title: The Walnuts and Healthy Aging Study (WAHA): Protocol for a Nutritional Intervention Trial with Walnuts on Brain Aging.
abstract: Introduction:An unwanted consequence of population aging is the growing number of elderly at risk of neurodegenerative disorders, including dementia and macular degeneration. As nutritional and behavioral changes can delay disease progression, we designed the Walnuts and Healthy Aging (WAHA) study, a two-center, randomized, 2-year clinical trial conducted in free-living, cognitively healthy elderly men and women. Our interest in exploring the role of walnuts in maintaining cognitive and retinal health is based on extensive evidence supporting their cardio-protective and vascular health effects, which are linked to bioactive components, such as n-3 fatty acids and polyphenols.Methods:The primary aim of WAHA is to examine the effects of ingesting walnuts daily for 2 years on cognitive function and retinal health, assessed with a battery of neuropsychological tests and optical coherence tomography, respectively. All participants followed their habitual diet, adding walnuts at 15% of energy (≈30-60 g/day) (walnut group) or abstaining from walnuts (control group). Secondary outcomes include changes in adiposity, blood pressure, and serum and urinary biomarkers in all participants and brain magnetic resonance imaging in a subset.Results:From May 2012 to May 2014, 708 participants (mean age 69 years, 68% women) were randomized. The study ended in May 2016 with a 90% retention rate.Discussion:The results of WAHA might provide high-level evidence of the benefit of regular walnut consumption in delaying the onset of age-related cognitive impairment and retinal pathology. The findings should translate into public health policy and sound recommendations to the general population (ClinicalTrials.gov identifier NCT01634841).
authors.affiliation: Center for Nutrition, Healthy Lifestyle and Disease Prevention, School of Public Health, Loma Linda University, Loma Linda CA, USA.
authors.forename: Sujatha
authors.initials: S
authors.lastname: Rajaram
authors.affiliation: Lipid Clinic, Endocrinology and Nutrition Service, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i SunyerBarcelona, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos IIIMadrid, Spain.
authors.forename: Cinta
authors.initials: C
authors.lastname: Valls-Pedret
authors.affiliation: Lipid Clinic, Endocrinology and Nutrition Service, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i SunyerBarcelona, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos IIIMadrid, Spain.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Cofán
authors.affiliation: Center for Nutrition, Healthy Lifestyle and Disease Prevention, School of Public Health, Loma Linda University, Loma Linda CA, USA.
authors.forename: Joan
authors.initials: J
authors.lastname: Sabaté
authors.affiliation: Lipid Clinic, Endocrinology and Nutrition Service, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i SunyerBarcelona, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos IIIMadrid, Spain.
authors.forename: Mercè
authors.initials: M
authors.lastname: Serra-Mir
authors.affiliation: Lipid Clinic, Endocrinology and Nutrition Service, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i SunyerBarcelona, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos IIIMadrid, Spain.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Pérez-Heras
authors.affiliation: Department of Psychology, School of Behavioral Health, Loma Linda University, Loma Linda CA, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Arechiga
authors.affiliation: Ophthalmology Service, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer Barcelona, Spain.
authors.forename: Ricardo P
authors.initials: RP
authors.lastname: Casaroli-Marano
authors.affiliation: Ophthalmology Service, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer Barcelona, Spain.
authors.forename: Socorro
authors.initials: S
authors.lastname: Alforja
authors.affiliation: Lipid Clinic, Endocrinology and Nutrition Service, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i SunyerBarcelona, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos IIIMadrid, Spain.
authors.forename: Aleix
authors.initials: A
authors.lastname: Sala-Vila
authors.affiliation: Lipid Clinic, Endocrinology and Nutrition Service, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i SunyerBarcelona, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos IIIMadrid, Spain.
authors.forename: Mónica
authors.initials: M
authors.lastname: Doménech
authors.affiliation: Lipid Clinic, Endocrinology and Nutrition Service, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i SunyerBarcelona, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos IIIMadrid, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Roth
authors.affiliation: Lipid Clinic, Endocrinology and Nutrition Service, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer Barcelona, Spain.
authors.forename: Tania M
authors.initials: TM
authors.lastname: Freitas-Simoes
authors.affiliation: Lipid Clinic, Endocrinology and Nutrition Service, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i SunyerBarcelona, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos IIIMadrid, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Calvo
authors.affiliation: Lipid Clinic, Endocrinology and Nutrition Service, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i SunyerBarcelona, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos IIIMadrid, Spain.
authors.forename: Anna
authors.initials: A
authors.lastname: López-Illamola
authors.affiliation: Center for Nutrition, Healthy Lifestyle and Disease Prevention, School of Public Health, Loma Linda University, Loma Linda CA, USA.
authors.forename: Ella
authors.initials: E
authors.lastname: Haddad
authors.affiliation: Center for Nutrition, Healthy Lifestyle and Disease Prevention, School of Public Health, Loma Linda University, Loma Linda CA, USA.
authors.forename: Edward
authors.initials: E
authors.lastname: Bitok
authors.affiliation: Center for Nutrition, Healthy Lifestyle and Disease Prevention, School of Public Health, Loma Linda University, Loma Linda CA, USA.
authors.forename: Natalie
authors.initials: N
authors.lastname: Kazzi
authors.affiliation: Center for Nutrition, Healthy Lifestyle and Disease Prevention, School of Public Health, Loma Linda University, Loma Linda CA, USA.
authors.forename: Lynnley
authors.initials: L
authors.lastname: Huey
authors.affiliation: Department of Ophthalmology, School of Medicine, Loma Linda University, Loma Linda CA, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Fan
authors.affiliation: Lipid Clinic, Endocrinology and Nutrition Service, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i SunyerBarcelona, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos IIIMadrid, Spain.
authors.forename: Emilio
authors.initials: E
authors.lastname: Ros
keywords: Alzheimer’s disease; age-related macular degeneration; aging; cognitive decline; dietary intervention; randomized trial; walnuts