Experiments on rats suggest that salmon protein can help to reduce obesity, the risk of contracting type 2 diabetes and concentrations of unhealthy fat in the blood.
“The type of protein in our food is important. Certain types of protein can play highly significant roles in the development of obesity, high blood sugar and high triglyceride fat content, all of which can lead to type 2 diabetes and cardiovascular disease,” says NIFES research scientist Bjørn Liaset.
It now appears that protein derived from salmon has particularly good properties in this respect, according to research results from NIFES that have recently appeared in the prestigious Journal of Biological Chemistry.
Rats that were fed hydrolysed salmon protein put on less weight than rats given other types of protein. “Hydrolysed” means that the protein is broken down into smaller components.
Fat around the stomach was most reduced. This is the fat that is regarded as a risk factor in the development of cardiovascular disease and type 2 diabetes.
In the experiments, the diet containing salmon protein also reduced blood triglyceride levels, which can cut the risk of cardiovascular disease, as well as lower concentrations of blood glucose and insulin. Type 2 diabetes is related to high rates of insulin production and high blood glucose.
The presence of particular amino acids is probably what gives salmon protein such positive effects.
“There are high levels of the amino acids taurine and glycine in salmon protein, and these probably help to raise the concentration of bile acids in the blood. And we know that higher plasma levels of bile acids can slow the development of obesity and reduce the concentrations of triglycerides and glucose,” says Liaset.
NIFES has previously carried out similar experiments in which rats were fed hydrolysed protein derived from saithe. The results pointed in the same direction as the salmon protein trials: rats given fish protein in their food put on less weight.
More detailed studies
“This time, we carried out more detailed studies and have managed to explain more of the mechanisms involved. This has brought us a good step further in finding out how hydrolysed fish protein can act against obesity,” says Liaset, although he stresses that these result cannot simply be transferred to human beings. Before we can conclude that the same mechanisms operate in humans, we will have to carry out thorough tests on our own species.
The results are based on work done in the five-year DOCMAR (Documentation of marine ingredients from by-products), one of whose aims is to document new properties and uses of raw material waste from the fishing and aquaculture industries.
This project was carried out as a part of the ‘DOCMAR’ research programme funded by Innovation Norway and RUBIN. It was supported by the Danish Natural Science Research Council, the Novo Nordisk Foundation and the Carlsberg Foundation, and was performed as part of the research programme of the Danish Obesity Research Centre, supported by the Danish Council for Strategic Research, Grant 2101-06-0005. Financial support was also received from the University of Bergen, Programme Committee on Nutrition, the Eckbo Foundation and the Research Council of Norway, Grant no. 200515-I30.
Contact: Bjørn Liaset
Telefon: +47 468 11 297