Walnuts and Healthy Aging (WAHA)
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.
Age Related Cognitive Decline
Age Related Macular Degeneration
Dietary Supplement: Walnuts
Other: habitual diet
|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|
- % 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.
- % 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.
|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)|
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
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.
|Contact: Joan Sabate, MD, DrPHfirstname.lastname@example.org|
|Contact: Emilio Ros, MD||+(34) 93 227 email@example.com|
|United States, California|
|Loma Linda University, Department of Nutrition||Recruiting|
|Loma Linda, California, United States, 92350|
|Contact: Joan Sabate, MD, DrPH 909-558-4598 firstname.lastname@example.org|
|Principal Investigator: Joan Sabate, MD, DrPH|
|Hospital Clinic, University of Barcelona||Recruiting|
|Barcelona, Spain, 08036|
|Contact: Emilio Ros, MD, PhD +34 93 2279383 email@example.com|
|Principal Investigator: Emilio Ros, MD, PhD|
|Principal Investigator:||Joan Sabate, MD, DrPH||Chair, Department of Nutrition|
|Principal Investigator:||Emilio Ros, MD, PhD||Director Lipid Clinic, Endocrinology & Nutrition Service|