Consumption of protein-enriched milk has minor effects on inflammation in older adults-A 12-week double-blind randomized controlled trial

Abstract

Introduction: Aging is associated with increased levels of circulating inflammatory markers and reduced muscle mass and strength.

Objective: We investigated whether intake of protein-enriched milk for 12 weeks would influence markers of inflammation among adults ≥70years of age with reduced physical strength.

Methods: In a double-blind randomized controlled intervention study, subjects were randomly allocated into two groups, receiving a protein-enriched milk (2×20g protein/d, n=14, mean (±SD) age 76.9±4.9 yrs) or an isocaloric carbohydrate drink (n=17, age 77.7±4.8 yrs) for 12 weeks. We measured serum and mRNA expression levels of inflammatory markers in PBMCs.

Results: Significant differences in the mRNA expression of nuclear receptor subfamily, group H, member 3 (NR1H3, encoding the LXRα transcription factor) and interferon gamma (INFG) were observed between groups. The mRNA level of TNFRSF1A was significantly reduced, while the mRNA level of dipeptidyl-peptidase 4 (DPP4) was significantly increased, in the control group. The serum level of TNFα increased significantly in the control group, while sTNFRSF1A increased significantly in both groups, but with no significant differences between groups.

Conclusion: Consumption of a low-fat, protein-enriched milk for 12 weeks had minor effects on inflammatory related markers in older adults compared to an isocaloric carbohydrate drink.

Keywords: High-protein; Inflammation; Milk protein; Older adults; Peripheral blood mononuclear cells; mRNA.