I would second Pete's suggestion to read Sinclair's book and maybe his twitter. They give hope.......
I feel very fortunate to have had a family doctor who was way ahead of the curve on aging and maintaining health matters. When he retired in his early 70's, I knew he still played soccer but he shared with whom he played, and I was like you still play with the 20 something mexican group at the park? He said yes and that he could still run as fast as they. Of course I believed him but it just blew me away. He also looked young and fit.
Sinclair's research says mammals can make themselves younger again.
I'd like to share in case it gives encouragement to others of a certain age. I started back playing ice hockey several months ago (had not played since college). My sprint was awful. Early on during an open hockey practice (pay 20 bucks and go practice), a D3 college kid and a minor league professional (1 step below NHL) were doing up the ice and back sprints, the college kids jokingly says, how about you oldtimer? Want to race? They were (depressingly) three strides ahead of me at the other end. One way to have looked at it, was my muscle cells were old and stiff and there is no change. I needed to stretch to increase my stride length and do sprints to increase explosiveness. And trust that my body would improve. After 6-8 weeks, I noticed a big improvement and one team mate after a game said I had wings on my F'n skates tonight. A week later, I had a race with the pro and he beat me by about a stride and a half and said, "you are flying today". Yesterday, he beat me by half a stride (which is not trivial distance and maybe he was tired). If one looks and trusts Sinclair's research and tries to restore fitness and vitality or maybe call it quality of life in the senior years, I think it is very possible to improve. Obviously, we won't be 20 years old again, but maybe a 65 yo can turn it back to when they were 45-50. Hope isn't a bad thing.
I think the answer is yes.