Klinisk institutt 1

Midtveisevaluering- Caroline Jensen

Midtveisevaluering for ph.d.-graden ved Universitetet i Bergen for kandidat Caroline Jensen

Caroline Jensen er tilknyttet Klinisk institutt 1. Veiledere er Dag Arne Lihaug Hoff, Jan Gunnar Hatlebakk,  Trygve Hausken og Gülen Arslan Lied 

PhD project

Health effects of a dietary supplement with cod protein hydrolysate


Overweight and obesity are increasing global health problems. These conditions are associated with increased risk of non-communicable diseases such as cardiovascular disease, type 2 diabetes mellitus and metabolic syndrome. Fish has potential favourable effects on metabolic health, and intervention studies have reported improved glucose regulation and effects on lipid metabolism after supplementation with fish protein. Evidence of the health effects of supplementation with a protein hydrolysate made from residual material from cod is limited, and it is incompletely understood how these hydrolysates may affect parameters of glucose metabolism.

The overall aim of the PhD project is to investigate the effects of a dietary supplement with cod protein hydrolysate on glucose metabolism and appetite regulation in healthy middle-aged to elderly subjects and overweight and/or obese subjects with metabolic syndrome. The PhD project consist of three clinical intervention studies.

Study I was a randomised, double-blind crossover trial where we assessed the acute effect of a cod protein hydrolysate in healthy adults aged 41-64 years. The study included two study days with 4-7 days wash-out period in between. The intervention consisted of 20 mg/kg bodyweight (BW) of cod protein hydrolysate (or control), given before a breakfast meal. We observed no differences between the protein hydrolysate and control for postprandial glucose or glucagon-like-peptide 1 (GLP-1) concentrations, but the postprandial insulin concentration was significantly lower when participants were given cod protein hydrolysate compared to control.

Study II was a dose-range crossover study in 31 individuals between 60 and 80 years. The participants received four different doses (10, 20, 30 or 40 mg/kg BW) of cod protein hydrolysate daily for one week, with one-week washout period in-between. Preliminary data reveals no significant differences in estimated maximum value of glucose, insulin or GLP-1 when comparing the lowest dose of 10 mg/kg BW of cod protein hydrolysate to the higher doses (20, 30 or 40 mg/kg BW), but our findings suggest that serum glucose and insulin levels tend to decrease with increasing amount of cod protein hydrolysate.