You may have heard of the Mediterranean diet. It came to light some 50 years ago, when researchers attributed the very low rates of heart disease in men on the Greek island of Crete to their traditional diet, as well as the hard outdoor work they did. Since then, many other studies have demonstrated links between the Mediterranean diet and various health benefits.
Earlier this year, a very large study done in Spain (the PREDIMED trial) found a 30% reduction in major cardiovascular events (heart attacks and strokes) in people who had risk factors like obesity, diabetes and smoking, if they followed a Mediterranean diet. Their diets included either four tablespoons of extra virgin olive oil a day or one ounce of nuts a day. The control group ate their usual diet.
But let’s take a step back: what are the basic components of a Mediterranean diet, aside from the olive oil or nuts, that the study participants were told they had to eat? At least three ½ cup servings of fruit and two of veggies each day, fish and beans at least three times a week, no red meat, and seven glasses of wine a week with meals if they drank.
The study didn’t restrict calories. Also, interestingly, the amounts and types of fat that the groups, including the control group, consumed turned out to not be all that different. This was Spain, after all! They all used olive oil. The group that ate the nuts had a little more of the “good” omega-3 polyunsaturated fats, and the group that had the extra olive oil had a little more “good” monounsaturated fat. But the differences there weren’t huge.
So, what made such a big difference in rates of heart attacks and strokes that the researchers stopped the study early, judging it unethical not to let the control group eat the diet that the other two groups were eating?
Well, the study didn’t tell us what it was about the diet that caused the big difference. Nonetheless, nutrition professionals have a “gut” feeling.
Here’s how we think about it: The Mediterranean diet isn’t the only healthy diet in the world. Many traditional diets have kept people healthy, although they haven’t all been rigorously tested like the Mediterranean diet. For instance, the Japanese have the longest life expectancy in the world, and they consume little to no olive oil or red wine. What all healthy diets have in common is that they are mostly plants, with small amounts of meat, and almost no processed foods. They are also based on foods that are native to the region.
So no matter which nourishing food tradition you choose, stick to one simple, central tenet: Eat mostly foods that look similar to how they looked when they came from the plant or animal that gave them to us to eat (of course, emphasizing plants over animals!). If you can’t easily identify what living thing that food came from, give it a pass. Example: Blueberries come from blueberry bushes, possibly right here in Vermont. But where do Twinkies come from? There are no Twinkie trees!
Maryann Ludlow, RD, CD, CDE is a registered dietitian at the UVM Medical Center.