Once the site of the largest amphibious assault in the Pacific in World War II, Okinawa has long since been known as the Japanese Hawaii and is heralded around the world for its beauty, culture, and tranquility. In recent years, the Okinawa prefecture has also seen international attention for another one of its accolades: the longevity of its residents.
It is widely thought that Okinawa has the largest centenarian ratio in the world, and this revelation spawned a diet craze that Google recently revealed was among the top-searched “eating plans” for 2013. Indeed, they’re doing something right. Compared to North Americans, Okinawans have 80 percent less breast cancer and prostate cancer, and less than half the ovarian and colon cancers. Here are a few reasons Okinawans may be among the healthiest in the world.
Diet and indigenous vegetables
Okinawan food, different from that of mainland Japan, possesses several key vegetables that could help to extend longevity. Chief among them are their purple sweet potatoes, which are rich in flavonoids, carotenoids, vitamin E and lycopene, and goya — a bitter “melon” that has been shown to lower blood sugar in diabetics. Okinawans also have low levels of the plasma homocysteine, which can be attributed to their ingestion of green, leafy vegetables.
Studies show that Okinawans also eat three servings of fish a week, a variety of whole grains, and more tofu and more Kombu seaweed than anyone else in the world. The majority of items in Okinawans’ diet allows them to eat more food with a lower caloric density — a key element in the “Okinawa Diet” that has been adopted by Westerners.
Hara hachi bu
Okinawans are known practicers of hara hachi bu, the Confucian teaching that advocates eating until one is 80 percent full. Though some are skeptics of this self-imposed calorie restriction, elderly Okinawans have a typical body mass of 18 to 22, compared to a typical BMI of 26 or 27 for adults over the age of 60 in the U.S.
Role of genetics
The heritability of human longevity purports that roughly a third of human lifespan may be genetic. The Okinawa Centenarian Study, an ongoing population-based study of centenarians and other selected elderly in the Okinawa prefecture that began in 1975, also reports that genetic factors are clearly important to human longevity — especially Okinawan longevity.
As previously mentioned when exploring the concept of hara hachi bu, Okinawans have remained remarkably lean in their long lives. In addition to a combination of genetic fortune and diet, Okinawans are known to exercise daily and spend time connecting the mind and body through focused activities such as tai chi.
Though all of the above factors have an undeniable impact on the longevity of the Okinawans, it’s hard to separate one from the other, said Dr. Bradley J. Willcox, who co-authored the book “The Okinawa Program: How the World’s Longest-Lived People Achieve Everlasting Health — And How You Can Too.” He said that, “There is no one most important factor. It is balance between the main factors. We call them four legs of a chair. If you don’t have those legs in balance, the chair will topple over.”