In Star Wars, the Clones are introduced in the story "Attack of the Clones". In this story it was explained that they were bred from the genetic template of Jango Fett. They underwent an accelerated growth to prepare them for battle in a reasonable time. My question is, after this do the clones age naturally or are they do they effectively not age?
They age faster than normal throughout their lifetime
In the canon novel Tarkin, Vader questions a clone trooper's ability to continue on active duty five years after the Clone Wars (in 14 BBY) due to his rapid aging:
When the stormtrooper operating the equipment accidentally allowed the flattened sphere to bang against the edge of the cargo hold’s retracted hatch, Vader stamped forward with his gloved hands clenched.
“I warned you to be careful!” he shouted up at the trooper.
“My apologies, Lord Vader. Wind shear from—”
“Excuses won’t suffice, Sergeant Crest,” Vader cut him off. “Perhaps you are aging too quickly to remain on active duty.”
Tarkin couldn’t make sense of the remark until he realized that Crest’s was a face he had seen countless times during the war—the face of an original Kamino clone trooper. The bare-headed others comprising Vader’s squad were human regulars who had enlisted after the war.
The fact that the clones age faster than normal throughout their lives was also confirmed out-of-universe in this video by Pablo Hidalgo of the Lucasfilm Story Group, which is in charge of Star Wars canon. Hidalgo explained that the clones were phased out and replaced with non-clone humans in the Stormtrooper Corps because the clones age at twice the normal rate. The relevant quote transcribed from the video is:
[...] 5 years before the events of Episode IV. By that time the clone operations that the Republic started for the Clone Wars -- they've been phased out. Clone troopers age at like twice the rate of normal people [...]