system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:Do donated organs age according to the donor´s age or do they adapt to the age of the new body?
gpt
The organs stay the age of the donor and generally deteriorate with time. Organs have a finite ability to generate new cells and wear with time. Also because even with immune suppression the donor organ is still subjected to intermittent attacks from the immune system, as well as the whole host of problems that can arise for immunosuppressed people (usually infections, vascular problems). 


Organs are assessed before they are given to someone so that the recipient isn’t given a poor quality donation. But a “healthy” 45 year olds heart likely still has some coronary artery disease.  the 20 year old recipient may start to get problems with angina or heart attacks in their 30s because of having a then 55 year old heart.