There may be another risk question worth asking

We are accustomed to asking: What is most likely to kill me?

Perhaps we should also be asking: What is most likely to make me unable to live the life I want to live?

The answers will overlap, but they will not always be the same.

Falls are an obvious example. A fall may happen in seconds, yet its consequences can affect mobility, confidence and independence for months or permanently. Fall prevention rarely generates the excitement that surrounds cholesterol, glucose, protein intake, VO₂ max or the newest longevity drug, but for an individual person its effect on the rest of life can be enormous.

Hearing is another example. Hearing loss can seem like an inconvenience rather than a serious health issue until we think about what hearing allows us to do. Conversation becomes harder. Groups become more difficult to navigate. Participation can gradually decrease. The world may quietly become smaller.

Vision can do the same.

And then there are abilities so ordinary that we barely notice them while we have them: getting out of a chair, climbing stairs, carrying groceries, driving somewhere alone, following a conversation in a noisy restaurant, preparing dinner, managing medications, paying bills or recovering after an illness sufficiently to return to normal life.

None of these appears on a death certificate as “lost independence.”

Yet together, they may determine what the final 10, 20 or even 30 years of someone's life actually feel like.

Perhaps healthspan is broader than we usually make it

The World Health Organization uses an interesting concept when it talks about healthy aging: functional ability.

The idea is broader than simply being free of disease. It includes whether people retain the abilities that allow them to be and do what they value, and it recognizes that those abilities depend partly on the person and partly on the environment around them.

I find that distinction useful because a person does not experience aging as a laboratory panel.

We experience aging through what we can still do.

Can I walk where I want to walk? Can I go somewhere by myself? Can I see and hear well enough to participate comfortably? Can I make my own decisions? Can I manage my home? Can I learn something new?

Can I continue working if I want to? Can I meet friends, travel, shop, cook, use technology and take care of the ordinary business of life without someone else gradually having to take over?

Those questions feel very different from asking whether every biomarker is optimal.

And perhaps both sets of questions belong in a serious discussion of longevity.

Maybe there is such a thing as “capability span”

We already distinguish between lifespan and healthspan. I wonder whether another concept might be useful, even if only as a way of thinking.

Capability span: the years during which we retain enough physical, cognitive, sensory and practical ability to continue living the life we choose.

I am not suggesting that medicine needs another official measurement. There are already established ways of assessing functional status and activities of daily living.

I am more interested in the question the concept forces us to ask.

If I hope to live to 90, 100 or beyond, what exactly am I trying to preserve for all those additional years?

Surely not simply a heartbeat.

I would want to preserve the ability to choose. To move. To think. To communicate. To participate. To remain interested in something. To take care of myself as much as possible and to decide how my own life is lived.

That begins to make longevity look somewhat different.



Some longevity interventions may not look medical at all

If preserving capability becomes part of the goal, our list of longevity interventions expands.

Strength and cardiovascular fitness still matter enormously. So do good medical care, appropriate screening and prevention of major disease.

But perhaps a hearing evaluation belongs on the longevity list too. So might correcting a vision problem, reviewing medications that cause dizziness, improving lighting on a staircase, removing something easy to trip over, or designing homes that remain usable as people's abilities change.

Maintaining friendships and reasons to leave the house may belong there. So may noticing that someone has not truly recovered after hospitalization rather than assuming that discharge means recovery is complete.

Some of these interventions are almost embarrassingly ordinary.

They do not sound futuristic. They do not involve a breakthrough molecule, sophisticated imaging or a new biological theory of aging.

But if one of them allows someone to live independently for another five years, how minor was it really?

A second map of longevity

I remain fascinated by the possibility that human beings may eventually live substantially longer lives.

But the prospect becomes less compelling if our primary measure of success is simply how long we can postpone death.

Disease prevention must remain part of the map. Cardiovascular disease, cancer, dementia, metabolic disease and the other major threats to health deserve every bit of attention they receive.

I am simply wondering whether they represent only one map.

Alongside it, perhaps each of us needs another question:

What threatens my ability to remain capable?

The answer at 45 may be very different from the answer at 65. At 85 it may change again. At 105, perhaps the priorities would surprise us.

It will also differ enormously from one person to another.

That may be one reason healthspan is so difficult to define. We are not simply trying to keep bodies alive and diseases away. We are trying to preserve enough capacity for people to continue inhabiting their own lives.

So perhaps the question is not only how many years we can add to life.

It is how many of those years can remain recognizably our own.



A Note from Marsha

Writing this left me with another question.  Knowing what capabilities we want to preserve is one thing. But what happens when one of them changes anyway?

Two people can lose exactly the same ability and experience very different losses of independence, depending on their surroundings, resources and ability to adapt.

For me, preserving independence also means keeping choices available. If a familiar task becomes harder, I want to consider what would allow me to continue: a different approach, a useful tool, a change in my surroundings, or a skill I can develop. The difficulty deserves attention, but so do the possibilities that remain. That is the question I carry into the next article: how do we keep one change from unnecessarily narrowing the rest of our lives?