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A Hugely Influential Study on the Mediterranean Diet Was Just Retracted

Photo: Maren Winter /Getty Images/iStockphoto

In 2013, the Mediterranean diet got an incredible vote of confidence from a study published in the New England Journal of Medicine, which found that the diet cut people’s risk of heart disease by 30 percent. That’s interesting(ish) enough on its own, but the real attention-grabbing piece of it was this: The link between the Mediterranean diet and heart health was so obvious that the researchers stopped their study early. And this is one delicious diet, by the way, including up to seven glasses of wine a week. It sounded too good to be true.

Maybe it was. Earlier this summer, the NEJM retracted the study, citing problems with the randomization process — and that matters, because randomization is what allows researchers to draw a clear line between cause and effect. Following the retraction, the study authors in June published a new study drawing the same conclusion, but using softer language around the cause-and-effect factor. People who followed the Mediterranean diet did indeed see their risk for heart disease drop, but it’s not necessarily clear that the diet was responsible for this improvement.

That said, with its emphasis on healthy fats and fresh produce, the diet itself still makes good nutritional sense. “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,’” David Allison, dean of the School of Public Health at Indiana University in Bloomington, told NPR. Now that you’re all caught up on the scandal within the nutrition science community, this seems like a good time learn more about the diet that started at all.

So what are the basics?

Despite the retracted study, the core tenets of the Mediterranean Diet remain the same. The goal is to mimic the traditional lifestyle and dietary habits of the people living in Mediterranean countries such as Greece and Spain. The Mayo Clinic lists the following as the eight key components of the diet:

• Eating primarily plant-based foods, such as fruits and vegetables, whole grains, legumes, and nuts.
• Replacing butter with healthy fats such as olive oil and canola oil.
• Using herbs and spices instead of salt to flavor foods.
• Limiting red meat to no more than a few times a month.
• Eating fish and poultry at least twice a week.
• Enjoying meals with family and friends.
• Drinking red wine in moderation, (though this is optional).
• Getting plenty of exercise.

Do experts still recommend it?

Yes! “If you look at the total body of evidence around it, then it’s kind of like … one piece of a puzzle,” Dr. Richard Bazinet, an associate professor of nutritional sciences at the University of Toronto, said of the retracted study. If you take that one puzzle piece out, does all the established evidence disappear? Not necessarily. “I still think people would say this has got some fairly strong evidence,” he said. It’s hard to argue with a diet that’s high in things like fresh fish, nuts, and olive oil, and lower in things like red meat, he added.

What are the benefits?

For starters, the increase of olive-oil consumption that the diet calls for has been linked to a decrease in your risk of contracting breast cancer. Other foods encouraged on the diet — like berries, garlic, and onion — have also been shown to reduce cancer risk. Beyond that, the National Institute of Health reports the omega-3 fatty acid in fish boosts function in the brain and in the immune system. And, by the way, you also might be interested in this: A recent study published in The Journal of Clinical Endocrinology & Metabolism showed that higher seafood intake can increase sexual desire and fertility. Altogether, it’s a combination of foods that just works well together. “They each do a little something — lower your cholesterol, blood pressure, and maybe inflammation,” says Dr. Bazinet. “When you add them up, it works. It is the opposite of a superfood. I worry that people eat a ‘superfood’ and a bad diet and get nowhere. Here is a lot of little steps in the right direction.”

But beyond the individual elements of the diet, it’s a flexible way of eating, which means it’s easier to personalize (which means it’s easier to stick to). “It’s based on more fruits and vegetables, more plant-based products, a little more fish a little bit of [nuts], some olive oil, [and] some wine,” Bazinet said, but “you don’t have to do it all at once. You’re allowed to say, ‘I don’t like that’ and take that part out. It’s kind of nice in that way, it’s got some flexibility.”

Okay, but what can’t you eat?

While the diet does involve a fair amount of flexibility, it does encourage you to stay away from processed foods and most animal fats.

Who should consider it?

Honestly? Just about everybody, said Dr. Bazinet. “I can’t think of anybody that [would be] negatively impacted by this diet,” he said.

How do you get started?

Dr. Bazinet recommends easing your way in. “It’s going out to some nice boutique shops trying some nice extra virgin olive oils, getting a feel of which one you really like buying, starting there,” he suggests. “And then going around trying some nuts that you might like. Try some olives. Go see a fishmonger and see what kind of fish is readily available right now. [Take it] one step at a time.” Not a bad diet, as diets go.

A Big Study on the Mediterranean Diet Was Just Retracted