Lab rats fed the ‘Western’ style diet pattern and supplemented with the algae mixture also have lower blood pressure and improved glucose and insulin tolerance, report researchers from the University of Southern Queensland, James Cook University, and The University of Queensland in Australia.
Writing in Nutrients, the researchers note that the potential anti-obesity benefits of the algae mixture may be linked to the bioactives present in Scenedesmus dimorphus and Schroederiella apiculate, which include protein, insoluble fiber, minerals, and omega-3s.
“However, the doses of these compounds [minerals and omega-3s.], either together or individually, in this study appear inadequate to reverse the high carbohydrate, high fat diet-induced metabolic changes based on previous studies. In contrast, the doses of insoluble fiber and possibly protein may be sufficient to produce therapeutic responses,” they wrote.
Led by Senthil Arun Kumar from the University of Southern Queensland, the researchers prepared mixtures of Scenedesmus dimorphus and Schroederiella apiculata as a supplement to the high carbohydrate, high fat diet . The algal mixtures, which were produced at the Centre for Macroalgal Resources & Biotechnology at James Cook University, contain 46% protein, 20% insoluble fiber, 4% minerals and 3% omega-3s.
Lab rats were randomly divided into four groups: Two groups ate a corn starch diet (and one group was supplemented with the algal mixture), while the other two groups were fed the high carbohydrate, high-fat diet (and one group was supplemented with the algal mixture) for eight weeks.
Results showed that the high carb, high fat-fed rats became obese and developed obesity-related metabolic issues, such as elevated blood pressure, insulin resistance, cardiovascular changes, and nonalcoholic fatty liver disease (NAFLD).
On the other hand, supplementing this diet with 5% algal mixture lowered total body and abdominal fat mass, said the researchers. The algal supplements also increased lean mass, and attenuated blood pressure increases, and improved glucose and insulin tolerance.
The algal mixture was also associated with improvements in endothelial function, and lower infiltration of inflammatory cells into heart and liver. NAFLD was also attenuated, they said.
Commenting on the potential role of the protein and insoluble fiber in Scenedesmus dimorphus and Schroederiella apiculate, Kumar and his co-workers noted that the fiber may act as a prebiotic to change the gut microbiome and affect the risk of obesity. The human dose equivalent to the dose consumed by the rats would be between 8.3 and 13.1 g/day, “which is similar to the mean dietary fiber intake (13.1–16.1 g/day) of the US population for 1999–2008”, they said.
“The dose of protein in this study in rats can be calculated as 0.57–0.60 g/kg body weight/day in humans, similar to the recommended dietary allowance of total protein of 0.8 g/kg body weight/day in the management of type 2 diabetes,” they added. “High protein diets are controversial as weight loss protocols but a meta-analysis showed beneficial effects on weight loss, glycated haemoglobin concentrations and blood pressure with these diets.”
“Further characterization of insoluble fiber and protein present in SC should be carried out to define the most active components given the impacts of the microalgal mixture on the wide range of signs of the metabolic syndrome induced by obesity,” they concluded.
2015, Volume 7, Number 4, Pages 2771-2787; doi:10.3390/nu7042771
“A Green Algae Mixture of Scenedesmus and Schroederiella Attenuates Obesity-Linked Metabolic Syndrome in Rats”
Authos: S.A. Kumar, M. Magnusson, L.C. Ward, N.A. Paul, L. Brown