To reverse aging by distributive telomere lengthening is a slow process, that requires a lot of young blood, he's probably hoping to age as slowly as possible with all his other activities and skin care but use the blood to reverse his aging, his son only has so much blood and sharing his own blood with his father is counter productive to revers his own aging, unless younger blood cells are just more efficient on top of the longer telomeres.

The age of vampirism has begun, the technology exists today I could have a product ready in a year with one of the big CRISPR labs working with mRNA, that would be a true anti-aging treatment if we just had one or two of the girls who have "syndrome x", they barely age, there are other defects but we could engineer a variety of replacement tissues and fluids with the extremely long telomeres of these girls, and if we strike it lucky we could create an MRNA injection which causes slower aging at the cellular level.

Until these products are produced you can bet child trafficking is going to skyrocket to keep the wealthy in young blood to counteract aging, they wont want to release these products until third world nations are sliding into reclining birth rates, and that probably isn't going to happen soon considering the wealthy need to source their blood bags from conflict zones.

This would have sounded schizoid as fuck a few years back but we now have proof positive telomere length defines cellular aging at the level of DNA and that cells can pass spare telomeres between cells they come into contact with including blood cells. The fastest way to shorten your telomeres is sun exposure btw, skin is a massive organ and sunlight damages DNA easily and shortened telomeres in skin will cause them to take from their neighbors until it has aged your whole body, this could also produce localized aging.

Everything he is doing is negated by going vegan. He is not going to age well and he is asking for lots of health issues.