Dr. Darragh Ennis
speaker
54 appearances
1 recordings
1 series
first heard Apr 2025
last heard Apr 2025
Dr. Darragh Ennis’s voice in public audio — every appearance, attributed to the second.
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Appearances
Your brain washes itself at nighttime. There's been studies where they've watched people when they're going to sleep, and they've seen pulses of cerebrospinal fluid going over the brain during sleep. They really think that this maintenance time of sleep helps remove bad things for your brain, toxin buildup.
Well, the why do we age is certainly a question with an answer. You know, there's very deep-rooted ways that our cells and the cells of all living things work that makes them age. And one of the main things, as, you know, anybody who works on aging will understand, is that our DNA, the code that makes us what we are and are the instructions for us being alive, has a lifespan in and of itself.
So, you know, every high school student knows that DNA gets copied. But what they don't realise is every time it gets copied, that copy is only a tiny fraction smaller than the original. And eventually it's too small and it just goes away, you know. So that in itself is a limit. It's a ticking clock and there's nothing we can do about it.
So, yeah, that's a bit of a problem for people who want to live forever, I'm afraid.
Well, it's a maximum clock. So most people don't reach that. That isn't the sort of critical factor in what ends up, you know, finishing us off, essentially. So we'll all get old and we'll all age. But there are other factors that will damage our cells, damage our DNA. You know, exposure to sunlight makes our skin look older.
the other lifestyle choices what we eat you know what we do how much exercise we take how happy we are how stressed we are so it can even be a case of you can sort of think yourself young and that is literally going to be physiologically true because stress responses age our cells and aged cells go into a state called senescence which is effectively where they shut down and start to die off and that's contagious other cells around it can pick it up
And the stress response is a big factor in senescence. So if you're a very stressed out person with a bad lifestyle, you're gonna age a lot quicker than someone who's just happy-go-lucky and looks after themselves. So you can maximize your chances of being younger for longer, but not forever.
Unfortunately, no.
Well, it's driven obviously by the heart, but our blood vessels are quite elastic and they swell and shrink as the pulse rate from your heart comes. So that elastic motion helps maintain blood pressure and it's the pressure of the system that keeps it all moving. So if you have a very closely pressurized system and a pump,
it means that it can reach right to the end of these tiny capillaries that are, you know, potentially a couple of meters away or a meter and a bit away from your heart. And yeah, it's just, it's a constant pressurized system with a constant flow. It's astonishingly efficient considering it's driven by, you know, a lump of muscle about the size of our fists. That doesn't make very much noise.
If you ever see how much noise and energy a water pump
The main thing to remember is that by the laws of physics, you can't make energy, you just change its form. That's all you do. You just mess about with the structure of it. So energy can't be made, it can't be destroyed. So we take the energy from chemical bonds in our food and we just put it into a system that our cells can use.
And it's really, really clever and massively efficient how it does so. And it's largely driven by mitochondria, which are small organelles in our cells. And the fun thing is most scientists think that they were originally independent organisms way back in our evolution when we were like single cells that were eaten, essentially, but survived.
And because they were so good at providing energy, they've become part of our setup. So they're an alien life form that over tens of millions of years has just come along with living animals and helps them provide their energy. So... that massively makes it more efficient. And yeah, it's just, it's a series of different reactions that make food energy into the energy that our cells can use.
And it's amazing. It's astounding, to be honest.
No, no. I do quite a lot of, you know, public events and things and people ask me science questions and I love that. I really do because it's my real passion. But a lot of people say things like, oh, you know, in 10,000 years will we have much longer fingers because we type and that's how evolution works. And it really isn't. Evolution...
only works if something makes you more likely to survive and have children. Those two things have to be together. So if it doesn't make you more likely to reproduce, then evolution throws it away and that's it. And it's random, completely random, but over enough time, it will eventually, you know, get us from one of those single celled organisms to the one that can get the bus to work.
But the amount of time is absolutely immense. You know, you're talking tens or possibly even over hundreds of millions of years.
Very rarely. Like you will occasionally get a very bizarre mutation that will completely change an animal. It will change its color or it will do something really, really weird to it. But yes, most of the time the change is extremely gradual and quite often, uh, it's because there's a cost to everything.
So having any part of your body or doing any action or producing anything costs the cells in your body something. You know, you have to make the proteins, you have to do all of this kind of thing. Or there is a cost as in it makes you more likely that another animal will eat you or it makes you less likely to reproduce.
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