The quest to live longer has been one of humanities oldest dreams, but at the same time, scientists have been seeking, some isolated communities have stumbled upon the answer.
In the remote Japanese island of Okinawa, in the Californian town of Loma Linda and in the mountains of Sardinia people live longer than anywhere else in the world.
In these unique communities a group of scientists have dedicated their lives to try to discover its secrets.
Horizon takes a trip around the world to meet people who can show us all to live longer lives and healthier. (Excerpt from bbc.co.uk)