Dietary cod protein reduces plasma C-reactive protein in insulin-resistant men and women

J Nutr. 2008 Dec;138(12):2386-91. doi: 10.3945/jn.108.092346.

Abstract

Chronic low-grade inflammation has been associated with insulin resistance and type 2 diabetes. Recently, we showed that cod protein (CP) improved insulin sensitivity in insulin-resistant subjects. In this study, we investigated the effects of dietary CP compared with those of other animal proteins on plasma concentrations of inflammatory markers, lipids, and lipoproteins in insulin-resistant subjects. Nineteen Caucasian men and women aged 40-65 y, overweight or obese (BMI > 25 kg/m(2)), and insulin resistant, rotated in a crossover design and consumed a CP diet and a similar diet containing lean beef, pork, veal, eggs, milk, and milk products (BPVEM) for 4 wk each. Diets differed only in protein source and thus provided equivalent amounts of dietary fibers, monounsaturated fat, PUFA [including (n-3) fatty acids], and SFA. Blood samples were collected before and after each experimental diet. Notably, the CP diet decreased high-sensitivity C-reactive protein (hsCRP; P = 0.021), whereas the BPVEM diet tended to increase it (P = 0.063), leading to a significant difference between diets (P = 0.041). Changes in plasma interleukin-6, tumor necrosis factor-alpha, and adiponectin concentrations did not differ between diets. Plasma total cholesterol (P = 0.0007), LDL cholesterol (P = 0.014), and apolipoprotein B (P = 0.005) were reduced only by the BPVEM diet. Thus, changes in total cholesterol differed between diets (P = 0.040), whereas changes in LDL cholesterol (P = 0.052) and apolipoprotein B (P = 0.075) tended to differ. Changes in all other lipids and lipoproteins did not differ between diets. Therefore, these results show that CP can lower hsCRP, a marker of inflammation associated with insulin resistance and type 2 diabetes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Animals
  • C-Reactive Protein / metabolism*
  • Cod Liver Oil / chemistry
  • Cross-Over Studies
  • Diet
  • Fatty Acids / analysis
  • Fatty Acids / blood
  • Female
  • Fish Proteins / administration & dosage*
  • Gadiformes*
  • Humans
  • Inflammation Mediators / blood
  • Insulin Resistance / physiology*
  • Lipids / blood
  • Lipoproteins / blood
  • Male
  • Middle Aged

Substances

  • Fatty Acids
  • Fish Proteins
  • Inflammation Mediators
  • Lipids
  • Lipoproteins
  • Cod Liver Oil
  • C-Reactive Protein