What Can We Learn From the Mediterranean Diet?

The Mediterranean lifestyle features a food culture rich in flavour, colour and tradition, and is considered one of the healthiest dietary models in the world. It originates from the ancient civilisations of the Mediterranean Basin and is a largely plant-based diet abundant in fruit, vegetables, whole grains, olive oil, moderate fish consumption and relatively limited meat consumption. The Candidature Dossier submitted to UNESCO defines the Mediterranean Diet: “…from the Greek word “diaita”- lifestyle – it is a social practice based on all the “savoir-faire”, knowledge, traditions ranging from the landscape to the table and covering the Mediterranean Basin, cultures, harvesting, fishing, conservation, processing, preparation, cooking and the way we consume, i.e., conviviality” [1]. In other words, the Mediterranean diet is more than just a style of cooking, it is a way of life.

The medical world first drew attention to the Mediterranean diet in the 1950s following the work of American scientist Ancel Keys. He was intrigued by the fact that the deprived small-town populations of southern Italy were strikingly healthier than the wealthy inhabitants of New York City. This led to his famous Seven Countries Study [2], where he identified the correlation between diet and cardiovascular health and labelled saturated fats as the major dietary villain. This has stimulated a flurry of research into the effects of diet on health and has led to an overwhelming agreement about the health benefits of the Mediterranean diet. 

Mechanisms for the Health Benefits of the Mediterranean Diet

But what are the underlying mechanisms driving the reduction in obesity, diabetes, metabolic syndrome, and cardiovascular disease seen in the Mediterranean? Key to its success is the high levels of healthy unsaturated fats. Cholesterol levels are made up of harmful low-density lipoproteins (LDLs) and protective high-density lipoproteins (HDLs) and it is the ratio of HDL:LDL that contributes to cardiovascular health. A diet higher in unsaturated fats (eg. olive oil, nuts, oily fish) and lower in saturated fats (eg. butter, animal fat) increases the HDL:LDL, which is associated with lower inflammation and better cardiovascular health. 

There has been much interest in the effects of the Mediterranean diet on healthy ageing and cognitive function. On a biochemical level, ageing has been found to be driven by the shortening of telomeres, which are the end strands of DNA molecules. This can be accelerated by inflammation and cell stress, leading to shorter life expectancy and age-related diseases. A diet high in antioxidants such the Mediterranean diet can help to minimise this stress and damage; indeed, studies have shown that people following the Mediterranean diet have longer telomere lengths, thereby promoting longevity [3].

And what about wine, a distinguishing feature of many Mediterranean cultures? There has been an abundance of research into the health implications of wine, with many conflicting results. Alcohol is responsible for a significant disease burden globally. However, there is evidence to suggest that the high levels of certain compounds such as polyphenols in red wine have cardioprotective antioxidant effects [4].  The bottom line is: everything in moderation. A moderate and responsible consumption of wine with meals, about one to two glasses a day for men and one glass a day for women, can be part of a healthy diet. 

Further research, however, has demonstrated that the health effects discussed are not a result of diet alone, but of adopting the full Mediterranean lifestyle. This involves minimising the other major modifiable cardiovascular risk factors by carrying out regular physical exercise and avoiding cigarette smoking (admittedly still a major issue in many Mediterranean countries). Therefore, the Mediterranean diet is about balance – a balance between energy intake and expenditure, while featuring foods rich in fibre, antioxidants and healthy fats.

So, after overwhelming evidence about the far-reaching health benefits of the Mediterranean diet, why isn’t everyone adopting it? This nation’s diet is amongst the worst in Europe. In the UK today, 63% of adults are overweight, and of them half are obese. [5]. Equally worrying is the fact that 1 in 5 children in the UK live with obesity [6]. Obesity is linked with reduced life expectancy and increased risk of various chronic diseases, such as cardiovascular disease, diabetes, cancer, and has a severe impact on mental health. Research has shown that obesity can shorten a person’s life by up to 10 years, a loss equal to the effects of lifelong smoking [7]. Therefore, more than ever we need big changes to fix our broken food system, and consequently the health of the nation.  

Barriers to the Mediterranean diet in the UK

1. Physical barriers 

A major barrier, particularly during the colder months, is poor availability of much of the fresh food of the Mediterranean diet. The closing of local shops such as greengrocers and fishmongers and rise in more sporadic but larger supermarket sites has resulted in some neighbourhoods finding themselves in food deserts. Here, the remaining local shops offer only a very limited range of foods that do not provide the components of a balanced diet. Those people who do not have adequate mobility or transport to access the big supermarkets therefore do not have access to buying fresh, nutritious food. Various initiatives to expand local shopping facilities, food cooperatives, food-growing schemes and mobile shops have been successful but are limited to specific neighbourhoods.

2. Economic barriers

The cost of fresh food presents another barrier to access. Research has shown that healthier foods are up to three times the cost per calorie of unhealthy foods [8]. The Food Standards Agency has revealed there are an estimated 4 million people in the UK who cannot afford a healthy diet, with one in seven people over the age of 65 at serious risk of malnourishment [9]. There is a need, therefore, for more government policies to subside the cost of healthier and nutritional foods through tax on unhealthy foods. The soft drinks industry levy (‘sugar tax’) implemented in the UK in 2018 is an example of a successful policy in reducing obesity levels in primary school children [10]. However, there should be policies to extend this to high-salt, high-fat or ultra-processed foods.

3. Educational barriers

Limited health literacy, an issue particularly in lower socioeconomic areas, can obstruct people from making positive dietary choices. There is a large variation in the implementation of the cooking and nutrition curriculum in UK schools. In over 50% of primary schools, children fail to receive 10 hours of food and nutrition education per year, while 10% of schools receive more than 30 hours [11]. This disparity is largely due to lack of support and resources for teachers, an issue more prominent in poorer socioeconomic areas. This disparity in food education and cooking skills may explain some of the national health inequalities we see linked to poor diet. 

4. Social/cultural barriers 

Some may also attribute poor dietary habits in the UK with people’s cultural relationship with food, in their eating and cooking habits. France, for example, is a geographically similar country to the UK but with a clear difference in how it embraces food. The value of the art of the table, association of meals with good company and sharing of food, cultivates a positive attitude towards cooking and eating. From a young age, children in France are encouraged to be interested in food. France celebrates an annual ‘Semaine du Goût’ – Week of Taste – which focuses on educating children about food and balanced diet. One of the reasons for France having one of the lowest obesity rates in Europe is the widespread positive cultural attitude towards food preparation and quality time spent eating together. Perhaps the UK would benefit from initiatives which aim to inspire interest in food and nutrition from a young age. 

Current and Future Interventions 

Current initiatives to tackle barriers to achieving a healthy diet include public information campaigns, such as 5-a-day, which encourages and informs people about healthy living through realistic targets and simple messaging. Many of the campaigns also aim to improve health literacy among children. These are particularly powerful, as negative dietary habits and their associated health risks can be compounded over a lifetime. Improving cooking skills in both children and adult populations is equally important in supporting a healthy diet. Local projects such as community kitchens are effective ways to boost confidence in cooking and thereby strengthen healthy eating habits. Doctors can often feel nutritional education lies outside of our remit. However, this is an aspect of patient care in which we can lead by example, such as through the creation of GP based community kitchens.

Food provision in the UK public sector needs tighter regulations. For example, the NHS is one of the country’s largest food providers, yet hospital food has a negative reputation for being unhealthy and poorly-prepared. The Department of Health in 2014 recommended setting standards for NHS food, but this has not been routinely monitored [12]. 

Unhealthy food is not only inexpensive but aggressively marketed in the UK. There is a need for stricter rules over the media advertising of high-fat and high-sugar foods, especially on platforms accessed by children. Some local authorities including Bristol and Transport for London have already begun to restrict the advertisement of junk food in council-owned spaces [13], however UK-wide policies would have a much greater impact. Moreover, to facilitate people in making healthier food choices, there is a need for clear labelling of the contents and ingredients of food. The food ‘traffic light’ system is an example of nutritional labelling that has been effective in the UK, however other countries have taken this a step further. In 2016, Chile was the first country to introduce a front-of-packet warning sign for any foods high in salt, sugar or saturated fats, which in turn led to a reduction in the purchasing of these foods [14]. Perhaps the UK should follow in Chile’s footsteps.

It is time to reshape our food culture. It is time to move away from ultra-processed, sugary, low-fibre foods and incorporate the freshness, seasonality and variety of food celebrated by the Mediterranean diet into our own. However, current strategies to do so are often biased towards emphasising individual responsibility rather than creating supportive environments that improve access to and normalise healthy diets. A healthy diet is not a lifestyle choice, it is a right.

References

1. La Diète Méditerranéenne 2010. Candidature transnationale en vue de l’inscription sur la Liste Représentative du Patrimoine Culturel Immatériel de l’Humanité. Espagne / Grèce / Italie/Maroc, Version Informations Additionnelles.
2. Keys A, Aravanis C, Blackburn H, Buzina R, Djordjevic BS, Dontas AS et al. Seven Countries: A Multivariate Analysis of Death and Coronary Heart Disease. Cambridge, MA: Harvard University Press; 1980
3. Crous-Bou M, Fung TT, Prescott J, Julin B, Du M, Sun Q et al. Mediterranean diet and telomere length in Nurses’ Health Study: population based cohort study. British Medical Journal; 2014; 349:g6674.
4. Kim JH, Auger C, Kurita I, Anselm E, Rivoarilala LO, Lee H.J et al. Aronia melanocarpa juice, a rich source of polyphenols, induces endothelium-dependent relaxations in porcine coronary arteries via the redox-sensitive activation of endothelial nitric oxide synthase. Nitric Oxide-Biol. Chem. 2013;35:54–64. 
5. NHS Statistics on Obesity, Physical Activity and Diet, England, 2020. https://digital.nhs.uk/data-and-information/publications/statistical/statistics-on-obesity-physical-activity-and-diet/england-2020/part-3-adult-obesity-copy [Accessed 14/01/2024]
6. National Child Measurement Programme, England 2018/19 School Year, NHS, 2019. https://digital.nhs.uk/data-and-information/publications/statistical/national-child-measurement-programme/2018-19-school-year [Accessed 14/01/2024]

7. Lung T, Jan S, Tan EJ, Killedar A, Hayes A. Impact of overweight, obesity and severe obesity on life expectancy of Australian adults. Int J Obes (Lond). 2019 Apr;43(4):782-789.
8. Jones, Nicholas RV, Annalijn I. Conklin, Marc Suhrcke, and Pablo Monsivais. The growing price gap between more and less healthy foods: analysis of a novel longitudinal UK dataset. PLoS One 9, 2014 (10): e109343
9. Francis-Devine B, Malik X, Danechi S, Food poverty: Households, food banks and free school meals, House of Commons Library, 2023
10. Rogers NT, Cummins S, Forde H, Jones CP, Mytton O, Rutter H et al. Associations between trajectories of obesity prevalence in English primary school children and the UK soft drinks industry levy: An interrupted time series analysis of surveillance data. PLoS Med. 2023 Jan 26;20(1):e1004160. 
11. JOFF (Jamie Oliver Food Foundation). 2017. A Report on the Food Education Learning Landscape. https://www.akofoundation.org/wp-content/uploads/2017/11/2_0_fell-report-final.pdf [Accessed 14/01/2024]

12. Department of Health (2014) The Hospital Food Standard Panel’s report on standards for food and drink in NHS health. DH. https://www.gov.uk/government/publications/establishing-food-standards-for-nhs-hospitals [Accessed 14/01/2024]

13. Scott LJ, Nobles J, Sillero-Rejon C, Brockman R, Toumpakari Z, Jago R et al. Advertisement of unhealthy commodities in Bristol and South Gloucestershire and rationale for a new advertisement policy. BMC Public Health. 2023 Jun 5;23(1):1078. 
14. Taillie LS, Bercholz M, Popkin B, Reyes M, Colchero MA, Corvalán C. Changes in food purchases after the Chilean policies on food labelling, marketing, and sales in schools: a before and after study. Lancet Planet Health. 2021 Aug;5(8):e526-e533.