One could speculate that it would depend on the direction this person was travelling in. In addition, as they returned to earth might they possibly age slightly faster, and so return to earth having aged the same as everyone else?
Relativity is wonderful, don't you think?

There is another discussion on this kind of thing here: http://www.theanswerbank.co.uk/DisplayAnswers.go?q
uestion_id=2601&category_id=18&index=0

If you think about age as a number then it can easily shade the answer, however seeing age as a process due to wear and tear then you would not see a difference i dont think because the 25 years would have been instant.

If 25 years were to have elapsed in its normal way then wear and tear on the person would show for that 25 years giving the sense of age. If the 25 years is instant then no wear and tear can happen.

If you travelled forward in time 25 within 1 minute or real time you wont incurr wear and tear over that minute as normal.

hope that makes sense and is really just my view with no scientific backup. I watched way too much back to the future movies growing up