Dredge-up

[eXorikos]

What do the processes of first, second and third dredge-up do with a star other than just change its spectrum?

[Chronos]

Dredge-ups allow for more efficient chemical enrichment of the interstellar medium, which was probably an important factor in metallizing the early universe.

[eXorikos]

But it doesn't do anything special to the star it self in terms of lifetime or structure?