Mediterranean Diet


Definition/Introduction

Mediterranean diet is a generic term used to describe the dietary pattern of individuals living in the countries along the coast of the Mediterranean Sea, including Greece, Italy, southern France, Crete, Spain, and parts of the middle east. This article will utilize the Mediterranean diet in a broad sense, from the time of its initial rise pre-globalization to its use today. Before large-scale trade became available in the 1950s, people would eat what was available to them based on their geography, creating a seasonal variability for most. The Mediterranian diet is primarily a plant-based diet with the contributions from animal-based products being comprised of fish and poultry with a limited quantity of dairy products. While the modern version of the diet utilizes a higher proportion of red meat and processed foods, the diet's primary focus remains the same - plant-based with healthy fats. 

The food choices in the Mediterranian diet are comprised mainly of green leafy vegetables with a variety of legumes, nuts (e.g., walnuts, almonds, pistachios), fresh fruits, and whole grains also included. As the Mediterranean region is a significant producer of olive oil, this is also a staple in the diet. Olive oil is a monounsaturated fat containing alpha-linoleic acid, an omega-3 essential fatty acid, which has been indicated to provide a cardioprotective benefit.[1] The reduction of risk factors[2][3][4] is believed to be the major contributor to the reduction in cardiovascular disease seen in those who adhere to the Mediterranian diet. Fish and other animals of the sea provide a great source of other omega fatty acids and are another predominant reason for the cardioprotective nature.[5] Another important element to acknowledge is the consumption of wine in moderation (specifically red), which has been suggested to provide multiple metabolic benefits. The most reproducible benefit appears to be in lipid metabolism, believed to be attributable to ethanol, but its microconstituents also may play important roles in hemostasis and inflammation.[6]

Issues of Concern

The requirement for strict adherence to this diet for the best preventative effects is not practical for most people in today's world. Therefore, it is of the utmost importance to realize benefits appear to be significantly diminished when adherence occurs in an episodic nature or when only certain parts of the diet are followed.[5] Recognizing the role the intestinal microbiome plays in overall immune, cardiovascular, endocrine, and, the more obvious, gastrointestinal system functions, and the realization that the microbiome may change in as few as four days aids in highlighting the importance of adherence to the diet.[7][8] It is also imperative to recognize that there should be some component of physical activity and that, as with all diets, moderation in consumption also plays an important role in the overall efficacy of the Mediterranian diet. The inter-individual variation between taste preferences is acknowledged, i.e., preferring salty over sweet, and produces a wide variation in adherence.[9] 

While most studies suggest improvements in cardiovascular risk factors, the quality of evidence for these studies is felt by some to be only low to moderate.[10] Additionally, some studies seem to reveal no improvement in the measured values of inflammatory markers or metabolic risk factors.[11] It is also noted that the majority of published studies focus on adult subjects, and additional studies in other age groups would be beneficial. However, arguably the most significant barrier to adherence would be that recommendations for what exactly comprises a Mediterranean diet are not homogenous between studies. 

Clinical Significance

The preventative benefits of the Mediterranean diet have been demonstrated throughout both observational and randomized control trials. The landmark study for support was the 'Seven Countries Study,' which suggested a significantly decreased risk for and lower rates of cardiovascular disease overall in those adhering to the Mediterranian diet, and other studies have since produced similar results.[12][13] There have also been several studies to demonstrate a decreased risk for members of certain subgroups, such as patients with non-alcoholic fatty liver disease, those with familial heterozygous hypercholesterolemia (HFH), and patients with recent myocardial infarction.[14][15][16] These findings would suggest the benefits could be further extrapolated, as well. Mediterranean diet has been recognized to improve glycemic control and insulin resistance in patients with diabetes with a high risk of cardiovascular disease.[17] There have also been several studies demonstrating a decrease in early vascular aging.[18] Given the above protective factors, it is likely the benefits of the Mediterranean diet can be extrapolated to include individuals with metabolic syndrome.[19] There is also a suggestion regarding reducing the development of other health issues, including osteoporosis, inflammatory bowel disease, preterm birth, macular degeneration, kidney stones, dry eye, cancers (breast and colorectal), neurocognitive disorders, and select patients with depression.[20][21][22][23][24][25][26][27][28][29][30][31]

Nursing, Allied Health, and Interprofessional Team Interventions

An interprofessional team that provides an integrated approach to patient care, particularly risk factor modification, can help achieve the best overall outcomes. Risk factor modifications are stressed to patients by primary care physicians daily. A patient referral to a registered dietician is likely to be beneficial. There should also be recommendations for routine aerobic exercise. It has become widely recognized that counseling on the importance of dietary changes should include a discussion of the Mediterranean diet, although continued studies will be beneficial.[32][33] [Level 1]

Therefore, the specific requirements of a strict Mediterranean diet are not homogenous and may be difficult to recommend. There was a large scale literature review of the Mediterranean diet performed by Davis et al. that attempted to define the quantities of each food group and specific nutrients; results were as follows:

  • Three to nine servings of vegetables
  • One-half to two servings of fruit
  • One to 13 servings of cereals
  • Up to eight servings of olive oil daily
  • Red wine daily in moderation

These recommendations resulted in approximately 2200 calories (9300 kJ) per day, with 37% as total fat, 18% as monounsaturated with 9% as saturated, and 33g of fiber per day.[34] [Level 1]

Nursing, Allied Health, and Interprofessional Team Monitoring

A scoring system for adherence to the Mediterranean diet exists and would help patients to recognize the importance of adherence based on a morbidity and mortality model for the development of specific illnesses.[35] It is important to continue to routinely encourage patients to perform risk factor modifications and to provide them with the resources needed to make the necessary lifestyle changes to improve their overall health. Routine blood monitoring can be performed, including blood lipids, hemoglobin A1c, and renal function.


Article Details

Article Author

Colton Rishor-Olney

Article Editor:

Melissa Hinson

Updated:

4/7/2021 8:57:26 AM

PubMed Link:

Mediterranean Diet

References

[1]

den Hartigh LJ, Conjugated Linoleic Acid Effects on Cancer, Obesity, and Atherosclerosis: A Review of Pre-Clinical and Human Trials with Current Perspectives. Nutrients. 2019 Feb 11;     [PubMed PMID: 30754681]

[2]

De Pergola G,D'Alessandro A, Influence of Mediterranean Diet on Blood Pressure. Nutrients. 2018 Nov 7;     [PubMed PMID: 30405063]

[3]

Esposito K,Maiorino MI,Bellastella G,Chiodini P,Panagiotakos D,Giugliano D, A journey into a Mediterranean diet and type 2 diabetes: a systematic review with meta-analyses. BMJ open. 2015 Aug 10;     [PubMed PMID: 26260349]

[4]

Doménech M,Roman P,Lapetra J,García de la Corte FJ,Sala-Vila A,de la Torre R,Corella D,Salas-Salvadó J,Ruiz-Gutiérrez V,Lamuela-Raventós RM,Toledo E,Estruch R,Coca A,Ros E, Mediterranean diet reduces 24-hour ambulatory blood pressure, blood glucose, and lipids: one-year randomized, clinical trial. Hypertension (Dallas, Tex. : 1979). 2014 Jul;     [PubMed PMID: 24799608]

[5]

Widmer RJ,Flammer AJ,Lerman LO,Lerman A, The Mediterranean diet, its components, and cardiovascular disease. The American journal of medicine. 2015 Mar;     [PubMed PMID: 25447615]

[6]

Fragopoulou E,Choleva M,Antonopoulou S,Demopoulos CA, Wine and its metabolic effects. A comprehensive review of clinical trials. Metabolism: clinical and experimental. 2018 Jun;     [PubMed PMID: 29408458]

[7]

Singh RK,Chang HW,Yan D,Lee KM,Ucmak D,Wong K,Abrouk M,Farahnik B,Nakamura M,Zhu TH,Bhutani T,Liao W, Influence of diet on the gut microbiome and implications for human health. Journal of translational medicine. 2017 Apr 8;     [PubMed PMID: 28388917]

[8]

Zhu C,Sawrey-Kubicek L,Beals E,Rhodes CH,Houts HE,Sacchi R,Zivkovic AM, Human gut microbiome composition and tryptophan metabolites were changed differently by fast food and Mediterranean diet in 4 days: a pilot study. Nutrition research (New York, N.Y.). 2020 Mar 26;     [PubMed PMID: 32330749]

[9]

Veček NN,Mucalo L,Dragun R,Miličević T,Pribisalić A,Patarčić I,Hayward C,Polašek O,Kolčić I, The Association between Salt Taste Perception, Mediterranean Diet and Metabolic Syndrome: A Cross-Sectional Study. Nutrients. 2020 Apr 22;     [PubMed PMID: 32331287]

[10]

Rees K,Takeda A,Martin N,Ellis L,Wijesekara D,Vepa A,Das A,Hartley L,Stranges S, Mediterranean-style diet for the primary and secondary prevention of cardiovascular disease. The Cochrane database of systematic reviews. 2019 Mar 13;     [PubMed PMID: 30864165]

[11]

Michalsen A,Lehmann N,Pithan C,Knoblauch NT,Moebus S,Kannenberg F,Binder L,Budde T,Dobos GJ, Mediterranean diet has no effect on markers of inflammation and metabolic risk factors in patients with coronary artery disease. European journal of clinical nutrition. 2006 Apr;     [PubMed PMID: 16306923]

[12]

Keys A,Menotti A,Aravanis C,Blackburn H,Djordevic BS,Buzina R,Dontas AS,Fidanza F,Karvonen MJ,Kimura N, The seven countries study: 2,289 deaths in 15 years. Preventive medicine. 1984 Mar;     [PubMed PMID: 6739443]

[13]

Fidanza F,Alberti A,Lanti M,Menotti A, Mediterranean Adequacy Index: correlation with 25-year mortality from coronary heart disease in the Seven Countries Study. Nutrition, metabolism, and cardiovascular diseases : NMCD. 2004 Oct;     [PubMed PMID: 15673059]

[14]

Asbaghi O,Choghakhori R,Ashtary-Larky D,Abbasnezhad A, Effects of the Mediterranean diet on cardiovascular risk factors in non-alcoholic fatty liver disease patients: A systematic review and meta-analysis. Clinical nutrition ESPEN. 2020 Jun;     [PubMed PMID: 32359737]

[15]

García Calvo S,Díaz-Soto G,Torres Torres B,López Gómez JJ,Villar Bonet A,Serrano Valles C,Jiménez Sahagún R,de Luis DA, [Metabolic control, cardiovascular profile, and adherence to the Mediterranean diet in a familial hypercholesterolemia cohort in a Public Health Program]. Nutricion hospitalaria. 2020 Apr 27;     [PubMed PMID: 32338018]

[16]

Singh RB,Rastogi SS,Verma R,Laxmi B,Singh R,Ghosh S,Niaz MA, Randomised controlled trial of cardioprotective diet in patients with recent acute myocardial infarction: results of one year follow up. BMJ (Clinical research ed.). 1992 Apr 18;     [PubMed PMID: 1586782]

[17]

Georgoulis M,Kontogianni MD,Yiannakouris N, Mediterranean diet and diabetes: prevention and treatment. Nutrients. 2014 Apr 4;     [PubMed PMID: 24714352]

[18]

GómezSánchez M,Gómez Sánchez L,Patino-Alonso MC,Alonso-Domínguez R,Sánchez-Aguadero N,Lugones-Sánchez C,Rodríguez Sánchez E,García Ortiz L,Gómez-Marcos MA, Adherence to the Mediterranean Diet in Spanish Population and Its Relationship with Early Vascular Aging according to Sex and Age: EVA Study. Nutrients. 2020 Apr 8;     [PubMed PMID: 32276498]

[19]

Mirabelli M,Chiefari E,Arcidiacono B,Corigliano DM,Brunetti FS,Maggisano V,Russo D,Foti DP,Brunetti A, Mediterranean Diet Nutrients to Turn the Tide against Insulin Resistance and Related Diseases. Nutrients. 2020 Apr 12;     [PubMed PMID: 32290535]

[20]

Jennings A,Mulligan AA,Khaw KT,Luben RN,Welch AA, A Mediterranean Diet Is Positively Associated with Bone and Muscle Health in a Non-Mediterranean Region in 25,450 Men and Women from EPIC-Norfolk. Nutrients. 2020 Apr 21;     [PubMed PMID: 32326165]

[21]

Cariello M,Contursi A,Gadaleta RM,Piccinin E,De Santis S,Piglionica M,Spaziante AF,Sabbà C,Villani G,Moschetta A, Extra-Virgin Olive Oil from Apulian Cultivars and Intestinal Inflammation. Nutrients. 2020 Apr 14;     [PubMed PMID: 32295122]

[22]

Peraita-Costa I,Llopis-González A,Perales-Marín A,Diago V,Soriano JM,Llopis-Morales A,Morales-Suárez-Varela M, Maternal profile according to Mediterranean diet adherence and small for gestational age and preterm newborn outcomes. Public health nutrition. 2020 Apr 29;     [PubMed PMID: 32345384]

[23]

Keenan TD,Agrón E,Mares J,Clemons TE,van Asten F,Swaroop A,Chew EY, Adherence to the Mediterranean diet and progression to late age-related macular degeneration in the Age-Related Eye Disease Studies 1 and 2. Ophthalmology. 2020 Apr 26;     [PubMed PMID: 32348832]

[24]

Rodriguez A,Curhan GC,Gambaro G,Taylor EN,Ferraro PM, Mediterranean diet adherence and risk of incident kidney stones. The American journal of clinical nutrition. 2020 Apr 9;     [PubMed PMID: 32271884]

[25]

Molina-Leyva I,Molina-Leyva A,Riquelme-Gallego B,Cano-Ibáñez N,García-Molina L,Bueno-Cavanillas A, Effectiveness of Mediterranean Diet Implementation in Dry Eye Parameters: A Study of PREDIMED-PLUS Trial. Nutrients. 2020 May 1;     [PubMed PMID: 32369989]

[26]

Dianatinasab M,Rezaian M,HaghighatNezad E,Bagheri-Hosseinabadi Z,Amanat S,Rezaeian S,Masoudi A,Ghiasvand R, Dietary Patterns and Risk of Invasive Ductal and Lobular Breast Carcinomas: A Systematic Review and Meta-analysis. Clinical breast cancer. 2020 Mar 28;     [PubMed PMID: 32362500]

[27]

Turati F,Carioli G,Bravi F,Ferraroni M,Serraino D,Montella M,Giacosa A,Toffolutti F,Negri E,Levi F,La Vecchia C, Mediterranean Diet and Breast Cancer Risk. Nutrients. 2018 Mar 8;     [PubMed PMID: 29518016]

[28]

Zhong Y,Zhu Y,Li Q,Wang F,Ge X,Zhou G,Miao L, Association between Mediterranean diet adherence and colorectal cancer: a dose-response meta-analysis. The American journal of clinical nutrition. 2020 May 2;     [PubMed PMID: 32359135]

[29]

Vinciguerra F,Graziano M,Hagnäs M,Frittitta L,Tumminia A, Influence of the Mediterranean and Ketogenic Diets on Cognitive Status and Decline: A Narrative Review. Nutrients. 2020 Apr 8;     [PubMed PMID: 32276339]

[30]

Keenan TD,Agrón E,Mares JA,Clemons TE,van Asten F,Swaroop A,Chew EY, Adherence to a Mediterranean diet and cognitive function in the Age-Related Eye Disease Studies 1     [PubMed PMID: 32285590]

[31]

Sánchez-Villegas A,Martínez-González MA,Estruch R,Salas-Salvadó J,Corella D,Covas MI,Arós F,Romaguera D,Gómez-Gracia E,Lapetra J,Pintó X,Martínez JA,Lamuela-Raventós RM,Ros E,Gea A,Wärnberg J,Serra-Majem L, Mediterranean dietary pattern and depression: the PREDIMED randomized trial. BMC medicine. 2013 Sep 20;     [PubMed PMID: 24229349]

[32]

Martínez-González MA,Salas-Salvadó J,Estruch R,Corella D,Fitó M,Ros E, Benefits of the Mediterranean Diet: Insights From the PREDIMED Study. Progress in cardiovascular diseases. 2015 Jul-Aug;     [PubMed PMID: 25940230]

[33]

Dernini S,Berry EM,Serra-Majem L,La Vecchia C,Capone R,Medina FX,Aranceta-Bartrina J,Belahsen R,Burlingame B,Calabrese G,Corella D,Donini LM,Lairon D,Meybeck A,Pekcan AG,Piscopo S,Yngve A,Trichopoulou A, Med Diet 4.0: the Mediterranean diet with four sustainable benefits. Public health nutrition. 2017 May;     [PubMed PMID: 28003037]

[34]

Davis C,Bryan J,Hodgson J,Murphy K, Definition of the Mediterranean Diet; a Literature Review. Nutrients. 2015 Nov 5;     [PubMed PMID: 26556369]

[35]

Sofi F,Macchi C,Abbate R,Gensini GF,Casini A, Mediterranean diet and health status: an updated meta-analysis and a proposal for a literature-based adherence score. Public health nutrition. 2014 Dec;     [PubMed PMID: 24476641]