I am 52 years old man. I was awarded my M.Phil. in 1989 in Clinical Chemisrty, and would like to do a Ph.D.
Any advice?

It's never too late, you are 41 years younger than this chap, go for it!

Ex-vicar, 93, breaks PhD record

I agree - never too late!

Yes, definitely never too old, go for it ! You may need to read up on the current 'status quo' of research, but I imagine you've probably already done that if you're thinking of doing one now. Let us know how it goes !

can a bag change your life?

Never to late. Go for it. If you would like to do and happy to do it.... Nothing too late !!