The quest to live longer has been one of humanities oldest dreams, but while scientists have been searching, a few isolated communities have stumbled across the answer.
On 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 on earth.
In these unique communities a group of scientists have dedicated their lives to trying to uncover their secrets.
Horizon takes a trip around the globe to meet the people who can show us all how to live longer, healthier lives. (Excerpt from bbc.co.uk.)