Landmark Study Of Heart Benefits Of Mediterranean Diet Stirs Controversy
You can check out some Lebanese recipes and scientific information about the diet from Lecia’s Facebook Live. She was joined in the kitchen with the chef at Zaytoon Lebanese restaurant and a Cleveland Clinic nutritionist.
In the kitchen at Zaytoon Lebanese restaurant in downtown Cleveland, owner David Ina throws together a few simple ingredients into a blender to make hummus.
"So we’re making the batch of our traditional hummus," Ina says. "Tahini, which is a sesame seed paste, fresh pressed lemon juice, a little water, fresh garlic, and we get organic chickpeas."
For years, the diet packed with fresh vegetables, legumes, and plenty of olive oil - known widely as the Mediterranean diet - was considered one of the best out there for heart and overall health.
In 2013, a landmark study conducted in Spain known as PREDIMED claimed the diet reduced the risk for heart attack and stroke among those at high risk for such problems. The findings were based upon what is considered the gold standard of scientific research, the randomized controlled trial. The study randomly assigned people to one of three diets: a Mediterranean diet with extra-virgin olive oil, a Mediterranean diet with mixed nuts, or a low-fat control diet.
But that study was retracted last month, when data investigator John Carlisle came across errors in how the participants were assigned to different groups.
In "(a) randomized controlled trial, randomized means that the allocation of a participant to a group is not in the control of any of the investigators," Carlisle said. "It’s done usually based upon a computer program nowadays. So you don’t know, if you’re the investigator, which group the person in front of you is going to be allocated to. The balance of those different measurements of the three different diets wasn’t consistent with random allocation and that is the sort of study the PREDIMED study said it was. It said it had randomly allocated individual participants to different diets, and the data they provided suggested that wasn’t the case."
But even when the authors of the PREDIMED study adjusted for the errors and provided a corrected version, they still found an association between the Mediterranean diet and improved heart health. While some doctors remain skeptical, others say the Mediterranean diet is one of the most widely studied diets, with a large supporting body of evidence, says Dr. Haitham Ahmed, a cardiologist at the Cleveland Clinic.
"If this was just one novel finding, then yes this would raise concern for me," Ahmed said. "But this is now one of hundreds, if not thousands of studies on the Mediterranean diet. When you’re seeing a consistent effect across all components of the biological pathway, and they’re all in alignment, then it just makes sense."
The bottom of the Mediterranean food pyramid is whole grains, like whole wheat bread, pasta, brown rice. Then there’s fresh produce, fruits and vegetables. It’s suggested you eat dairy and cheese daily, but in moderation, and red meats and poultry are eaten even less frequently.
Olive oil is the base of daily dietary fat, which replaces butter. It’s the combination of these foods in the diet that may contribute to lowering cholesterol, Ahmed says.
"It’s less saturated fat, which is harmful, and it has more mono-unsaturated fat which comes from olive oil, which leads to less dangerous cholesterol and plaque buildup," Ahmed said.
Fresh Fruit and Vegetables Key to the Diet
Back at Zaytoon, cooks are chopping fresh parsley and vegetables in the kitchen as David Ina points to a photo of an orchard in his family’s village in Lebanon.
"So my dad worked these fields as a kid, picking apples and picking figs and different fruits and veggies," Ina said. "Those are my biggest takes from going to Lebanon: The food itself is delicious, everything there is natural and organic already."
It’s clear that there’s one thing about the Mediterranean diet that differentiates it from other recent diet fads: It’s hundreds, if not thousands of years old, a tried and true way of life, rooted in tradition rather than a modern-day fad.