In the 1st episode of best wishes it says he still the age as when he started his journey 10 he should be at least 30 by now. in the first season it said he had been traveling for months after he beat misty.
The date of Ash's birth, according to Takeshi Shudo's anime novelizations, is 10 years, 10 months, and 10 days exactly prior to the day he began his Pokémon journey. Being that the same novelization declares that Pokémon Trainers obtain their first Pokémon in April of the year following their 10th birthday, and the anime itself began broadcast on the first of that month in 1997 in Japan, Ash's birthday, if April 1 was the first day of his journey, would be May 22.
-bulbapedia
No strangely the creator of pokemon said something like ash will never age nor die but he should be 24 by now
