I went grocery shopping over the weekend and if you knew anything about my normal eating habits, you would have been rather surprised by the things I brought home with me: tons of fruits and vegetables, a huge bag of potatoes, shrimp, haddock, whole grain bread, nuts galore, yogurt, and even a little granola. I don’t think there was a single stick of butter in the entire lot. This all happened because I was drastically impressed by a conversation I had with Northeastern professor of nutrition, Katherine Tucker.

I asked her to talk to me about the results of a new study from her colleagues at the University of Navarra in Spain, which, as you probably heard from significant reporting on the subject last week, validated the positive health effects of the so-called “Mediterranean diet.” They published their results in the New England Journal of Medicine, putting a signed, sealed, and delivered stamp on something we’ve been pretty sure about for a while.

“What’s unique about it is that it’s a real, sufficiently powered longitudinal study,” said Tucker. “It’s not just observational, but a randomized trial.” The study authors randomly assigned people from a range of demographics to one of three groups — the participants either ate a low fat diet or a traditional mediterranean diet for a period of eight years. Both groups were provided considerable support from nutrition counselors. The Mediterranean diet group was split further into two groups, one that ate more nuts than the others and one that used more olive oil. The study authors did this in order to tease out the effects of different beneficial compounds found in the two ingredients. Both of the MeDiet groups (as the researchers called them) had significantly fewer cardiovascular events than the low-fat group.

“It’s a big deal,” said Tucker. “It’s just stronger scientific evidence that the Mediterranean diet is important and that it does work.” So what kind of data did we have before? The observational kind that Tucker mentioned above. In studies like her own Puerto Rican Health Study, researchers have tracked the eating patterns of large cohorts of people over long periods of time. They’ve noticed that those who follow the traditional diet eaten in places like Spain, Italy, and Greece have overall better health. They get less cancer, they have better cognitive function, and have fewer heart attacks. But these studies aren’t controlled or randomized, meaning that a lot of other factors — like exercise or genetic makeup — could be playing a role in the outcomes. This is the first time those observations were backed up by a randomized trial, considered by many to be the gold standard for research.

It’s also notable that the low-fat group had a much harder time sticking to the protocol. So much so that the study authors had to reconfigure the design. But the MeDiet groups had much better compliance. Why? Because everything in the Mediterranean diet is so delicious! You get to eat bread dripping in olive oil with a nice glass of Sangiovese to wash it down.

“It is based on good quality, whole foods and a balanced dietary pattern that evolved over the millennia. And it seems to agree with our bodies,” said Tucker. “It’s anti-inflammatory, it has a balance of nutrients, it doesn’t include too many refined carbohydrates, it’s not too high in saturated fat. It’s just a real balanced diet.”

So it turns out that part of the solution to the biggest health challenge of our time has been staring us in the face for centuries. Low fat diets aren’t the answer, said Tucker, because they’re so hard to stick to and they don’t provide all the nutrients we need. Same goes for any other kind of diet the excludes a major subset of nutrients that our body needs to be healthy, like high protein or low carb diets.

Tucker is on the advisory committee for the African Heritage & Health program of Oldways, a nonprofit food and nutrition education organization whose mission is to guide people to good health through heritage. The group has long touted the benefits of traditional diets, including those of both Mediterranean and African heritage among others.