Collagen cross-linking, brain cell death, and arterial clogging may occur irreversibly by 20 months of age in mice.

“something like the damage will have occurred that's irreversible collagen cross-linking and death of some brain cells and clogging of the arteries or whatever is going to get you it started already by the time you're in your 50s and 60s or for Mouse by the time you're in your 20th or 21st month”