Brazil Nuts Effects on Selenium Status and Cognitive Performance
Brazil Nuts Effects on Selenium Status and Cognitive Performance
Some studies reported that selenium status is associated with cognitive function. However
 only a few reports have investigated whether selenium supplementation can benefit cognitive
 performance and in most of them selenium supplementation was not exclusive. Also, none of
 those reports have used foods rich in selenium as a source of supplementation. Thus, the aim
 of our study was to investigate whether the consumption of Brazil nuts improves cognitive
 function. We hypothesized that the daily consumption of Brazil nuts would have benefits on
 selenium status, increase antioxidant enzyme activity and improve cognitive function in older
 adults with MCI.
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.
Inclusion Criteria:

 -  aged 60 years or older,

 -  fluent in Portuguese,

 -  free of any other significant neurologic or psychiatric diseases

 Exclusion Criteria: