2010 Volume 27 Pages 21-27
The digestion products of protein can interrupt the intestinal absorption of acidic and neutral sterols. The intake of certain protein hydrolysates is more effective in lowering serum cholesterol than the intake of intact protein. In this study, we hypothesized that, compared to intact fish protein, dietary fish peptides prepared by the treating of fish protein with papain alter lipid absorption in rats. Male Wistar rats were divided into the following three dietary groups, each composed of seven rats: casein (20 %), fish protein (10 %) + casein (10 %), and fish peptides (10 %) + casein (10 %), each with cholesterol (0.5 %) and cholic acid (0.1 %). Compared with dietary casein, dietary fish peptides decreased serum and liver cholesterol, whereas fecal acidic and neutral sterols excretions were higher. The fish protein diet had similar effects as the fish peptides diet, although the effects of the fish protein diet were weaker than those of the fish peptides diet.The hypocholesterolemic effects of fish protein and peptides were mediated by increased fecal acidic and neutral sterols excretions, which were due to the digested products of fish protein and peptides having reduced micellar solubility of cholesterol and increased bile acid binding capacity. The results suggested that the intake of fish peptides is more effective in the suppression of lipid absorption than the intake of intact fish protein. This finding may be of benefit to patients with hypercholesterolemia.
