[Relationship between educational level and dementia: social factor and age-related chronic disease].

Dementia is an age-related chronic syndrome, whose the first cause is a neurodegenerative disease: Alzheimer's disease (AD). In spite of some controversies, educational level is now considered as a major risk factor for dementia and AD. The protective effect of a high level of education could be related to a preservation of cognitive reserve and a reinforcement of brain reserve. Moreover, subjects with a high level of education have a better access to health care and a better management of vascular risk factors. With the general improvement of the educational level, the age-related incidence of AD and dementia should decrease in the future.