Britons eating a Mediterranean diet could lower their risk of developing cardiovascular disease including conditions such as heart attack and stroke, according to research published today in the open access journal BMC Medicine.

In this study, the first of its kind carried out in a UK population, the researchers found that healthy individuals with greater adherence to a Mediterranean-type diet had about an 11% lower risk of future cardiovascular disease compared to individuals who had poor adherence. The work was led by PhD student Tammy Tong, together with colleagues Dr Fumiaki Imamura, Professor Nicholas Wareham, Professor Kay-Tee Khaw, and Dr Nita Forouhi.

Dr Nita Forouhi, lead author from the Medical Research Council Epidemiology Unit at the University of Cambridge, UK, said:

We estimate that one in 25 of all new cardiovascular disease cases or one in eight cardiovascular deaths in our UK based study population could potentially be avoided if this population increased their adherence to the Mediterranean diet.”

The Mediterranean diet is typically high in fruits, vegetables, whole grains, nuts and olive oil, while low in red meats and moderate in dairy, fish, poultry and wine. The UK National Institute for Health and Care Excellence recommends a Mediterranean based diet for people already diagnosed with cardiovascular disease, to prevent further cardiovascular episodes such as heart attack and stroke. However, until now the association of the Mediterranean diet with both preventing the disease occurring in the first instance and preventing further cardiovascular episodes has not been examined in the UK.

Dr Forouhi adds:

The benefits of the Mediterranean diet for cardiovascular health are well documented in countries of the Mediterranean region, but this is the first study to evaluate this in the UK. If our findings are broadly representative of the overall UK population, then we can assume that higher level of adherence to the Mediterranean diet could have significant impact in lowering the cardiovascular disease burden in the UK.”

The researchers collected data from 23,902 initially healthy Britons taking part in the EPIC-Norfolk prospective cohort study. The participant’s diets were measured using food frequency questionnaires and participants were followed up for an average of 12 to 17 years to investigate the association between adherence to the Mediterranean diet and the occurrence of new-onset CVD and deaths during that time.

The Mediterranean diet was defined using a 15 point score based on guideline recommendations from a Mediterranean dietary pyramid published by the Mediterranean Diet Foundation. This is the first time these guidelines were tested for their associations with health. There are other definitions of what constitutes a Mediterranean diet, but when alternative definitions were used in this study, the findings were broadly similar. In the study population of more than 23,000 adults, the lowest score was 3.2 and the highest score was 13.1, with half the population having a score below 8.4, highlighting the variable degree of adherence to this type of diet in a UK population.

Dr Forouhi adds:

Encouraging greater adoption of the Mediterranean diet looks like a promising component of a of a wider strategy to help prevent cardiovascular disease, including other important factors such as not smoking and maintaining a healthy weight, blood cholesterol and blood pressure.”

The authors acknowledge that these findings are based on an observational study and so a cause and effect relationship cannot be assumed. However, they were careful to make comprehensive adjustments for lifestyle and other factors that could potentially distort the findings, and together with the consistency of results with other studies elsewhere their current findings provide robust evidence for a link. Dr Forouhi concludes:

Our study shows that higher versus lower adherence to a Mediterranean-type diet is linked with lower future CVD risk in the UK but our challenge now is to understand the social, economic and cultural factors that might support or prevent people being able to keep to this dietary pattern in the UK.

• Paper: Tammy Tong, Nicholas Wareham, Kay-Tee Khaw, Fumiaki Imamura, Nita Forouhi Prospective association of the Mediterranean diet with cardiovascular disease incidence and mortality and its population impact in a non-Mediterranean population: the EPIC-Norfolk Study BMC Medicine; 29 September 2016; DOI:10.1186/s12916-016-0677-4

Note on the EPIC Norfolk Study

The European Prospective Investigation of Cancer (EPIC) began as a large multi-centre cohort study primarily looking at the connection between diet, lifestyle factors and cancer, although the study was broadened from the outset to include other conditions. EPIC was designed to be a long-term study, following a large number of people over many years. EPIC-Norfolk is part of a Europe-wide programme, which is described on our international page.

With the help of over 30,000 people living in Norfolk, EPIC-Norfolk aims to provide data-based evidence for health policies to prevent or delay disease onset and maintain health and independence in older people. To achieve this goal, it is trying to understand the factors that are most often present when people stay healthy and also factors more likely to be present should they develop a particular health condition or disease.

EPIC-Norfolk participants are men and women who were aged between 40 and 79 when they joined the study and who lived in Norwich and the surrounding towns and rural areas. They have been contributing information about their diet, lifestyle and health through questionnaires and health checks over two decades.

EPIC-Norfolk is led jointly by Professor KT Khaw (Clinical Gerontology Unit, University of Cambridge) and Professor Nick Wareham (MRC Epidemiology Unit).