I’m often shocked at how some seventy-year-olds look like they are in their fifties, and some fifty-year-olds look like they are in their seventies. Is this due to genetics? Lifestyle? Good luck? We often see news stories of centenarians (people over 100-years-old) talking about their “secrets” to living long and they often claim that it must be their daily Dr. Pepper or evening whiskey. These anecdotes make great news clips, but they likely confuse many of us, since we’ve long been taught that Dr. Pepper can take the paint off a car and alcohol use can lead to disturbed sleep and even cancer.
If you look at individual centenarian stories, you’ll likely come away a bit confused and feeling like centenarians just won the genetic lottery—that living an extra-long life is a bit like playing the slots in Vegas. But then there are projects, such as “The Blue Zones” where various clusters of centenarians are found throughout the world and there are several commonalities between those clusters. This might lead us to think there is something more than pure luck in reaching old age.
The interesting thing about the Blue Zones centenarians is that they all seem to be really healthy. They are able to get up and down from sitting rather easily, they are sharp witted, and they often reveal a youthful spirit full of enthusiasm and goals. And, importantly, they all seem to die in their sleep of “old age”. And that leads us to understanding how longevity and lifespan differ from healthspan.
Some could argue that this is just semantics, and really it is. However, understanding these different definitions can help us redefine how we think about aging. So, “longevity” is typically defined as having a long life (so reaching 100-years-old is a longevity achievement). “Lifespan” is defined as the potential length of life a species could reach (so how long a human could potentially live). “Healthspan” is defined as the period of life that one is healthy.
Okay, so let’s use these definitions. What’s so impressive about most 100-year-olds that you meet? It’s typically shocking to me that all the centenarians I’ve met are so spry. They are typically mentally sharp and physically very capable. If you see a centenarian lying ill in a bed, it’s often because he or she is about to actually die. So, most centenarians have not only achieved longevity but they’ve also achieved a long healthspan—they are chronologically old but they have been relatively healthy in old age. As for lifespan, the oldest person documented is Jeanne Calment, a Frenchwoman who rode a bicycle until age 100 and apparently smoked until she was 117. She lived to 122. As of now, this is thought to be around the human lifespan limit.
I often try to explain the difference in longevity and healthspan to those who make the argument, “Well, I don’t care if I live a long time” when I try to get them to stop smoking or to change their diet to prevent diabetes and heart disease. The issue is that this argument fails to recognize the difference in longevity (living a long time) and healthspan (living healthy in old age). While preventing lung disease and diabetes will likely increase your length of life (longevity), it will most certainly increase your disease-free-years (your healthspan). Again, you rarely see a centenarian linger for years in a hospital bed. They often just die in their sleep. If they do die of illness, it’s often quick. Most would agree that they would rather live a life of health and function up until death rather than a life of being unable to get out of a chair until a prolonged illness causes their death.
So! Let this be our call to action. It’s healthspan that we’re after. The number doesn’t really matter. We are all going to get older. We are all going to die. What we can do, and should do is focus on living our best, richest lives, meaning lives that are fulfilling; lives that are filled with strong, disease-free, functioning bodies that allow us to squeeze all the good stuff (adventure, family, friendships) out of life up until the day we die.
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