The elixir of youth,
a potion that can hold back the hands of time,
once seemed impossible.
Over the years, many have claimed to have found such a potion.
None have.
'Til now.
At the start of the 21st Century,
we are at last learning the secrets of how to build a longer lasting human.
The search for the elixir of youth starts inside the cell.
Here, rogue elements cause most of the damage that we call ageing.
If we can reduce this damage,
we might slow the seemingly inevitable decline to old age.
Scientists have recently shown
that it's possible to double the lifespan of an animal.
Here was a perfectly normal animal which just simply lived twice
as long as its genetic counterparts.
And experts in ageing now believe that human lifespan can also be doubled,
to well over a 150 years.
I think 150 years is really a conservative estimate.
I wouldn't be surprised if it's not substantially longer.
Over the last century,
life expectancy has almost doubled.
We can expect to live a good 30 years longer than our great grandparents.
To double our current lifespan,
molecular biologists are manipulating our cells.
For the first time, they have proof that delaying ageing is possible.
But not everyone thinks it should be done.
If you talk to any molecular geneticist in the world today,
they will have to admit to you that this could happen.
They may hate it, with all of their heart they may hate it,
but they have to admit that
the technology exists for this to happen.
Drugs that have doubled the lifespan of animals may soon be tested on humans.
But are we ready for the changes a true elixir of youth would bring?
Long ago, some animals learnt the trick of living a very long time.
The hydra, for example.
This microscopic fresh water creature looks unremarkable,
but the hydra possesses one impressive ability,
time passes, but its youth and vigour never decline.
Strangest of all, when researchers break hydras down to their very cells,
something extraordinary occurs.
In a matter of hours, out of the mass of cells rise fully grown hydras.
Hydras, however, are very simple.
We are not.
The human body is made up
from 100 million million million different cells.
Some are manufactured continuously.
A 170 billion red cells form daily to carry oxygen.
10 billion white cells form to fight disease.
Others, like the cells of the nose and ear,
renew themselves so vigorously,
they just keep on growing all life long.
But, eventually, something goes wrong.
Cur cells start to feign, our skin wrinkles,
our hair greys, and eye-sight fades.
Is there anything we can do to turn back the clock?
Leading choreographer, Gillian Lynne,
doing an impressive job at staying young.
She keeps age at bay through sheer hard work.
She exercises for three hours everyday.
It's hard to believe she's 75 years old,
and can still go toe to toe with the 20 year olds.
The difficulty about trying to fight the ageing process is that
we're told that from the age of 25 the body starts to deteriorate.
I can't say that it's easy, it isn't, and it's mostly painful.
If you want to remain at all young, there are no shortcuts.
Well, as you see,
I've done quite well in keeping age at bay by exercising.
But there's one bit of me I'm afraid I can't control at all,
look at this, the famous skin test.
Slow like a tortoise.
And the effects of ageing are not just superficial.
These days, Gillian can only dance thanks to artificial hip joints.
Regular exercise will help you live a little longer,
but keeping forever young requires something more.
One man who claims he does possess that
extra something is Doctor Ron Livesy.
He runs a private anti-ageing clinic in New York.
He believes his treatment programme will slow down,
even reverse the ageing process.
He's in his mid-50s and he's on it himself.
I've noticed many benefits over the past five years.
I've regained my lean body mass and
lost approximately 60Ibs of abdominal fat.
My immune system is clearly working much better,
because I no longer get frequent colds
and no longer require sick days from work.
My bad cholesterol is now normal,
my good cholesterol has gone from being low to a quite healthy range.
Diane Gilman is one of Doctor Livesy's clients.
At 56, she has also decided not to give in to age.
I was always the kind of person that
believed you could fight mother nature.
If you ate right, if you exercised right,
if you got enough sleep,
and at about 50 years old I just hit a brick wall.
Mother nature said, aha, those aren't the plans I have for you.
I couldn't fight all of the things that were happening to me,
many of which I didn't even understand were about ageing.
Horrible back pains, terrible pains and cramps in my legs.
Diane's main weapon in the war against ageing
is called human growth hormone.
Whilst we're going through childhood and adolescence,
our bodies are churning out large amounts of growth hormone.
It helps build muscle and repair tissues.
At about the age of 25, levels peak,
then start to drop off.
By the time we reach old age,
our bodies are producing very little.
Diane is injecting herself with just enough growth hormone
to push her levels back to those she had when she was 25.
This requires two shots a day, at a cost of over $1,000 a month.
I will never forget the first day that
I injected myself with human growth hormone.
I felt like a watch.
If you have a watch where you can see all the cogs
and mechanisms working on the back,
it was like everything was working and going in one direction,
which everything came to a halt
and then started to go in another direction.
It really has turned back the hands of time.
Diane's daily injections have helped transform one symptom of ageing,
removing those extra pounds from her waistline.
The short term slimming effect of growth hormone is well known to doctors.
This patient has had a brain tumour.
It stopped him producing growth hormone.
He is being given doses of artificial growth hormone,
and he's experiencing the same loss of fat as Diane.
He's in the hands of hormone expert, Professor Stephen Shalet.
It does have a profound effect,
the amount of fat on their body is dramatically reduced,
and the amount of muscle is significantly increased.
This scan is of the cross section of a middle aged man.
It shows light areas of fat,
not only round the belly, but also inside.
Thick layers cover the major organs.
After six months of growth hormone, much of the fat has gone.
Could it be that growth hormone is the wonder drug,
the key to building a long living human?
I think it's unfortunate that one of the tags
that growth hormone was given was the elixir of youth.
There is no objective evidence
that growth hormone treatment prolongs life.
And there is a risk in using growth hormone when you're middle aged.
Cancer.
Growth hormone could encourage cancer cells to spread more rapidly.
The risks of an individual developing cancer,
far outweigh any potential benefits,
so I think it's extremely unwise,
and a road that we should not go down.
I weighed the risks and the conclusion I came to was,
you know what, I got nothing to lose here.
I've got everything to gain.
And so far, so good.
I'm up for the challenge.
I would like to see what the next 100 years brings for me.
While it is extremely unlikely that Diane will live to over a 150,
there are some animals that can.
Animals like Harriet.
She is over 170 years old,
which makes her one of the oldest creatures on the planet.
She was born before Victoria was Queen.
She was already five years old
when Charles Darwin paid her a visit
on his historic voyage to the Galapagos Islands.
Harriet may not be immortal,
but she's living proof that some animals
are much more successful than we are at resisting ageing.
The question is, how?
Clues lie in a shared ancestor,
one who lived a long, long time ago.
Four billion years ago, when life started on this planet,
the world looked very different.
Volcanoes were active, belching in to the atmosphere,
a mixture of carbon dioxide and sulphur.
These gases would have coloured the sky red.
Blue green algae dominated the planet.
They used the energy from the sun
and combined it with the gases in the atmosphere to make food.
But, as they spread over the planet,
these algae produced this new gas:
Oxygen.
Levels in the atmosphere slowly rose from almost nothing to over 20%,
and turned the sky blue.
But for early life, oxygen was a major hazard,
because oxygen is a highly explosive, reactive gas.
One man who knows just how dangerous it can be,
is pyrotechnics specialist, Malcolm Armstrong.
Oxygen is one of the most reactive gases on planet earth.
Chemical explosions require two components, fuel and oxygen.
Here, Malcolm fills a tube with a little fuel and a little oxygen.
The effect is underwhelming.
Now, keep the same amount of fuel and increase the oxygen.
I've put 300 times the amount of oxygen in here.
And it becomes a very different story.
Oxygen is dangerous.
Two and a half billion years ago,
oxygen would have killed most of the life forms
it came in contact with.
But one microbe found a way of
harnessing the explosive power of this gas.
It's called a mitochondrion.
Each mitochondrion became a miniature power station.
What followed next was one of the most important steps
in the history of life on this planet,
and is perhaps the most vital clue of all as to why we age.
Two of the many single cells joined forces.
The tiny power plant, one of the mitochondria,
was absorbed in to another primitive cell.
Life on earth changed forever.
Today, mitochondria live inside the cells of every living creature.
An expert in molecular biology,
John Burn, is fascinated
by our relationship with this early organism.
Most people had never heard the word mitochondria,
and yet the cells in my brain that are thinking of these words,
and the cells in my tongue that are helping to form them,
get their energy from mitochondria.
Every living creature on this planet has mitochondria within their cells.
They are the power plants that fuel all life, including us.
They're like millions of tiny batteries,
and when it was first suggested
that mitochondria might once have been free living bacteria,
it seemed almost impossible to believe.
These ancient bacteria really are everywhere.
For example, in the tails of sperm.
A new laser scanning microscope allows us to see,
for the first time, how individual sperm are powered by mitochondria.
They are the glowing section in the tail
that propel the sperm in their frantic journey to fertilise the egg.
And it's the same story with eggs.
They are so densely packed with mitochondria,
that under the laser they glow, like the sun.
Mitochondria are the power sources
that will drive the growth spurt to build a new human.
Cur every movement is powered by them.
And our every breath brings them the oxygen they need.
But there's a heavy cost.
With every breath we age.
Life giving oxygen is slowly killing us.
Because oxygen isn't just explosive, it's corrosive.
When oxygen touches pure iron it starts
a chemical reaction that turns it to rust.
This nail turned rusty by exposure to oxygen has been eaten away.
And if oxygen can do this to metal...
just imagine what it can do to your body.
It seems almost unbelievable that we're sitting here in 20% oxygen,
breathing it, depending on it,
and yet that same oxygen inside our body is actually doing damage,
it's like rusting us from the inside.
If you think about it, the atmosphere
should probably have a health warning.
The trouble is that it's not just oxygen that's corrosive.
So are its by-products.
Inside the mitochondria,
most of the oxygen we breath is transformed in to life giving energy.
But not all.
Some oxygen degrades in to particles called free radicals.
The trade-off, more power but more damage,
intrigues biologists like Gordon Lithgow.
Mitochondria is really like an alien invader.
It's a bit of a pact with the devil.
We get from the mitochondria lots of cheap free energy,
but also it's possible we get ageing.
The mitochondria are a bit like
a nuclear power station in your back garden,
lots of cheap, free energy,
but highly toxic by-products that have to be managed.
One released, free radicals can damage any part of any cell in the body.
Worst of all, they strike at the genes at the heart of every cell.
So what's the proof that this battering
inside leads to the decay we know as ageing?
Forensic pathologist, Dick Shepherd,
sees the sign of oxygen and
free radical damage almost every working day.
We see damage caused by oxygen in almost everybody that we examine.
It's present at a cellular level,
but we see it with the naked eye
in the brain and the heart and the lungs.
The lungs are the first point
at which the atmospheric oxygen reaches in to the body,
passes through tiny little spaces
that are lined by single layers of cells in to the blood stream.
But, of course, these cells,
although they are there to transport the oxygen,
are also particularly vulnerable.
And this is normal lung, smooth surface,
big blood vessel running down the middle of it.
There are no holes, there are no abnormalities.
A lifetime of exposure to pollutants like smoking, will change that.
Tobacco smoke dramatically increases
the production of free radicals in the body,
leading to cancer and other lung disorders.
In this lung, the damage is obvious.
The damage done by free radicals can also be seen in other organs.
Cardiovascular disease, that's disease of the heart
and the blood vessels is the number one killer throughout the world.
As it circulates, blood carries oxygen and free radicals around the body.
Over time, they can damage artery walls.
Combined with cholesterol,
this leads to furring up of important blood vessels.
This is the inside of the aorta,
the biggest blood vessel of the body.
A thin, smooth tube, a perfect vessel for the transport of blood.
And this is what an aorta that's got severe fatty deposits looks like.
The fat has been affected
by the oxidation and formed this rancid butter
which has caused weakening of the wall.
The fatty deposition starts in our 20s,
but it may be 40 years or so until the effects
become obvious to the individual.
The brain is about 2% of the weight of the human body,
but consumes about 20% of the oxygen.
And we're all worried about the effects of dementia as we get older,
and we do know that the brain cells are
particularly susceptible to the toxic effects of oxygen.
A young brain glows with huge numbers of mitochondria.
But as time goes by,
the free radicals produced
by the enormous energy demands of the brain,
begin to kill the mitochondria.
One by one, the batteries fail.
And so does our brain.
Memory becomes impaired,
and thinking becomes confused.
When we dissect brains we can sometimes see those changes.
Old brains show extensive signs of free radical damage.
In some brains, like this one,
the damage is greatest amongst the cells that control movement.
Normal brains have a healthy dark line of these specialist cells,
but in the brain on the right, the dark cells are no longer visible.
They have been destroyed by the products of oxygen.
Given that we know the effects of oxygen,
it's not a surprise that we age or we grow old.
What is surprising though is that
we actually live so long and remain so healthy.
The link between oxygen and ageing helps
explain a curious observation made over a 100 years ago.
The observation that most animals
have a fixed number of heart beats in their lifetime, around a billion.
A shrew lives life in the fast lane.
Its heart skips along at 500 beats a minute,
using up all its heartbeats in less than four years.
By contrast, an elephant's heart pumps a leisurely 30 times a minute.
It can live up to 80 years.
And a tortoise, like Harriet,
with a very low resting heart rate, just goes on and on.
The more you rush around, the more oxygen you need,
and the more free radicals you product.
And more free radicals means more damage.
If free radicals are the main reason why we age,
then perhaps we should be looking at ways
to reduce the amount we produce.
Michael Young is in training.
He's hoping that his training will allow him
to live an exceptionally long and healthy life.
Michael is nowhere near as fit or
as strong as the men he's swimming with.
But he's convinced that despite outward appearances,
it is he who will win the race of life.
Michael is 42 years old, and determined to live at least as long again.
His life plan is not based on exercise, but diet.
Essentially, it's an attempt to grow older more slowly, really,
and to minimise the dangers from all these degenerative diseases
that are going to happen by the time
most people are 60 or 70, they're going to start.
And I want them to start a little bit later in my life,
and that's what I'm on this diet for.
Michael has read extensively on the science of ageing,
and for the past three years he's been putting theory in to practice.
He has begun a radical vegetarian based diet.
That's because fruit and vegetables
are the best source of vitamins, like A, C and E.
These are so-called antioxidants.
They help soak up free radicals.
But fruit and veg alone will not greatly extend life.
So Michael also plans to reduce
the amount of free radicals his body produces.
He's trying to do this by eating less, far, far less.
I find Fridays is a good day for actually eating not very much,
because that's the day when I go to my war games club,
and the excitement of the war games club,
and playing with the model soldiers takes my mind off the fact
that I'm actually quite hungry.
And so often I'll manage on just perhaps an apple on Fridays.
Michael is, by profession, a military strategist,
and when it comes to ageing, he has studied the odds.
He eats less than 1500 calories a day.
And this diet isn't a short term tactic,
it's a lifelong campaign.
Michael is right that a diet high in fruit and veg
and low in fat will help him avoid mid life diseases.
But, will eating less help him live longer?
It sounds unlikely, unless you know the dramatic tale of two mice.
For mice, everything is in fast forward.
From tot to teens in a few months, then old age and death at two.
But this isn't inevitable.
In what is now a classic experiment, researchers took two young mice.
One mouse was allowed to eat as much as she liked.
She lived a typical couch potato existence,
and died soon after reaching two.
The other mouse led a spartan existence.
She got half the number of calories.
She lived on, bright and active,
dying at the grand old age of three.
In human years, that over 120.
It must have been one of the really exciting moments in science,
back in the 30s, when they suddenly realised
that simply by changing how much food a mammal ate,
they could change how long it lived.
I mean, it opened up all sorts of po