Is science gonna actually cure death?
The idea of why we age or can you reverse aging
or be immortal has actually been a topic
of interest for centuries.
I think a lot of people don't realize
how much power we actually have over our aging process.
Most people think of age
or aging in terms of chronological time.
So we all know how many years we've been alive,
and we usually measure our aging
in terms of months, days, years since we were born.
We almost give it a magic number.
So you're old when you're 65,
or you're old when you can see it in the mirror.
And we put a lot of emphasis and importance on this measure,
but actually this isn't the number that counts.
Scientists think aging is starting even before birth,
and it's really this continuous process that's happening
over our entire lives.
The most obvious thing that people associate with aging
is changes in their skin, changes in body composition,
graying of hair.
We experience functional changes:
our ability to walk, our balance, vision, hearing.
And also changes
in our risk of developing different diseases.
But in reality,
these aren't where aging is actually starting.
These are what we would call the emergence
or the manifestations of aging.
We really think aging
is starting at the molecular and cellular level,
and once that reaches a given threshold,
that's when we actually can start seeing this
in the mirror in our everyday lives.
I'm Dr. Morgan Levine.
I study the science of aging,
and my book is called "True Age."
So if I were to ask someone how old they were,
their immediate response
is going to be however many candles they blew out
in their last birthday.
It's the number on their driver's license or their passport.
And really what this is, is this is our chronological age.
It's just the amount
of chronological time you've been alive.
This number doesn't hold that much meaning,
except that it happens to be correlated
with this concept of biological aging.
So unlike chronological age,
biological age is a thing that we care about.
And what scientists mean by biological age
is the degree to which your biology has changed
over a given amount of time,
and we think these changes are gonna be maladaptive.
They're gonna lead to more dysfunction, more decline,
and ultimately more disease.
And we can actually see these changes on our faces
in terms of skin wrinkling, in our hair with graying.
But aging is starting at a molecular level,
and over time, this is gonna give rise
to all the functional changes
and manifestations that we tend to see with aging.
Many diseases of aging can actually be attributed
to dysfunction decline in specific organ systems.
So something like diabetes can be thought of
as a decline in our metabolic system.
Things like Alzheimer's disease are declines and dysfunction
in our central nervous system.
And another disease of aging called sarcopenia,
which is the muscle wasting that we see with aging,
can be thought of as declines
in our musculoskeletal systems.
People have been saying that we should try
and quantify this concept of biological age since the 1980s.
So Alex Comfort was the first person that proposed
that there was this idea of biological age
that could be measured.
But it probably wasn't until around 2010, 2012
that people were actually putting forth algorithms
that we could show and validate were decent,
although maybe not perfect measures
of this concept of biological aging.
It's gonna tick forward in a monochromatic fashion-
vs. biological age we actually think is malleable.
We know that aging can be slowed.
We see this when comparing across species.
Species don't decline all at the same rate.
Some of them actually do this at such a slow rate,
what we call 'negligible senescence,'
that we actually can't observe aging in those systems.
So usually to tell how fast different organisms are aging,
we look at their 'survival curve.'
Do you see an increased risk of mortality in a population
as a function of time?
And we think of that as the overall rate
at which that type of species is actually aging.
And we also can see this in humans.
Clearly, not everyone who has lived 50 years
has declined in terms of their health status
and functioning to the same degree.
So this is really where we get into this idea
of can we measure biological age?
A great way for people to actually use this science
is to track their Phenotypic age.
We came up with this idea of Phenotypic age back in 2018.
This was really meant to capture your overall phenotype
or physiological rate of aging.
We tried to actually use very commonplace clinical chemistry
or lab measures.
So these are things that you would go
to your physician for your annual appointment,
and probably are already getting measured.
Things like functioning of different organs
including our liver, kidney.
They capture metabolic health, they capture lipids,
and to some degree, they're also capturing things
like our inflammation and immune profile.
And we think this measure of aging is really important
because it captures the physiological changes
that we actually think precede the dysfunction
that we see arising in disease.
If you looked at a population,
you'd expect to see a normal distribution
where you find most people are predicted
to be the same biological
or Phenotypic age as they are chronologically.
But we know there's also spread on either side,
and when we look at the average, for instance,
United States population,
we see that kind of that standard deviation
is around five years.
Granted, you can get extreme outliers,
so people who look 10 or maybe even 20 years older
or younger than expected for their chronological age,
but most people will fall
in that kind of plus or minus five years
of their chronological age.
If you have already visited your doctor
and you've got an annual blood test,
you probably can get your Phenotypic age test for free.
So there are online calculators
that list the nine biomarkers
that you actually need to calculate your Phenotypic age.
These are freely available on the web.
So all you would need to do
is go and find your most recent lab test,
input the values,
and the algorithm will actually produce
a Phenotypic age measure for you.
So a lot of people are probably thinking,
"I don't want to know what my biological age is.
I'm scared I'm gonna get a higher number.
I need to be on my best behavior for a month
before I actually track it."
But it's really important to remember
that this number's not set in stone.
It's not dictated by our genes,
and there's so much you can do to actually impact it.
So it's more important to actually have that information,
and to actually use that
to try and improve your life overall.
So can we reverse aging?
Until the science actually comes up with drugs or treatments
to actually try and target aging,
lifestyle right now is actually our best ticket
in terms of slowing our aging process.
Living systems are adaptive.
We adapt to our environment.
We adapt to the things we experience.
So you can actually boost things like resilience
through different lifestyle behaviors.
For instance, physical activity can increase our resilience
and buffer us against further stressors down the road.
Different dietary regimens
can increase our resilience as well.
Whether we're obese, what we're eating,
whether we smoke or drink,
actually has a very massive impact
on people's Phenotypic age overall.
And these aren't new things.
These are things that we've been told about
from let's say, our mothers or grandmothers.
So they shouldn't be a surprise to people,
but I think people don't realize how much
these actually impact how fast they're gonna age,
and also their propensity
for developing different age-related diseases.
Aging is the biggest risk factor
for most of the diseases that people worry about.
And scientists think that rather than trying to treat each
of those diseases individually,
if we were to actually slow the rate
at which people were aging
and slow the decline in our different kind of organ
and physiological systems,
we could either prevent
or perhaps lessen the impact of many of these diseases.
So it's not just giving people a longer life,
but it's keeping them healthy
and functional for as long as possible.
In the end, it's really important
for people just to realize how much power they actually have
in terms of impacting the way in which they're gonna age
and impacting the risk of disease.
Our risks of disease are not written in our genes.
Yes, we will probably all age,
and we're not going to essentially stop that.
But the rate at which that happens
and the length of time that you can maintain health
and optimal functioning, really comes down to a lot
of what you do in your everyday life.
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