OKINAWA IS famed for the longevity of its residents. The small Japanese island, far south-west of the mainland, boasts a life expectancy for 65-year-old girls that’s virtually a yr increased than the country-wide common, and round 4 years greater than that of Britain or America.
In consequence, researchers searching for a life-extending elixir (see Technology Quarterly) have lengthy appeared to Okinawans for his or her secret. Consuming a vegetable-rich weight loss program, staying lively and having a way of function have all been advised as candidates. However one pre-print research supplies a extra prosaic rationalization for outstanding reported longevity in sure components of the world: information errors.
Estimates of the ages of the exceptionally aged are sometimes inaccurate. Few very outdated individuals have start certificates. Some have no idea their true age. And public data will be woefully unreliable. A authorities audit in 2010 uncovered 230,000 supposedly residing Japanese centenarians who have been lifeless or lacking. Some errors are real errors, however others could also be the results of deliberate efforts by people or relations to commit pension fraud.
Saul Newman of Oxford College got down to take a look at whether or not such errors may clarify why some locations seem like longevity hotspots. He gathered numbers of centenarians, semi-supercentenarians (these over 105 years outdated) and supercentenarians (these over 110) ostensibly residing in areas of America, Britain, Italy, France and Japan utilizing a patchwork of dying data, censuses and databases logging outdated individuals.
Dr Newman discovered that clusters of excessive reported longevity tended to happen in areas the place record-keeping would possibly conceivably be extra lax, or the place residents might need extra incentive to say pensions fraudulently. In Britain, Italy, France and Japan data confirmed outdated individuals residing in poorer, crime-ridden areas as extra more likely to attain extraordinary ages. Okinawa, for instance, has a poverty price practically twice the Japanese common and 1.6 occasions as many listed centenarians for every reported nonagenarian.
There have been additionally curious paradoxes within the distribution of centenarians that might be simply defined by reporting errors. In Italy provinces the place extra individuals attain the age of 105 are inclined to have extra individuals die earlier than 55. On the island of Sardinia, famend for its abundance of very outdated individuals, residents have among the many lowest possibilities of reaching midlife of any Italians.
Essentially the most concrete proof that errors might be inflicting variations within the numbers of very outdated individuals got here from America. Between 1841 and 1919, states launched start certificates, making age estimates extra correct and fraud tougher. By aligning information on the numbers of outdated individuals in every state with the date that start registration was launched, Dr Newman discovered that it resulted in a 69% drop within the prevalence of supercentenarians.
Variations in way of life and well being care in all probability trigger variability in life expectancy throughout international locations, however they can’t totally clarify why some locations seem to have so many centenarians. One secret to an extended life? Throw away your start certificates. ■
Chart sources: “Supercentenarian and noteworthy age data exhibit patterns indicative of clerical errors and pension fraud”, by S. Newman, working paper; UN; ESPON