Mediterranean diet reduces risk of heart disease but only for the rich and educated

Adhering to the Mediterranean diet reduces your risk of cardiovascular disease, but only if you are part of higher socioeconomic groups, scientists have found.

In recent years, multiple studies have provided evidence of the benefits of the Mediterranean diet. Characterised by a high consumption of vegetables, fruits, fish and olive oil and a low consumption of meat, this diet has indeed been associated to a reduced risk of cardiovascular problems, cancer and neurodegenerative diseases.

Diet however is tightly connected to people's socioeconomic status, and less advantaged groups tend to report lower adherence to healthy dietary patterns.

In the study, published in the International Journal of Epidemiology, researchers investigated how differences in people's level of education and income is linked to their dietary patterns and risk of suffering from cardiovascular problems.

The researchers analysed the data of 18,991 adults aged 35 years or older and part of an Italian cohort. They looked at their household income and education level as indicators of their socioeconomic status. The Mediterranean diet score – ranging from 0 to 9 to indicate compliance – was also assessed.

The follow-up lasted 4.3 years, during which 252 cardiovascular disease events were reported among the participants. The scientists' analyses confirmed that adhering to the Mediterranean diet was associated with a lower risk of cardiovascular disease, but these benefits appeared to be influenced by people's socioeconomic status.

Comparing people who adhered similarly to the Mediterranean diet, the scientists found a reduction in cardiovascular risk only in those with higher educational level and/or greater household income.

This may be because there is a great diversity of products belonging to the Mediterranean diet, and substantial differences in consuming these products. The study revealed for example that people with higher income consumed products richer in antioxidants and polyphenols, and also had a greater diversity in fruit and vegetables choice. Those in the lower socioeconomic groups were potentially more likely to buy 'Mediterranean' food with lower nutritional value

Cooking methods also differed widely, potentially explaining the differences between people who adhered strictly to the same diet.

"For the first time our study has revealed that the socioeconomic position is able to modulate the health advantages linked to Mediterranean diet. In other words, a person from low socioeconomic status who struggles to follow a Mediterranean model, is unlikely to get the same advantages as a person with higher income, despite the fact that they both similarly adhere to the same healthy diet," said first author Marialaura Bonaccio, researcher at the Department of Epidemiology and Prevention in Italy.

Designing public health strategies

As a result, the scientists believe that it is urgent to design public health strategies that address the widening disparities between people in accessing healthcare, including differences in accessing healthy diets.

"This study highlights the need to address socioeconomic disparities in health by more targeted and effective strategies that facilitate those most in need, be able to access foods with higher nutritional values and thereby adopt healthier eating patterns, and have better health outcomes," Clare Collins, Professor in Nutrition & Dietetics at the University of Newcastle (Australia), who was not involved with the study, told IBTimes UK.

Before this can happen however, more research on the topic will probably needed to address some of the limitations of this particular study, which some researchers argue lack statistical power.

"A limitation of the study is the relatively small number of deaths 252 out of 18,991 men over 4.3 years which is only 0.3% per year. This is because the average age was relative young around 53 - most CVD events over the age of 60. Many cases of premature cardiovascular death (CVD) are linked to smoking, high blood pressure and inherited high blood cholesterol (which is not affected much by diet). There was only a difference of 11 cases of CVD between high and low adherence to the Mediterranean diet which could be a statistical fluke," Thomas Sanders, Emeritus Professor of Nutrition & Dietetics at King's College London, told IBTimes UK.