The study, carried out on a population in the United Kingdom (UK), calculated an 11% reduction in risk in those who closely followed a Mediterranean-like diet when compared to those on a different diet.
Whilst the benefits of the low saturated fat, high fruit and vegetable diet have been extensively studied, its adoption in a culture unfamiliar of its core components has been less so.
According to Dr Nita Forouhi, study lead author from the Medical Research Council Epidemiology Unit at the University of Cambridge, UK, studying a British sample has indicated that it is possible to adopt elements of a Mediterranean diet,
“This can be achieved by increasing consumption of fruits and vegetables for example,” she said. “Individuals can still adopt a Mediterranean style diet, while still respecting local eating habits.”
“We did not investigate the factors that would make it easy or affordable to follow this type of diet in the UK. We need to acknowledge that there are cultural, economic and social factors that may either support or put people off from following it.”
The UK National Institute for Health and Care Excellence believes the Mediterranean-based diet may benefit people already diagnosed with cardiovascular disease, to prevent further cardiovascular episodes such as heart attack and stroke.
What is the Mediterranean diet?
The diet is typically high in the cereal, fruits, vegetables, legumes and olive oil content, low in red meats, and moderate in the consumption of fermented dairy products, fish, poultry and wine.
Med diet in the UK
The switch to a more fruit and vegetable-heavy diet may be of benefit to those living in the UK, where cardiovascular disease (CVD) accounts for around 155,000 deaths, or more than a quarter of all deaths each year. Healthcare costs for CVD are estimated to be €12.5bn (£11bn) per year.
Researchers from the university amassed information from 23,902 healthy individuals as part of the EPIC-Norfolk prospective cohort study.
Dietary habits were collected using food frequency questionnaires and individuals were followed up for approximately 12 to 17 years.
A Mediterranean dietary pyramid was then used by the team in which a 15 point score was adopted to define what constituted a Mediterranean diet.
They observed 7606 separate events of CVD (2818/100,000 person-years) and 1714 CVD deaths (448/100,000) within the study population.
“Our findings suggest that the MDS based on the Mediterranean dietary pyramid had the strongest associations with cardiovascular outcomes,” the study noted.
“We further estimated that 3.9 % of total CVD incidence, 8.5 % of IHD or stroke incidence, and 12.5 % of CVD mortality in the EPIC-Norfolk cohort could have been avoided by increasing adherence to the Mediterranean diet.”
The findings suggest that adherence to the diet may contribute to a viable measure that could effectively prevent CVD cases in the UK.
While the study is observational in nature, previous trials from randomised controlled trials in Mediterranean countries have shown a causal effect between the Mediterranean diet and CVD.
“There are huge costs and logistical challenges of conducting clinical trials of dietary factors,” said Forouhi.
“For now, our study adds to the body of evidence suggesting that the adoption of a Mediterranean-type diet may be one lifestyle strategy to help prevent CVD and improve health in the UK, alongside other lifestyle changes such as increasing physical activity and not smoking.”
Study reaction
Dr Ian Johnson, nutrition researcher and emeritus fellow at the Institute of Food Research, said: “Studies of this type can’t prove a causal link or show which aspects of the diet, such as low consumption of saturated fat, higher consumption of vegetables and grains, or high consumption of olive oil, are most important.”
“However that is probably the wrong question. It seems likely that the various components of this dietary pattern complement each other, but that is a matter for further research.”
Forouhi added to this, stating that it was the overall combination of the different dietary components in a Mediterranean-type diet that was beneficial for health, rather than any particular aspect of the diet.
“When we removed one diet component at a time from the Mediterranean diet score, the overall results were unchanged.”
“So what we really find is that the whole is greater than the sum of its parts. This highlights the importance of paying attention to the overall diet, instead of focusing on any one food group.”
Source: BMC Medicine
Published online ahead of print, DOI: 10.1186/s12916-016-0677-4
“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.”
Authors: Nita Forouhi et al.