1) There is no "epigenetic clock theory". There is an epigenetic clock though, and it's a well established system[0]. They are talking about measuring a cellular "age" by measuring the methylation/acetylation tags on DNA and histones. These tags are essential for specialized cellular function and a core part of Horvath's/Sinclair's "epigenetic theory of aging".
2) Sinclair is not a quack, and to depict him as such doesn't help whatever opinion you're parroting. The guy has quite the resume, and obviously playing the social media game doesn't mean you should dismiss that.
3) Linking a tweet that essentially says "no you're wrong" is adding to the noise and isn't helpful. Brenner is saying reversing epigenetic age isn't going to make you immortal, which is true. It doesn't mean Sinclair's work is BS.
Follow Brenner for a while on Twitter and you'll come to realize most of Sinclair's public claims are pure BS.
> There is no "epigenetic clock theory". There is an epigenetic clock though
Well, there's an epigenetic clock wikipedia page, but yes it's a theory that those epigenetic markers are meaningful indicators of age. Except there are pro-aging molecules like hGh which reverse some of the epigenetic markers despite being pro-aging.
I don't know man, I'm just a SWE, so I'll leave this to the PhD's, but clearly many of Sinclair's claims are false, similarly to Dr. Huberman. A lot of SiValley folks have bought into their futuristic promises despite most of them relying on poor science.
