title: Mediterranean Diet and Invasive Breast Cancer Risk Among Women at High Cardiovascular Risk in the PREDIMED Trial: A Randomized Clinical Trial.
abstract: OBJECTIVE
  Breast cancer is the leading cause of female cancer burden, and its incidence has increased by more than 20% worldwide since 2008. Some observational studies have suggested that the Mediterranean diet may reduce the risk of breast cancer.
  
  
  OBJECTIVE
  To evaluate the effect of 2 interventions with Mediterranean diet vs the advice to follow a low-fat diet (control) on breast cancer incidence.
  
  
  METHODS
  The PREDIMED study is a 1:1:1 randomized, single-blind, controlled field trial conducted at primary health care centers in Spain. From 2003 to 2009, 4282 women aged 60 to 80 years and at high cardiovascular disease risk were recruited after invitation by their primary care physicians.
  
  
  METHODS
  Participants were randomly allocated to a Mediterranean diet supplemented with extra-virgin olive oil, a Mediterranean diet supplemented with mixed nuts, or a control diet (advice to reduce dietary fat).
  
  
  METHODS
  Breast cancer incidence was a prespecified secondary outcome of the trial for women without a prior history of breast cancer (n = 4152).
  
  
  RESULTS
  After a median follow-up of 4.8 years, we identified 35 confirmed incident cases of breast cancer. Observed rates (per 1000 person-years) were 1.1 for the Mediterranean diet with extra-virgin olive oil group, 1.8 for the Mediterranean diet with nuts group, and 2.9 for the control group. The multivariable-adjusted hazard ratios vs the control group were 0.32 (95% CI, 0.13-0.79) for the Mediterranean diet with extra-virgin olive oil group and 0.59 (95% CI, 0.26-1.35) for the Mediterranean diet with nuts group. In analyses with yearly cumulative updated dietary exposures, the hazard ratio for each additional 5% of calories from extra-virgin olive oil was 0.72 (95% CI, 0.57-0.90).
  
  
  CONCLUSIONS
  This is the first randomized trial finding an effect of a long-term dietary intervention on breast cancer incidence. Our results suggest a beneficial effect of a Mediterranean diet supplemented with extra-virgin olive oil in the primary prevention of breast cancer. These results come from a secondary analysis of a previous trial and are based on few incident cases and, therefore, need to be confirmed in longer-term and larger studies.
  
  
  BACKGROUND
  ISRCTN.org Identifier: ISRCTN35739639.
authors.affiliation: Department of Preventive Medicine and Public Health, University of Navarra-School of Medicine, Pamplona, Navarra, Spain.|Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Estefanía
authors.initials: E
authors.lastname: Toledo
authors.affiliation: Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Human Nutrition Unit, Faculty of Medicine and Health Sciences, Biochemistry Biotechnology Department, Universitat Rovira i Virgili, Reus, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Salas-Salvadó
authors.affiliation: Department of Preventive Medicine and Public Health, University of Navarra-School of Medicine, Pamplona, Navarra, Spain.|Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Carolina
authors.initials: C
authors.lastname: Donat-Vargas
authors.affiliation: Servicio Navarro de Salud-Osasunbidea, Pamplona, Navarra, Spain.|IdiSNA, Navarra Institute for Health Research, Pamplona, Navarra, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Buil-Cosiales
authors.affiliation: Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Department of Internal Medicine, Institut d'Investigacions Biomèdiques August Pi I Sunyer, Hospital Clinic, University of Barcelona, Barcelona, Spain.
authors.forename: Ramón
authors.initials: R
authors.lastname: Estruch
authors.affiliation: Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Lipid Clinic, Department of Endocrinology and Nutrition, Institut d'Investigacions Biomèdiques August Pi I Sunyer, Hospital Clinic, University of Barcelona, Barcelona, Spain.
authors.forename: Emilio
authors.initials: E
authors.lastname: Ros
authors.affiliation: Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Department of Preventive Medicine, University of Valencia, Valencia, Spain.
authors.forename: Dolores
authors.initials: D
authors.lastname: Corella
authors.affiliation: Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Cardiovascular and Nutrition Research Group, Institut de Recerca Hospital del Mar, Barcelona, Spain.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Fitó
authors.affiliation: Departments of Nutrition and Epidemiology, Harvard School of Public Health, Boston, Massachusetts.|Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Frank B
authors.initials: FB
authors.lastname: Hu
authors.affiliation: Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|University Hospital of Alava, Vitoria, Basque Country, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Arós
authors.affiliation: Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Department of Preventive Medicine, University of Malaga, Malaga, Spain.
authors.forename: Enrique
authors.initials: E
authors.lastname: Gómez-Gracia
authors.affiliation: Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Instituto de Investigación Sanitaria de Palma (IdISPa), Hospital Universitario Son Espases, Palma de Mallorca, Spain.
authors.forename: Dora
authors.initials: D
authors.lastname: Romaguera
authors.affiliation: Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Department of Family Medicine, Primary Care Division of Sevilla, Sevilla, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Ortega-Calvo
authors.affiliation: Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Research Institute of Biomedical and Health Sciences, University of Las Palmas de Gran Canaria, Las Palmas, Spain.
authors.forename: Lluís
authors.initials: L
authors.lastname: Serra-Majem
authors.affiliation: Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Lipids and Vascular Risk Unit, Internal Medicine, Hospital Universitario de Bellvitge-IDIBELL-UB, Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Pintó
authors.affiliation: Primary Care Division of Barcelona, Institut Català de la Salut and IDiap-Jordi Gol, Barcelona, Spain.|Centro de Investigación Biomédica en Red Epidemiología y Salud Pública, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Helmut
authors.initials: H
authors.lastname: Schröder
authors.affiliation: Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Human Nutrition Unit, Faculty of Medicine and Health Sciences, Biochemistry Biotechnology Department, Universitat Rovira i Virgili, Reus, Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Basora
authors.affiliation: Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Department of Preventive Medicine, University of Valencia, Valencia, Spain.
authors.forename: José Vicente
authors.initials: JV
authors.lastname: Sorlí
authors.affiliation: Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Human Nutrition Unit, Faculty of Medicine and Health Sciences, Biochemistry Biotechnology Department, Universitat Rovira i Virgili, Reus, Spain.
authors.forename: Mònica
authors.initials: M
authors.lastname: Bulló
authors.affiliation: Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Lipid Clinic, Department of Endocrinology and Nutrition, Institut d'Investigacions Biomèdiques August Pi I Sunyer, Hospital Clinic, University of Barcelona, Barcelona, Spain.
authors.forename: Merce
authors.initials: M
authors.lastname: Serra-Mir
authors.affiliation: Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|IdiSNA, Navarra Institute for Health Research, Pamplona, Navarra, Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Martínez-González
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000178:diet therapy / Q000453:epidemiology / Q000517:prevention & control; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000517:prevention & control; D038441:Diet, Mediterranean / Q000523:psychology / Q000706:statistics & numerical data; D004041:Dietary Fats; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D009754:Nuts; D000069463:Olive Oil; D011322:Primary Prevention / Q000379:methods / Q000706:statistics & numerical data; D040242:Risk Reduction Behavior; D013995:Time; D016896:Treatment Outcome
chemical_list: D004041:Dietary Fats; D000069463:Olive Oil