If you’ve followed the headlines, you know that the Mediterranean diet has been associated with a range of health benefits. The recent PREDIMED study, conducted by university researchers, hospital clinicians, primary-care physicians, nutritionists and epidemiologists in Spain, has linked it to reduced risks of heart disease and cognitive decline. Other studies have suggested preventive benefits against certain cancers, diabetes, Parkinson’s disease and depression.
So it may surprise you to learn that there’s no such thing as an official Mediterranean diet—not in the sense that there’s a South Beach or Zone or Atkins diet. The dietary plans tested in recent studies showing the benefits of the Mediterranean diet vary widely—from 2 ounces of vegetables daily to 19 ounces, for example. But by and large, none of them is that far off from the latest Dietary Guidelines for Americans.
“What these studies are really showing is that a diet consistent with current guidelines, whether it is called a Mediterranean-style diet or heart-healthy diet, is effective,” says Alice H. Lichtenstein, the Gershoff Professor of Nutrition Science and Policy at the Friedman School and director of the Cardiovascular Nutrition Laboratory at the HNRCA.
The first important scientific research to show that people in countries ringing the Mediterranean might be on to something nutritionally was the Seven Countries Study, led by Ancel Keys of the Mayo Foundation after World War II. The long-running study examined the diets and health of almost 13,000 middle-aged men in the United States, Japan, Italy, Greece, the Netherlands, Finland and Yugoslavia.
Surprisingly, well-fed American men had higher rates of heart disease than men in countries where the deprivations of the war had restricted their diets. Residents of the Greek island of Crete enjoyed the best cardiovascular health, a difference scientists largely ascribed to their diet, which was heavy on fruits and vegetables, grains, legumes and fish.
Keys, along with Harvard researcher Mark Hegsted, was among the first to posit a connection between animal fats—saturated fat—and heart disease. These findings helped the American Heart Association begin a campaign in 1956 to convince people that diets high in beef, butter and lard increased the risk of coronary heart disease. Keys and Hegsted also understood that the unsaturated fats found in liquid vegetable oils had beneficial cardiovascular effects—a message lost in the mid-1980s, when public health campaigns focused on reducing total fat intake.
If you want to take advantage of the health benefits of eating “like a Mediterranean,” it’s best to think of such a dietary plan as a Mediterranean-flavored version of the latest Dietary Guidelines for Americans [pdf]. Following a healthy diet might be easier when it’s given this Mediterranean twist, as many of the flavors Americans enjoy are included—in moderation.
But you’ll have to put out of your head many of the elements most Americans associate with Italian, Greek and other Mediterranean cuisines. Although the first thing that pops to mind when most of us think “Mediterranean food” is pasta, the grains used in familiar pasta dishes are processed. The healthy Mediterranean eating plans universally emphasize whole grains instead, much like the Dietary Guidelines for Americans.
It’s questionable how accurately this reflects the actual traditional eating habits of people in Mediterranean countries. “I have not seen whole grains in Italy or Greece,” says Lichtenstein. “If you’re eating paella, that’s certainly white rice. And what bread or pasta in the Mediterranean region is whole grain?”
The heaping helpings of cheese we associate with pasta dishes and pizza are out, too. Cheese is high in saturated fat, one of the primary ingredients that this healthy diet tries to avoid. The unofficial but widely adopted Mediterranean diet promoted by the nonprofit group Oldways notes that low- and nonfat cheese “may be preferable” and calls for limiting total saturated-fat intake to no more than 7 to 8 percent of calories.
If you think of sausage as essential to Italian dining and lamb as synonymous with Greek cuisine, you’ll need to practice moderation with both. It would help, in fact, if you forget everything you think you know about Mediterranean food—mostly from restaurants that have Americanized the cuisine and ramped up the meat, saturated fat and calories at the expense of vegetables, fruit and legumes.
Even in the countries bordering the Mediterranean Sea, traditional healthy ways of eating are increasingly ceding to more American-style fare, driven by convenience and economics. Think instead of Mediterranean fare consumed by the less-prosperous peoples of the region circa 1960.
As the Oldways group explains, “The ‘poor’ diet of the people of the southern Mediterranean, consisting mainly of fruits and vegetables, beans and nuts, healthy grains, fish, olive oil, small amounts of dairy and red wine, proved to be much more likely to lead to lifelong good health.”
“The other important thing to remember,” Lichtenstein says, “is that people in the southern Mediterranean tended to be physically active as a way of life.”
By the Numbers
A recent meta-analysis of 41 prospective cohort studies of a total of 2.9 million participants found that adhering to a Mediterranean-style diet dropped the risk of cardiovascular disease and mortality. Quantifying this healthy diet, however, has proven challenging. That same analysis found wide ranges among what qualified as a Mediterranean diet in the studies. For legumes, for example, averages ranged from as little as 2 ounces a week to more than 18 ounces a week.
The meta-analysis, presented at a recent meeting of the European Association for Cardiovascular Prevention and Rehabilitation, attempted to calculate optimal daily intakes of most of the key components of a Mediterranean diet. Based on the 41 pooled studies, the optimal daily intakes (converted to ounces and rounded) were:
Dairy products: 5.8 oz. for men, 7 oz. for women
Fruit: 5 oz. for men, 4.4 oz. for women
Vegetables: 4.4 oz. for men, 5 oz. for women
Cereals/grains: 4.6 oz. for men, 4.4 oz. for women
Meat: 2.7 oz. for men and women
Fish: 0.7 oz. for men, 0.9 oz. for women
Legumes: 0.35 oz. for men and women
If you’re trying to put these averages into practice, you might think of them as guidelines for consumption across an entire week. To average 0.7 to 0.9 ounces of fish daily, for example, you’d need to eat about two 3-ounce servings per week (as is already recommended by the American Heart Association).
The meta-analysis did not provide specific amounts for red wine, olive oil and nuts, yet those last two foods were singled out by the Spanish PREDIMED study. All the participants followed a Mediterranean-style diet, but with a twist. The researchers gave one-third of them extra-virgin olive oil and another third a combination of walnuts, almonds and hazelnuts. Both groups showed cardiovascular benefits compared with a control group, which has led some to speculate that the benefits seen in the study must be linked specifically to olive oil and nuts.
In an editorial in the New England Journal of Medicine accompanying those findings, Lawrence J. Appel of Johns Hopkins and Linda Van Horn of Northwestern University wrote, “Our sense is that the policy implications of the PREDIMED trial relate primarily to the supplemental foods. Specifically, in the context of a Mediterranean-style diet, increased consumption of mixed nuts or substitution of regular olive oil with extra-virgin olive oil has beneficial effects on cardiovascular disease.”
But before you start guzzling olive oil, Lichtenstein issues this caution. “The emphasis on cardiovascular benefits for olive oil goes against all the data suggesting that polyunsaturated fats are better than monounsaturated fats,” she says. Other studies, Lichtenstein notes, have shown vegetable oils higher in polyunsaturated fats to be even more heart-healthy than the mostly monounsaturated fats in olive oil; these include sunflower, safflower, soybean and corn oil. And nuts can backfire for your blood pressure if you choose salty varieties that boost your sodium intake.
Generally, though, “eating like a Mediterranean” might be a tasty way to plan and stick to an overall healthy diet.
A version of this article first appeared in the Tufts University Health & Nutrition Letter.