Hello @khokonmia, hope you are doing alright. Truly we have concerns for old age because we do not like losing control of our body functions.

old age is a name of helplessness

I agree with this phrase of yours because it becomes a burden to others to do for you all that you can't do. Vegetables and fatty food (not too much) helps to prevent aging.
The best and widely known exercise is walking, one of the best in physical therapies too.

Thank you for this and good luck