Looks to me: No one needs to grow old - I mean 'if the growing old means growing weak with age'.
But we still age, as we know no other way! For we have seen every one else aging with each passing day!
Aging is identified with growing sick! Of course that's true, as very few people become healthy as they grow old. And they are very exceptional, and but they follow the suit with others sooner or later, as they too know no other way!
As soon as man enters into adolescent age, he starts developing negative or stressful perspective about life, to the varying degree. Sooner or later it's affecting his mentality, and hence physiology. This effect keep on advancing as no one really tries to stop it, nor it's easy to do so.
The basic damage that can be felt, when something, even very primitive, happens that we don't like, is on our nervous system. Believe all other diseases happen and hasten to the extent the nervous system is bad or damaged. If your nervous system is in the right state, you are absolutely healthy. Nervous system is at the receiving end of our continued thought patterns & habitual actions, and is very much a victim of conflict between the two.
No medicine can save us, if there's big tug-of-war between our thoughts and actions. But everyone prefers medicine as short cut to relieve pain, which does n't work in the long run. Life becomes complicated, if our thoughts and actions(habits or emotions) going in different directions.
It's not easy to align your actions with your thoughts or thought processes, and but it happens with being a little more objective. It requires work on your mind and emotions. But if you can do that basic thing, you are in the right direction to slow 'aging process'. And it's the right thing to do.