In Part II: Battle Tendencies of Jojo's Bizarre Adventures, the long-running manga series (and more relevantly to me, its ongoing anime adaptation of the same name) we learn that the martial arts technique known as Hamon (or the Ripple) enhances longevity and youthfulness of users, with Joseph's teacher Lisa Lisa and Straizo being the most obvious examples of this use of Hamon. By the end of the installment, Joseph has mastered the use of Hamon to a great extent.
But then when we we see him again 50 years later in Part III: Stardust Crusaders, he's obviously nowhere near his prime, nor physically out of the normal range for a 67 year old, and most definitely looks his age.
On the other hand, his daughter Holly, who's supposed to be 45 at this time, looks almost as young as 50 year-old Lisa Lisa during Part II (and Holly's youthful looks are explicitly remarked on in the first episode of Part III, so I'm assuming it's deliberate and
given Lisa Lisa being Jojo's mom, I am also assuming there's a hereditary component to it if Holly benefits from it without being a Hamon user at all.
As such, why is Jojo so obviously aged, despite being a very proficient user of Hamon, while Holly looks young, despite her being not? (If my assumption about the reason for Holly's young looks is incorrect, please feel free to learn me :)
Is there any information in the manga, or from interviews or additional features from Araki?