[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.
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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.
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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.
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- [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 locations 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.