How Okinawans dropped the baton                             

            For a couple of decades Okinawa was noted for having the largest per-capita number of centenarians on the planet. There were nearly one thousand Okinawans over the age of 100 in 2007 among a population of less than one million. They are a remarkably healthy lot, with only a fraction of the diseases that are so common in the U.S.: coronary heart disease, breast cancer and hip fracture, just to name a few. In their 90s they live independently and are sharp enough to know the names of all their great-grandchildren.

            What is it about these persons who were born just after the turn of the last century? Okinawa is the poorest prefecture in Japan, and that may hold the key. Throughout most of their lives, which included decades of war, their meager diet consisted mostly of plant foods (including seaweed), almost no red meat and a moderate amount of fish.  They consume much less rice than Westerners suppose and the sweet potato is a daily staple. With few labor-saving devices they rely on muscle power for all their household chores, transportation and work-related activities.

            The average life expectancy of the Japanese in Okinawa was the highest in the world but it is now in decline. The oldest are being weighed down by the youngest. Within a couple of decades after World War Two ended, the Westernization of the Okinawan lifestyle was in full force. The youth of Okinawa have embraced fast food, refined grains, automobiles and computers. The result? Young Okinawans have the highest rate of obesity in Japan and type 2 diabetes is skyrocketing.

            In two or three decades the centenarians will be gone and so will most of those now in their mid-seventies. Their children, born into the second half of the 20^th century, won’t grow old gracefully – or even grow old. We already have evidence of that among Okinawans who migrated out of Japan. In Brazil the life expectancy of immigrant Okinawans is 64, not 84.

            There is no Okinawan longevity secret. One of their lifestyle principles, however, is to stop eating before reaching satiety. They call it Hara hachi bu -- Eat until you are 80 percent full. Biologists have shown that the life span of various species can be extended by as much as 150 percent by reducing calorie intake to about 70 percent of the calculated requirement. The oldsters forgot to tell the kids.