Among the age-related diseases, the development of cognitive impairments, in particular dementia, is the most devastating for the individual and has great social and healthcare costs. Accurate information is needed about the prevalence and incidence of cognitive disordes and the physiology of the aging brain. In particular, only scant data are available about the the relationship between aging, ... [Show full abstract] cognitive status and nutritional factors. In order to to address these issues, we planned the longitudinal Conselice Study of physiological and pathological brain aging. The municipality involved in the study is in Ravenna province, in the Northern Italian region Emilia-Romagna. All individuals aged 65 years and older residing in the study area at January 1, 1999 (n = 1353) were considered eligible for the prevalence phase. Cases of cognitive impairment in the study population were identified through an extensive clinical and neuropsychological assessment. Laboratory tests (including homocysteine, vitamin B6, vitamin B12, and folate blood measurements), nutritional assessment, and neuroradiological imaging were also performed. This study might provide information on the pathophysiology of brain aging and might have important public health relevance in planning health services for elderly people.