Centenarian

A centenarian is a person of extreme longevity who has passed the barrier of 100 years of age, an age far superior to the average lifespan in any country. Because of their extreme survival, centenarians have been the subjects of many scientific studies. Stories of extreme longevity have emerged from many different cultures and times. In ancient Greece, with its healthy Mediterranean diet, culture of physical activity, and sanitation, a person who could escape trauma or dying in childbirth could have lived to 100.

Today, the number of centenarians is increasing along with aging populations. The United States is a good example of this phenomenon—it has the highest number of centenarians in the world, numbering about 55,000; the number of centenarians in the United States is expected to surpass 800,000 by 2050. This is far more than the approximately 450,000 centenarians estimated to be alive in the world today.

Gerontological researchers are interested in identifying longevity factors by studying centenarians. This research has already helped scientists to identify genetic causes for longevity, such as genes that regulate immune and inflammatory responses, lipid metabolism, and insulin signaling pathways. Concerning their morbidity profile, centenarians have in common the [Page 360]delay of or escape from the most lethal age-related diseases, and can be classified into three groups: those surviving potentially lethal diseases with onset prior to their 80th birthdays, those delaying such diseases’ onset after the age of 80, and those escaping them altogether. Apparently, longevity strategies may vary between men and women, because they distribute unevenly into these groups. Much more than a populational curiosity, centenarians represent the potential of human longevity and are themselves important sources of knowledge about longevity-related factors.