The health benefits of the Mediterranean diet are well documented but up until now most research has looked at its effect on the general population which tends to be made up of healthy people.
“What happens to people who have already suffered from cardiovascular disease? Is the Mediterranean diet optimal for them too?" asked Professor de Gaetano, head of the department of epidemiology and prevention at the Italian Neuromed Institute, at the European Society of Cardiology (ESC) congress on Sunday.
Researchers led by Gaetano looked at data from the Moli-Sani cohort which collected data from 25,000 individuals living in the Molise region.
Among these, researchers identified 1,197 people who had a history of cardiovascular disease, such as coronary heart disease and stroke.
By tracking food intake by using a food frequency questionnaire (developed by EPIC, the European Prospective Investigation into Cancer) and gathering data on all-cause deaths from local vital statistics offices, the team of researchers calculated that for individuals with a higher adherence to the Mediterranean diet, death from any cause was reduced by 37% in comparison to those with poor adherence.
Meanwhile, a two-point increase in adherence to the Mediterranean diet was associated with a 21% reduced risk of death once controlling for factors including age, sex, energy intake, education, smoking and leisure time.
The secret to success
Many components of the Mediterranean diet have been identified as contributing to its health halo, such as the importance given to eating together as a family and strict adherence to regular meal times with little snacking in between compared to northern European countries.
But according to the Neuromed researchers its biggest impact comes from its heart-healthy ingredients, in particular vegetables, fish, fruit and nuts and olive oil, high in monounsaturated, whcih all help reduce chronic inflammation.
"Although the basic physiopathological and biochemical mechanisms of protection remain to be elucidated, we believe that low-grade inflammation - a parameter related to mortality in our population - could be blunted by the Mediterranean-style eating," lead author of the research Dr Marialaura Bonaccio told FoodNavigator.
Don't ditch diet for drugs
Bonaccio said the study's findings meant that people with cardiovascular disease should be advised on the beneficial health effects of a healthy diet such as the Mediterranean one, and healthcare professionals should consider diet along with drug prescription.
"Of course diet should be the very first action of prevention and governments should seriously make an effort in order to guarantee to all an appropriate access to healthy diets. For instance, VAT on fruits and vegetables could be considerably reduced."
Despite these benefits, Bonaccio said there has been a general gradual shifting away from the Mediterranean diet in recent years.
"A dramatic drop was recorded since 2007, the period when the global economic crisis [occurred], with prevalence of high adherence falling from over 30% to 18% in the whole population recruited in the Moli-sani study.
"We also documented that financial resources have become strong determinants of the adherence to this dietary pattern just after the recession started in 2007-2008, while they had no or limited role in the previous years," she added.
"Good dietary habits are [also] strongly patterned according to socioeconomic position with the more disadvantaged reporting difficulties in following a Mediterranean-type diet. Such findings may be related either to the highest cost of healthy foods, for example fresh fish, or to the fact that healthy diets are generally time-consuming.
"Whatever the reason, people deserve an equal access to health independently from their socioeconomic status. This is a major challenge our societies are called to deal with."
Source: European Heart Journal
Poster presented at the European Society of Cardiology Congress 2016
“Higher adherence to Mediterranean diet is associated with lower risk of overall mortality in prospective results from the MOLI-SANI study”
Authors: Bonaccio, A. Di Castelnuovo, S. Costanzo, M. Persichillo, M.B. Donati, G. De Gaetano, L. Iacoviello