how have Simi Garewal and Rekha kept themselves looking so great?

Simi Garewal and Rekha are among few actors from the golden age of Bollywood who have remained forever young. What's the secret behind their timeless beauty? Is it really just good diet, and workout? I'd assume most actors have had access to these, yet their peers have aged significantly, let's look at Jia Bachan, and even the younger Amrita Singh. Is cosmetic surgery not involved??