The so-called “Mediterranean diet” ― rich in fruits, vegetables, fish and whole grains ― is world-famous as a heart-healthy food regimen, but according to a new study, it may only provide cardiovascular advantages to the wealthy and highly educated.
Researchers examined 18,991 participants ages 35 and older from the Malise region of southern Italy, and found that for the population as a whole, eating a Mediterranean diet lowered the risk of developing cardiovascular disease by 15 percent over the course of four years.
Yet when the researchers examined different groups within that population, those cardiovascular benefits only applied to people earning more than 40,000 euros per year (about $47,000) or for those with post-secondary education.
“For the other socioeconomic groups, no benefits associated with the Mediterranean diet were observed,” Marialaura Bonaccio, lead study author and researcher at IRCCS Istituto Neurologico Mediterraneo Neuromed told HuffPost. “This was an impressive result indeed.”
A possible explanation for the finding could be that people observe the Mediterranean diet to different degrees, Bonaccio hypothesized. In the study, richer and more educated people were more likely to report eating a wide variety of fruits and vegetables, to prefer whole-grain bread, and to cook using healthy methods such boiling and stewing instead of frying, roasting or grilling.
“This disparity seems to be driven by the fact that those in the higher socioeconomic status consumed a higher amount of whole grains, organic foods, MUFAs [monounsaturated fatty acids], vitamin D, calcium, fiber, polyphenol and antioxidants,” said James DiNicolantonio, a cardiovascular research scientist at Saint Luke’s Mid America Heart Institute and author of The Salt Fix, who was not associated with the study.
Bonaccio and DiNicolantonio both cautioned that the observational study could not prove that socioeconomic status affected heart health, but did reveal a relationship between the two.
Improving Access To A Variety Of Healthful Foods
The study adds to an existing body of research linking lower socioeconomic status to poorer health.
A lack of access to stores with healthy foods and a lack of time to prepare them are both potential barriers to healthy eating. So is price. Since high-quality Mediterranean foods are expensive, it can be harder for low-income people to incorporate a wide variety those foods into their diets.
To improve access, Bonaccio suggested reducing taxes for the highest-quality Mediterranean foods (olive oil of dubious origin should carry a higher tax than extra-virgin or certified olive oil, she suggested).
Bonaccio also pointed to the importance of nutrition education.
“Everyone is likely aware that eating fruits and vegetables is good for health, but few may know that variety in such foods may be as important as quantity,” she said.
Since the research, like many nutrition studies, relied on diet recall, its conclusions also depend on how honest or accurate participants were about their eating habits.
“It is generally very difficult for people to keep accurate food records, and there is a tendency for participants to record their diets in the best possible light,” Dr. Barbara Berkeley, a weight management expert who practices medicine in Beachwood, Ohio, told CNN.
Still, she supported the study’s findings. “A healthy diet is likely not the sum of its parts but the quality of its elements,” Berkeley said.
The study was published in the International Journal of Epidemiology on July 31.