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Completed

NCT Number: NCT01634841

Walnuts and Healthy Aging

This will be a systematic investigation of the role of walnuts in preventing or slowing age related cognitive decline and age related macular degeneration. 700 subjects will be recruited between 2 sites, Loma Linda University in California, USA and Hospital Clinic in Barcelona, Spain. Participants will be randomly assigned to either the walnut group or the control group for a 2 year intervention. Baseline and annual data will be collected and analyzed.

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Key information

Conditions

Age Related Cognitive Decline Age Related Macular Degeneration Eye Diseases Macular Degeneration Retinal Degeneration Retinal Diseases

Age range

63 year–79 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Hospital Clinic, University of Barcelona, Barcelona, Spain

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About this study

Epidemiological studies suggest that nutrients such as n-3 polyunsaturated fatty acid, antioxidants and B-vitamins may protect against age related cognitive decline. Small human studies have shown beneficial effects of polyphenol rich foods on cognition and age related macular degeneration. Walnuts are a rich source of n-3 polyunsaturated fatty acid, alpha-linolenic acid, antioxidants, polyphenols and other bioactive compounds. A 2-year intervention will be conducted with healthy, elderly subjects to investigate the role of walnuts in preventing or slowing age related cognitive decline and age related macular degeneration.

350 subjects, age 63 to 79 years, will be recruited at each of 2 sites, Loma Linda University in California and Hospital Clinic in Barcelona. Participants will be randomly assigned to one of two groups: walnut group (habitual diet with 1 or 2 oz/d walnut supplement) or control group (habitual diet only). At baseline and yearly, cardiometabolic risk factors, red blood cell membrane fatty acids, urinary polyphenols and biomarkers of inflammation and oxidation will be measured. Eye exam, blood pressure and cognitive function tests will be measured at the beginning and end of 2 years. At the Barcelona site only, participants will be given a brain MRI and carotid ultrasound.

Descriptive results will be reported as mean plus/minus standard deviation. Primary analysis will be carried out on the basis of groups as randomly assigned. Results will be presented as appropriate effect sizes with a measure of precision (95% CI). Analysis of covariates gender, age, educational status will be conducted.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 63 to 79 years old
  • healthy men and women
  • able to attend clinic at a study sites

Exclusion criteria

  • illiteracy or inability to understand the protocol
  • unable to undergo neurophysiological tests
  • morbid obesity (BMI greater than or equal to ≥ 40 kg/m2)
  • uncontrolled diabetes (HbA1c>85)
  • uncontrolled hypertension
  • prior cerebrovascular accident
  • any relevant psychiatric illness, including major depression
  • advanced cognitive deterioration, dementia
  • other neurodegenerative diseases (i.e. Parkinson's disease)
  • any chronic illness expected to shorten survival (heart, liver, cancer, etc)
  • bereavement in the first year of loss
  • bad dentures unless fixable dental prostheses are used
  • allergy to walnuts
  • customary us of fish oil or flaxseed oil supplements
  • eye related exclusion criteria

Treatment and study plan

walnuts

Dietary Supplement

30 to 60g (1 to 2 oz) per day of walnuts

habitual diet

Other

Dietary information will be provided

Primary outcomes

  1. Changes from baseline in global cognitive composite score

    Time frame: 2 years

    The composite score will be calculated using the scores from the tests listed below. We will calculate the standardized scores of each test as the score of each participant minus the group mean and divide by its standard deviation. The composite score is the mean of the standardized scores.

    The 12 tests are: Rey Auditory Verbal Learning Test (RAVLT), Rey-Osterrieth Complex Figure (ROCF), Semantic Fluency (Animals), Boston Naming Test (BNT), Visual Object and Space Perception Battery (VOSP), Block Design section from the Wechsler Adult Intelligence Scale (WAIS-III), Trail Making Test (TMT), FAS Word Fluency, Stroop Color Word Test, Symbol Digit Modalities Test (SMDT) Digit Span from the WAIS-III and Conners Continuous Performance Test (CPT-II).

  2. Changes from baseline in macular degeneration

    Time frame: 2 years

    This will be assessed: by stereoscopic digitized color fundus images graded by International Classification System for Age-Related Maculopathy (score range. 0 to 4; the higher the score, the worse the condition); by optical coherence tomography (OCT) measurements of macular thickness (in µm); by optical coherence tomography (OCT) measurements of retinal nervous fiber layer thickness (in µm).

Secondary outcomes

  1. Change from baseline in brain cortical thickness

    Time frame: 2 years

    Changes will be assessed by brain magnetic resonance imaging (MRI) on a randomly selected subset of participants. Only in Barcelona center. Unit of measure is mm2.

  2. Change from baseline in voxel-based morphometry

    Time frame: 2 years

    Changes will be assessed by brain magnetic resonance imaging (MRI) using GM density maps on a randomly selected subset of participants. Only in Barcelona center. Unit of measure is GM density.

  3. Change from baseline in white matter hyperintensity volumes

    Time frame: 2 years

    Changes will be assessed by brain magnetic resonance imaging (MRI) on a randomly selected subset of participants. Only in Barcelona center. Unit of measure is mL.

  4. Change from baseline in perfusion arterial spin labeling

    Time frame: 2 years

    Changes will be assessed by brain magnetic resonance imaging (MRI) on a randomly selected subset of participants. Only in Barcelona center. Unit of measure is ml/100 g/min.

  5. Changes from baseline in brain activation

    Time frame: 2 years

    Changes will be assessed by Functional MRI (fMRI) on a randomly selected subset of participants. Only in Barcelona center. There are no units of measure.

Other outcomes

  1. Change in carotid Intima-media thickness (mm)

    Time frame: 2 years

    Changes will be assessed by high-resolution ultrasound. Only in Barcelona center.

  2. Incidence of plaque presence in carotid artery (yes/no)

    Time frame: 2 years

    Changes will be assessed by high-resolution ultrasound. Only in Barcelona center.

  3. Change in carotid atheroma plaque height (mm)

    Time frame: 2 years

    Changes will be assessed by high-resolution ultrasound. Only in Barcelona center.

  4. Change in body mass index (kg/m2)

    Time frame: 2 years

    BMI will be calculated as weight in kilograms divided by height in metres squared

  5. Change in waist circumference (cm)

    Time frame: 2 years

    Waist circumference will be measured to the nearest 0.5 cm by using an anthropometric tape midway between the lowest rib and at the iliac crest at minimal respiration

  6. Change in total fat (g)

    Time frame: 2 years

    Changes will be assessed by Dual-energy X-ray absorptiometry. Only in Barcelona center.

  7. Change in Total lean tissue (g)

    Time frame: 2 years

    Changes will be assessed by Dual-energy X-ray absorptiometry. Only in Barcelona center.

  8. Change in fasting serum total cholesterol (mg/dL)

    Time frame: 2 years

    Fasting serum total cholesterol will be measured by a standard enzymatic method

  9. Change in fasting serum LDL-cholesterol (mg/dL)

    Time frame: 2 years

    Fasting serum LDL-cholesterol will be estimated by the Friedewald formula

  10. Change in fasting serum HDL-cholesterol (mg/dL)

    Time frame: 2 years

    Fasting serum HDL-cholesterol will be measured by a precipitation technique

  11. Change in fasting serum triglycerides (mg/dL)

    Time frame: 2 years

    Fasting triglycerides will be measured by a standard enzymatic method

  12. Change in serum brain-derived neurotrophic factor (pg/mL)

    Time frame: 2 years

    Assessed by ELISA

  13. Change in serum soluble-Selectin (ng/mL)

    Time frame: 2 years

    Assessed by ELISA

  14. Change in serum soluble-intercellular Adhesion Molecule 1 (ng/mL)

    Time frame: 2 years

    Assessed by ELISA

  15. Change in serum soluble-vascular cell adhesion molecule 1 (ng/mL)

    Time frame: 2 years

    Assessed by ELISA

  16. Change in serum amyloid A (ng/mL)

    Time frame: 2 years

    Assessed by ELISA

  17. Change in serum granulocyte-macrophage colony-stimulating factor (pg/mL)

    Time frame: 2 years

    Assessed by ELISA

  18. Change in serum interferon-gamma (pg/mL)

    Time frame: 2 years

    Assessed by ELISA

  19. Change in serum interleukin-1beta (pg/mL)

    Time frame: 2 years

    Assessed by ELISA

  20. Change in serum interleukin-6 (pg/mL)

    Time frame: 2 years

    Assessed by ELISA

  21. Change in serum tumor necrosis factor alpha (pg/mL)

    Time frame: 2 years

    Assessed by ELISA

Sponsors and collaborators

Lead sponsor

Loma Linda University

Other

Collaborators

  • California Walnut Commission
  • University of Barcelona

Registry information

Official study title

Effect of Daily Ingestion of Walnuts for 2 Years on Age-related Cognitive Decline and Macular Degeneration in Healthy Elderly Subjects: A Randomized, Single Blind, Dual Center, Controlled Trial

Acronym: WAHA

Important dates

Study start
2012
Primary completion
2016
Study completion
2016
First posted
Jul 6, 2012
Registry last updated
Jun 24, 2021

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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