In the Western world, the life expectancy for most of us is around 80 years of age. But in every corner of the planet, there are people who live extraordinarily longer than the average person. Scientists are discovering that unlocking the genetic secrets of animals and humans who live longer than most is the key to helping the rest of us wind back our cellular clocks naturally, live longer lives and can even improve fertility. In Live Long Die Young, Anja Taylor went on a 5-day fast that experiments are showing promising results for in the fight against the four major diseases of getting old.