For years, the Mediterranean diet has been applauded for its health benefits. But a study published Monday in the International Journal of Epidemiology made some interesting findings about the disconnect in who reaps the benefits of the diet. Specifically, the study found those with higher education or more income benefit from the diet, which reduces the risk of cardiovascular issues.
Mediterranean diets focus on consuming plant-based foods like veggies, nuts, whole grains, and fruits. For non-vegetarians, fish and poultry are recommended with less of an emphasis on red meat. It also calls for swapping in olive oil for other oils and butters.
Marialaura Bonaccio, lead author of the new study and a researcher at IRCCS Istituto Neurologico Mediterraneo Neuromed in Italy, looked at over 18,000 subjects living in southern Italy and followed the participants over the course of five years. The team gathered an array of data: physical activity, body mass index (BMI), smoking status, health history, education, household income, and marital status.
After analyzing the data, researchers found a higher socioeconomic status to be indicative of the health effects of a Mediterranean diet. Specifically, the heart-healthy benefits seemed to only apply to those with a college education or earning more than 40,000 euros (about $47,000 at 0.84 euro to the dollar) a year.
"The cardiovascular benefits associated with the Mediterranean diet in a general population are well-known," Bonaccio says in a statement. "Yet 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 of a person with higher income, despite the fact that they both similarly adhere to the same healthy diet."
Why does this disparity exist? Bonaccio tells CNN diets — not just the Mediterranean diet — "focus on quantity, rather than on quality" of food. Those with higher education or greater income presumable have access to higher-quality food.
"You can buy the two- to three-euro bottle [of olive oil] or you can have a 10-euro bottle," Bonaccio tells Scientific American. "Probably these two bottles are different in their nutritional contents — in the context for example of polyphenols or other nutritional compounds."
Should food quality really be the culprit behind the socioeconomic disconnect, then it is likely that a similar gap exists in all diets, not just Mediterranean ones. The findings of this study spotlight the importance of looking into how food quality (and socioeconomics) factor into other diets and whether diets should place a higher emphasis on food quality.