- Here are two mice.
Believe it or not,
they're the same age.
The difference is in the treatment of their cells.
Let me explain.
Over the course of a person's life,
or in this case, a mouse's life,
cells accumulate damage.
They react in one of three ways.
They self-correct, they die or they retire.
These retired or zombie cells contribute heavily
to the aging process.
One mouse has had these zombie cells removed,
the other hasn't.
So how does this experiment relate to us,
human beings living longer
or maybe even forever?
I'm science writer Swapna Krishna.
Let's explore the future of aging.
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For most of human history,
the average life expectancy was 35 years.
People died young
but that all changed over the course of the 20th century
in what's been called The Great Escape
because of three main drivers:
vaccines, germ theory and antibiotics.
All those innovations have led
to a lot more people sticking around a lot longer.
By 2050, one in six people will be over the age of 65.
We're approaching a planet of eight billion people
and it's not because of escalating birth rates.
It's because babies and old people just aren't dying
as much as they used to.
For most of us, the last 30 years of life
will be some combination of juggling chronic disease
and general frailty.
That's to say at 60, 70, 80 plus,
your life will look and feel a lot different
than your younger years.
So what if we could slow aging way down
or just make it less horrible?
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First, we need to talk about aging.
What is aging?
What's actually happening in the body?
- That's kind of a million dollar question
and that's what everybody's trying to address.
- The general thinking is that aging is due
to the build up of damage within a person's body over time.
Remember the phrase dying of old age?
Well, these days, we can get more specific
because older people mostly die
as the result of diseases,
things like cancer or heart disease
and aging makes you more vulnerable.
Every eight years,
your chances of dying from disease roughly double.
So instead of trying to tackle all the diseases
that kill us,
scientists are going after the root cause: aging itself.
On a cellular level,
one way to tackle aging is to prevent
or inhibit senescence.
That's when our cells stop growing
and replicating and kind of become zombie cells.
When you're young, your immune system clears them out easily
but as we age.
- The number of senescence cells increase
and our immune system, its function decreases.
So you get this tipping point
where you start having too many senescence cells,
not enough functional immune cells.
- These senescence cells bombard nearby cells,
releasing chemicals that break down connective tissue
and trigger inflammation,
which is the root cause of many age-related diseases,
lik cancer, Alzheimer's and heart disease.
So can we just get rid of those senescence cells?
In 2016, a team of scientists did just that in mice.
Senescence cells contain the protein p16.
Scientists were able to create a drug
that targets p16 specifically,
killing senescence cells in the process.
The mouse that received the drug
was faster and stronger
until the last few months before death.
Its life was about 1/4 longer
and it was also healthier.
That discovery spawned a whole new chapter
of research called senolytics,
treatments that clean out those senescence cells.
- Everybody's jumping into the space.
Google, in collaboration with Abbvie,
started a company called Calico
and put billions of dollars into developing drugs
for healthy aging.
That says yes, people are believing
that this is possible.
- There's a catch here though.
The p16 protein is also responsible
for suppressing tumors.
If we're clearing out these senescence cells regularly,
it could trigger tumor and cancer growth.
We are just not sure of the long-term impacts yet,
but the key is preserving the good
while preventing the bad side effects.
Next, let's look at our genes,
the blueprint for how our body works and ages.
There's a whole set of experiments
called epigenetic engineering.
Basically, reprogramming our cells to be younger
so that they can do what they do best:
repair our damaged tissue.
- If you think what people in aging are interested in
is can you just take any cell
and just make it a young version of that same cell type?
It's going to be more difficult
than I think people are hoping to actually do it
in a body, especially like a human body
but I think it's just a really exciting thing
to just see where it kind of goes.
- But we're missing one
of the most blindingly brilliant aging discoveries ever:
healthy behaviors.
Yep.
Eat your veggies, exercise
and get enough sleep.
Oh, and stop smoking and drinking.
So where is all this leading us?
What does the future hold for aging?
For example, if you don't have the money to sign up
for reprogramming your cells,
are you just going to be left out?
There are already huge gaps in life expectancy and health.
In the US, for example,
the top 1% of earners live 10 to 15 years longer
than the bottom 1%.
Researchers like Paul Robbins
are looking at cheap publicly accessible drugs
and supplements that could have real effects
on extending the lifespan.
But none of that has been proven yet.
On the other hand, bioethicists,
like Dr. Paul Wolpe are a little more cynical.
He says that the entire enterprise
of increasing lifespans is misguided.
He points out that in a capitalist society,
we have to think about resources
and economic strain on younger generations.
- One of the great ironies of this
is that the very same Silicon Valley people
who are supporting this economically
wouldn't dream of hiring a 50-year-old for anything.
Right?
They would hire a 17-year-old
before they'd hire a 50-year-old.
- And if increasing our healthy years leads
to living longer, what does that mean for a planet
with finite resources
that is already approaching eight billion people?
- The goal is to really increase health spans.
So let's say we all,
let's say we live until we are like 80 or 90,
do we want to live healthy
until 60 and then the last 30 years of our life
just be bedridden and be miserable?
Or do we want to maybe live healthy
until we are 88?
And maybe the last two years we have somewhat
of a reduced quality of life.
- But will living longer make us happier?
Maybe or maybe not.
Isn't immortality usually a super villain origin story?
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- You have the lonely elderly,
it is a identified problem,
nothing to do with aging research.
Somehow magically when people live older,
that problem is supposed to disappear.
- Then there's the issue of living a long life
versus a purposeful one.
Are the two mutually exclusive?
As data from Star Trek once said,
- "Mortality gives meaning
to human life, captain."
- There are fundamental changes we'd have to make
to our societies if people lived healthier lives for longer
but the human lifespan
has already been increasing for centuries
and we've made the adjustments.
And it's clear that our elder care system
needs serious overhaul.
It's also important to take note
of who would have access to these kinds of treatments.
Just the wealthy presumably,
which would increase already stark inequalities.
Perhaps by focusing on health,
and living fulfilled lives,
we can bring about a revolution in aging
that will avoid long, slow declines
and instead allow people to live
and die in a meaningful way.
Thanks for watching.
What do you think the future of aging will look like?
What will the biggest challenge be?
Let us know what you think in the comments.
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