Mediterranean diet study short on details
DEAR DOCTOR: A recent study found that rich people benefit more from the Mediterranean diet than poor people. What gives?
DEAR READER: The Mediterranean diet cuts out refined and processed foods, unhealthy fats and limits sugar. Instead, the emphasis is on a variety of fresh fruits and vegetables, leafy greens, nuts, legumes, unrefined grains and cereals, olive oil and modest consumption of fish, lean meat and dairy products. Past studies have tied the diet to improved cardiovascular health, lower cancer risk and increased longevity.
So when researchers in Italy analyzed four years of self-reported dietary data from 19,000 women and men, they weren’t surprised that those who followed the Mediterranean diet had a lower incidence of heart problems.
But there was a catch. After the participants were further sorted according to levels of income and education, the benefits of the diet were not universal. People with lower income levels didn’t show a reduction in cardiovascular risk. Digging deeper, the researchers learned that while everyone in the study adhered
to the basic principles of the Mediterranean diet, when it came to the specific foods being eaten, marked differences emerged. That’s where education comes in.
According to the study, participants with more education ate the widest range of fruits and vegetables. Individuals with higher income levels ate the most nuts, whole grains, fresh fruits and fish. The diets of those on the lower end of the education and income scale included more meat, less fish, less variety in fruit and vegetable choices, and cooking methods that were less healthful.
The authors acknowledge the pitfalls of drawing conclusions from studies with self-reported data. At the very least, when it comes to the health outcomes of the Mediterranean diet, details matter. And in the bigger picture, the differences in income and education meant everyone in the study wasn’t on the same diet after all.
Elizabeth Ko, M.D., is an internist and primary care physician at UCLA Health.
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