Went vegetarian ~13 years ago. No regrets, no problems, no complaints.
Now, there are even commercial companies that measure Epigenetic age of cells with a technique called DNA methylation.
References: https://investinaustria.at/en/news/2022/03/epigenetic-clock-...
https://www.mydnage.com/?gclid=Cj0KCQjwheyUBhD-ARIsAHJNM-Mrk...
The reference you gave measure blood or urine samples which would probably not be representative of epithelial cells. Also i like non-descriptive but professional looking stock photos of multi-pipettes and the ubiquitus vortex genie 2. Extra points for consecutive photos of the same tip-rack in obviously proffessional use.