As a result of over 70 million people born during the Baby Boom, older adults are the fastest growing segment of the population in the United States. Centenarians, those who live to age 100 or older, are a rapidly expanding subgroup of the older adult population.
Researchers are naturally interested in biological factors that account for the unusual longevity of this group. In our recent study of 268 centenarians from Utah, psychological and social factors were considered alongside the biological to determine how experiences from all three areas might work together in extending the lives of the very old. Responses were collected from 24 living centenarians and 244 close relatives or caregivers of the recently deceased to determine what the oldest among Utah’s centenarian population have in common.
Most of the centenarians in our study were female (77%), which is somewhat expected given that females tend to live longer than males. While still a significant minority, the number of centenarian men in our study (23%) is a step up from the 15% proportion of centenarian men found in the New England Centenarian Study. Of interest, although women are more likely than men to see their one hundredth birthday, there is no indication that females live any longer than males once both have crossed the 100-year threshold.
Key findings from our biological data suggest that decreased sleep latency, or taking a shorter time to fall asleep, is associated with increased longevity among centenarians.
Key findings from our biological data suggest that decreased sleep latency, or taking a shorter time to fall asleep, is associated with increased longevity among centenarians. Specifically, centenarians who typically fell asleep in less than 30 minutes at night saw more days past their 100th birthday than those who lay awake for half an hour or more. Other studies have suggested that poor sleep quality and not feeling well-rested during the day are associated with higher mortality. Those who sleep too long or not long enough are also at greater risk.
Psychological factors were also found to be correlated with longer life among Utah centenarians. Centenarians or a proxy family member were asked to indicate how satisfied the centenarians were with their life overall. Centenarians with higher life satisfaction tended to live longer than those with lower satisfaction scores. Life satisfaction is also related to health in later life. Previous research has suggested that although happiness as a psychological factor does not tend to cure illness, it can serve to prevent the onset of sickness in older adults, potentially extending life.
When considered independently, close attachment to another adult was a predictor of longer life.
Social relationships also appear to help extend longevity among centenarians. As individuals age they often become more selective about how they expend their social energy, yet the relationships that do remain are typically strong. When considered independently, close attachment to another adult was a predictor of longer life. When considered together with biological and psychological factors, this association became less relevant. Other studies indicate that male centenarians who are married tend to live longer and thus benefit from the companionship of a spouse, while females over 100 tend to live longer when they are single.
The impact of better sleep, higher life satisfaction, and quality adult relationships on active life expectancy (the duration of a person’s life without significant disability) is not yet known. Our hope is that insights from our research will help the growing number of centenarians who wish to make the most of their second century on earth.
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