1 Preventive and Clinical Nutrition, Department of Nutrition, Exercise and Sports, Faculty of Science, Københavns Universitet2 Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio3 Department of Health, Nutrition and Management, Faculty of Health Sciences, Oslo and Akershus University College of Applied Sciences, Oslo4 Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio and Institute of Clinical Medicine, Internal Medicine, Kuopio University Hospital, Kuopio5 Institute of Biomedicine, University of Eastern Finland, Kuopio6 Institute of Public Health and Clinical Nutrition, University of Eastern Finland & Institute of Clinical Medicine, Internal Medicine, Kuopio University Hospital, Kuopio7 Department of Medicine (H7), Karolinska Institute, Stockholm8 Unit for Nutrition Research, University of Iceland and Landspitali - The National University Hospital of Iceland, Reykjavik9 Biomedical Nutrition, Pure and Applied Biochemistry, Lund University, Lund10 Department of Endocrinology, Skåne University Hospital, Lund11 Biomedical Nutrition, Pure and Applied Biochemistry, Lund University & Department of Clinical Nutrition, Skåne University Hospital, Lund12 Department of Public Health and Caring Sciences, Clinical Nutrition and Metabolism, Uppsala University, Uppsala13 Institute of Clinical Medicine, Department of Internal Medicine and Biocenter Oulu, University of Oulu, and Medical Research Center, Oulu University Hospital, Oulu14 Institute of Biomedicine and Biocenter of Oulu, University of Oulu, Oulu15 Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark.16 Institute of Public Health and Clinical Nutrition, University of Eastern Finland & Research Unit, Kuopio University Hospital, Kuopio17 Preventive and Clinical Nutrition, Department of Nutrition, Exercise and Sports, Faculty of Science, Københavns Universitet
BACKGROUND: Previously, a healthy Nordic diet (ND) has been shown to have beneficial health effects close to those of Mediterranean diets. OBJECTIVE: The objective was to explore whether the ND has an impact on gene expression in abdominal subcutaneous adipose tissue (SAT) and whether changes in gene expression are associated with clinical and biochemical effects. DESIGN: Obese adults with features of the metabolic syndrome underwent an 18- to 24-wk randomized intervention study comparing the ND with the control diet (CD) (the SYSDIET study, carried out within Nordic Centre of Excellence of the Systems Biology in Controlled Dietary Interventions and Cohort Studies). The present study included participants from 3 Nordic SYSDIET centers [Kuopio (n = 20), Lund (n = 18), and Oulu (n = 18)] with a maximum weight change of ±4 kg, highly sensitive C-reactive protein concentration <10 mg/L at the beginning and the end of the intervention, and baseline body mass index (in kg/m(2)) <38. SAT biopsy specimens were obtained before and after the intervention and subjected to global transcriptome analysis with Gene 1.1 ST Arrays (Affymetrix). RESULTS: Altogether, 128 genes were differentially expressed in SAT between the ND and CD (nominal P < 0.01; false discovery rate, 25%). These genes were overrepresented in pathways related to immune response (adjusted P = 0.0076), resulting mainly from slightly decreased expression in the ND and increased expression in the CD. Immune-related pathways included leukocyte trafficking and macrophage recruitment (e.g., interferon regulatory factor 1, CD97), adaptive immune response (interleukin32, interleukin 6 receptor), and reactive oxygen species (neutrophil cytosolic factor 1). Interestingly, the regulatory region of the 128 genes was overrepresented for binding sites for the nuclear transcription factor κB. CONCLUSION: A healthy Nordic diet reduces inflammatory gene expression in SAT compared with a control diet independently of body weight change in individuals with features of the metabolic syndrome. The study was registered at clinicaltrials.gov as NCT00992641.
American Journal of Clinical Nutrition, 2015, Vol 101, Issue 1, p. 228-239