[How to define old age: successful aging and/or longevity].

In half a century, the number of nonagenarians and/or centenarians has dramatically increased, particularly due to the increase in life expectancy at old age. However, successful aging is more important than longevity. All along their life, people can act to preserve their health, their physical and mental abilities as well as their autonomy. This requires a healthy diet, having physical and intellectual appropriate activities and a right use of medical care. Finally, maintaining a social role and a raison d'être in old age are also major factors in successful aging.