hypercholesterolemia, and consequently to reduce risk of development of cardiovascular disease," wrote lead author Jenny Paxman from the University of Sheffield.
Metabolic syndrome (MetS) is a condition characterised by central obesity, hypertension, and disturbed glucose and insulin metabolism. The syndrome has been linked to increased risks of both type 2 diabetes and CVD.
The results are published in this month’s issue of Nutrition Research.
Paxman and co-workers recruited 14 men with an average age of 26.9 and an average BMI of 23.9 kg per sq. m. The randomised, single-blinded, controlled 2-way crossover trial divided the volunteers into two groups – the intervention group where they consumed a single 100 ml strong-gelling sodium alginate-based drink before a meal, and the control group that consumed a 100 ml drink containing 0.25 g of hydroxypropyl methylcellulose (HPMC).
All 14 volunteers consumed both drinks, with a seven-day washout period separating the experiments. The alginate formulation included 1.5 g of sodium alginate with calcium carbonate.
The researchers measured the uptake of glucose, cholesterol, and triacylglycerols in the men, and found that peaking in cholesterol levels was decreased in the five subjects classified as overweight/obese. On the other hand, no significant effects were observed in the nine subjects with a healthy BMI.
Moreover, peaking of glucose was related to body fat, with more body fat associated with stronger glucose peaks. Consumption of the alginate-gelled drink also reduced this correlation “demonstrating the potential to repair the altered glycemic response of the overweight/obese subjects to the levels seen in healthy subjects”, said the researchers.
No effects on triacylglyceride levels were observed.
Mechanism and future directions
The research suggests that the alginate is acting at the small intestine level, said the researchers, in order to alter the intestinal uptake and availability of certain nutrients.
“This is a pilot study whose limitations primarily refer to the small numbers of subjects in the group,” wrote Paxman. “Future studies based on this pilot should use larger sample size.”
“The observation that subjects with high body fat have altered uptake was serendipitous and merits further investigation,” she added.
The researchers were affiliated with the University of Sheffield, Sheffield Hallam University, and Technostics Ltd. Both Technostics and the University of Sheffield funded the study.
Source: Nutrition ResearchAugust 2008, Volume 28, Issue 8, Pages 501-505 “Alginate reduces the increased uptake of cholesterol and glucose in overweight male subjects: a pilot study”Authors: J.R. Paxman, J.C. Richardson, P.W. Dettmar, B.M. Corfe