u/No_University1916

I’ve always had a question about Brand’s age at the end of Interstellar.
When Cooper enters Gargantua, Murph is roughly in her mid-30s. By the time Cooper reunites with her, she’s over 90 years old. That means around 55+ years have passed for Murph.
Brand, however, is on Edmunds’ Planet, which appears to experience time much more normally than Miller’s Planet. If that’s the case, shouldn’t a similar amount of time have passed for Brand as well?
Let’s say Brand was around 45–50 years old when Cooper entered Gargantua. If 55+ years passed, she should be around 100 years old by the end of the movie. Yet the ending seems to imply that she’s still alive and healthy enough for Cooper to travel to Edmunds’ Planet and find her.
The common explanation is cryosleep. However, that raises another question: does cryosleep in the Interstellar universe significantly slow or nearly stop biological aging? If cryosleep only keeps someone unconscious, Brand should still age normally. But if it effectively pauses metabolism, then her biological age could be much lower than her chronological age.
So am I missing something, or is the implication that cryosleep in Interstellar dramatically reduces aging? I’d love to hear how others interpret this.