feed for fish and fish as food
Less abdominal fat with fish protein hydrolysate in the diet
New research at the National Institute of Nutrition and Seafood Research (NIFES) shows that hydrolysed proteins – peptides – from fish can affect the production and distribution of bile acids and thus reduce the development of obesity in rats.
Obesity is an increasing problem, nationally and internationally, but preventive action can be taken, which includes having a balanced diet. This is an area where it is natural to include fish and other seafood. NIFES has carried out a number of studies where rats have been fed with fish proteins in hydrolysed form, i.e. broken down into shorter components called peptides. When the lactic protein in the feed is replaced by hydrolysed fish proteins, the level of bile acids in the body increases and the rats develop less fatty tissue, especially in the abdomen. Studies are now being carried out by NIFES to establish the underlying mechanisms that this involves.
- New results show that the source of the hydrolysed proteins, and their structure, can affect the production of bile acids in the body, and thus the development of obesity, says researcher Bjørn Liaset at NIFES in Bergen.
Liaset explains this as follows: Proteins are assembled from amino acids, and proteins from different sources consist of varying amounts of the different amino acids. For instance, proteins from fish and seafood are rich in taurine compared with most other protein sources (including lactic protein, also called casein and soy). In both humans and rodents (mice and rats), taurine bonds with bile acids in the digestive system. Taurine is important for the production of bile acids in the body and for the functions they have. One important function is to split the large fat globules which are deposited in the intestine into smaller droplets, and in so doing play an important role in fat digestion. Bile acids also act as a signal substance which affects fat metabolism and fat combustion.