title: Consumption of extra-virgin olive oil rich in phenolic compounds improves metabolic control in patients with type 2 diabetes mellitus: a possible involvement of reduced levels of circulating visfatin.
abstract: OBJECTIVE
  Phenolic compounds naturally contained in extra-virgin olive oil (EVOO) have demonstrated anti-inflammatory and antioxidant properties. The present study aimed at evaluating the effects of a polyphenol-rich extra-virgin olive oil (EVOO) (high-polyphenol EVOO, HP-EVOO) on the metabolic control and the production of specific pro-/anti-inflammatory adipokines in overweight patients with type 2 diabetes mellitus (T2D).
  
  
  METHODS
  Eleven overweight T2D patients not in treatment with insulin were invited to follow their habitual diet for a total of 8 weeks. During the first 4 weeks (wash-out period), they were asked to consume refined olive oil (ROO, polyphenols not detectable) and then to replace ROO with HP-EVOO (25 mL/day, 577 mg of phenolic compounds/kg) for the remaining 4 weeks. Anthropometric parameters, fasting glycaemia, glycated haemoglobin (HbA1c), high-sensitive C-reactive protein, plasma lipid profile, liver function and serum levels of TNF-α, IL-6, adiponectin, visfatin and apelin were assessed at the end of each 4-week period.
  
  
  RESULTS
  HP-EVOO consumption significantly reduced fasting plasma glucose (P = 0.023) and HbA1c (P = 0.039) levels as well as BMI (P = 0.012) and body weight (P = 0.012). HP-EVOO ingestion determined a reduction in serum level of aspartate aminotransferase (AST, P = 0.0056) and alanine aminotransferase (ALT, P = 0.024). Serum visfatin levels strongly decreased after HP-EVOO ingestion (P = 0.0021).
  
  
  CONCLUSIONS
  Daily consumption of polyphenol-rich EVOO might improve metabolic control and circulating inflammatory adipokines profile in overweight T2D patients.
authors.affiliation: Unit of Nutrition, Department of Veterinary Public Health and Food Safety, Italian National Institute of Health, Viale Regina Elena 299, 00161, Rome, Italy. carmela.santangelo@iss.it.
authors.forename: C
authors.initials: C
authors.lastname: Santangelo
authors.affiliation: Unit of Nutrition, Department of Veterinary Public Health and Food Safety, Italian National Institute of Health, Viale Regina Elena 299, 00161, Rome, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Filesi
authors.affiliation: Unit of Nutrition, Department of Veterinary Public Health and Food Safety, Italian National Institute of Health, Viale Regina Elena 299, 00161, Rome, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Varì
authors.affiliation: Unit of Nutrition, Department of Veterinary Public Health and Food Safety, Italian National Institute of Health, Viale Regina Elena 299, 00161, Rome, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Scazzocchio
authors.affiliation: Department of Experimental Medicine, Section of Medical Pathophysiology, Food Science and Endocrinology, Sapienza University of Rome, Viale del Policlinico 155, 00161, Rome, Italy.
authors.forename: T
authors.initials: T
authors.lastname: Filardi
authors.affiliation: Food Quality and Design Group, Wageningen University, Wageningen, The Netherlands.
authors.forename: V
authors.initials: V
authors.lastname: Fogliano
authors.affiliation: Unit of Nutrition, Department of Veterinary Public Health and Food Safety, Italian National Institute of Health, Viale Regina Elena 299, 00161, Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: D'Archivio
authors.affiliation: Unit of Nutrition, Department of Veterinary Public Health and Food Safety, Italian National Institute of Health, Viale Regina Elena 299, 00161, Rome, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Giovannini
authors.affiliation: Department of Experimental Medicine, Section of Medical Pathophysiology, Food Science and Endocrinology, Sapienza University of Rome, Viale del Policlinico 155, 00161, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Lenzi
authors.affiliation: Department of Experimental Medicine, Section of Medical Pathophysiology, Food Science and Endocrinology, Sapienza University of Rome, Viale del Policlinico 155, 00161, Rome, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Morano
authors.affiliation: Unit of Nutrition, Department of Veterinary Public Health and Food Safety, Italian National Institute of Health, Viale Regina Elena 299, 00161, Rome, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Masella
mesh_terms: D000284:Administration, Oral; D015415:Biomarkers / Q000097:blood*; D016207:Cytokines / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D054409:Nicotinamide Phosphoribosyltransferase / Q000097:blood*; D000069463:Olive Oil / Q000737:chemistry*; D050177:Overweight / Q000150:complications; D010636:Phenols / Q000008:administration & dosage*
chemical_list: D015415:Biomarkers; D016207:Cytokines; D000069463:Olive Oil; D010636:Phenols; D054409:Nicotinamide Phosphoribosyltransferase
keywords: Cytokines; HbA1c; Olive oil; Polyphenols; Type 2 diabetes mellitus; Visfatin