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Brazil Nuts Effects on Selenium Status and Cognitive Performance

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02121457
Recruitment Status : Completed
First Posted : April 23, 2014
Last Update Posted : April 23, 2014
Information provided by (Responsible Party):
Barbara Rita Cardoso, University of Sao Paulo

Brief Summary:
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.

Condition or disease Intervention/treatment Phase
Mild Cognitive Impairment Dietary Supplement: Brazil nut Dietary Supplement: selenium Not Applicable

Detailed Description:
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.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 31 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Effects of Brazil Nuts Consumption on Selenium Status and Cognitive Performance in Older Adults With Mild Cognitive Impairment: a Randomized Controlled Pilot Trial
Study Start Date : May 2011
Actual Primary Completion Date : August 2012
Actual Study Completion Date : August 2012

Arm Intervention/treatment
No Intervention: Control Group
This group did not receive any intervention.
Experimental: Treatment Group
This group took one Brazil nut daily during 6 months.
Dietary Supplement: Brazil nut
Participants of the treatment group were instructed to take one Brazil nut daily during 6 months. Brazil nuts were supplied in 2-month allowances at no cost together with written nutritional information and a calendar to monitor the compliance. Compliance was monitored in intervals of 2 months by checking the calendar and counting returned nuts. Compliance was considered to be adequate if ≥85% of Brazil nuts were consumed. All subjects were instructed to maintain their normal diet and to avoid additional Brazil nuts during the study.

Dietary Supplement: selenium

Primary Outcome Measures :
  1. Selenium level in plasma and erythrocyte [ Time Frame: 6 months ]

Secondary Outcome Measures :
  1. cognitive performance [ Time Frame: 6 months ]
    Cognitive performance was measured by using six sub-testes from the CERAD neuropsychological battery have been administered to assess fundamental cognitive abilities.

Other Outcome Measures:
  1. Oxidative stress parameters [ Time Frame: 6 months ]
    Oxidative stress was evaluated by measuring glutathione peroxidase activity, Oxygen radical absorbance capacity (ORAC) and Malondialdehyde (MDA).

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Ages Eligible for Study:   60 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • aged 60 years or older,
  • fluent in Portuguese,
  • free of any other significant neurologic or psychiatric diseases

Exclusion Criteria:

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02121457

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University Of são Paulo
São Paulo, SP, Brazil, 05508000
Sponsors and Collaborators
University of Sao Paulo
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Study Director: Silvia F Cozzolino, PhD University of São Paulo
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Responsible Party: Barbara Rita Cardoso, Bárbara Rita Cardoso, University of Sao Paulo Identifier: NCT02121457    
Other Study ID Numbers: Doutorado-2014
First Posted: April 23, 2014    Key Record Dates
Last Update Posted: April 23, 2014
Last Verified: April 2014
Keywords provided by Barbara Rita Cardoso, University of Sao Paulo:
cognitive performance
brazil nuts
oxidative stress
Additional relevant MeSH terms:
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Cognitive Dysfunction
Cognition Disorders
Neurocognitive Disorders
Mental Disorders
Molecular Mechanisms of Pharmacological Action
Protective Agents
Physiological Effects of Drugs
Trace Elements
Growth Substances