Julia B. on the limitations of animal models
Julia B. tweets:
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 or 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 and none of the 300+ mouse interventions in Alzheimer’s Disease has proven effective in humans.” (sidenote: You Have Come A Long Way Baby: Five Decades of Research on the Biology of Aging from the Perspective of a Researcher Studying Aging by Arlan Richardson in The Journals of Gerontology: Series A, 2021.)
Here’s a link to the NIA ITP (Interventions Testing Program). The only thing so far that seems to extend lifespan in both male and 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 and inhibition of systemic inflammation (sidenote: Rejuvenation of brain, liver and muscle by simultaneous pharmacological modulation of two signaling determinants, that change in opposite directions with age by Melod Mehdipour et al in Aging (Albany NY), 2019.) . Systemic inflammation seems to lead to stem cell blockade.