The well-known Mediterranean diet, rich in fruits, olive oil, fish, vegetables, and nuts, has been the diet of choice for many for as long as most can remember. Over the years, many studies have linked the healthy diet to reduced risks of heart disease, including heart attack and stroke.
Now, the New England Journal of Medicine has retracted and replaced a study on the popular Mediterranean diet from 2013 due to concerns on how the study was executed after discovering errors that put into question the diet’s actual health benefits, reported NPR.
Although the diet garnered significant attention, and those who followed the diet were found to be healthier according to the study in 2013, the recent discovery shows that its been harder to link people’s lifestyles and food choices to the Mediterranean diet, especially after noticing randomization issues from when the study was first conducted.
According to NPR, the New England Journal of Medicine, one of the oldest and most prestigious peer-reviewed medical journals, was concerned with how the study was executed and chose to retract the paper after Dr. John Carlisle of Torbay Hospital in England began his own study on clinical trials and placed the Mediterranean diet on his list of questionable studies last year.
The Mediterranean diet’s study, which was originally conducted by Dr. Martínez-González and his team at the University of Navarra in Spain, evaluated more than 7,400 participants ranging from ages 55 to 80 and assigned them to one of three diets: the Mediterranean diet with at least four tablespoons of extra virgin olive oil per day; the Mediterranean diet with an ounce of mixed nuts; or a traditional low-fat diet.
It turned out that Dr. Carlisle’s suspicions were accurate and around 14 percent of the study’s participants hadn’t been assigned randomly to either diet, causing the study to lose its accuracy.
“This affected only a small part of the trial,” said Martínez González. “When the researchers reanalyzed the data excluding the nonrandomized people, the results were the same. Still, because everybody wasn’t randomly assigned to different groups, the study can no longer claim the diet directly caused those health benefits. We need to tone down the results, but it is just a little bit.”
However, the new study’s results aren’t that different from the 2013 study. The corrected study still proves that those who followed the diet had fewer strokes and heart attacks, but without crediting the diet as the only reason for those benefits unlike before.
As NPR reported, the results were fairly similar between both studies. The major difference between both studies was that the authors were careful in their choice of words when publicizing and touting the benefits of the diet and used “softer language” in comparison to the study in 2013. Still, most people will still likely recommend the diet as a healthy choice.
“I don’t know anybody who would turn around from this and say, ‘Now that this has been revealed, we should all eat cotton candy and turn away from the Mediterranean diet,” said David Allison, Dean of the School of Public Health at Indiana University, as reported by NPR.