During the past century, life expectancy in the United States has increased rapidly with advances in public health and living standards, improved diet, and rising levels of education. In 1900, life expectancy in the United States was 47 years. By 2014, U.S. life expectancy had increased to 79 years, and those who reached age 65 could expect to live another 19 years.

The increase in U.S. life expectancy is a public health success story. However, people surviving into their 80s, 90s, and beyond also experience a higher risk of age-related health problems and disability. Scientists hope to slow the process of aging to extend people’s lives and increase the number of years that they spend in good health and disability free, a period of life called “health span.”


The Census Bureau projects that the number of U.S. centenarians could rise to more than 600,000 by 2060.

Most people know about the importance of eating a healthy diet, exercising, maintaining a healthy weight, and avoiding smoking to prevent disease and increase longevity. But researchers have identified many other factors—including genetics, social connections, early-life experiences, and even certain personality traits—that may affect life expectancy.

This report highlights recent work by National Institute on Aging (NIA)-supported researchers:

  • Older adults in their 90s who are resilient—who can adapt positively under adverse circumstances—have a much higher likelihood of living to age 100 compared with peers who have lower levels of resilience.
  • Compared with the overall U.S. population, the oldest old (ages 95 and older) have more positive attitudes towards life, are more extroverted, and experience less general emotional distress (are less neurotic).
  • The link between social connections and health is well established: Older adults who are socially isolated face a risk of premature death that is on par with the health risks associated with smoking.
  • Researchers estimate that between 15 percent and 25 percent of the overall variation in human longevity may be explained by genetic differences in the population.
  • Men with the genetic variant known as FOXO3 have almost three times the odds of living to nearly 100 years of age than their peers without the genetic variant.
  • On average, long-lived individuals have fewer chronic diseases, better mental health, and better physical and cognitive function than nonsurviving members of their age cohort.
  • Among long-lived individuals, men tend to be healthier than women, whites healthier than nonwhites, and highly educated people tend to have better cognitive function than their less-educated peers.
  • Among those ages 65 and older, researchers find that the increase in years spent without disability (disability-free life expectancy) outpaced the increase in disabled life over the past 40 years.

The prevalence of activity limitations is increasing among adults ages 55 to 64, raising concerns that baby boomers will face more health challenges in old age compared with their parents’ generation.

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