I don't think anyone on this forumn can really answer that question for you, be cause everyone's needs are different.
As a young rider, I was fast, strong, and generally indestructable. That all held true until my 40's, and none of those things are much true anymore.
How do you do on hilly terraine? Are there any 10% grades where you live? What is the steepest hill you can climb? Do you feel like you have adequate gearing now?
If you are happy with your current gearing, then leave well enough alone. If you want more gearing, then the easiest thing to do will be to max out the gear cassette. If you have a long cage rear derailleur, then you can go to 32 or 34 tooth rear cluster (32 or 34 being the number of teeth on the biggest sprocket). If that is not enough, then you can try putting a smaller granny gear in the crank. I have not had impressive changes from that. Your next change (in order of ascending expense) is to put in a mountain bike crank set, but that often means putting in a mountain bike front derrailleur as well.