Effects of a Mediterranean-Style Diet on Cardiovascular Risk Factors

Ann Intern Med 4 July 2006, Volume 145 Issue 1, 1-11. © 2006 American Medical Association. All rights reserved. Effects of a Mediterranean-Style Diet on Cardiovascular Risk Factors - A Randomized Trial, Ramon Estruch, MD, PhD; Miguel Ángel Martínez-González, MD, PhD; Dolores Corella, PhD; Jordi Salas-Salvadó, MD, PhD; Valentina Ruiz-Gutiérrez, PhD; María Isabel Covas, PhD; Miguel Fiol, MD, PhD; Enrique Gómez-Gracia, MD, PhD; Mari Carmen López-Sabater, PhD; Ernest Vinyoles, MD, PhD; Fernando Arós, MD, PhD; Manuel Conde, MD, PhD; Carlos Lahoz, MD, PhD; José Lapetra, MD, PhD; Guillermo Sáez, MD, PhD; Emilio Ros, MD, PhD, for the PREDIMED Study Investigators. Correspondence to Ramon Estruch, MD, PhD

Background: The Mediterranean diet has been shown to have beneficial effects on cardiovascular risk factors.

Objective: To compare the short-term effects of 2 Mediterranean diets versus those of a low-fat diet on intermediate markers of cardiovascular risk.

Design: Substudy of a multicenter, randomized, primary prevention trial of cardiovascular disease (Prevención con Dieta Mediterránea [PREDIMED] Study).

Setting: Primary care centers affiliated with 10 teaching hospitals.

Participants: 772 asymptomatic persons 55 to 80 years of age at high cardiovascular risk who were recruited from October 2003 to March 2004.

Interventions: Participants were assigned to a low-fat diet (n = 257) or to 1 of 2 Mediterranean diets. Those allocated to Mediterranean diets received nutritional education and either free virgin olive oil, 1 liter per week (n = 257), or free nuts, 30 g/d (n = 258). The authors evaluated outcome changes at 3 months.

Measurements: Body weight, blood pressure, lipid profile, glucose levels, and inflammatory molecules.

Results: The completion rate was 99.6%. Compared with the low-fat diet, the 2 Mediterranean diets produced beneficial changes in most outcomes. Compared with the low-fat diet, the mean changes in the Mediterranean diet with olive oil group and the Mediterranean diet with nuts group were -0.39 mmol/L (95% CI, -0.70 to - 0.07 mmol/L) and - 0.30 mmol/L (CI, -0.58 to - 0.01 mmol/L), respectively, for plasma glucose levels; -5.9 mm Hg (CI, -8.7 to -3.1 mm Hg) and - 7.1 mm Hg (CI, -10.0 to -4.1 mm Hg), respectively, for systolic blood pressure; and -0.38 (CI, -0.55 to - 0.22) and - 0.26 (CI, -0.42 to -0.10), respectively, for the cholesterol-high-density lipoprotein cholesterol ratio. The Mediterranean diet with olive oil reduced C-reactive protein levels by 0.54 mg/L (CI, 1.04 to 0.03 mg/L) compared with the low-fat diet.

Limitations: This short-term study did not focus on clinical outcomes. Nutritional education about low-fat diet was less intense than education about Mediterranean diets.

Conclusion: Compared with a low-fat diet, Mediterranean diets supplemented with olive oil or nuts have beneficial effects on cardiovascular risk factors.

Pengaruh diet Mediterrania terhadap Faktor Risiko Kardiovaskuler

Telah diketahui bahwa diet Mediterrania dapat memperbaiki faktor risiko penyakit kardiovaskuler (PKV). Para ahli di Spanyol hendak membandingkan pengaruh diet Mediterrania (tinggi lemak golongan MUFA) dibanding diet rendah lemak terhadap faktor risiko PKV.

Penelitian berlangsung dari 2003 sampai 2004, diambil dari 10 sentra kesehatan dan dilakukan randomisasi, melibatkan 772 pasien asimptomatik risiko tinggi PKV, berusia 55-80 tahun. Pasien di-randomized menjadi kelompok diet rendah lemak (n=257) atau salah satu dari dua jenis diet Mediterrania, yaitu kelompok yang mendapat 1 liter perminggu virgin olive oil (n=257) atau 30g perhari kacang (n=258). Evaluasi dilakukan tiap 3 bulan terhadap berat badan, tekanan darah, profil lipid, kadar gula darah, dan penanda inflamasi.

Ternyata dibanding diet rendah lemak, kedua diet Mediterrania yang tinggi lemak MUFA lebih unggul dalam hal menurunkan kadar gula darah, menurunkan tekanan sistolik, menurunkan rasio kolesterol terhadap HDL. Diet Mediterrania dengan olive oil menurunkan kadar C-reactive protein (CRP adalah penanda inflamasi) dibanding diet rendah lemak.

Kesimpulan dari penelitian ini adalah diet Mediterrania yang tinggi lemak MUFA (sumber MUFA dari olive oil atau kacang) lebih unggul dalam memperbaiki faktor risiko PKV dibanding diet rendah lemak.