AMA #35: "Anti-Aging" Drugs NAD+, metformin, & rapamycin

I just have a hard time believing that there's going to be an epigenetic signature that I think will be more valuable than some of the most tried-and-true phenotypic tests: V02 max, zone 2 threshold, grip strength, muscle mass, fat-free mass index—all of these sorts of things that are so highly, and I believe causally, linked to longevity.

There are going to be some people who will argue that we have remarkable biomarkers for aging, and then you'll have others—and I'm probably more in this camp—that would argue, actually, we don't really have any good biomarkers for aging.

When people talk about epigenetic clocks, what they're specifically talking about are chemical modifications, either to the DNA or to the histones that pack the DNA. And these chemical modifications control gene expression.