What the Okinawan Centenarian Study has proven is the importance of a plant-based diet, high-fiber foods, limited animal protein and anti-oxidant rich foods.
A Plant-Based Diet
A major factor in the extraordinary health enjoyed by Okinawan seniors is their distinct diet. It is plant-based, high in fiber, omega-3 fatty acids, and flavanoids and low in protein. It includes low to moderate alcohol intake, plenty of fruits and vegetables, and very low levels of saturated fat and sodium.
Eighty percent of the calories in their low-calorie diet are plant-based. They eat plenty of rice, a wide range of vegetables, fruits, sea vegetables (e.g., seaweed) and soy products. Of the twenty percent of animal-based calories they do consume, most of it is cold-water fish or stewed meats from which the fat has been rendered. The fats they eat—fish, soy products, or cold-pressed canola oil—are largely monounsaturated or rich in omega-3 fatty acids. They indulge in alcohol and sweets only moderately and drink green tea, a healthy choice loaded with antioxidants, very often.
There are many things about the Okinawan diet that contribute to the long lives and good health of its elders. First of all, fiber is a central pillar in many healthful diet guidelines. A high-fiber diet helps maintain a sense of fullness and satiety that keeps people from overeating. It also aids in proper, efficient and pain-free digestion. Fiber comes from whole grains, fruits and vegetables. Grains and vegetables are complex carbohydrates (versus the simple carbohydrates in refined flour and sugar that break down more slowly) and help maintain healthy glycemic loads. These loads help the pancreas produce enough insulin to process the spikes in blood sugar levels caused by eating excessive amounts of simple carbohydrates. Along with providing fiber, the large amount of fruits and vegetables in the traditional Okinawan diet provides these seniors with essential minerals and antioxidants, which in turn fight free radicals in their systems.
Limited Animal Protein
The Okinawan high-fiber, vegetable-laden diet is low in protein. Most North Americans eat between two and four times as much protein that they need on a daily basis. Much of this protein takes the form of meat and dairy products, which also contain saturated fat. Saturated fat leads to unhealthy cholesterol levels and the production of artery-clogging homocysteine. When a high level of animal product consumption is combined with a lack of folate, an essential mineral (found in leafy, dark green vegetables) that helps regulate homocysteine levels, the problem compounds.
Furthermore, when we eat protein, our bodies also need to process the byproducts: ammonia and urea. Both of these toxins are processed through our kidneys, which are dependent on the liver functioning properly. An excessive amount of protein puts pressure on a host of vital organs.
The protein Okinawan elders do eat tends to come from two sources: cold-water fish and soy. Each brings something to the ultra-healthy Okinawan diet. Cold-water fish tends to be fatty, but that fat needs to stay liquid even in cold temperatures. Unlike other animal fats that solidify, the fat in cold-water fish remains free flowing. It is polyunsaturated and has omega-3 fatty acids, but doesn't have the same artery-clogging properties as saturated fat. Okinawans eat, on average, three servings of fish—mostly cold-water fish like mackerel, salmon and tuna—per week, causing them to have higher levels of omega-3 fatty acids in their systems than North Americans do. Omega-3s are seemingly miracle workers; they are cancer-preventing, brain-function-enhancing, and heart-protecting.
Okinawan elders also eat several servings of soy (tofu, miso and tempeh) products daily. Along with being an excellent source of low-fat protein, soy contains high levels of flavonoids, strong antioxidants that fight free radicals in any system they inhabit. Flavonoids also provide a source of natural, weak estrogens that can block the body's own estrogen that causes breast cancer and prostate cancer. In short, Okinawans high consumption of soy may explain their remarkably low rates of cancer. It also helps maintain bone density and muscle mass, keeping older Okinawans looking, feeling, and acting younger than Westerners of the same age.
Low Alcohol Consumption
The Okinawan diet is as remarkable for what it doesn't include as for what it does. Along with consuming limited red meat and almost no dairy products, drinking low to moderate amounts of alcohol helps further protect Okinawan seniors. Some alcohol, especially when enjoyed with food, has been shown to have some health benefits. Yet alcohol increases the body's estrogen production, which in turn can increase the possibility of developing hormone-dependent cancers. High alcohol consumption also destroys folate in the systems, which, as mentioned above, are important players in maintaining heart health, avoiding strokes, and promoting proper brain functioning.
Refined sugar and other sweets have a limited role in the traditional Okinawan diet. This helps Okinawans avoid blood sugar spikes, stress on the pancreas, empty calories, and unnecessary cravings. Okinawan seniors also engage in a practice of hara hachi bu. Hara hachi bu means eating until only 80 percent full, which is much easier to do when foods are nutritious and don't induce a physical desire to overeat. This naturally results in a low-calorie diet that, in turn, helps keep Okinawan elders slim throughout their lives, with a lean body mass (between 18 to 22 on the body mass index) and a low glycemic load (rate of blood sugars).
One theory of aging regards human bodies much like cars: they run and run and run until they simply burn out and die. One of the main demands we make on our bodies is the consumption and digestion of food, a process that also leads to the production of free radicals, or unstable molecules. By limiting their caloric intake, Okinawans limit how much food their bodies need to process and thus correspondingly decrease the amount of free radicals in their bloodstream.