OK, here goes a second time - I already had tried to post once before but it didn't take it.

Although I have not personally ever changed careers (only 1.5 years into my first!), I just want to say that you shouldn't let your age hold you back from applying to an academic program if it's something you really want to do. When I was in veterinary school, there was one woman in my year and one in the year below me that were over the age of 50. The woman in the year behind me (just graduated in May), is going to be 60 next year. Just because you are older doesn't mean you don't have something to contribute to the profession you want to enter. In fact, I wish I had more life experience. It would really help in relating to a lot of my clients - that and when you're older everyone assumes you know what you're doing. No one trusts the 26 year old doctor as much as the 50-something!