The science of cells that never get old | Elizabeth Blackburn


Where does the end begin? Well, for me, it all began
with this little fellow. This adorable organism — well, I think it’s adorable — is called Tetrahymena
and it’s a single-celled creature. It’s also been known as pond scum. So that’s right, my career
started with pond scum. Now, it was no surprise
I became a scientist. Growing up far away from here, as a little girl I was deadly curious about everything alive. I used to pick up lethally poisonous
stinging jellyfish and sing to them. And so starting my career, I was deadly curious
about fundamental mysteries of the most basic building blocks of life, and I was fortunate to live in a society
where that curiosity was valued. Now, for me, this little
pond scum critter Tetrahymena was a great way to study
the fundamental mystery I was most curious about: those bundles of DNA
in our cells called chromosomes. And it was because I was curious
about the very ends of chromosomes, known as telomeres. Now, when I started my quest, all we knew was that they helped
protect the ends of chromosomes. It was important when cells divide. It was really important, but I wanted to find out
what telomeres consisted of, and for that, I needed a lot of them. And it so happens
that cute little Tetrahymena has a lot of short linear chromosomes, around 20,000, so lots of telomeres. And I discovered that telomeres
consisted of special segments of noncoding DNA right
at the very ends of chromosomes. But here’s a problem. Now, we all start life as a single cell. It multiples to two.
Two becomes four. Four becomes eight, and on and on to form
the 200 million billion cells that make up our adult body. And some of those cells
have to divide thousands of times. In fact, even as I stand here before you, all throughout my body,
cells are furiously replenishing to, well, keep me
standing here before you. So every time a cell divides,
all of its DNA has to be copied, all of the coding DNA
inside of those chromosomes, because that carries
the vital operating instructions that keep our cells in good working order, so my heart cells can keep a steady beat, which I assure you
they’re not doing right now, and my immune cells can fight off bacteria and viruses, and our brain cells
can save the memory of our first kiss and keep on learning throughout life. But there is a glitch
in the way DNA is copied. It is just one of those facts of life. Every time the cell divides
and the DNA is copied, some of that DNA from the ends
gets worn down and shortened, some of that telomere DNA. And think about it like the protective caps
at the ends of your shoelace. And those keep the shoelace,
or the chromosome, from fraying, and when that tip
gets too short, it falls off, and that worn down telomere
sends a signal to the cells. “The DNA is no longer being protected.” It sends a signal. Time to die. So, end of story. Well, sorry, not so fast. It can’t be the end of the story, because life hasn’t died
off the face of the earth. So I was curious: if such wear and tear is inevitable, how on earth does Mother Nature make sure we can keep our chromosomes intact? Now, remember that little
pond scum critter Tetrahymena? The craziest thing was,
Tetrahymena cells never got old and died. Their telomeres weren’t shortening
as time marched on. Sometimes they even got longer. Something else was at work, and believe me, that something
was not in any textbook. So working in my lab with
my extraordinary student Carol Greider — and Carol and I shared
the Nobel Prize for this work — we began running experiments and we discovered
cells do have something else. It was a previously undreamed-of enzyme that could replenish,
make longer, telomeres, and we named it telomerase. And when we removed
our pond scum’s telomerase, their telomeres ran down and they died. So it was thanks
to their plentiful telomerase that our pond scum critters never got old. OK, now, that’s
an incredibly hopeful message for us humans to be
receiving from pond scum, because it turns out that as we humans age,
our telomeres do shorten, and remarkably,
that shortening is aging us. Generally speaking,
the longer your telomeres, the better off you are. It’s the overshortening of telomeres that leads us to feel and see
signs of aging. My skin cells start to die and I start to see fine lines, wrinkles. Hair pigment cells die. You start to see gray. Immune system cells die. You increase your risks of getting sick. In fact, the cumulative research
from the last 20 years has made clear that telomere attrition is contributing to our risks
of getting cardiovascular diseases, Alzheimer’s, some cancers and diabetes, the very conditions many of us die of. And so we have to think about this. What is going on? This attrition, we look and we feel older, yeah. Our telomeres are losing
the war of attrition faster. And those of us who feel youthful longer, it turns out our telomeres
are staying longer for longer periods of time, extending our feelings of youthfulness and reducing the risks
of all we most dread as the birthdays go by. OK, seems like a no-brainer. Now, if my telomeres are connected to how quickly
I’m going to feel and get old, if my telomeres can be
renewed by my telomerase, then all I have to do to reverse
the signs and symptoms of aging is figure out where to buy
that Costco-sized bottle of grade A organic
fair trade telomerase, right? Great! Problem solved. (Applause) Not so fast, I’m sorry. Alas, that’s not the case. OK. And why? It’s because human genetics has taught us that when it comes to our telomerase, we humans live on a knife edge. OK, simply put, yes, nudging up telomerase
does decrease the risks of some diseases, but it also increases the risks
of certain and rather nasty cancers. So even if you could buy
that Costco-sized bottle of telomerase, and there are many websites
marketing such dubious products, the problem is you could
nudge up your risks of cancers. And we don’t want that. Now, don’t worry, and because, while I think
it’s kind of funny that right now, you know, many of us may be thinking,
“Well, I’d rather be like pond scum,” … (Laughter) there is something for us humans in the story of telomeres
and their maintenance. But I want to get one thing clear. It isn’t about enormously
extending human lifespan or immortality. It’s about health span. Now, health span is the number
of years of your life when you’re free of disease,
you’re healthy, you’re productive, you’re zestfully enjoying life. Disease span, the opposite of health span, is the time of your life
spent feeling old and sick and dying. So the real question becomes, OK, if I can’t guzzle telomerase, do I have control
over my telomeres’ length and hence my well-being, my health, without those downsides of cancer risks? OK? So, it’s the year 2000. Now, I’ve been minutely scrutinizing
little teeny tiny telomeres very happily for many years, when into my lab walks
a psychologist named Elissa Epel. Now, Elissa’s expertise is in the effects
of severe, chronic psychological stress on our mind’s and our body’s health. And there she was standing in my lab, which ironically overlooked
the entrance to a mortuary, and — (Laughter) And she had a life-and-death
question for me. “What happens to telomeres
in people who are chronically stressed?” she asked me. You see, she’d been studying caregivers, and specifically mothers of children
with a chronic condition, be it gut disorder,
be it autism, you name it — a group obviously under enormous
and prolonged psychological stress. I have to say, her question changed me profoundly. See, all this time
I had been thinking of telomeres as those miniscule
molecular structures that they are, and the genes that control telomeres. And when Elissa asked me
about studying caregivers, I suddenly saw telomeres
in a whole new light. I saw beyond the genes and the chromosomes into the lives of the real people
we were studying. And I’m a mom myself, and at that moment, I was struck by the image of these women dealing with a child with a condition very difficult to deal with,
often without help. And such women, simply, often look worn down. So was it possible their telomeres
were worn down as well? So our collective curiosity
went into overdrive. Elissa selected for our first study
a group of such caregiving mothers, and we wanted to ask:
What’s the length of their telomeres compared with the number of years
that they have been caregiving for their child with a chronic condition? So four years go by and the day comes
when all the results are in, and Elissa looked down
at our first scatterplot and literally gasped, because there was a pattern to the data, and it was the exact gradient
that we most feared might exist. It was right there on the page. The longer, the more years that is, the mother had been
in this caregiving situation, no matter her age, the shorter were her telomeres. And the more she perceived her situation as being more stressful, the lower was her telomerase
and the shorter were her telomeres. So we had discovered something unheard of: the more chronic stress you are under,
the shorter your telomeres, meaning the more likely you were
to fall victim to an early disease span and perhaps untimely death. Our findings meant
that people’s life events and the way we respond to these events can change how you
maintain your telomeres. So telomere length wasn’t
just a matter of age counted in years. Elissa’s question to me, back when she first came to my lab,
indeed had been a life-and-death question. Now, luckily, hidden
in that data there was hope. We noticed that some mothers, despite having been carefully caring
for their children for many years, had been able to maintain their telomeres. So studying these women closely revealed
that they were resilient to stress. Somehow they were able
to experience their circumstances not as a threat day in and day out but as a challenge, and this has led to a very important
insight for all of us: we have control over the way we age all the way down into our cells. OK, now our initial curiosity
became infectious. Thousands of scientists
from different fields added their expertise
to telomere research, and the findings have poured in. It’s up to over 10,000
scientific papers and counting. So several studies
rapidly confirmed our initial finding that yes, chronic stress
is bad for telomeres. And now many are revealing that we have more control
over this particular aging process than any of us could ever have imagined. A few examples: a study from the University
of California, Los Angeles of people who are caring
for a relative with dementia, long-term, and looked at their caregiver’s
telomere maintenance capacity and found that it was improved by them practicing a form of meditation for as little as 12 minutes
a day for two months. Attitude matters. If you’re habitually a negative thinker, you typically see a stressful situation
with a threat stress response, meaning if your boss wants to see you, you automatically think,
“I’m about to be fired,” and your blood vessels constrict, and your level of the stress
hormone cortisol creeps up, and then it stays up, and over time, that persistently
high level of the cortisol actually damps down your telomerase. Not good for your telomeres. On the other hand, if you typically see something stressful
as a challenge to be tackled, then blood flows to your heart
and to your brain, and you experience a brief
but energizing spike of cortisol. And thanks to that habitual
“bring it on” attitude, your telomeres do just fine. So … What is all of this telling us? Your telomeres do just fine. You really do have power
to change what is happening to your own telomeres. But our curiosity
just got more and more intense, because we started to wonder, what about factors outside our own skin? Could they impact
our telomere maintenance as well? You know, we humans
are intensely social beings. Was it even possible
that our telomeres were social as well? And the results have been startling. As early as childhood, emotional neglect, exposure to violence, bullying and racism all impact your telomeres,
and the effects are long-term. Can you imagine the impact on children of living years in a war zone? People who can’t trust their neighbors and who don’t feel safe
in their neighborhoods consistently have shorter telomeres. So your home address
matters for telomeres as well. On the flip side, tight-knit communities,
being in a marriage long-term, and lifelong friendships, even, all improve telomere maintenance. So what is all this telling us? It’s telling us that I have the power
to impact my own telomeres, and I also have the power to impact yours. Telomere science has told us
just how interconnected we all are. But I’m still curious. I do wonder what legacy all of us will leave for the next generation? Will we invest in the next young woman or man peering through a microscope
at the next little critter, the next bit of pond scum, curious about a question
we don’t even know today is a question? It could be a great question
that could impact all the world. And maybe, maybe you’re curious about you. Now that you know
how to protect your telomeres, are you curious what are you going to do with all those decades
of brimming good health? And now that you know you could impact
the telomeres of others, are you curious how will you make a difference? And now that you know the power
of curiosity to change the world, how will you make sure
that the world invests in curiosity for the sake of the generations
that will come after us? Thank you. (Applause)


100 Responses

  1. Lajwanti Shahani

    December 25, 2017 6:35 am

    Amazing how science finds evidence from things and places we would never consider. Excellent talk 🙂

  2. Carrie Perkins

    December 26, 2017 8:04 am

    I'm forty five and studying gcse biology. The more I learn the more incredible our world becomes. The more I learn the more I can understand what people like Elizabeth are devoting their lives to understanding. Thanks Ted Talks.

  3. Josh T

    December 26, 2017 6:14 pm

    This woman is that absolute genius teacher you had in hs or college that always made jokes that weren't funny but she chuckled anyway like she didn't practice it in the mirror a half dozen times that morning.

    I hurt myself with this comment 🙁

  4. troy lenny

    December 26, 2017 7:17 pm

    Very interesting – demonstrates the urgency needed to reduce global conflict, for all.

    Does anyone know where I may finding cutting-edge research, about aging?

  5. Krittin Kalra

    December 28, 2017 7:09 pm

    The message is loud and clear – the body follows the mind. We have known this for a long time now and the brilliant research Elizabeth and scientists like her are doing reaffirm of how important our mental state is. In today's world, we give little importance to mental health. Look at our education systems for example; how much education were we given on how to handle our emotions and stressful situations. And as Elizabeth pointed out, the effects in the length of telomere are even visible in children, so that means we have to have some sort of curriculum wherein children are taught on how to get hold of their emotions. Mental health is something that can be taught. I hope we make progress in this direction.

  6. Sharl Tyunder

    January 2, 2018 8:42 pm

    Am lost on commenting.
    be assured,no such thing i happen to be as a ‘gun’ to be triggered,/only been rude with the joke!?/.
    I meant to pay respect with the ⁉️, /Mrs./, in not been sure as to the simplicity of having to ignore ‘at least’ a tittle of ‘honour’?(suits You for regards???),or simply a means’s of approaching an Elder without trying to influence misunderstanding.
    Anyway,no fuss;
    What do You think of the rest of the note,is were my curiosity should die-or had to i be surprised,Friend(⁉️).

  7. Maddie Patrick

    January 23, 2018 7:57 am

    Damn, that means my telomeres are not looking too hot right now. xD this was so interesting though. I have always heard that stress can shorten your lifespan, but I never knew why or if it was even true! I'm a psychology major so this really got me thinking…and I realized that NOW IM STRESSING ABOUT WEARING DOWN MY TELOMERES BY STRESSING. XDD

  8. Άγγελος Καλαθάς

    March 31, 2018 11:32 am

    So basically what stoic and eastern philosophers have said centuries ago backed by science.

  9. Michael Hartman

    April 22, 2018 12:02 am

    While I have followed her work for some years, this is the first time I have seen her speak. She is such a charming person. Thank you.

  10. Biological Statistics

    April 23, 2018 2:45 pm

    This is how the school systems are killing young kids by stressing them on the daily.

  11. Igor Babii

    June 2, 2018 12:18 pm

    Greate lecture! A lot of thanks! So I invite anyone ho wants making more longer yours telomeres in Clinic of healthy vessels. Welcome to Kiev, Ukraine!

  12. dlp3350

    June 14, 2018 3:07 pm

    Dr. Blackburn first came to my attention in a documentary titled Stress: Portrait of a Killer, which mainly focused on Robert Sapolsky's work, but included a segment on Dr. Blackburn and exactly the study with Eliza Eppel that she mentions here. For those interested in finding the full effects of stress on our lives and health, I heartily (no pun intended) recommend that video as well.

  13. Dongseong Hwang

    July 13, 2018 8:49 pm…3244.5735.0.9048.….0…1.1.64.psy-ab..0.2.232…0j0i5i30k1j0i8i30k1j0i8i10i30k1.0.o4VLQAXgnsQ

  14. Didivs Ivlianvs

    July 17, 2018 1:52 am

    How about whatever version of telomerase that allows the zygote of the next generation to start over with brand new telomeres?


    August 6, 2018 12:27 pm

    The biology of belief and environment. This is the new science on aging and disease.

  16. Salvador Hirth

    August 17, 2018 12:14 pm

    After watching this informative video, couples can now include a new argument to stop discussions:
    " _enough! you are shrinking my telomeres! "

  17. Anders Ledell

    August 20, 2018 8:44 pm

    There is a typo in the title. Because this video is discussing a single type of science, it should say "the science of cells that never gets old." Alternatively, it could read the "sciences of cells that never get old."

  18. Ryan Grocott

    August 29, 2018 10:41 am

    If I say “telomeres” one more time, that’s 36 “telomeres” in this “telomeres” upped rhythm.

  19. Robert

    September 11, 2018 6:53 pm

    Can someone explain to me my question. (An Unethical Question FOR SCIENCE) Since telomeres gets shorten as dna divides, the telomeres in our sperms/eggs should be technically be new right? Can't we do something about that since we actually produce new full length telomeres in sperms/eggs everyday/month

  20. SD

    September 20, 2018 7:20 am

    These evolutionists have read every book except for the Bible and if they were to read the Bible they would then truly understand. These bodies, earth and universe is just a digital simulation. From a Christian point of view this is amazing but it is nothing compared to what you will receive if you except the Lord Jesus Christ as your Savior and repent of all your sins in His name.

  21. The Ultimate Reductionist

    October 17, 2018 10:48 pm

    To Bi below:
    These christians have read only ONE book – the unimportant bible – but NEVER ANYTHING outside that.
    If they were to read Karl Marx's "Das Capital" or Dr Peter Singer's "Animal Liberation", then they would truly understand.

  22. joe momma

    November 8, 2018 11:12 am

    Just fast often to protect your telomeres and trigger autophagy, autophagy will clean up those damaged cells that lead to cancer. With no products/treatments to sell it will be a long time before this catches on.

  23. chronok

    November 22, 2018 2:52 pm

    I find it super stupid that such little telomere experimentation was done with humans. Basically almost none in the grander scheme of things. Let's see how Bill Andrews bet against alzheimer plays out. The first dying patient (advanced alzheimers) should be tested on 10th of december.

  24. Marcos Rivera

    November 24, 2018 3:06 pm

    How does this only have 120,000 views? It should be viewed by millions but people are only curious about the new fornite skin, funny youtube videos, movies, juul pods and celebrities.

  25. Finn Manning

    November 25, 2018 1:25 am

    The way she describes and talks about this topic just grabs your attention and makes you think of more questions, I love it

  26. Yusef Endure

    December 7, 2018 1:35 am

    I had heard some of this info before, but how she put it all together brought home another profound example of how we humans are all connected. All life is connected. Blown away. Thanks for sharing this video.

  27. szman167

    December 12, 2018 6:33 pm

    Sorry I disagree, telemoraze does not increase cancer chances, it does the opposite since your body is not stronger and able to defeat the cancer VIRUS, never get Vaccines, ever!!!

  28. Sara Abell Gayfield

    January 25, 2019 8:19 am

    I learned about Elizabeth Blackburn a few years back, I'll never forget her-she is an inspiration!

  29. Lucas S.

    January 30, 2019 11:55 am

    I want to be a microbiologist but sadly, even though I love Biology, I am too afraid of not getting a job. I am probably going to study pharmacy, even though Biology is my passion 🙁

  30. MaddenFootball Talk

    February 15, 2019 9:02 pm

    Great information but how do we lengthen them, what can be taken or eaten to remove this cap. I mean ancient accounts speak of a cap placed on our chromosomes to stop ppl from living 1000's of years old. The God's got upset with ppl and did that. So glad this is discovered but how to reverse this is the mission

  31. zzcaptain (Mast IV)

    March 3, 2019 6:04 am

    just another video about blocking science from really helping people to get a chance to live longer.

  32. maulik ramanandi

    March 6, 2019 2:29 am

    Really informative and an interesting talk.
    Tq so much for your efforts and love from India 😇

  33. Francis Tremblay

    April 27, 2019 6:19 am

    The whole presentation was just fine. On the other hand, the outro was not necessary at all and somewhat too much.

  34. SQ K

    June 24, 2019 1:34 am

    what a waste of research money. even my 9 year old kid already knew stress leads to illness and shorter life. you don't need to look at pond scum to come to that same conclusion. tell me something I don't know

  35. Kuhtuva Malli

    June 28, 2019 4:10 am

    Supercool stuff! But now I start think a possibilty that Telomeres affect my genetic susceptibility to being stressful human. Which I am.

  36. 김경미

    June 29, 2019 4:39 am

    작은 힌트도 놓치지 않는 태도가 결국 대단한 발견을 찾아내게 되었네요. 정말 존경합니다.

  37. John O'Neill

    July 7, 2019 12:10 pm

    Chemical, physical and emotional stress. All effect gene expression. Take for example nutrients. We know that new cells require essential nutrients, building blocks. Amino acids, EFA's, minerals. If we don't get these we produce defective cells. Eliminate chemical, physical and emotional stressers. Eat a good healthy diet, get exercise, look after the mind and always continue learning.
    Great talk.

  38. UHFStation1

    July 12, 2019 9:59 pm

    I really hope we discover a way to add to telomeres to our DNA. Because as soon as we start killing off senescent cells we will need to divide healthy cells to replace them which basically trades better health for less life.

  39. Jennifer York

    August 10, 2019 5:59 pm

    Her book – The Telomere Effect – genuinely changed my life & how I live it – I would highly highly recommend giving it a read.

  40. TnMtnRdr

    August 17, 2019 12:54 pm

    Plant cells do not age. They are frequently tissue propagated endlessly. So eat live plant products and it helps add life to our bodies. Definitely appears to work. Plus gardening is low stress occupation. The few people I've heard of who went 100% with it have experienced wonderfully reduced aging rate, and disease elimination.


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