Cited by 3,616Nutritional Studies and DietNuts composition and effectsFatty Acid Research and Health

Primary Prevention of Cardiovascular Disease with a Mediterranean Diet Supplemented with Extra-Virgin Olive Oil or Nuts

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Estruch, Ramón, Ros, Emilio, Salas-Salvadó, Jordi, Covas, Maria-Isabel, Corella, Dolores, Arós, Fernando, Gómez-Gracia, Enrique, Ruiz-Gutiérrez, Valentina +13 more·2018·New England Journal of Medicine

Abstract

BACKGROUND: Observational cohort studies and a secondary prevention trial have shown inverse associations between adherence to the Mediterranean diet and cardiovascular risk. METHODS: In a multicenter trial in Spain, we assigned 7447 participants (55 to 80 years of age, 57% women) who were at high cardiovascular risk, but with no cardiovascular disease at enrollment, to one of three diets: 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). Participants received quarterly educational sessions and, depending on group assignment, free provision of extra-virgin olive oil, mixed nuts, or small nonfood gifts. The primary end point was a major cardiovascular event (myocardial infarction, stroke, or death from cardiovascular causes). After a median follow-up of 4.8 years, the trial was stopped on the basis of a prespecified interim analysis. In 2013, we reported the results for the primary end point in the Journal. We subsequently identified protocol deviations, including enrollment of household members without randomization, assignment to a study group without randomization of some participants at 1 of 11 study sites, and apparent inconsistent use of randomization tables at another site. We have withdrawn our previously published report and now report revised effect estimates based on analyses that do not rely exclusively on the assumption that all the participants were randomly assigned. RESULTS: A primary end-point event occurred in 288 participants; there were 96 events in the group assigned to a Mediterranean diet with extra-virgin olive oil (3.8%), 83 in the group assigned to a Mediterranean diet with nuts (3.4%), and 109 in the control group (4.4%). In the intention-to-treat analysis including all the participants and adjusting for baseline characteristics and propensity scores, the hazard ratio was 0.69 (95% confidence interval [CI], 0.53 to 0.91) for a Mediterranean diet with extra-virgin olive oil and 0.72 (95% CI, 0.54 to 0.95) for a Mediterranean diet with nuts, as compared with the control diet. Results were similar after the omission of 1588 participants whose study-group assignments were known or suspected to have departed from the protocol. CONCLUSIONS: In this study involving persons at high cardiovascular risk, the incidence of major cardiovascular events was lower among those assigned to a Mediterranean diet supplemented with extra-virgin olive oil or nuts than among those assigned to a reduced-fat diet. (Funded by Instituto de Salud Carlos III, Spanish Ministry of Health, and others; Current Controlled Trials number, ISRCTN35739639 .).

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Crossref · 10.1056/nejmoa1800389

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  • Diets emphasizing whole, minimally processed foods-such as vegetables, fruits, whole grains, legumes, nuts, seeds, and lean protein sources-have been consistently associated with a reduced risk of obesity, type 2 diabetes, hypertension, and cardiovascular disease.

    “Diets emphasizing whole, minimally processed foods—such as vegetables, fruits, whole grains, legumes, nuts, seeds, and lean protein sources—have been consistently associated with a reduced risk of obesity, type 2 diabetes, hypertension, and cardiovascular disease [164,165,166,167].”

    From Lifestyle Medicine for Obesity in the Era of Highly Effective Anti-Obesity Treatment (2025) · cites this paper as [165]

    The Discussion (p. 10) reports fewer major cardiovascular events among high-risk participants assigned to Mediterranean diets supplemented with olive oil or nuts, and the paper describes prior associations with lower cardiovascular risk. It does not establish reduced risks of obesity, type 2 diabetes, or hypertension; those conditions appear as participant risk factors rather than outcomes supporting this claim. (LLM, conf=0.90)

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  • The Mediterranean diet, rich in olive oil, vegetables, legumes, nuts, and fish, promotes weight maintenance and cardiovascular health even without strict calorie limits.

    “The Mediterranean diet, rich in olive oil, vegetables, legumes, nuts, and fish, promotes weight maintenance and cardiovascular health even without strict calorie limits [100].”

    From Obesity: Clinical Impact, Pathophysiology, Complications, and Modern Innovations in Therapeutic Strategies (2025) · cites this paper as [100]

    The Discussion (p. 12) reports fewer major cardiovascular events among high-risk participants assigned to an energy-unrestricted Mediterranean diet with extra-virgin olive oil or nuts. Interventions and Measurements (p. 3) confirms that no total calorie restriction was advised. Although weight was measured annually (p. 4), the cited passages do not report that the diet promoted weight maintenance. (LLM, conf=0.88)

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  • In the PREDIMED trial, a Mediterranean-style eating pattern intervention enriched with olive oil or nuts significantly reduced CVD incidence in both people with and without diabetes.

    “a Mediterranean-style eating pattern intervention enriched with olive oil or nuts significantly reduced CVD incidence in both people with and without diabetes (91).”

    From Nutrition Therapy for Adults With Diabetes or Prediabetes: A Consensus Report (2019) · cites this paper as [91]

    The Results (p. 1) report significantly lower rates of major cardiovascular events for both Mediterranean-diet groups than for controls. Participant Selection and Randomization (p. 2) shows that the trial included people with and without diabetes, but the available subgroup statement (End Points, p. 9) does not establish a statistically significant reduction separately in each group. (LLM, conf=0.86)

    Experimental — accuracy not yet measured
  • Improvements in dietary quality rather than restrictive dietary counseling have shown benefits in primary and secondary cardiovascular disease prevention.

    “To date, improvements in dietary quality rather than restrictive dietary counseling have shown benefits in primary and secondary CVD prevention,98,99”

    From Malnutrition and Cachexia in Inpatients With Acute Cardiac Conditions: A Scientific Statement From the American Heart Association (2026) · cites this paper as [99]

    The Discussion (p. 12) reports fewer cardiovascular events with an energy-unrestricted Mediterranean diet than with advice to follow a reduced-fat diet, supporting the primary-prevention part. The paper also mentions a secondary-prevention trial associated with lower cardiovascular risk (p. 2), but it does not establish that improving dietary quality outperforms restrictive dietary counseling for secondary prevention. (LLM, conf=0.84)

    Experimental — accuracy not yet measured
  • In the same systematic review, the Mediterranean diet provided benefits for cardiovascular health.

    “provided bene fi ts for cardiovascular health (76,77).”

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Authors
Estruch, R., Ros, E., Salas-Salvadó, J., Covas, M.-I., Corella, D., Arós, F., Gómez-Gracia, E., Ruiz-Gutiérrez, V., Fiol, M., Lapetra, J., Lamuela-Raventos, R. M., Serra-Majem, L., Pintó, X., Basora, J., Muñoz, M. A., Sorlí, J. V., Martínez, J. A., Fitó, M., Gea, A., Hernán, M. A., & Martínez-González, M. A.
Affiliations
  • Instituto de Salud Carlos III (ES)
  • From the PREDIMED (Prevención con Dieta Mediterránea) Network (RD 06/0045) (R.E., J.S.-S., F.A., E.G.-G., V.R.-G., R.M.L.-R., L.S.-M., X.P., J.B., J.V.S., J.A.M., M.A.M.-G.) and Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (R.E., E.R., J.S.-S., M.-I.C., D.C., F.A., M. Fiol, J.L., R.M.L.-R., L.S.-M., X.P., J.B., J.V.S., J.A.M., M. Fitó, A.G., M.A.M.-G.), Instituto de Salud Carlos III, Madrid, the Department of Internal Medicine, Hospital Clinic (R.E.), the...
  • Universitat de València (ES)
Venue
New England Journal of Medicine
Published
2018-06-21
Volume
378
Issue
25
Pages
1388-1389
ISSN
  • 0028-4793 (ISSN-L)
  • 1533-4406
OpenAlex
W2807970930
Cited by
3,616
References
32
Citations by year
2026: 470 · 2025: 472 · 2024: 431 · 2023: 489 · 2022: 406 · 2021: 445 · 2020: 455 · 2019: 322 · 2018: 111 · 2017: 4 · 2015: 2 · 2014: 3
FWCI
317.46
Type
journal article
Language
en
Open access
Locations
  • New England Journal of Medicine (publishedVersion)
  • PubMed (publishedVersion)
  • Dipòsit Digital de la Universitat de Barcelona (Universitat de Barcelona) (submittedVersion, public-domain)
  • Acceda (Universidad de Las Palmas de Gran Canaria) (submittedVersion)
  • DIGITAL.CSIC (Spanish National Research Council (CSIC)) (submittedVersion)
  • Docusalut (Conselleria de Salut i Consum del Govern de les Illes Balears) (submittedVersion)
  • RISalud Institutional Health Repository of Andalucía (submittedVersion, other-oa)
Funders
  • Public Health Division of the Department of Health of the Autonomous Government of Catalonia (Public Health Division of the Department of Health)
  • Instituto de Salud Carlos III (CIBERobn, CP06/00100, P11/02505, PI 05/2584, PI 07/0473, PI04/0954, PI07/0240, PI07/0954, PI07/1138, PI10/01407, PI10/02658, PI11/01647, RTIC G03/140, RTIC RD06/0045)
  • Departamento de Educación, Gobierno de Navarra (P27/2011)
  • Generalitat Valenciana (ACOMP06109, CS2010-AP-111, CS2011-AP-042, GVACOMP2010-181, GVACOMP2011-151)
  • Patient-Centered Outcomes Research Institute (ME-1503-28119)
  • Ministerio de Ciencia e Innovación (AGL-2009-13906-C02, AGL2010-22319-C03)
  • Centro Nacional de Investigaciones Cardiovasculares (CNIC 06/2007)
  • Consejería de Salud de la Junta de Andalucía (PI0105/2007)
  • Fundación Mapfre (Fundación Mapfre 2010)
Topics
  • Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Nutritional Studies and Diet
  • Health Sciences › Nursing › Nutrition and Dietetics › Nuts composition and effects
  • Health Sciences › Nursing › Nutrition and Dietetics › Fatty Acid Research and Health
Keywords
Mediterranean diet, extra virgin olive oil, mixed nuts, primary prevention, cardiovascular disease, major adverse cardiovascular events, myocardial infarction, stroke, cardiovascular mortality, high cardiovascular risk, dietary intervention, protocol deviations, propensity score, intention-to-treat analysis

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