Background A Mediterranean diet is favourable for cardiometabolic risk.
Objective To examine the residual effect of a green Mediterranean diet, further enriched with green plant-based foods and lower meat intake, on cardiometabolic risk.
Methods For the DIRECT-PLUS parallel, randomised clinical trial we assigned individuals with abdominal obesity/dyslipidaemia 1:1:1 into three diet groups: healthy dietary guidance (HDG), Mediterranean and green Mediterranean diet, all combined with physical activity. The Mediterranean diets were equally energy restricted and included 28 g/day walnuts. The green Mediterranean diet further included green tea (3–4 cups/day) and a Wolffia globosa (Mankai strain; 100 g/day frozen cubes) plant-based protein shake, which partially substituted animal protein. We examined the effect of the 6-month dietary induction weight loss phase on cardiometabolic state.
Results Participants (n=294; age 51 years; body mass index 31.3 kg/m2; waist circumference 109.7 cm; 88% men; 10 year Framingham risk score 4.7%) had a 6-month retention rate of 98.3%. Both Mediterranean diets achieved similar weight loss ((green Mediterranean −6.2 kg; Mediterranean −5.4 kg) vs the HDG group −1.5 kg; p<0.001), but the green Mediterranean group had a greater reduction in waist circumference (−8.6 cm) than the Mediterranean (−6.8 cm; p=0.033) and HDG (−4.3 cm; p<0.001) groups. Stratification by gender showed that these differences were significant only among men. Within 6 months the green Mediterranean group achieved greater decrease in low-density lipoprotein cholesterol (LDL-C; green Mediterranean −6.1 mg/dL (−3.7%), −2.3 (-0.8%), HDG −0.2 mg/dL (+1.8%); p=0.012 between extreme groups), diastolic blood pressure (green Mediterranean −7.2 mm Hg, Mediterranean −5.2 mm Hg, HDG −3.4 mm Hg; p=0.005 between extreme groups), and homeostatic model assessment for insulin resistance (green Mediterranean −0.77, Mediterranean −0.46, HDG −0.27; p=0.020 between extreme groups). The LDL-C/high-density lipoprotein cholesterol (HDL-C) ratio decline was greater in the green Mediterranean group (−0.38) than in the Mediterranean (−0.21; p=0.021) and HDG (−0.14; p<0.001) groups. High-sensitivity C-reactive protein reduction was greater in the green Mediterranean group (−0.52 mg/L) than in the Mediterranean (−0.24 mg/L; p=0.023) and HDG (−0.15 mg/L; p=0.044) groups. The green Mediterranean group achieved a better improvement (−3.7% absolute risk reduction) in the 10-year Framingham Risk Score (Mediterranean−2.3%; p=0.073, HDG−1.4%; p<0.001).
Conclusions The green MED diet, supplemented with walnuts, green tea and Mankai and lower in meat/poultry, may amplify the beneficial cardiometabolic effects of Mediterranean diet.
Trial registration number This study is registered under ClinicalTrials.gov Identifier no NCT03020186.
- metabolic syndrome
- cardiac risk factors and prevention
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GT and AYM contributed equally.
Correction notice This article has been corrected since it was published Online First. The reported numbers for changes in Triglycerides were updated.
Contributors IrS, GT, and AYM designed the research, conducted the study, analysed the data, wrote the manuscript, and are responsible for final content. IrS, AR, AT, and MJS conceived and designed the research. HZ, AKa, and ER designed the research. MSt, JT, UC, JH, AKö, KL, MvB, and MB analysed the data. HZ, AKa, SL, MSh, NI, ER, DB, and EP conducted the study. AS, AKa, AR, AT, IlS, IY, and MJS reviewed and edited the manuscript. All authors had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis as well as for the decision to submit the manuscript for publication. The corresponding author has the right to grant on behalf of all authors and does grant on behalf of all authors, an exclusive license (or non-exclusive for government employees) on a worldwide basis to the BMJ Publishing Group Ltd and its Licensees to permit this article (if accepted) to be published in HEART editions and any other BMJPGL products to exploit all subsidiary rights.
Funding This work was supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Projektnummer 209933838 – SFB 1052; the Deutsche Forschungsgemeinschaft, Obesity Mechanisms; the Israel Ministry of Health (grant no. 87472511), Israel Ministry of Science and Technology (grant 3-13604); and the California Walnuts Commission. None of the foundations was involved in any stage of the design, conduct, or analysis of the study and had no access to the study results before publication.
Competing interests IrS advises the nutritional committee of Hinoman, Ltd. All other authors have no relevant conflict of interest to disclose.
Patient consent for publication Not required.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement Data are available upon reasonable request. Data may be obtained from a third party and are not publicly available. All data of the trial are stored in an encrypted file on the Ben-Gurion University protected servers. Data may be available upon request and approval of the study’s principal investigator (Shai I).
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