'Diets' That Promote Health (and Always Have)

The Mediterranean diet is believed to be responsible for the low rates of chronic heart disease in the 16 countries bordering the Mediterranean Sea.

So some nutritionists are taking a stab at more precisely describing dietary patterns, using statistical analysis to measure what foods tend to cluster together in the diets of healthy (or not healthy) people. For example, a "prudent" eating pattern is characterized by higher intakes of fruit, vegetables, whole grains, legumes, and fish, says Teresa Fung, a nutritionist at Simmons College in Boston. That pattern has been shown to be associated with a lower risk of coronary heart disease, type 2 diabetes, and colorectal cancer, as well as lower body mass index.

The prudent diet has some key similarities with most of the ethnic eating patterns. "A better diet, however you define it, almost always includes more fruits and vegetables, less processed meat, more whole grains, fish, nuts, and low-fat dairy," says Katherine Tucker, a nutritional epidemiologist at Tufts University's Friedman School of Nutrition Science and Policy.

The beauty of the pattern approach is that it's not necessary to know exactly what mechanism is leading to better health. "It could be one thing or multiple things," says Fung. For example, research recently suggested that the higher amounts of choline, an essential nutrient in the vitamin B family, and another nutrient called betaine—both of which are abundant in a Mediterranean diet—reduce inflammation, which may contribute to a host of diseases, says Steven Zeisel, director of the Nutrition Research Institute at Kannapolis, a branch of the UNC Chapel Hill School of Public Health. "But the truth is, I'd be foolish to rush out and eat those nutrients. I can eat closer to that pattern—less red meat, more olive oil—and not worry about which is the active ingredient," he says. In fact, it's not even clear that these patterns are healthier because of what's in them—it may be what's absent. "As soon as you eat the Mediterranean diet, you're eating less steak," says Gardner. "Maybe it had nothing to do with that. What we know is that if you eat that way, you're healthier."

So, is it that easy: We all just have to eat like the Greeks (or the Vietnamese, or the ancient Maya)? Well, yes and no. First, most of the evidence comes from observation, not rigorous scientific trials, so it doesn't prove cause and effect. But there's enough observational data to convince most researchers, and there is some experimental evidence: Trials showed that eating a low-sodium diet based on whole grains, poultry, fish, and nuts and lighter on the red meat, fats, and sweets lowered blood pressure.

A second caveat is that these ancient dietary patterns were long paired with a way of life that doesn't much exist in America—and it included a lot of exercise, says Pollan. Men in postwar Crete didn't laze around dunking bread in olive oil all day; they chased goats up hills. Even now, people in the Mediterranean and other parts of the world are more active, whether through vocation or because there's so much more walking as part of daily life. That's why the traditional food pyramids from Oldways all include exercise. (The government recommends 30 minutes a day of moderate exercise for heart health and 60 to 90 minutes a day for weight loss.)