Effects of Brazil Nuts Consumption on Selenium Status and Cognitive Performance in Older Adults With Mild Cognitive Impairment: a Randomized Controlled Pilot Trial

We enrolled older patients with MCI who attended the Memory and Aging Unit of the Geriatrics Division, University of São Paulo Medical School (Brazil). All participants fulfilled the criteria proposed by the International Working Group on Mild Cognitive Impairment (Winblad et al., 2004), which include the following: (1) the person is neither normal nor demented; (2) there is evidence of cognitive deterioration shown by subjective report in conjunction with objective cognitive deficits; and (3) activities of daily living are preserved and complex instrumental functions are either intact or minimally impaired. The diagnosis of MCI was based on a comprehensive neuropsychological assessment which included the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neuropsychological battery (Welsh et al., 1994; Bertolucci et al., 2001). Participants were recruited from May 2011 to August 2012. Eligible subjects were aged 60 years or older, fluent in Portuguese, and free of any other significant neurologic or psychiatric diseases. None of them presented major depression or psychosis, had a regular intake of Brazil nuts, used supplements with selenium, or had intolerance to oleaginous food. An informed consent was obtained before the interview from all participants. The research protocol was approved by the Research Ethics Comittee of the Faculdade de Ciências Farmacêuticas da Universidade de São Paulo.