Longevity

Also known as: Life span, life expectancy

Anatomy or system affected: All

Definition: A broad concept that encompasses the progressive biopsychosocial changes associated with advancing age. The average lifespan expected under ideal conditions.

Key term:

life expectancy: the average lifespan expected of a group

Overview

Lifespan or life expectancy are terms that are often used synonymously with longevity, although "life expectancy" is used more commonly when referring to demographics and population data, while "longevity" is a more philosophical term and perhaps less well-defined.

It has been speculated that with age comes wisdom: the culmination of years of experience, memories, and lessons learned informs a person’s perspective on life and what kind of legacy one wants to leave behind. Conversely, the process of aging also increases a person’s risk of dying: Many theories suggest that years of physical and emotional (internal), and environmental (external) influences render a person more susceptible to acute illness or the development of chronic disease. Modern medicine—pharmaceuticals, therapies, technology—has the capability to extend life well beyond previously held norms. In 2020, the Centers for Disease Control and Prevention'sHealth, United States: 2019 reported that in 2018 the average life expectancy in the United States at birth was 81.2 years for women and 76.2 years for men, with an average of 78.7 years for the total population. The US Census Bureau reported from its 2019 population estimates that the 65-and-older population was the fastest-growing population in much of the developed world, growing by over a third between 2010 and 2019. With the technological advances that have been made, it begs the relevant question: Can aging be cured? And if it can, should it?

The concept of longevity, the progression from birth to death, has been recognized by human beings for hundreds of years, but the ethical discussion of whether or not we should exercise the right to live as long as possible is a relatively new one. Charles Darwin, the English naturalist and major contributor to the theory of human evolution, would argue that death is the result of natural selection; a process that is expected and a natural happenstance when adverse events suffered outmatch the ability of the body to sustain life. Longevity has also been explored in fictional literature. Shakespeare often depicted a person’s life as a series of “roles” acted out on the societal stage, roles that are gradually lost as old age progresses until death finally arrives—the final act. Less metaphorically, Jonathan Swift’s popular novel Gulliver’s Travels relates the story of the Struldbrugs, a nation of humans that never die but still suffer the ravages of time and advancing age, eventually sightless, demented, crippled, as the body deteriorates but death never arrives—living but not living. While graphic and extreme, perhaps modern-day Struldbrugs can be identified in hospitals across the developed world as machines and technology are often utilized to sustain quantity of life but do little to preserve quality of life.

Further inquiry in the fields of population biology, psychology, ethics, and anthropology will undoubtedly lend new insights into the evolving concept of longevity.

Longevity Claims

Statista reported that in 2021 there were approximately ninety-seven thousand centenarians (those who are aged 100 years or older) living in the United States, and of that amount, about fifty to eighty were supercentenarians—individuals who were aged 110 years or older. Researchers, scientists, and medical professionals agree that one's life span is greatly determined by a combination of genetics, lifestyle, and mental and physical health, but the longer one lives, the more genetics comes in to play. A 2012 study published in the scientific journal PLOS One indicated that while no specific longevity gene seemed to contribute to an extremely long life, individuals who lived to age 110 and beyond all seem to have been able to delay any serious medical condition or disease until later in life. In other words, they all share the quality of having several of the "right" genes that protected them from developing serious illness until much later in life. The study further noted that the older the individual, the shorter their periods of disability and disease. This "compression of morbidity hypothesis" is the notion that the longer one spends alive, the less time one spends sick before death. It is believed that future genetic testing and study of supercentenarians can help scientists to discover new and effective treatments for diseases such as cancer and heart disease.

Individual claims of longevity and reaching supercentenarian status were once difficult to confirm because of scientific and research constraints. Today, however, groups such as Guinness World Records and the Gerontology Research Group (GRG) are dedicated to verifying such claims. L. Stephen Cole, cofounder of the Gerontology Research Group, states that this list of supercentenarians, which is updated regularly, averages about seventy entries. Individuals claiming to be aged 110 or older must first prove their age with two to three pieces of documentation before they are added to GRG's database. Cole admits that there are most likely many true supercentenarians who do not make GRG's list only because they cannot provide the necessary documentation. China and India, for example, did not begin tracking birth and death records until the early 1900s.

Bibliography

"65 and Older Populatiuon Grows Rapidly as Baby Boomers Age." US Census Bureau, 25 June 2020, www.census.gov/newsroom/press-releases/2020/65-older-population-grows.html. Accessed 20 July 2021.

Albert, Steven M., and Vicki A. Freedman. Public Health and Aging: Maximizing Function and Well-Being. 2nd ed. New York: Springer, 2010. Print.

Adams, John M. "GRG World Supercentenarian Rankings List." Supercentenarian Research Foundation. GRG, 22 June 2016. Web. 24 June 2016.

Andersen, S. L., et al. "Health Span Approximates Life Span Among Many Supercentenarians: Compression of Morbidity at the Approximate Limit of Life Span." Journal of Gerontology Series, vol. 67, no. 4, Apr. 2012, pp. 395–405.

Arias, Elizabeth. “United States Life Tables, 2018.” National Vital Statistics Reports, vol. 69, no 12, Nov. 2020, pp. 1–44. Centers for Disease Control and Prevention, www.cdc.gov/nchs/data/nvsr/nvsr69/nvsr69-12-508.pdf. Accessed 20 July 2021.

Buchholz, Katharina. "Is 100 the New 80?: Centenarians Are Becoming More Common." Statista, 5 Feb. 2021, www.statista.com/chart/18826/number-of-hundred-year-olds-centenarians-worldwide/. Accessed 20 July 2021.

Cochran, Norris, et al. Health, United States: 2019. National Centers for Health Statistics, Centers for Disease Control and Prevention, US Dept. of Health and Human Services, 2021, www.cdc.gov/nchs/data/hus/hus19-508.pdf#Highlights. Accessed 20 July 2021.

Moody, H.R. Aging: Concepts and Controversies. 6th ed. Los Angeles: Pine Forge, 2010. Print.

Sebastiani, Paola, et al. "Genetic Signature of Exceptional Longevity in Humans." PLOS One. Public Library of Science, 18 Jan. 2012. Web. 24 June 2016.

Thomas, William H. What Are Old People For? How Elders Will Save the World. Acton: Vanderwyk & Burnham, 2007. Print.