Do humans age the same in space as they do on earth?

Yes, approximately. Because of higher velocity, astronauts age slightly less than their counterparts on earth, when they are in space, but only by a tiny amount.

On the other hand, weightlessness and radiation contribute to bone loss and other ill health effects; so it might be said that even though time is slightly slowed-down for astronauts, they can suffer a deterioration of their health.