Walnuts and Healthy Aging (WAHA)

This study is ongoing, but not recruiting participants.
University of Barcelona
Information provided by (Responsible Party):
Joan Sabate,DrPH, MD, Loma Linda University
ClinicalTrials.gov Identifier:
First received: June 20, 2012
Last updated: January 28, 2016
Last verified: January 2016
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.

Condition Intervention
Age Related Cognitive Decline
Age Related Macular Degeneration
Dietary Supplement: Walnuts
Other: habitual diet

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Investigator)
Primary Purpose: Prevention
Official 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

Resource links provided by NLM:

Further study details as provided by Loma Linda University:

Primary Outcome Measures:
  • % Change in cognitive decline from baseline [ Time Frame: 2 years ] [ Designated as safety issue: No ]
    Baseline data will be collected using the following neuropsychological evaluations: NART, WAIS III tests of intelligence; ROCF, RAVLT for memory; BNT and semantic category evocation for language; VOSP for perception; copy ROCF for praxis; TMT A, TMT B, FAS word fluency, Stroop test, SDMT, CPT II, CANTAB for frontal cognition. From baseline we hypothesize there will be a 5% difference in cognitive decline between the walnut intervention group and the control group when tests are performed again after the 2 year intervention.

Secondary Outcome Measures:
  • % change in macular degeneration from baseline [ Time Frame: 2 years ] [ Designated as safety issue: No ]
    We hypothesize that 30 to 45g per day of walnuts will delay the onset and progression of macular degeneration in healthy elderly subjects. This will be determined by a difference of 5% in the thickness of the retina as measured by OCT.

Estimated Enrollment: 700
Study Start Date: April 2012
Estimated Study Completion Date: December 2016
Estimated Primary Completion Date: May 2016 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Walnut group
This group will have their habitual diet supplemented with 30 to 45g (1 to 1.5 oz) of walnuts daily.
Dietary Supplement: Walnuts
30 to 45g (1 to 1.5 oz) per day of walnuts
Active Comparator: Control group
This group will eat their habitual diet and refrain from eating walnuts.
Other: habitual diet
Dietary information will be provided

Detailed Description:

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 1.5 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.


Ages Eligible for Study:   63 Years to 79 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes

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
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT01634841

United States, California
Loma Linda University, Department of Nutrition
Loma Linda, California, United States, 92350
Hospital Clinic, University of Barcelona
Barcelona, Spain, 08036
Sponsors and Collaborators
Loma Linda University
University of Barcelona
Principal Investigator: Joan Sabate, MD, DrPH Chair, Department of Nutrition
Principal Investigator: Emilio Ros, MD, PhD Director Lipid Clinic, Endocrinology & Nutrition Service
  More Information

Responsible Party: Joan Sabate,DrPH, MD, Principal Investigator, Chair, Department of Nutrition, Loma Linda University
ClinicalTrials.gov Identifier: NCT01634841     History of Changes
Other Study ID Numbers: 5120066  670715-3833 
Study First Received: June 20, 2012
Last Updated: January 28, 2016
Health Authority: United States: Institutional Review Board
Spain: Ethics Committee

Keywords provided by Loma Linda University:
age related cognitive decline
age related macular degeneration
healthy elderly subjects

Additional relevant MeSH terms:
Cognition Disorders
Macular Degeneration
Eye Diseases
Mental Disorders
Neurocognitive Disorders
Retinal Degeneration
Retinal Diseases

ClinicalTrials.gov processed this record on May 26, 2016