How does the slowing work?

[Liri 01]

So-I know the Aes Sedai slow-but how much?

[2RiversFan]

I don't recall getting an exact answer from within the books, but I think Jordan implies that because Channelers touch the Source, they are revitalized/rejuvenated.  At least, that is the way I've always taken it to be.  I haven't ever thought to ask that question myself, much less try to look it up on this forum or elsewhere.

 

There may be something said about this in the books when we meet one of the Channelers (Kin/Damane) that are really old but haven't been bound by the Oath Rod, which shortens the Aes Sedai's lives.  More properly said as:  The Oath Rod reduces the potential length of life of the Channeller.

[SinisterDeath]

In the Wheel of Time Companion, starting on Page 702 "strength in the one power", talks about how strength in power, correlates directly to how long lived one becomes.

 

The Strongest man, could live up to 800 years.
The Strongest Woman could also live up to 800 years, but a man of equal power as the strongest female would only live up to 720 years.

Near the bottom end,  prolonged life only goes so far as 135 .

 

It says nothing as to "when" the anti-aging takes affect, nor if a "100 year" lifespan is stretched out over 800 years... or if they remain youthful looking, even in their last year.

 

[Jsbrads2]

Just like Aes Sedai age, one presumes channelers who are not binded age as well. The 300 year old Damane shows a bit of wrinkles near her eyes, women of the kin who are hundreds of years old look middle aged. 
perhaps channelers won’t spend hundreds of years incapable of walking etc, but the visual signs of age do appear. 

[icspots]

Rereading Crown of Swords currently and just went back over the part when Elayne and Nynaeve first meet the Kin.  On the way back from that meeting Elayne is explaining to Nynaeve about slowing in regards to how old the women they’ve met must be in order to show gray hair (and notes they don’t have the Ageless look, but they haven’t figured that out yet).  Women who channel start slowing around age 20-25.  Elayne’s example is another Accepted who Nynaeve believes to be her own age who has a younger sister with gray hair.  So she’s likely twice Nynaeve’s age but still appears roughly the same age.

[Kalessin]

And then there's the young-old Alivia, 414 years young and having been damane from about 13 or 14, and still thinks of herself as a teenager.

 

Any hint of just how old Lews Therin was when the War of Power swept over the Age of Legends?

[Thrasymachus]

He was a bit over 400 years old when he died, and only about halfway through his total expected lifespan.

[Jsbrads2]

Alivia doesn’t think she is a teenager. She just hasn’t learned anything outside of channeling since she was a teenager. So normal stuff like learning about men, was barred to her. She doesn’t understand money well. Huge gaps in what she knows.