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  • Aging is an age-related decrease in viability and increase in vulnerability.

  • It means that, your capacity to respond to external stresses, and your capacity to function

  • decreases with age.

  • You become more vulnerable to diseases.

  • One of the major causes of mortality in the elderly is influenza, which is just the common

  • flu.

  • The thing with aging, of course, it entails different levels and different organs and

  • different systems in the body, which makes it very complex and relatively difficult to

  • study.

  • We actually don't know much about aging in the sense of its mechanisms.

  • Why we age, what drives the process of aging from a cell or molecular perspective--is still

  • relatively poorly understood.

  • I mean, if you look at it evolutionary, our life span only recently has been so long.

  • I mean the life span 150 years ago was something like 40 years old.

  • And a thousand years ago it was maybe 25.

  • When our species evolved and when most species evolved, most of the animals die when they're

  • young.

  • So there was really no pressure or very weak pressure,

  • for us to avoid aging or to live longer.

  • There are hypotheses, for example:

  • That there's damage to DNA, that then probably affects cell renewal and stem cells, which,

  • in turn, prevents repairing the body and contributes to loss of viability.

  • Then there's the free radical theory of aging.

  • This idea that as mitochondria in our cells, as they burn energy with oxygen, it generates

  • these very highly reactive compounds, which creates damaging oxidative stress, which in

  • turn accumulates with age, and that's the cause of aging.

  • There's also things like the telomeres.

  • So Telomeres are the tips of chromosomes and they shorten with cell division.

  • But because it occurs with age as well, people say, well maybe, this drives the process of

  • aging.

  • So after about age 30, your chances of dying double every eight years

  • This is fairly standard for human populations. No matter where you're from or where you live...

  • In a third world country, they may have higher mortality to begin with, but you'll still

  • see this exponential increase in mortality.

  • But then you have very unique creatures. One example are birds. Now birds actually live

  • longer than would be expected for their body size because, you know, they can fly and avoid

  • predators.

  • One of the species that we're interested in is an organism called the naked mole rat.

  • Which lives over 30 years.

  • Why?

  • Because it lives in this protected environment...

  • Then there is evolutionary reason, there is evolutionary pressure to live longer.

  • One of the interesting things about the naked mole rat is that it's extremely cancer resistant.

  • There's not been a single case of cancer in hundreds of naked mole rats.

  • So longevity is plastic. Not only are there species that live much

  • longer time than we do, but there are species that appear not to age. Like some species

  • of turtles.

  • Probably one of the greatest breakthroughs in the field so far is that you can manipulate

  • individual genes and it has a very significant impact on aging.

  • We know, for instance, that if you start manipulating DNA repair systems, sometimes, say, for example,

  • in mice, you get what looks like accelerated aging.

  • On the other hand, you can turn off a single gene in mice like growth hormone receptor

  • and increase life span by 50%.

  • There're also interventions that modulate aging.

  • So the most famous of them all is Caloric Restriction: restricting the amount of calories

  • animals eat while keeping nutrients like vitamins and minerals healthy.

  • And this has been known for decades to extend life span in rodents like 50%.

  • And they're healthier for longer and you know it's quite impressive.

  • So one of the things, for instance, our lab does, is, well, if you know of a gene that

  • mediates the effects of caloric restriction, then it may be a suitable target for you to

  • develop drugs that target that gene in order to have the same effect of caloric restriction

  • without you having to go on a diet.

  • Which, let's face it, most people don't want to.

  • We do a mixture of bioinformatics and experimental work.

  • We try to look for common patterns amongst these genes as a way to identify new genes

  • that modulate longevity.

  • And we want to identify which genes are regulating the other genes, so, key regulators of the

  • whole pathways.

  • And the thing to remember about aging in general is that it's very time-consuming and expensive

  • to do experiments. That's one of the problems of aging research.

  • If you could slow down the process of aging just by seven years, this would reduce in

  • half the incidence of age-related diseases at every single age.

  • This would have a massive impact on human life span, on human health.

  • I generally make the analogy of the Wright brothers

  • They used to look at birds and they said, listen, there are birds.

  • They are heavier than air, and they can fly. So if birds can fly, so can we make airplanes.

  • There's no law of nature that says that aging is immutable.

  • On the contrary. What we know now is that aging is surprisingly plastic.

  • In the sense that it can be manipulated by genes, it can be manipulated by evolution,

  • it can be manipulated by diet.

  • When I was younger, I think maybe ten years old, I realized that everyone ages and dies.

  • And I thought, well, why should that be, I mean, can't we do something about it?

  • So I thought, well, I'll do it. I'll study aging and I'll figure it out and I'll find

  • a solution for it.

  • So people don't have to age and die.

Aging is an age-related decrease in viability and increase in vulnerability.

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エイジングとは? (What is Aging?)

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