The Mediterranean Diet: What Do We Know?

Article by Jessica Noon

The Mediterranean diet was established in the 1960’s, originating primarily from the Mediterranean countries of Greece, Spain and Italy. Since then, the diet has been praised for its applicability for a number of health conditions and more specifically, the prevention and management, namely cardiovascular diseases and type 2 diabetes.

Adhering to the Mediterranean diet

The Mediterranean diet is considered as more manageable for most people in comparison to alternative diets as it does not have the main aims of cutting down calories or significantly increasing physical activity but rather, to increase the variety and quantity of wholefoods consumed, more specifically including wholegrains, legumes and nuts. Overall, this diet allows for a certain amount of flexibility which is viewed as a significant positive.

People generally comply to the Mediterranean diet well due to its adequate fat content and food variety. Other diets that have been associated with similar health benefits as the Mediterranean diet are generally low in fat and utilise calorie or food group restrictions which may lead to a reduced compliance as a result of decreased palatability.

The main barrier to the Mediterranean diet is considered to be its expense. Due to the focus of the Mediterranean diet being on cooking fresh and seasonal ingredients, the price compared to the typical Western diet is often higher which may be off putting for some. However, further on in this article we look at some simple ways of implementing the Mediterranean diet in a more cost-effective way.



What is the Mediterranean diet?

The key food groups included in a Mediterranean diet are:

  • Fruits and vegetables

  • Legumes and pulses

  • Cereals, of which the majority are wholegrain

  • Oily fish

  • Olive oil

  • Moderate alcohol, mainly red wine drank alongside meals

  • Nuts and seeds

  • Moderate dairy products

  • Moderate poultry

If we consider the nutrient content of each food group included in a Mediterranean diet from the table below, we can see that by consuming this diet we are provided with a huge variety of nutrients. This includes a considerable amount of fibre which is generally lacking in Western diets. As well as being high in the food groups listed above, the Mediterranean diet is low in some other food groups. The diet is low in refined sugar, red meat and saturated fat. These are some food groups that are generally high in Western diets and are consequentially thought to contribute to the recent surge in obesity, cardiovascular diseases and diabetes.

What are some of the health benefits of the Mediterranean diet?

The main health benefits associated with a Mediterranean diet are:

  • Reduced risk of cardiovascular disease

  • Reduced risk of cancer

  • Reduced risk of frailty and resultant fractures

  • Reduced risk of type 2 diabetes

  • Improved cognitive health

  • Improved mental health and reduced risk of depression

Let us consider some of these in greater detail.

Reduced risk of cardiovascular disease

Cardiovascular diseases develop over a long period of time as a result of genetics and diet. Making dietary changes for better heart health is well established from research with the Mediterranean diet being the gold standard for cardiovascular health.

The PREDIMED study investigated the long-term effects of the Mediterranean diet on CVD incidence in high-risk men, aged 55 to 75, and women, aged 60 to 80, over 8 years. The PREDIMED diet considered the following 3 groups:

  • Mediterranean diet supplemented with extra-virgin olive oil

  • Mediterranean diet supplemented with nuts

  • Control diet

The results of the PREDIMED study hypothesised that the risk of CVD was reduced in high-risk groups from the consumption of both Mediterranean diets in comparison to the control group.

CVD is greatly impacted by the fat content of a diet and the resultant body composition from such a diet. By shifting from a Western diet to a Mediterranean diet, the profile of fats consumed changes considerably. Western diets are generally high in saturated fat and low in MUFA (monounsaturated fatty acids) and PUFA (polyunsaturated fatty acids) whereas, a Mediterranean diet consists of very little saturated fat and a greater proportion of MUFA and PUFA.

A Mediterranean diet is also a great source of antioxidants which aid in reducing oxidative stress and minimising inflammation. These are both considered contributors to cardiovascular disease development.

Regarding hypertension specifically, we can highlight that the lower salt content of a Mediterranean diet has a positive impact. Hypertension is generally a result of the overconsumption of salt in the diet. In a typical Western diet, there is a high consumption of salt from ultra-processed foods. In comparison, a Mediterranean diet is generally focused on home cooking with fresh ingredients so the salt consumed is what is added in during food preparation, which can be more closely monitored and can positively impact the likelihood of not developing hypertension.

Reduced risk of type 2 diabetes

Type 2 diabetes development is very much a result of impaired control of blood glucose concentration which is impacted by the type of carbohydrates being consumed. Complex carbohydrates increase a person’s blood glucose levels more slowly hence these being endorsed over more refined carbohydrates. The Mediterranean diet is generally low in refined carbohydrates and high in complex carbohydrates and is therefore suggested as beneficial for reducing risk of type 2 diabetes.

Research has also suggested that MUFA has a positive impact on the risk of type 2 diabetes development. Olive oil has been specifically associated with a reduction in inflammation, oxidative stress and acute hyperglycaemia, which are contributors to type 2 diabetes development.

Improvement in cognitive health

Cognitive deterioration as we age is associated with increased oxidative stress which results in damage. Adherence to a Mediterranean diet has been associated with a slower rate of cognitive decline and a lower risk of developing MCI (mild cognitive impairment), Alzheimer’s disease or dementia. These associations are thought to be a result of the high antioxidant concentration in a Mediterranean diet which work to neutralise the stress caused by oxidative free radicals.

Improvement mental health

The development of depression and the stability of mental health is multifaceted, and it is therefore difficult to build hypotheses of how nutrition may impact these factors. However, from research it has been suggested that the antioxidant and fibre content of a Mediterranean diet may have a positive impact on mental health. As with cognitive decline, antioxidants help to reduce oxidative stress. In regards to fibre, it is a great food source for our gut microbes which is thought to help to improve and maintain our microbiota-gut-brain axis.

The sustainability of the Mediterranean diet

Along with the health benefits, a Mediterranean diet is also associated with being more sustainable and environmentally friendly, a huge bonus for the planet conscious among us. Diet adherence has shown the following reductions:

  • Water footprint of between 19% and 43%

  • Greenhouse gases emissions by 72%

  • Land use by 58%

  • Overall energy consumption of 52%

  • Overall water consumption of 33%

 

Getting started with the Mediterranean diet

As previously mentioned, cost may be a barrier to implementing the Mediterranean diet, especially now with the rising cost of essentials. To get started, here is a list of easy and affordable store cupboard staples that could help you to incorporate Mediterranean eating.

  • Canned beans, lentils and chickpeas

  • Frozen fruit and vegetables

  • Olive oil

  • Wholewheat couscous, pasta and rice

  • Tinned sardines or salmon


Going forward

Living longer sounds great, but we all want to do it in the best physical and mental condition possible. The Mediterranean diet is not only associated with greater longevity but also with an improved quality of life and overall health as we age. Incorporating a more Mediterranean approach to food and cooking, may support our overall health as we age.

This blog post was written by Jessica Noon @noontrition, a master’s Dietetics student at Manchester Metropolitan University. Jessica holds a bachelor's degree in chemical engineering from The University of Sheffield and a postgraduate certificate in human nutrition from The University of Chester. Jessica has particular research interests in the areas of intuitive eating and gut health. Personally, Jessica loves to run and bake.

References: 

(1) AlAufi N. S., Chan Y. M., Waly M. I., Chin Y. S., Mohd Yusof B. N., Ahmad N., 2022. Application of Mediterranean Diet in Cardiovascular Diseases and Type 2 Diabetes Mellitus: Motivations and Challenges. Nutrients, 14(13), pp. 2777.

(2) Davis C., Bryan J., Hodgson J., Murphy K., 2015. Definition of the Mediterranean Diet; a Literature Review. Nutrients, 7(11), pp. 9139-53.

(3) A. Martínez-González M., Salas-Salvadó J., Estruch R., Corella D., Fitó M., Ros E., 2015. Benefits of the Mediterranean Diet: Insights from the PREDIMED Study. Progress in Cardiovascular Diseases, 58(1), pp 50-60.

(4) Schwingshackl L., Morze. J., Hoffmann G., 2020. Mediterranean diet and health status: Active ingredients and pharmacological mechanisms. Br J Pharmacol, 177(6), pp. 1241-1257.

(5) World Health Organization, 2019. Sustainable Healthy Diets: Guiding Principles. Food & Agriculture Organization.

(6) Yin W., Löf M., Chen R., Hultman C. M., Fang F., Sandin S., 2021. Mediterranean diet and depression: a population-based cohort study. Int J Behav Nutr Phys Act, 18(1), pp. 153.

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