Fish protein is not widely used in foods but some companies are beginning to promote it for its benefits to gastrointestinal and immune health.And as the proteins market expands rapidly, there could be room for new sources.
A team from the National Institute of Nutrition and Seafood Research in Bergen, Norway compared the effects of fish protein hydrolysate, soy protein, and casein, as a control, on lipid metabolism in Wistar rats and genetically obese Zucker rats.
In Zucker rats both fish and soy protein treatment reduced the plasma cholesterol level. The fish protein altered the fatty acid composition in liver, plasma, and triacylglycerol-rich lipoproteins in the obese rats.The scientists also found that the HDL cholesterol to total cholesterol ratio was greater in these rats and in the Wistar rats fed fish and soy protein compared with those fed casein.
But while the results showed similar effects on fatty acid metabolism, fish and soy protein may benefit cholesterol levels owing to different mechanisms, they write in this month's Journal of Nutrition (134:1320-1327).
They conclude that fish protein hydrolysate "may have a role as a cardioprotective nutrient".