Dietary Cod Protein Improves Insulin Sensitivity in Insulin-Resistant Men and Women
A randomized controlled trial
- Véronique Ouellet, BSC12,
- Julie Marois, MSC12,
- S. John Weisnagel, MD, FRCPC34 and
- Hélène Jacques, PHD12
- 1Institute of Nutraceuticals and Functional Foods, Laval University, Quebec City, Quebec, Canada
- 2Department of Food Science and Nutrition, Laval University, Quebec City, Quebec, Canada
- 3Diabetes Research Unit, CHUL Research Center, Quebec City, Quebec, Canada
- 4Department of Social and Preventive Medicine, Division of Kinesiology, Laval University, Quebec City, Quebec, Canada
- Address correspondence and reprint requests to Hélène Jacques, Department of Food Science and Nutrition, Paul-Comtois Building, Laval University, Quebec G1K 7P4, Canada. E-mail: helene.jacques{at}aln.ulaval.ca
Abstract
OBJECTIVE—The purpose of this article was to compare the effects of cod protein to those of other animal proteins on insulin sensitivity in insulin-resistant human subjects.
RESEARCH DESIGN AND METHODS—Insulin sensitivity (M/I) was assessed using a hyperinsulinemic-euglycemic clamp in 19 insulin-resistant subjects fed a cod protein diet and a similar diet containing lean beef, pork, veal, eggs, milk, and milk products (BPVEM) for 4 weeks in a crossover design study. Both diets were formulated to differ only in protein source, thus providing equivalent amounts of dietary fibers and monounsaturated, polyunsaturated (including n-3), and saturated fatty acids (1.1:1.8:1.0). β-Cell function, estimated by oral glucose tolerance test–derived parameters, was also assessed.
RESULTS—There was a significant improvement in insulin sensitivity (P = 0.027) and a strong tendency for a better disposition index (β-cell function × M/I) (P = 0.055) in subjects consuming the cod protein diet compared with those consuming the BPVEM diet. When median baseline M/I (4.8 × 10−3 mg · kg−1 · min−1 · pmol−1) was taken into account, an interaction on the 30-min C-peptide–to–30-min glucose ratio, used as an index of β-cell function, was observed between diet and M/I status (P = 0.022). Indeed, this ratio strongly tended to increase in subjects with low M/I consuming the cod protein diet compared with those consuming the BPVEM diet (P = 0.065).
CONCLUSIONS—Dietary cod protein improves insulin sensitivity in insulin-resistant individuals and thus could contribute to prevention of type 2 diabetes by reducing the metabolic complications related to insulin resistance.
- BPVEM, lean beef, pork, veal, eggs, milk, and milk products
- FPG, fasting plasma glucose
- IAUC, incremental area under the curve
- IGT, impaired glucose tolerance
- NGT, normal glucose tolerance
- OGTT, oral glucose tolerance test
- PUFA, polyunsaturated fatty acid
Footnotes
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Published ahead of print at http://care.diabetesjournals.org on 6 August 2007. DOI: 10.2337/dc07-0273. Clinical trial reg. no. NCT00400036, clinicaltrials.gov.
Additional information for this article can be found in an online appendix at http://dx.doi.org/10.2337/dc07-0273.
A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C Section 1734 solely to indicate this fact.
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- Accepted July 31, 2007.
- Received February 9, 2007.
- DIABETES CARE
