title: Effects of different dietary approaches on inflammatory markers in patients with metabolic syndrome: A systematic review and meta-analysis.
abstract: OBJECTIVE
  Chronic low-grade inflammation has been associated with insulin resistance, diabetes, atherosclerosis, obesity, and metabolic syndrome (MetS). A proinflammatory environment contributes to several metabolic disturbances and possibly the development of MetS. Dietary approaches have defined impact on immune function and putative antiinflammatory effects. The aim of this study was to assess the effects of different dietary approaches on markers of inflammation in patients with MetS. Further effects on weight loss and fasting insulin were analyzed.
  
  
  METHODS
  Medline/PubMed, Scopus, and the Cochrane Library were screened in September 2014 for randomized controlled trials (RCTs) on different dietary approaches for participants with MetS as defined by National Cholesterol Education Program Adult Treatment Panel III. Primary outcomes were markers of the immune system. Secondary outcome was body weight and fasting insulin. Standardized mean differences (SMD) and 95% confidence intervals (95% CIs) were calculated.
  
  
  RESULTS
  Thirteen randomized controlled trials with a total of 2017 patients were included. Low-fat diets (29 ± 2% energy from fats) decreased C-reactive protein compared with control diets (SMD: -0.98; 95% CI: -1.6 to -0.35; P = 0.002). Low-carbohydrate diets (23 ± 10% energy from carbohydrates; SMD: -0.33; 95% CI: -0.63 to -0.03; P = 0.004) and multimodal interventions (SMD: -1.02; 95% CI: -1.97 to -0.07; P = 0.04) were able to induce significant weight loss. Low-carbohydrate diets were able to decrease insulin (SMD: -0.33; 95% CI: -0.63 to -0.03; P = 0.03).
  
  
  CONCLUSIONS
  C-reactive protein; however, this effect is also dependent on weight loss. Furthermore, low-carbohydrate diets have beneficial effects on insulin and body weight. Dietary approaches should mainly be tried to reduce macronutrients and enrich functional food components such as vitamins, flavonoids, and unsaturated fatty acids. People with MetS will benefit most by combining weight loss and anti-inflammatory nutrients.
authors.affiliation: Institute of Social Medicine, Epidemiology and Health Economics, Charité-University Medical Centre, Berlin, Germany and Immanuel Hospital Berlin; Immanuel Hospital Berlin, Department of Internal and Complementary Medicine, Berlin, Germany. Electronic address: nico.steckhan@charite.de.
authors.forename: Nico
authors.initials: N
authors.lastname: Steckhan
authors.affiliation: Institute of Social Medicine, Epidemiology and Health Economics, Charité-University Medical Centre, Berlin, Germany and Immanuel Hospital Berlin; Immanuel Hospital Berlin, Department of Internal and Complementary Medicine, Berlin, Germany.
authors.forename: Christoph-Daniel
authors.initials: CD
authors.lastname: Hohmann
authors.affiliation: Institute of Social Medicine, Epidemiology and Health Economics, Charité-University Medical Centre, Berlin, Germany and Immanuel Hospital Berlin; Immanuel Hospital Berlin, Department of Internal and Complementary Medicine, Berlin, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Kessler
authors.affiliation: Department of Internal and Integrative Medicine, Kliniken Essen-Mitte, Faculty of Medicine, University of Duisburg-Essen, Essen, Germany.
authors.forename: Gustav
authors.initials: G
authors.lastname: Dobos
authors.affiliation: Institute of Social Medicine, Epidemiology and Health Economics, Charité-University Medical Centre, Berlin, Germany and Immanuel Hospital Berlin; Immanuel Hospital Berlin, Department of Internal and Complementary Medicine, Berlin, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Michalsen
authors.affiliation: Department of Internal and Integrative Medicine, Kliniken Essen-Mitte, Faculty of Medicine, University of Duisburg-Essen, Essen, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Cramer
mesh_terms: D015415:Biomarkers / Q000097:blood*; D001835:Body Weight; D002097:C-Reactive Protein / Q000378:metabolism; D016208:Databases, Factual; D004032:Diet / Q000379:methods*; D050528:Diet, Carbohydrate-Restricted; D018752:Diet, Fat-Restricted; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage; D005227:Fatty Acids / Q000008:administration & dosage; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage; D005419:Flavonoids / Q000008:administration & dosage; D006801:Humans; D007328:Insulin / Q000097:blood; D024821:Metabolic Syndrome / Q000097:blood / Q000178:diet therapy*; D018977:Micronutrients / Q000008:administration & dosage; D016032:Randomized Controlled Trials as Topic
chemical_list: D015415:Biomarkers; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D005419:Flavonoids; D007328:Insulin; D018977:Micronutrients; D002097:C-Reactive Protein
keywords: Diets; Inflammation; Meta-analysis; Metabolic syndrome; NCEP ATP III; Nutrients; Systematic review