What is the Mediterranean Diet (MedDiet)?
This nutritional model is based on the traditional dietary intake of the populations living in the regions surrounding the Mediterranean Sea.1
General descriptions of the MedDiet are similar amongst publications, emphasising the same key components. The definitions include guidelines for high intake of extra virgin (cold pressed) olive oil, vegetables including an abundance of leafy green vegetables, fruits, cereals, nuts and legumes, moderate intake of red wine, limited intakes of fish and white meat, processed meat, dairy products , and low intakes of eggs and sweets.2
How does it work?
The MedDiet provides elements of a diet high in fiber and complex carbohydrates, low in saturated fat and cholesterol, and high in monounsaturated fatty acids It has a balanced omega-6 to omega-3 polyunsaturated fatty acid ratio, is rich in antioxidants and vitamins.
Cardiovascular Disease (CVD) Benefits: In the National Institutes of Health-AARP Diet and Health Study cohort, consisting of 380,296 people followed for 5 years, the risk of mortality for CVD was significantly lower in men and women with a higher adherence to the Mediterranean Diet.4
Decreased Metabolic Syndrome: In general, results from clinical, cross-sectional, and prospective studies support the health benefits of a MedDiet eating pattern against MetS. The clinical diagnosis of MetS is having at least three of the following conditions: a waist circumference > 102 cm for men and > 88 cm for women; high TG levels (≥150 mg/dL); low HDL-C (<40 mg/dL for men and <50 mg/dL for women); high blood pressure (BP ≥130/85 mmHg) on at least two separate measurements; and high fasting glucose (≥100 mg/dL or ≥5.6 mmol/L). Olive oil and fish consumption (components of the MedDiet) have been correlated with healthy biomarkers associated with antiproliferative effects in the gut.5
Diabetes Prevention: The increasing incidence of type 2 diabetes throughout the world is closely linked to westernized dietary patterns, physical inactivity, and raising rates of obesity. Lifestyle changes are effective measures to prevent diabetes, and weight loss is the main predictor of success. Research supports a MedDiet high in unsaturated fat that can be a useful tool for preventing diabetes. Education of the population on the MedDiet might be a safe public health approach to delay or prevent development of diabetes.6
Non-alcoholic fatty liver disease: (NAFLD) represents the most common chronic liver disease in Western countries, being considered as the hepatic manifestation of metabolic syndrome. NAFLD has a common pathogenic background to that of metabolic syndrome, and shares many risk factors such as obesity, hypertension, insulin resistance and dyslipidemia. Diet plays a key role in the management of NAFLD patients. Among all the diets that have been proposed, a Mediterranean diet was the most effective dietary option for inducing weight loss together with beneficial effects on all the risk factors associated with metabolic syndrome and NAFLD. Over the last few years, research has demonstrated a beneficial effect of a Mediterranean diet in NAFLD.7
Cancer remains one of the major causes of premature death worldwide as it is ranked second to cardiovascular diseases in current statistics. Approximately 5–10% of all tumor diseases are caused by genetic predisposition, while the pathogenesis of the remaining 90–95% can be explained by unfavorable environmental conditions or an unhealthy lifestyle. The latter can mainly be characterized by an unbalanced diet, lack of exercise, and consumption of alcohol and tobacco.
The World Cancer Research Fund (WCRF) assumes that 3–4 million cases of cancer worldwide might be avoided by adopting a healthier lifestyle. It has been suggested that approximately 30% of cancers can be prevented by a healthy diet. Adherence to a MedD and the small number of studies investigating corresponding pathogenetic mechanisms, systematic reviews and meta-analyses of observational studies provide evidence that a MedD exerts protective functions with respect to tumor incidence and mortality. In a clinical trial, choice of diet orientated towards a Mediterranean pattern was found to be associated with reduced all-cause mortality as well as a 61%-decrease in cancer incidence. 8
Decreased cognitive disorders. A recent systematic review and meta-analysis by Wu and Sun provides significant evidence of an inverse association between Mediterranean diet and the risk of developing cognitive disorders. It is reported that adherence to Mediterranean diet was related to lower levels of C-reactive protein and interleukin. The neuro-protective effects of the Mediterranean diet may relate to its ability of reducing inflammation and oxidative stress, which are also linked to the pathophysiology of degenerative disease.9
Stroke: According to the The EPIC-Norfolk study greater adherence to the Mediterranean diet was associated with lower risk for stroke suggesting that the Mediterranean diet reduces stroke risk. Benefits appear to come from the additive effects of combining a diet high in fish, fruits, vegetables, nuts and beans, cereals, and potatoes, with lower intakes of meat and dairy accompanied by a lower ratio of unsaturated to saturated fat.10
Elements of the Mediterranean Diet
- Whole (non-refined) grains are an integral part of the MedDiet and have been shown to decrease the risk of heart disease, diabetes and cancer.
- Fresh native fruit and vegetables are found throughout markets in the mediterranean. Fruits and vegetables contain an abundance of vitamins, mineral, fiber, complex carbohydrates, that lower the risk of heart disease and cancer.
- Nuts, like olive oil are an essential part of the MedDiet for antiquity. Nuts are rich in monounsaturated fats, omega-3 fatty acids, protein, fiber and vitamins.
- Olive Oil is the heart of the MedDiet, rich in monounsaturated fat that is beneficial for heart health. Regular use is also is associated with a reduced risk of cancer, diabetes and inflammatory diseases such as asthma and arthritis.
- Beans are also consumed on a large basis in the Mediterranean region and are a rich source of soluble and insoluble fiber which help curb appetite and reduce cholesterol.
- Oily fish prevalent in the MedDiet provides a rich source of protein and omega-3 fatty acids which have a favorable impact on cholesterol and triglyceride levels and reduce the risk of heart attack. They also reduce the risk of inflammation. Avoid tilefish, swordfish, shark, and king mackerel as these have high levels of mercury content.
- Red Wine moderate consumption has been shown to lower the risk of coronary heart disease. Red Wine contains polyphenols and resveratol, two substances to promote heart health.
Finally, people living in the Mediterranean countries tend to have a more relaxed, less stressful lifestyle. They spend more time enjoying their meals with friends and family and often take short naps after lunch. A recent study has shown taking a regular midday nap reduces risk of death by heart disease by 37%.11
1. Willett WC, Sacks F, Trichopoulou A, et al. Mediterranean diet : a cultural model for healthy eating. Am J Clin Nutr. 1195;61
2. Davis C, Bryan J, Hodgson J, Murphy K. Definition of the Mediterranean Diet; a Literature Review. Nutrients. 2015;7(11):9139-53. Published 2015 Nov 5. doi:10.3390/nu7115459
3 Sofi F, Abbate R, Gensini GF, Casini A. Accruing evidence on the benefits of adherence to the Mediterranean diet on health: an updated systematic review and meta-analysis. Am J Clin Nutr. 2010;92:1189-1196
4. D’Alessandro A, De Pergola G. Mediterranean Diet and Cardiovascular Disease: A Critical Evaluation of A Priori Dietary Indexes. Nutrients. 2015;7(9):7863-88. Published 2015 Sep 16. doi:10.3390/nu7095367
5. Salas-Salvadó J, Bulló M, Babio N, et al. Reduction in the incidence of type 2 diabetes with the Mediterranean diet: results of the PREDIMED-Reus nutrition intervention randomized trial. Diabetes Care. 2010;34(1):14-9.
6Romagnolo DF, Selmin OI. Mediterranean Diet and Prevention of Chronic Diseases. Nutr Today. 2017;52(5):208-222.
7 Sofi F, Casini A. Mediterranean diet and non-alcoholic fatty liver disease: new therapeutic option around the corner?. World J Gastroenterol. 2014;20(23):7339-46.
8 Schwingshackl L, Schwedhelm C, Galbete C, Hoffmann G. Adherence to Mediterranean Diet and Risk of Cancer: An Updated Systematic Review and Meta-Analysis. Nutrients. 2017;9(10):1063. Published 2017 Sep 26. doi:10.3390/nu9101063
9 Wu L, Sun D. Adherence to Mediterranean diet and risk of developing cognitive disorders: An updated systematic review and meta-analysis of prospective cohort studies. Sci Rep. 2017;7:41317. Published 2017 Jan 23. doi:10.1038/srep41317
11. The Complete Mediterranean Diet. Ozner M, 2014