Longevity: can ageing be reversed?

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The Economist
Ageing has always been inevitable but fasting, epigenetic reprogramming and parabiosis are just some...
Video Transcript:
[Music] aging it's the price we pay for living but it might not always be this way I think that in 50 years we'll be able to take a 20-year-old and give them a treatment they'll be Peter Pan they'll be forever young increasingly science is revealing how we can slow our biological clocks the rate of Aging is malleable and these tantalizing glimpses of an ageless future are attracting huge money big investors are zeroing in on age reversal research but does the science live up to the hype can we really slow down aging or even stop it
all together when I started the field it was like well let's let's see we moved from Hope to realizing the promise [Music] if we can slow aging enough so that we don't have diseases of Aging then we will be happy but there will be a side effect we might live longer I want you to walk back to me calling off every other letter of the alphabet starting with a a c she might not look it but gy is 98 years old she's a participant in the longevity genes project at the Albert Einstein College of Medicine
in New York my brother died in his mid 80s my sister is now 103 I have a younger sister who is 90 my father died 5 days short of 95 my mother died at 85 or [Music] 86 not only longer they live he here for the past 25 years near barel has studied the long lived in a bid to unlock the mystery of Aging when I started studying the centenarian the question is do they just live longer or do they also leave healthier and the answer is yes they're healthy we have discovered several genes in
our centenarians if we can imitate them if we can understand what happens to them we can create it as a drug or or some other intervention that we could use near is just one of a growing number of scientists chasing a future where aging is no longer inevitable but what is aging the longer you live the greater the impact of molecular and cellular damage in your body bringing you closer to death as to why we age one explanation is the Disposable Soma Theory there's an evolutionary trade-off between repair and reproduction it's not obvious why an
animal should become more damaged as it gets older and The evolutionary explanation is a thing called disposable Soma Theory and for that you have to understand that the purpose of an organism is to reproduce and since it's always at risk of getting killed by the outside world it makes sense to get your reproducing done as fast as possible so organisms tend to reproduce when they're young evolutionary pressure to keep them in full working order as they get older uh diminishes an adult human's risk of death doubles roughly every 8 years at 30 years of age
your odds of dying in the next year are less than 0.1% at 60 years of age that risk is 1% by the time you turn 90 it's over 15% but this isn't true for all animals alabra giant tortoises for example can live to well over 100 and as adults their risk of death remains roughly constant at just over 2% per year biologically speaking they hardly age at all so if aging isn't fixed Maybe maybe it can be changed in the 1930s a paper by Clive McCay a scientist at Cornell University in New York state proved
just that with one simple modification he revealed a way to make animals stay healthy for longer and even prolong their lives McKay found that if he restricted the diet of rats to near starving levels he could increase their lifespan by up to 30 3% that was the first time that we discovered that agent could be slowed down and it's true of pretty well every animal it's been tested on from yeast to dogs it sounds counterintuitive but in evolutionary terms it fits with the Disposable Soma theory if you are um solving then reproduction is possibly not
top of your list of things to do you want to survive and so a mechanism that will PR long life then to allow the animal to arrive at a point where it can reproduce successfully makes sense Evolution will wish to preserve the animal for better times but it does preserve Health as well it's not that you uh have a horrible old age you have a healthy old age but keeping yourself hungry for a longer healthier life is far from ideal the trick would be to fool the body into thinking it's starving when it's not and
the key to that may lurk in our DNA [Music] [Music] in the 1990s Cynthia Kenyan made headlines when her groundbreaking work with round worms showed for the first time that genes can play a part in aging amazingly we found that changing a gene called daff 2 could in one Fell Swoop double the lifespan of the animal and caus it to age much more slowly than normal so that it stayed young much longer than normal since then scientists have tweaked various genes in round worms resulting in mutants that can live to over 5 months old 10
times longer than those without the genetic changes we now know from work from our lab and from other labs that the reason that this Gene change slows down aging is because the genes that we changed are involved in a kind of programmed system of resiliency they make the animals less sensitive to pathogens they improve the ability of the animal to repair its DNA all sorts of things it's pretty amazing they're the same changes responsible for increasing lifespan in near starving animals only this time the animal can eat as much as it wants because its genes
have been tricked into thinking it's starving and humans have the genes they're right there in us but we don't yet know whether they affect our lifespan or not researchers have discovered other genes that affect Aging in humans but changing genes in people is irreversible a more practical way to slow aging would be to change not genes themselves but how they're read modifying something called The epig genome epigenetics literally means on top of genes so you can think of it as a layer of information that are added to the DNA the epigenome Tells genes when to
turn on and off there is a very promising um therapeutic Avenue that is being investigated now called epigenetic reprogramming tweaking the epigenome of mice has already shown it's possible to turn back a cell's biological clock in particular manipulating four proteins known as yam AKA factors and if you express those yamanaka factors in Old cells they change the epigenome and push the cell back in time epigenetic treatments are showing so much potential that research money is flooding in startups betting they can modify the epig genome to slow down aging are popping up all over Silicon Valley
and elsewhere the claims might sound outlandish but but the science is real epigenetics um or epigenetic patterns are laid down by enzymes which by Nature catalyze mostly reversible reactions and therefore if we can Target the correct enzymes to change those patterns and convert them back to the youthful pattern then it means that epigenetics is a drugable field of research in terms of anti-aging while a drug that can fight aging at the DNA level remains closer to Theory than practical application other methods of turning back the biological clog already exist for the past few years I've
been endeavoring to build the world's best anti-aging protocol some attempts to slow aging are raising eyebrows take Brian Johnson the man whose Zeal for a long life is viewed as obsessive by many these are all the supplements I take in his quest to remain Forever Young he's pushed boundaries even using his own son's blood we'll lead her out we'll lead her in for me as macabra as it sounds it seems to work in animals it's known as parabiosis it's almost like out of a vampire story parabiosis is when you take two animals of the same
species and Link their blood circulations together if you do it with animals of significantly different ages so one's quite young and one's quite old the older animal lives longer than you would expect although how much of this is down to special qualities in the younger blood is open to debate there probably are some factors that are crossing over from the young to the old but it look as though a lot of the effect is coming simply from the dilution of the bad factors in the old animal and blood isn't the only gift the young can
donate to provide the old with youthful figure if you transplant E from a young animal to an old animal that will extend its lifespan not much is known yet about why this works but the microbiome the bacteria in the gut changes with age presumably it's adapting to the the host we know the composition of the microbium changes as the animal gets older and it becomes more specific so this might be a way that you can gu its longevity through the gut it might take blood and guts to stay this young but a range of different
drugs are also showing promise at slowing down aging and some of them have been on pharmacist shelves for years a class of drugs that includes dasatinib used to treat leukemia has been found to extend life in Animals by attacking a major contributor to aging there's a certain kind of cell called a senescent cell it could have been any cell in your body but when it becomes ccent it stops stops dividing no longer proliferates and it becomes highly inflammatory it's a little Center of inflammation right there in your body and that's a problem because inflammation is
linked to a variety of age related diseases in animals where they've cleared ccent cells it's really remarkable the animals don't live that much longer but they're much healthier currently there are nearly 20 clinical trials globally for therapies that clear ccent cells but this isn't the only class of drug that shows promise in slowing aging this one is metformin it's been also taken off label for longevity purposes met forming is a common drug to treat diabetes but also the people who are using that are protected against variety of age related diseases metformin mimics dietary restrictions by
lessening the amount of sugar the body produces and absorbs the way it works inside a cell isn't completely understood but it reduces inflammation and helps break down accumulated rubbish in studies diabetics taking metformin have lived longer and healthier than people not on the drug whether they were diabetic or Not Another drug that seems to slow aging is Ramy already approved for use with organ transplants rap myin is an immunosuppressant it changes the way that nutrients are are sensed and changes the way that they're metabolized in ways which are useful to extending life Romy boosts the
way cells clear up junk that builds up inside them with age this means they can function better like a younger version of themselves whether they're drugs that already exist or new ones that change our epig genome anti-aging treatments are are coming and the need for them has never been greater we all know that we have a demographic shift in which fewer young people are supporting more old people so it's really really important that our older people stay vibrant and Youthful and productive it's also something we all want for ourselves and for our family and people
we love and for everybody a future where we grow old with aging would benefit billions and give the world an economic Boon too it's not a billion doll question it's trillions the last two years of medical expense of centenarians is third of those who di at 7 if people lived longer with a sharper decline in old age it would reduce medical expenses resulting from age related diseases although it's impossible to put a price on on extra years of healthy life one day hopefully more of us will be as independent into old age as gy as
I look back who ever thought of 98 when I was in my 60s I never thought of that but today 50 is like being a baby I want to beat my sister right now my sister is 103 I want to be able to live that long 120 thank you for watching to read more about the science of Life Extension click the link and don't forget to subscribe
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