Is the American diet really so bad that it's time to look to other countries for help?
That's the premise behind a spate of recent books and Web sites touting plant-heavy diets of various far-away places. Looking at traditional diets has become something of a fad in recent years. Numerous books, including The Jungle Effect and The China Study, have tried to document the link between diet and great health in various countries and regions. Researchers, for example, are still trying to understand how a sweet-potato-based diet may boost longevity on the Japanese island of Okinawa, home to a large population of centenarians. But you don't have to wait for the definitive answer--The Okinawa Diet Plan can be bought right now.
The latest entrant is The Five Factor World Diet by celebrity trainer and author Harley Pasternak. During his far-flung travels with stars like Jessica Simpson and Hillary Duff, Pasternak noticed that people in many of the countries he visited were slimmer and ate a more nutritious diet than most Americans. The experience left Pasternak (who has a master's degree in exercise physiology and nutrition) convinced that Americans have a lot to learn from the rest of the world.
His book lists countries with healthy diets that also have long life expectancies and low obesity rates. These metrics best capture the effects of a lifetime of good eating and exercise habits, he argues. Japan tops his list because it has a 1.5% obesity rate (for men) and an 82-year life expectancy, vs. a 36.5% obesity rate and a 78-year life expectancy in the United States. South Korea, China and Singapore also do well. France makes the list with a 6.6% obesity rate and an 81-year life expectancy, as do Italy, Spain and Greece. Pasternak's rankings aren't scientifically rigorous, but they may shed light on how other countries eat well and manage to stay healthy.
What virtually all these countries have in common are low-fat diets rich in fish, lean protein, vegetables, fruits and beans. Plant-based diets can reduce cholesterol levels, while fruits and vegetables also contain antioxidants that may protect against cancer. Consumption of certain omega-3 fatty acids found in fish may reduce heart disease risk. Many of the traditional diets only include small amounts of red and processed and salt-cured meats, whose consumption may increase risk of colorectal and stomach cancers.
Most of the countries in question practice portion control. Although they indulge in high-fat cheeses, cured pork and condensed milk coffee drinks, they rarely pig out like Americans. "Whether you adopt one or multiple things [from these countries] and bring them into your life," says Pasternak, "you'll be healthier and lose weight and keep it off."
Beyond this common-sense message, science doesn't have much to say about which traditional cuisines are the healthiest. It's impossible to tell whether the long life expectancies of some countries are actually the result of better health care systems, not better eating habits. No researcher has developed a method to accurately measure the comparative health benefits of one country's diet vs. another, says Harvard epidemiologist Dimitrios Trichopoulos. "We have no evidence because we don't have a yardstick," he says. There are indications that Japanese and Chinese diets, for example, are protective against chronic diseases and improve longevity, but Trichopoulos says that they haven't been studied enough to say that conclusively.
The one exception, he says, is the Mediterranean diet, high in olive oil, fruits and vegetables, and whole grains. A 2008 meta-analysis of 12 studies of 1.6 million subjects found that people who stick closely to the Mediterranean diet had a 9% lower death rate than people who ate the same diet less stringently, according to the results published in the British Medical Journal. Numerous other studies show it can protect against heart disease.
But pinpointing the most beneficial components of Mediterranean diet is tough, says David Jenkins, a University of Toronto nutrition professor. "It could be pasta, bulgur, hummus, fava beans," he says, "What we generally mean is a diet with more fruits and vegetables and less dependence on red meat."
Trichopoulos says that traditional diets have pitfalls of their own. The Japanese, for instance, eat lots of nutrient-laden cruciferous vegetables like cabbage, broccoli, bok choy, and their main sources of protein are fish and soy. That's the good news. The downside: Thanks to a preference for cured foods, they also consume colossal amounts of sodium, which can lead to high blood pressure and more strokes.