Open Access Research article

Mediterranean dietary pattern and depression: the PREDIMED randomized trial

Almudena Sánchez-Villegas12*, Miguel Angel Martínez-González13, Ramón Estruch14, Jordi Salas-Salvadó15, Dolores Corella16, Maria Isabel Covas17, Fernando Arós18, Dora Romaguera1109, Enrique Gómez-Gracia111, José Lapetra112, Xavier Pintó113, Jose Alfredo Martínez114, Rosa María Lamuela-Raventós115, Emilio Ros11617, Alfredo Gea13, Julia Wärnberg111 and Lluis Serra-Majem12

Author Affiliations

1 Biomedical Research Center Network on Obesity and Nutrition (CIBERobn) Physiopathology of Obesity and Nutrition, Institute of Health Carlos III, Madrid, Spain

2 Department of Clinical Sciences, University of Las Palmas de Gran Canaria, PO Box 550, 35080 Las Palmas de Gran Canaria, Spain

3 Department of Preventive Medicine and Public Health, University of Navarra, Pamplona, Spain

4 Department of Internal Medicine, Institut d’Investigacions Biomediques August Pi Sunyer (IDIBAPS), Hospital Clinic, University of Barcelona, Barcelona, Spain

5 Human Nutrition Unit, IISPV, Universitat Rovira i Virgili, Reus, Spain

6 Department of Preventive Medicine, University of Valencia, Valencia, Spain

7 Lipids and Cardiovascular Epidemiology Research Unit, Institut Municipal d’Investigacio Medica (IMIM), Barcelona, Spain

8 Department of Cardiology, University Hospital Txagorritxu, Vitoria, Spain

9 Research Unit, University Hospital Son Espases, Palma de Mallorca, Spain

10 School of Public Health, Imperial College London, London, UK

11 Department of Preventive Medicine, University of Malaga, Malaga, Spain

12 Department of Family Medicine, Primary Care Division of Sevilla, Centro de Salud San Pablo, Sevilla, Spain

13 Lipids and Vascular Risk Unit, Internal Medicine, Hospital Universitario de Bellvitge, Hospitalet de Llobregat, Barcelona, Spain

14 Department of Nutrition and Food Sciences, Physiology and Toxicology, University of Navarra, Pamplona, Spain

15 Nutrition and Food Science Department–XaRTA, INSA, University of Barcelona, Barcelona, Spain

16 Lipid Clinic, Department of Endocrinology and Nutrition, Hospital Clınic, Barcelona, Spain

17 Institut d’Investigacions Biomediques August Pi Sunyer (IDIBAPS), Hospital Clınic, Barcelona, Spain

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BMC Medicine 2013, 11:208  doi:10.1186/1741-7015-11-208

Published: 20 September 2013

Abstract

Background

A few observational studies have found an inverse association between adherence to a Mediterranean diet and the risk of depression. Randomized trials with an intervention based on this dietary pattern could provide the most definitive answer to the findings reported by observational studies. The aim of this study was to compare in a randomized trial the effects of two Mediterranean diets versus a low-fat diet on depression risk after at least 3 years of intervention.

Methods

This was a multicenter, randomized, primary prevention field trial of cardiovascular disease (Prevención con Dieta Mediterránea (PREDIMED Study)) based on community-dwelling men aged 55 to 80 years and women aged 60 to 80 years at high risk of cardiovascular disease (51% of them had type 2 diabetes; DM2) attending primary care centers affiliated with 11 Spanish teaching hospitals. Primary analyses were performed on an intention-to-treat basis. Cox regression models were used to assess the relationship between the nutritional intervention groups and the incidence of depression.

Results

We identified 224 new cases of depression during follow-up. There was an inverse association with depression for participants assigned to a Mediterranean diet supplemented with nuts (multivariate hazard ratio (HR) 0.78; 95% confidence interval (CI) 0.55 to 1.10) compared with participants assigned to the control group, although this was not significant. However, when the analysis was restricted to participants with DM2, the magnitude of the effect of the intervention with the Mediterranean diet supplemented with nuts did reach statistical significance (multivariate HR = 0.59; 95% CI 0.36 to 0.98).

Conclusions

The result suggest that a Mediterranean diet supplemented with nuts could exert a beneficial effect on the risk of depression in patients with DM2.

Trial registration

This trial has been registered in the Current Controlled Trials with the number ISRCTN 35739639

Keywords:
Mediterranean diet; Depression; Trial; Primary prevention; Nuts; Olive oil; Low-fat; Diabetes