You'd have thought such a fascinating discovery would have been big news in the West, but it went largely unnoticed for a number of reasons. First, only a few small research reports made it into the English-language scientific literature. Most of the interesting findings (more than 100 peer-reviewed studies) were published in the Japanese scientific literature always in Japanese, making them fairly inaccessible to Western scientists. Second, gerontology and preventive medicine research were relatively new in the 1970s, and baby boomers were not old enough to get the diseases of premature aging. Research dollars were only just beginning to flow into this area of investigation. Nutritional research was generally considered unscientific and unproductive, not much of a contribution to science or medicine. Finally, Okinawa's role as a battleground in World War Two and its continuing problems with U.S. and Japanese military bases tends to overshadow its role as an area of extreme longevity.

The Reason for the Dramatic Increase in the Number of Centenarians in Okinawa
This dramatic phenomenon is not only occurring in Okinawa but also can be seen in the United States and many other countries. The increase in the number of centenarians worldwide is largely due to healthier lifestyles, more emphasis on preventive medicine, and better healthcare. The phenomenon is more profound in Okinawa probably due to a combination of all three factors, which result in greater mortality reductions at older ages, and more people living closer to their individual genetic potentials. (

The word "centenarian" means people who have lived one hundred years or more, in other words, people who have lived a "century." Centenarians are important to study because they are living examples of successful aging. According to our collaborators from the New England Centenarian Study, most centenarians have been remarkably healthy and experienced a rapid terminal decline late in life, resulting in a compression of morbidity to their final years (see Hitt R, et al. Lancet 1999;354:652).

Okinawa's elders (aged > 70 years) and centenarians in particular, also seem to have experienced a slower age-related decline and markedly delayed or avoided entirely the chronic diseases of aging, such as Alzheimer's Disease, cardiovascular disease and cancer. This is in marked contrast to younger Okinawans, who lead a less healthy lifestyle and experience higher mortality levels than similarly aged Japanese in mainland Japan.

How Many Centenarians are There?

Ushi Okushima, 100

Currently, there are approximately 27,000 centenarians in the United States, or a little more than 10 centenarians per 100,000 people, although this is difficult to estimate precisely since there was no national birth registration system in the U.S. until 1940. Approximately 90% of them are women and 10% are men. This ratio is about the same or a little higher than other developed countries. On the other hand, in Okinawa, there used to be only 32 centenarians in 1976 when the Okinawa Centenarian Study was started, however, there are now over 400 centenarians in a population of 1.3 million, or 34 centenarians per 100,000 people, and 86% of them are women.

Do Super-Centenarians Exist in Okinawa or Elsewhere? Reports that came from the former Soviet state of Georgia and surrounding states in the Caucasus Mountains, Hunza Valley in Pakistan or Vilcabamba in Ecuador claimed unprecedented concentrations of centenarians, with many living beyond the age of 120 years. In-depth studies of these populations have shown that age-exaggeration is rampant and life expectancy is actually shorter than in the U.S., nor are there high concentrations of centenarians.

Ishikichi Tanaka, 101

The reasons behind the age exaggeration are complex but include the prestige that goes along with being the oldest individual in a village, avoidance of military service while young by assuming the identity of a deceased elder, and a general tendency for the elderly to inflate their ages. Age inflation exists in most age databases that rely on census data for their centenarian statistics, including in the U.S., where a national birth registration system did not exist at the time centenarians were born (see Leaf A. J Am Ger Soc 1982;30:485-7). In Okinawa, a family registry