The centenarian tide is on the rise

Story highlights

  • The death rate among the oldest of the old started dropping in recent years, following the trend in most other age groups
  • Decreases in deaths due to heart disease and other common killers could explain some of the decline in death rate

(CNN)Death rates have been dropping for Americans of almost every age for decades now. A study of centenarians, Americans 100 years and older, suggests that they are joining the ranks, as their death rates started to decline in 2008.

Using data from the United States Census Bureau and death certificates filed in the United States, a study by the Centers for Disease Control and Prevention determined the death rate and causes of death in this oldest-of-the-old population between 2000 and 2014.
The study reported that, although Americans in their very golden years are still rare, the population has grown by 44% in recent years, from 50,281 in 2000 to 72,197 in 2014.
    The study found that, after increasing 10% between 2000 and 2008, the death rate for female centenarians dropped 14% between 2008 and 2014 to 36.5 deaths for every 100 women. The death rate among males in this age group dropped by 20% from 2008 to 2014, after increasing 41% between 2000 and 2008, and was 33.2 per 100 in 2014.
    "It looks like the population 100 and older is living longer now so the [death] rate has decreased, but I don't know exactly what caused that," said Dr. Jiaquan Xu, an epidemiologist at the CDC National Center for Health Statistics and author of the study, which was released in January.
    It is also not clear what the death rate of centenarians looked like before the 21st century, and whether the recent decline is a new trend or a continuation of a past trend. The study did not include earlier years before 2000 because the age reported on death certificates was less reliable, Xu said.
    There are many reasons that good data were hard to come by for centenarians back then, and it has not necessarily gotten much better since 2000, said Dr. Thomas Perls, geriatrician and director of the New England Centenarian Study at Boston Medical Center. For one, it has been hard for the Census Bureau to get a good handle on how many centenarians there are in the United States, Perls said. And when an elderly family member passes away, their relatives might overestimate their age on the death certificate. "It's a story that grew and grew, like the fish (you caught) that got bigger and bigger," Perls said.
    Because of these reasons, it is hard to know if the death rate among Americans 100 and up has truly been on the decline since 2008. It is probably some part fact and some part artifact, Perls said.
    "It could decline as we have better medical care, as people take on healthy habits and exercise more and don't smoke ... but I don't know if it will decrease by 20%," as was seen among male centenarians between 2008 and 2014, Perls said

    What do centenarians die of?

    Although Xu is not sure what could account for the declining death rate he found among centenarians, he does think at least part of it could be because fewer are dying of common killers, such as heart disease and stroke.
    The study found that, between 2000 and 2014, the rates of death due to heart disease, stroke and flu and pneumonia, which were the top three causes of death for female and male centenarians in 2000, dropped by 24%, 31% and 48%, respectively.
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    "If you diagnose chronic diseases (such as heart disease) earlier and get proper treatment, those can be controlled or even prevented. Then people with those kinds of diseases could live longer," Xu said. As for the lower rates of flu and pneumonia, they are probably due to more vaccinations, as well as older people just being healthier in general and better able to recover from the flu, he added.
    Over this period, other less common causes of death crept up. The death rates due to Alzheimer's disease, high blood pressure (and related problems such as kidney disease) and respiratory diseases grew by 119%, 88% and 34%, respectively, between 2000 and 2014. Alzheimer's shot up from the fifth to the second leading cause of death among female centenarians from 2000 to 2014; among men, it was not on the top five in 2000 to number five in 2014.
    However, Perls doubts there has really been an increase in the number of centenarians who have and are dying from Alzheimer's. "Doctors are much better now about accurately indicating whether a person (in their 100s) has Alzheimer's. Either they didn't recognize it before or thought, 'What do you expect for your age?' So I think it's just reported much more," he said.

    A 'hardy' bunch

    Although it might sound like good news that centenarians seem to have joined nearly every other age group (other than middle-aged white Americans) in living longer, it is too soon to celebrate. "Once people get to be so old, the majority, I think, need help for their daily life. So I'm not sure if it is a good thing or a bad thing. It is a quality of life issue," Xu said.
    But there is at least some reason to be optimistic. "What we have found ... is that even with pretty significant physical limitations and impairments, their subjective well being and amount they value life is surprisingly high," said Kathrin Boerner, associate professor of gerontology at the University of Massachusetts Boston.
    Nevertheless, the explosion in the very aging population, those 95 years and older, and the chronic diseases that most of them have is already creating an "intense burden for the health care system," Boerner said, adding that it is "totally not ready for it."
    There are many questions around how to care for the oldest of the old, and it probably doesn't just come down to building more nursing homes, Boerner said. Many of them want to stay in their own homes, and research suggests they are doing that. "In our studies, 60% of those 95 years and above are living in the community. They are not necessarily healthy but they are a hardy people," Boerner said.
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