Personal anecdote: I'm around the same age as OP and until recently also felt like my thinking was slowing down over the years.
I went for many years without an exercise habit. About 5 months ago I started lifting weights. The transformation has defied all my expectations and the biggest unexpected benefit is that my mind has become sharper, faster and more focused. I essentially feel like I've reversed a decade's worth of brain and body aging by going into the gym and lugging some iron around a couple times a week.
Around the same time I started cutting back on alcohol intake and cleaned up my diet a bit. So it could be any of these factors but I think it's a combination of all of them, as you get older, you need to maintain your body or it'll deteriorate and take your mind with it.
I went for many years without an exercise habit. About 5 months ago I started lifting weights. The transformation has defied all my expectations and the biggest unexpected benefit is that my mind has become sharper, faster and more focused. I essentially feel like I've reversed a decade's worth of brain and body aging by going into the gym and lugging some iron around a couple times a week.
Around the same time I started cutting back on alcohol intake and cleaned up my diet a bit. So it could be any of these factors but I think it's a combination of all of them, as you get older, you need to maintain your body or it'll deteriorate and take your mind with it.