A low dietary intake of cod protein is sufficient to increase growth, improve serum and tissue fatty acid compositions, and lower serum postprandial glucose and fasting non-esterified fatty acid concentrations in obese Zucker fa/fa rats.
OBJECTIVE
Studies in rats suggest that fish proteins may improve lipid and glucose regulation and could thus be a potential tool in the treatment of obesity-related comorbidities. To date, all published rat studies on dietary fish protein have been designed with 50 or 100% of dietary proteins from fish. As it is not common, nor advised, to consume fish as the only protein source in a healthy diet, mechanistic studies on the effects of diets with low dose fish proteins are needed. Here, we investigate whether a low dose of cod protein would affect glucose homeostasis and lipid metabolism in obese Zucker fa/fa rats.


METHODS
Twelve male obese Zucker fa/fa rats consumed diets where cod proteins accounted for 25% of the total protein intake with the remaining 75% from casein (COD) or 100% of protein as casein (CAS) for 4 weeks.


RESULTS
Rats fed COD achieved a higher body weight without affecting adiposity and thigh muscle mass after 4 weeks, but liver weight and hepatic cholesterol level were higher than in CAS-fed rats. Fasting serum level of non-esterified fatty acids and 2 h postprandial glucose level were lower in COD than in CAS. The fatty acid metabolism was beneficially affected by the COD diet, with e.g., higher ratio of n-3/n-6 PUFAs in serum, liver and adipose tissue when compared to CAS.


CONCLUSIONS
A low intake of cod protein (25% of protein intake) was sufficient to beneficially affect lipid metabolism and postprandial glucose regulation in obese fa/fa rats.
Department of Clinical Medicine, University of Bergen, PO Box 7804, 5020, Bergen, Norway.
Aslaug
A
Drotningsvik
Department of Chemistry, University of Bergen, Bergen, Norway.|Nofima BioLab, Fyllingsdalen, Norway.
Svein Are
SA
Mjøs
Blue Protein, Austevoll, Norway.
Ingmar
I
Høgøy
Nutrimar AS, Trondheim, Norway.
Tore
T
Remman
Department of Clinical Medicine, University of Bergen, PO Box 7804, 5020, Bergen, Norway. oddrun.gudbrandsen@k1.uib.no.
Oddrun Anita
OA
Gudbrandsen
D000273:Adipose Tissue / Q000378:metabolism*; D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood; D004032:Diet; D004044:Dietary Proteins / Q000008:administration & dosage*; D005215:Fasting; D005230:Fatty Acids, Nonesterified / Q000097:blood*; D005231:Fatty Acids, Unsaturated / Q000097:blood; D029941:Fish Proteins / Q000008:administration & dosage*; D048389:Gadus morhua; D007328:Insulin / Q000097:blood; D008049:Lipase / Q000097:blood; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D009765:Obesity / Q000097:blood*; D009929:Organ Size; D019518:Postprandial Period; D051381:Rats; D011924:Rats, Zucker; D017747:Seafood
D001786:Blood Glucose; D004044:Dietary Proteins; D005230:Fatty Acids, Nonesterified; D005231:Fatty Acids, Unsaturated; D029941:Fish Proteins; D007328:Insulin; D002784:Cholesterol; D000410:Alanine Transaminase; D008049:Lipase
Fish protein; Inflammation; Insulin; Obesity; Tumor necrosis factor-alpha