Differential effects of dietary protein sources on postprandial low-grade inflammation after a single high fat meal in obese non-diabetic subjects

Abstract

Background: Obesity is a state of chronic low-grade inflammation. Chronic low-grade inflammation is associated with the pathophysiology of both type-2 diabetes and atherosclerosis. Prevention or reduction of chronic low-grade inflammation may be advantageous in relation to obesity related co-morbidity. In this study we investigated the acute effect of dietary protein sources on postprandial low-grade inflammatory markers after a high-fat meal in obese non-diabetic subjects.

Methods: We conducted a randomized, acute clinical intervention study in a crossover design. We supplemented a fat rich mixed meal with one of four dietary proteins - cod protein, whey isolate, gluten or casein. 11 obese non-diabetic subjects (age: 40-68, BMI: 30.3-42.0 kg/m2) participated and blood samples were drawn in the 4 h postprandial period. Adiponectin was estimated by ELISA methods and cytokines were analyzed by multiplex assay.

Results: MCP-1 and CCL5/RANTES displayed significant postprandial dynamics. CCL5/RANTES initially increased after all meals, but overall CCL5/RANTES incremental area under the curve (iAUC) was significantly lower after the whey meal compared with the cod and casein meals (P = 0.0053). MCP-1 was initially suppressed after all protein meals. However, the iAUC was significantly higher after whey meal compared to the cod and gluten meals (P = 0.04).

Conclusion: We have demonstrated acute differential effects on postprandial low grade inflammation of four dietary proteins in obese non-diabetic subjects. CCL5/RANTES initially increased after all meals but the smallest overall postprandial increase was observed after the whey meal. MCP-1 was initially suppressed after all 4 protein meals and the whey meal caused the smallest overall postprandial suppression.

Trial registration: ClinicalTrials.gov ID: NCT00863564.

Figure 1

The plot show mean (+SEM) responses for CCL5/RANTES in plasma in the 4 h postprandial period after the four meals consumed by 11 obese non-diabetic subjects. Meals consisted of an energy-free soup plus 80 g fat (from butter) and 45 g carbohydrate consumed with either 45 g cod protein, 45 g whey protein, 45 g gluten or 45 g casein.

Figure 2

The plot show mean (+SEM) responses for MCP-1 in plasma in the 4 h postprandial period after the four meals consumed by 11 obese non-diabetic subjects. Meals consisted of an energy-free soup plus 80 g fat (from butter) and 45 g carbohydrate consumed with either 45 g cod protein, 45 g whey protein, 45 g gluten or 45 g casein.