What was the most successful attempt to date...?

Question

What was the most successful attempt to date of achieving immortality, and what knowledge was involved?

Answer 1

No such attempt has been remotely successful. What we have learned is that the genetic mechanism responsible for life has only limited reproductive capability (except for germ cells), so life span is limited by the maximum number of cell divisions. Unless genetic engineers figure out how to change this, life span will continue to be limited to about 130 years.

Answer 2

Some dudes in India live to be 125 years old. Ayurvedic medicine. (Ayurveda)