He's found the best way to live an extended life - be rich. He has access to health care and doctors most people can't afford & preventative tests that typical insurance doesn't cover. Of course, just because you have access to that type of health care, doesn't mean you take advantage of it - Warren Buffett famously put off his colorectal exams forever, nearly costing him dearly.
The other aspect of this article that I wanted to see was whether he's chosen to use hormone replacement - it says "he's ripped. His arms are guns. His abs come in a pack" and later "Losing muscle to age clearly spooks him". Those are all nice, but seemingly biophysically impossible for a 77 year old man.