(suspenseful music) (electricity buzzing) - [Narrator] When people talk about going from young to old, usually the first thing that comes to mind is time, right?

The length of time.

There's no question that we have been successful at making people live longer.

What's a little bit unclear is that we've been successful at making people live healthier longer.

Probably the most important goal isn't even so much about how long we live, it's about how well we live.

(bell dings) - Dr. Matt Kaeberlein is a professor of laboratory medicine and pathology, at the University of Washington.

There, he studies something of vital importance to every living person.

Aging.

(jaunty music) - We are interested in understanding how and why animals and people age.

And in particular, what are the mechanisms that cause different animals or different people to age at different rates.

I didn't appreciate, I think aging maybe, as much as I do now, having experienced it.

Aging is a personal thing for everybody, we all experience aspects of it that are not always so pleasant.

But once we can understand that, we actually have the opportunity to intervene in that process and hopefully delay a lot of those changes that go along with the aging.

(elevator creaking) Wow, service.

- [Narrator] For Matt, unlocking the secrets of aging didn't start with people or even with complex multicellular organisms.

- We're almost there, I promise.

- [Narrator] He had to begin with something that ages much faster than us.

He started by studying yeast.

- [Matt] These cells will undergo cell division, usually about 20, 25 times and then they'll stop, that's a process called senescence.

Our cells do that as well.

So one metric that we have always used, is this idea of lifespan.

How long can the organism continue to function until it stops functioning and dies?

We can actually do the experiment in three weeks, right?

It doesn't take three years or 30 years.

- [Narrator] Measuring lifespan isn't particularly difficult.

But what Matt really wants to measure is health span.

Basically, the amount of time, one spends in good health.

Determining health span and how we might extend it, has major implications for aging.

But could that mean that Matt might one day unlock the key to living forever?

- Can I look at those guys?

You know I think this idea of immortality it's a fun idea to think about unfortunately, it often gets portrayed as that's what the field is trying to do.

The best we've done is make a mouse live about 60% longer than it would otherwise.

So until we can make a mouse immortal, we probably shouldn't talk about making people immortal.

Cool.

Now I'm not opposed to living forever by the way.

- [Narrator] For now, reaching for immortality remains firmly in the realm of science fiction.

But studying the biology of aging, still has the potential to benefit our lives.

(gentle music) And our best friends lives, in surprising ways.

- You need brushing you know all this, relax.

I shouldn't have said that word.

it occurred to be that I know about all these interventions that slow aging in laboratory animals and in mice.

What if some of them work the same in dogs?

The soon as I sort of had that mental shift that, it might actually be possible to make people's pets live three, four, five years longer in good health, I was kind of like a, it was done deal, I had to do it.

- [Narrator] Matt took this idea and started working on it, through the dog aging project.

This study analyzes data collected from over 30,000 dogs.

And some owners enroll their dogs in further small trials, to see if a drug called rapamycin, can extend their pets lives.

- [Matt] All right, come on Mr.

So the observation is, when we treat animals or cells with rapamycin, kind of tricks the cell into thinking there's not as much food around, that slows aging, increases life span, increases health span.

The statistics are that something like 50% of pet owners, consider their pet to be part of their family.

And I consider Dobby to be part of my family - [Narrator] While Matt can keep Dobby alive forever, more quality time spent with our pets, is still priceless.

- [Matt] You know, it's been thinking about that relationship and the relationship that a lot of people have with their pets.

That probably is the most profound personal thing I've learned from the study.

I think it's love.

I mean, I think we love our pets.

Maybe not exactly the same thing as your human child, maybe for some people it does, but it's close.

And so I think it's that feeling, that emotion that connection that we have with our pets, that's important.

The more time that you can spend in health, that your family members can spend in good health, that your pets can spend in good health, it's about the quality time that you have, with those people and animals that you love.