[calm music]

[Narrator] At a certain age, for many,

their body starts feeling like it's falling apart.

Medications pile up,

doctor's appointments fill the calendar.

Aging is inevitable, but what if it wasn't?

Great news about aging that probably most of us don't know

is we actually have a lot more control

over the aging process than we think.

[Narrator] Let's take a look at the latest science

and how it might be possible to slow our own aging.

[calm music]

According to Dr. Levine's upcoming book True Age,

we have two ages: our chronological age,

the one we celebrate at our birthdays,

and our biological age, our body's lifespan.

Biological age can be defined as the state of decline

or the state of divergence that your body has undergone

as a function of time.

[Narrator] Lethargy, graying, balding, wrinkling,

dementia, playing bingo,

we know the symptoms of aging, but what causes it?

As we age, our cells change a lot of their states

and they can actually transition

to different kinds of cells.

One type of cellular state is what's called senescence.

Various types of cells can convert to this,

and a lot of people refer to senescent cells

as zombie cells.

That's because these are cells that due to some stress

basically lose the ability to proliferate

or to make copies of themselves,

so they're no longer gonna generate new cells.

At the same time, these cells are resistant to death.

When cells undergo some damage,

one way to prevent cancer is that damaged cells

are just gonna commit suicide and be taken out of the body.

But senescent cells, they remain in the body,

so they're not dead, but they're also not proliferative.

So this is why people refer to them as zombie cells.

[Narrator] Wait, aging might be caused by zombie cells

within our own body?

Some people believe that senescent cell accumulation

is the main driver of aging,

that this drives the inflammation that we see with aging,

which ultimately is driving the dysfunction

that arise throughout our bodies.

Is still debatable whether senescence is truly driving it,

but there is some interesting experiments

giving some evidence to this.

So people can actually take cells

and have actually injected them into mice,

and what you see is that this actually can shorten

the lifespan of a mouse.

They're constantly excreting

a bunch of pro-inflammatory cytokines

and also growth factors.

They can also make the neighboring cells

prone to becoming cancerous.

As more and more of these senescent cells

accumulate in tissues, we see a lot of tissue dysfunction.

People think that this is actually contributing

to various age-related conditions that we see.

[calm music]

The average 30-year-old chronologically

is probably 30 years old biologically,

but you have some distribution where you have probably

about half of your 30-year-olds are gonna be older

biologically than they are chronologically,

and another half which is younger.

[calm music]

[Narrator] So how can someone find out their true age,

their biological age?

Scientists have defined what we call hallmarks of aging,

molecular or cellular changes

that we see tend to track with the aging process.

There's two different types of data you can use

to estimate your biological age.

One might be your clinical data,

the basic lab tests that you might go get

from your doctor's office.

[Narrator] This is basically what you're getting

when you have a yearly physical and the doctor screens

your cholesterol, thyroid, and glucose levels.

So you would get back your results and you could input it

into online calculators that are already available.

[Narrator] Biological markers are one way

to get a sense of a person's biological age.

What's another test?

One that my lab actually studies

called epigenetic modifications.

This is not changes in the DNA sequence itself.

It's the activity of genes,

so something that's happening on top of the DNA.

So it's basically turning off or repressing

certain parts of the genome while activating others.

In 2018, we developed one of these biological age measures

based on epigenetics.

We measure the amount of these chemical modifications

at very specific sites on your genome

to actually give you your biological age.

[Narrator] So an epigenetic test is different

from clinical blood work tests.

Epigenetics measures the stuff

attached to specific locationss throughout your genome.

And by looking at this pattern, we can say to someone

whether they have the biological features of someone

who is actually the same chronological age as them,

or hopefully like someone younger than them.

We developed an algorithm that could be used to predict

biological age as accurately as possible.

Now this is available to consumers.

You basically have this tube here that you would spit into,

fill it up to the line, and then put it back in the box.

And it actually ships to a laboratory

that's gonna extract your DNA

and measure these chemical modifications to your DNA,

run it through the algorithm that we developed,

and in a few weeks you get an email saying,

Here's your biological age.

[Narrator] But the trillion dollar question

for the medical industry is, can we reverse aging,

in a Benjamin Button sort of way?

Can you actually take people who have aged

and actually revert them back to a healthier state?

Right now there is not cutting edge science

for changing your biological age.

It's really what your mother or grandmother

or father told you.

Don't smoke, drink moderately, get a lot of exercise,

although not excessively.

Sleep, in terms of your quality of sleep,

but also get enough sleep.

And try and maintain low levels of stress from day to day.

But there's a lot on the horizon

in terms of what the scientific field is discovering.

Maybe in the next decade or two

we might have therapeutics to slow the aging process.

[Narrator] Remember the zombie cells from earlier

that many believe drive aging?

One approach centers on removing

senescent cells from the body.

Scientists have been really determined to try and target

and remove these cells.

There's actually a new class of drugs

that scientists are testing called senolytics,

which actually target what we call

the Achilles' heel of these cells.

So the fact that these cells are resistant to death,

so this is an upregulation of a certain pathway,

they actually target cells that have this upregulation,

kill them, and then they get removed by our immune system.

[Narrator] That sounds like an idea still on the horizon.

What about a secret fountain of youth hack for today?

As of right now there's no secret hack.

There are places throughout the world

that we call blue zones which are these regions

or hotspots of longevity,

places where you have a much higher proportion of people

who survive to at least 100.

These places are kind of scattered throughout the world.

There's one in the United States

called Loma Linda in California.

And people aren't sure why these blue zones exist.

Perhaps these are areas where people

have better health behaviors or perhaps even less stress.

There are definitely the shared nutritional habits

of these groups.

However, it hasn't been definitively shown

whether these factors are directly responsible

to the longevity advantage we see in these populations.

[Narrator] What about Dr. Levine?

Has she tried to intervene to slow her own aging?

I have measured my biological age repeatedly

over the last year.

I ended up being younger biologically

than I was chronologically,

but given how much effort I put in,

it wasn't really where I wanted it to be.

So now over the next year I'm really making an effort

to be much more rigorous to see if I can actually figure out

how to get that number even lower.

We all know what our lifespan means, right?

It's the amount of time you're going to be alive.

But more important than lifespan

is something that aging researchers call health span,

the amount of time in your life without any disease

or without the onset of the physical impairments

that tend to be associated with aging.

And when we talk about intervening in the aging process,

this is what we're actually trying to extend.

We don't want to just keep people living longer

in an unhealthy state.

We want to keep them living longer

in the healthiest state possible for as long as possible.