Like everyone else has said, his age is irrevelant. I am 29 and will be starting as a D1 next month.
I did research on 10 -15 schools in the eastern half of the US before applying last year. The only school that I saw that requires all core courses to be less than 5 years old is Univ. of Tenn. The Univ. of Indiana requires Biochem.
If possible, he should try to take some upper level science courses and get A's. One, high grades will boost his GPA a little. And, two he can get some good rec. letters from recent faculty members.
With his GPA / time off he needs to shoot for 20+ on the DAT. If he does as good as his sister he can probably pick where he wants to go.
Good Luck to you both.