13 Sep 2020 · via @JuliaB_fitness 🐦
Julia B. writes on twitter:
There is no evidence that anything that extends lifespan in lower animals would have any lifespan extending effects in already long-lived humans. And conversely, no evidence that something with antiaging effects in humans would necessarily improve life/healthspan in rodents.
“One cannot assume that drug interventions in mice will automatically translate to humans, only about one in ten successful mouse cancer interventions ever makes it to the clinic & none of the 300+ mouse interventions in AD has proven effective in humans.” — You Have Come A Long Way Baby: Five Decades of Research on the Biology of Aging from the Perspective of a Researcher Studying Aging
Here’s a link to the NIA ITP (Interventions Testing Program), the only thing so far that seems to extend lifespan in both male/female mice (that won’t have side effects in humans) is seemingly Glycine. But then again I don’t think it really matters.
The benchmark must be de facto rejuvenation, like Mike/Irina Conboy et al has shown with Oxytocin + inhibition of systemic inflammation (systemic inflammation seems to lead to stem cell blockade). — Rejuvenation of brain, liver and muscle by simultaneous pharmacological modulation of two signaling determinants, that change in opposite directions with age
José Luis Ricón Fernández de la Puente frames the root cause of aging as a potential mix of noise and a programmed component:
You have to think about what are the ultimate root causes. And I think this is probably going to be just two things:
Noise. I think when cells replicate, maybe they don‘t fully replicate perfectly, maybe the epigenome is not easy to maintain through life. So one needs to fix that.
And then second, you have this programmed component. Maybe your body doesn‘t really want you to have a big thymus. Maybe it doesn‘t really want you to take in zinc. Because lack of zinc may be more useful to tackle pathogens you have already seen but not so for newer ones. There are some papers and speculate why it might be, why it might not be.
To drive home the point that this programmed aging thing matters:
If you look at one of the reasons the small worm C. elegans die is because of their intestines. Their intestines are initially taking some fat from the body to feed and generate eggs — from which new worms will hatch.
But as they age and there are no more eggs to generate, this mechanism continues working, even though the worm is not eating as much nor moving as much.
This mechanism continues acting in a way that the worm is eating itself, but because there are no eggs it just generates a lot of fat within itself.
So you have all these mechanisms that sound like they‘re great when you‘re young, but not so when you are older.
While discussing the stories we tell ourselves about death, José Luis Ricón Fernández de la Puente points out a very striking phenomenon:
Eric: What do you think about the cultural problem around lifespan extension? Many people are aversed to extending lifespan. Do you think that that‘s something that will just get over as we get closer to the technology? What do you think about the cultural resistance there? Because I think that‘s holding a lot of people back now for maybe working on it, maybe having more money, more government funding.
Aubrey de Grey calls this cultural resistance the “pro-death trance”. He argues that because aging and death is so prevalent — for all of our history, we haven‘t been able to get over it — we have developed this idea that it is actually OK.
It‘s like a Stockholm syndrome of some kind. You think that the bad thing is actually good. We begin to think, “Maybe it‘s good to have death (or aging). That‘s what‘s bring meaning to our lives.”
It seems to me that this psychological phenomenon is much more common within our lives than we realize.
I would say the same thing happens not only with death (or kidnapping as in the original Stockholm syndrome) but also with tragedies (like diseases or accidents) and also parenthood.
I guess there is something about the mean-making machine in our heads that makes us twist the miseries we face in life into something “good” — or even desirable.