I'm 48 and I do feel that I can get more years out of life because I'm more aware and focused on making it happen. I've been fortune that I grew up playing hockey and developed an almost religious belief in the power of working out. It's the best way to stay sharp mentally, feel better physically, and stave of the effects of aging as best we can right now. We are also supremely lucky because our knowledge in this space has increased hugely; my parents had no clue about eating right, or working out, or any of that. My father at 48 looked like you would expect a 48 year old to look like; living in colorado, which is a hyper healthy state full of cross-fitters, runners and olympians trainers, it's striking how young older folks look. I often get mistaken for late 30's, and growing up it would be unthinkable that someone my age could play against 20-something Division 1 college players and be affect. I do this regularly, and I'm grateful I'm able to do it still.
I'm also a big believer in vitamins and supplements, but I know that's a major point of contention (I regularly get razzed by my surgeon buddy at hockey about spending money to color my piss). I disagree though, and I'll spare the lecture on why I believe so because ultimately it comes down to whether or not it helps you personally. I've posted in the past about the positive effects of fish-oil, ubiquinol w/ PQQ and Resveratrol in particular.
Bottom line, it depends on your goals. Mine is to live a 1000 years or so. I started telling my friends this about 20 years back, I think I'd just read K. Eric Drexler's Engines of Creation and probably one of Kaku's physics books and the written to me was clearly on the wall - progress would work in my favor, if I worked hard to keep myself in great shape, I just might make it far enough in life to see these cascading breakthrough's that will eventually propel man's lifespan into the hundreds and beyond. I do realize this is a long shot, but at the same time have nothing to lose by using this to drive my workout and health.
Regarding the 20 something culture... be careful on that... it's natural it seems as one gets older to lament how things have changed, how the 'young folks' are different and the world is changing. In reality we've changed, they are mostly the same, just as angst driven, excited for the future and full of hope and promise and probably a bit too optimistic. This is great, really, don't let it get you down and try to remember/embrace that way of thinking.
I just started a blog on all this stuff, only a bit of content so far but I plan to write a few pieces a week:
https://existentialquandary.wordpress.com