The Combined Effect of the Mediterranean Diet and Intermittent Fasting on Hypertension

Overview

Hypertension (HT) is an important risk factor for cardiovascular diseases (CVD) and death. Approximately 16.9 million people in Turkey have HT. Nutritional habits play an important role in the development of HT. DASH (Dietary Approaches to Stop Hypertension) and the Mediterranean diet (MD) have been found to be effective in lowering blood pressure and reducing cardiometabolic risks. The DASH diet stands out with its low sodium, saturated fat, simple sugar and cholesterol content, while it is rich in fiber, potassium, magnesium and anti-inflammatory components. The MD is based on healthy foods such as olive oil, vegetables, fruits, fish and nuts, and contains antioxidants and healthy fatty acids. This study will investigate whether the sodium-restricted MD can offer a model comparable to DASH. In addition, the effects of the intermittent fasting diet (IFD) model alone and in combination with the MD on blood pressure will be examined. It has been observed that IFD reduces blood pressure by reducing energy intake and acting on the autonomic nervous system. The aim of this project is to evaluate the effects of MD, IFD and both of them on hypertension and to present a new and original approach in this field.

Interventions

• Other Face-to-face nutrition education
  All participants will receive face-to-face nutrition education from specialist dietitians in accordance with the principles of nutrition for hypertension. Nutrition education will be provided through prepared brochures. The brochures will be given to participants as gifts. Nutrition education will cover topics such as hypertension and nutrition, nutrients, the importance of micronutrients, foods containing salt, reading labels, limiting salt consumption, healthy fat consumption, fibre consumptio
• Other Intermittent Fasting Diet
  Training will be provided to all participants through a food and nutrition photo catalogue so that portions can be recorded correctly and within standard limits when keeping a food diary. Participants will restrict their food intake to a 16-hour period by applying the 16/8 Intermittent Fasting Diet model and will eat and drink whatever they want during the remaining 8 hours. During this 16-hour period, they will consume non-energy drinks consisting of water, unsweetened tea, unsweetened herbal t
• Other Mediterranean Diet
  Training will be provided to all participants through a food and nutrition photo catalogue to ensure that portions are recorded correctly and within standard limits when keeping a food diary. In addition, the dietician will provide this group with a diet plan calculated for energy, macro and micro nutrients, which will be different each week for the first four follow-ups. The diet plans provided will be prepared in accordance with the Mediterranean Diet food pyramid. Participants' energy require

Primary outcome measures

• Blood pressure [Time frame: At enrollment, 1 week later than enrollment, 2 weeks later than enrollment, 3 weeks later than enrollment, 4 weeks later than enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment]

Secondary outcome measures (12)

• Height in cm [Time frame: At enrollment, 1 week later than enrollment, 2 weeks later than enrollment, 3 weeks later than enrollment, 4 weeks later than enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment]
• Body weight in kg [Time frame: At enrollment, 1 week later than enrollment, 2 weeks later than enrollment, 3 weeks later than enrollment, 4 weeks later than enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment]
• Body Mass Index (BMI) in kg/m² [Time frame: At enrollment, 1 week later than enrollment, 2 weeks later than enrollment, 3 weeks later than enrollment, 4 weeks later than enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment]
• Waist circumference in cm [Time frame: At enrollment, 1 week later than enrollment, 2 weeks later than enrollment, 3 weeks later than enrollment, 4 weeks later than enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment]
• Fasting plasma glucose in mg/dL [Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment]
• HbA1c in % [Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment]
• Insulin in µU/mL [Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment]
• Triglycerides in mg/dL [Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment]
• HDL cholesterol in mg/dL [Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment]
• LDL cholesterol in mg/dL [Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment]
• Total cholesterol in mg/dL [Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment]
• Urea in mg/dL [Time frame: At enrollment, 13 weeks later than enrollment, 26 weeks later than enrollment]

Eligibility criteria

Inclusion criteria

• Newly diagnosed hypertension patients
• Individuals with blood pressure >140/90 mmHg
• Individuals with a body mass index (BMI) in the range of 18.5-25 kg/m²
• Individuals aged 40-65 years

Exclusion criteria

Participants will be excluded if they have any of the following:

• Type 2 Diabetes Mellitus
• Type 1 Diabetes Mellitus
• Cardiovascular disease
• Liver disease
• Kidney disease
• Gastrointestinal disease
• Respiratory disease
• Psychiatric disorders
• Women who are pregnant or breastfeeding
• Severe food allergies
• Current smokers or individuals consuming alcohol regularly
• History of major surgery within the last 6 months

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

Turkey (Türkiye) · 1 center

• Medipol Mega University Hospital — Istanbul

Publications

• Filippou C, Thomopoulos C, Konstantinidis D, Siafi E, Tatakis F, Manta E, Drogkaris S, Polyzos D, Kyriazopoulos K, Grigoriou K, Tousoulis D, Tsioufis K. DASH vs. Mediterranean diet on a salt restriction background in adults with high normal blood pressure or grade 1 hypertension: A randomized controlled trial. Clin Nutr. 2023 Oct;42(10):1807-1816. doi: 10.1016/j.clnu.2023.08.011. Epub 2023 Aug 18. PMID 37625311
• Zou Y, Tang J, Zhang F, Chen D, Mu L, Xu H, Yu P, Ren Y, Mei Y, Mu L. Effect of low-sodium salt applied to Chinese modified DASH diet on arterial stiffness in older patients with hypertension and type 2 diabetes. Nutr Hosp. 2023 Oct 6;40(5):967-974. doi: 10.20960/nh.04622. PMID 37534516
• Zhou X, Lin X, Yu J, Yang Y, Muzammel H, Amissi S, Schini-Kerth VB, Lei X, Jose PA, Yang J, Shi D. Effects of DASH diet with or without time-restricted eating in the management of stage 1 primary hypertension: a randomized controlled trial. Nutr J. 2024 Jun 17;23(1):65. doi: 10.1186/s12937-024-00967-9. PMID 38886740
• Zhou B, Perel P, Mensah GA, Ezzati M. Global epidemiology, health burden and effective interventions for elevated blood pressure and hypertension. Nat Rev Cardiol. 2021 Nov;18(11):785-802. doi: 10.1038/s41569-021-00559-8. Epub 2021 May 28. PMID 34050340
• Guideline: Sodium Intake for Adults and Children. Geneva: World Health Organization; 2012. Available from http://www.ncbi.nlm.nih.gov/books/NBK133309/ PMID 23658998
• World Health Organization (WHO). "Obesity and overweight". https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight. Last access: 12.02.2024
• Valenzuela-Fuenzalida JJ, Bravo VS, Valarezo LM, Delgado Retamal MF, Leiva JM, Bruna-Mejias A, Nova-Baeza P, Orellana-Donoso M, Suazo-Santibanez A, Oyanedel-Amaro G, Gutierrez-Espinoza H. Effectiveness of DASH Diet versus Other Diet Modalities in Patients with Metabolic Syndrome: A Systematic Review and Meta-Analysis. Nutrients. 2024 Sep 10;16(18):3054. doi: 10.3390/nu16183054. PMID 39339654
• Urquiaga I, Echeverria G, Dussaillant C, Rigotti A. [Origin, components and mechanisms of action of the Mediterranean diet]. Rev Med Chil. 2017 Jan;145(1):85-95. doi: 10.4067/S0034-98872017000100012. Spanish. PMID 28393974

Identifiers

NCT: NCT07189637 · E-10840098-202.3.02-3317 · 2025/48

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗