Walnuts and Healthy Aging

Age Related Macular Degeneration Clinical Trial

— WAHA  

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01634841
• Other study ID #: 5120066
• Secondary ID: 670715-3833
• Status: Completed
• Phase: N/A
• Start date: April 2012
• Est. completion date: May 2016

Study information

• Verified date: June 2021
• Source: Loma Linda University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

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 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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 708
• Est. completion date: May 2016
• Est. primary completion date: May 2016
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 63 Years to 79 Years

Eligibility

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

Related Conditions & MeSH terms

• Age Related Cognitive Decline
• Age Related Macular Degeneration
• Cognitive Dysfunction
• Macular Degeneration

Intervention

Dietary Supplement:
• Walnuts
30 to 60g (1 to 2 oz) per day of walnuts

Other:
• habitual diet
Dietary information will be provided

Locations

Country	Name	City	State
Spain	Hospital Clinic, University of Barcelona	Barcelona
United States	Loma Linda University, Department of Nutrition	Loma Linda	California

Sponsors (3)

Lead Sponsor	Collaborator
Loma Linda University	California Walnut Commission, University of Barcelona

Countries where clinical trial is conducted

United States,  Spain, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Change in carotid Intima-media thickness (mm)	Changes will be assessed by high-resolution ultrasound. Only in Barcelona center.	2 years
Other	Incidence of plaque presence in carotid artery (yes/no)	Changes will be assessed by high-resolution ultrasound. Only in Barcelona center.	2 years
Other	Change in carotid atheroma plaque height (mm)	Changes will be assessed by high-resolution ultrasound. Only in Barcelona center.	2 years
Other	Change in body mass index (kg/m2)	BMI will be calculated as weight in kilograms divided by height in metres squared	2 years
Other	Change in waist circumference (cm)	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	2 years
Other	Change in total fat (g)	Changes will be assessed by Dual-energy X-ray absorptiometry. Only in Barcelona center.	2 years
Other	Change in Total lean tissue (g)	Changes will be assessed by Dual-energy X-ray absorptiometry. Only in Barcelona center.	2 years
Other	Change in fasting serum total cholesterol (mg/dL)	Fasting serum total cholesterol will be measured by a standard enzymatic method	2 years
Other	Change in fasting serum LDL-cholesterol (mg/dL)	Fasting serum LDL-cholesterol will be estimated by the Friedewald formula	2 years
Other	Change in fasting serum HDL-cholesterol (mg/dL)	Fasting serum HDL-cholesterol will be measured by a precipitation technique	2 years
Other	Change in fasting serum triglycerides (mg/dL)	Fasting triglycerides will be measured by a standard enzymatic method	2 years
Other	Change in serum brain-derived neurotrophic factor (pg/mL)	Assessed by ELISA	2 years
Other	Change in serum soluble-Selectin (ng/mL)	Assessed by ELISA	2 years
Other	Change in serum soluble-intercellular Adhesion Molecule 1 (ng/mL)	Assessed by ELISA	2 years
Other	Change in serum soluble-vascular cell adhesion molecule 1 (ng/mL)	Assessed by ELISA	2 years
Other	Change in serum amyloid A (ng/mL)	Assessed by ELISA	2 years
Other	Change in serum granulocyte-macrophage colony-stimulating factor (pg/mL)	Assessed by ELISA	2 years
Other	Change in serum interferon-gamma (pg/mL)	Assessed by ELISA	2 years
Other	Change in serum interleukin-1beta (pg/mL)	Assessed by ELISA	2 years
Other	Change in serum interleukin-6 (pg/mL)	Assessed by ELISA	2 years
Other	Change in serum tumor necrosis factor alpha (pg/mL)	Assessed by ELISA	2 years
Primary	Changes from baseline in global cognitive composite score	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 years
Primary	Changes from baseline in macular degeneration	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).	2 years
Secondary	Change from baseline in brain cortical thickness	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 years
Secondary	Change from baseline in voxel-based morphometry	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.	2 years
Secondary	Change from baseline in white matter hyperintensity volumes	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.	2 years
Secondary	Change from baseline in perfusion arterial spin labeling	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.	2 years
Secondary	Changes from baseline in brain activation	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.	2 years