Recipient Organization
UNIV OF CALIFORNIA
(N/A)
LOS ANGELES,CA 90095
Performing Department
(N/A)
Non Technical Summary
Coronavirus disease 2019 (COVID-19), the viral multi-system illness caused by the novel coronavirus SARS-CoV-2, has resulted in significant morbidity and mortality across the world. Approximately 30% of patients experience "Long-COVID" syndrome presenting with symptoms such as cognitive difficulties ('brain fog'), fatigue, dyspnea, autonomic dysfunction, depression and anxiety, lasting beyond 12 weeks causing significant disability, and threaten health and wellbeing of millions around the world. At the current time there is no effective treatment for long-COVID.Walnuts contain a mixture of nutrients and phytochemicals include monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), and alpha-linolenic acid (ALA) that are important to human health. Cross-sectional studies found that walnut consumption was directly associated with cognitive function. Walnuts are rich source of ellagitannins and ellagic acid that can be further converted by intestinal microbiota to urolithins. All those compounds have been reported to exhibit numerous beneficial effects on human health Our recent study at UCLA demonstrated that daily consumption of pomegranate juice, another rich source of ellagitannins stabilized the ability to learn visual information over a 12-mo period in in middle-aged and older adults [8]. We have shown pomegranate and mixed nuts including walnuts could increase blood microbiome metabolites of tryptophan metabolite indole propionate (IPA) and serotonin levels via change of gut microbiota. Both IPA and serotonin play an essential role in gut-brain axis including cognitive function.Our proposed pilot study will include 76 adults (ages 50-80 years) with documented diagnosis of SARS-CoV2 infection presenting with long-COVID symptoms lasting longer than 12 weeks. They will be randomized 1:1 to usual care vs. an intervention group that will include 2 oz (57g) of walnuts daily into their habitual diet for 12 weeks. We will compare the improvement in symptoms of cognitive complains of "brain fog", fatigue and depression of the active intervention group vs. usual care. In this pilot study, we will assess all aspects of cognition, including Episodic Memory, Executive Function, Processing Speed, Working Memory, Attention, and Language, in order to determine the most sensitive outcome measures as well as to estimate the effect sizes for planning a future RO1/UO1 or other funding for an efficacy trial. Additionally, we will also test the methodology prior to application for a larger clinical trial to assess recruitment feasibility, adherence, safety, and acceptability of the interventions in this population. We will explore the mechanism of how walnut consumption affects brain fog, fatigue and mood symptoms by measure bacterial tryptophan metabolites. The outcome of the investigation of the benefit of walnut consumption will provide important novel information on using dietary sources of polyunsaturated fatty acids and phytochemicals to mitigate the common symptoms of long-COVID.
Animal Health Component
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Research Effort Categories
Basic
0%
Applied
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Developmental
100%
Goals / Objectives
Our proposed pilot study will include 60 adults (ages 50-80 years) with documented diagnosis of SARS-CoV2 infection presenting with long-COVID symptoms lasting longer than 12 weeks. They will be randomized 1:1 to usual care vs. an intervention group that will include 2 oz (57g) of walnuts daily into their habitual diet for 12 weeks. We will compare the improvement in symptoms of cognitive complains of "brain fog", fatigue and depression of the active intervention group vs. usual care. In this pilot study, we will assess all aspects of cognition, including Episodic Memory, Executive Function, Processing Speed, Working Memory, Attention, and Language, in order to determine the most sensitive outcome measures as well as to estimate the effect sizes for planning a future RO1 efficacy trial. Additionally, we will also test the methodology prior to application for a larger RO1 to assess recruitment feasibility, adherence, safety, and acceptability of the interventions in this population.Aim 1. To determine if daily consumption of walnuts for 12 weeks leads to improved cognition, fatigue and mood symptoms in subjects with long-COVID.Hypothesis 1a. Compared to the usual care group, subjects in the walnut group will show greater improvement in cognition (Memory and Executive Function) from baseline to the end of intervention. We will also explore the improvement in other cognitive domains (Processing Speed, Working Memory, Attention, and Language).Hypothesis 1b. Compared to the usual care group, subjects in the walnut group will show greater improvement in fatigue, and mood symptoms from baseline to the end of intervention.Between-group and within-group effect sizes for all outcome measures will be estimated to allow planning of a future RO1.Aim 2. To determine if daily consumption of walnuts for 12 weeks leads to benefits in clinical parameters, dietary quality and quality of life in subjects with long-COVID.Hypothesis 2a. Subjects in the walnut group will show improved clinical parameters (vital signs, body weight, body compositions) and improved dietary quality than those in the usual care group.Hypothesis 2b. Subjects in the active intervention arm will exhibit higher quality of life at the completion of the study compared to subjects in usual care.Aim 3. To examine feasibility, retention rates and adherence in this randomized trial of daily walnut consumption vs. usual care in subjects with long-COVID.Hypothesis 3. The current trial design will be feasible as assessed by retention rates (subjects complete at least 75% of post-randomization study visits). Compliance, as measured by blood fatty acids, urine ellagic acid and urolithin metabolites will be monitored in all subjectsExploratory Aim 4. To explore the mechanism of how walnut consumption affects brain fog, fatigue and mood symptoms.Hypothesis 4: Subjects in the walnut group will show decreased inflammation and increased beneficial bacterial tryptophan metabolites than those in the usual care group. The outcome of the investigation of the benefit of walnut consumption will provide important novel information on using dietary sources of polyunsaturated fatty acids and phytochemicals to mitigate the common symptoms of long-COVID.
Project Methods
Primary Outcome:Memory and executive functions. These will be measured by gold standard neuropsychological tests: Verbal episodic memory (Rey Auditory Verbal Learning Test-Revised); Executive Function including mental set switching (Trails B), working memory (Wechsler Adult Intelligence Scale (WAIS) -IV Digit Span, Wechsler 2008); Information Processing speed (WAIS-IV Symbol Search Test Wechsler 2008), Sustained attention (Digit Vigilance Test,) and rapid word generation (CFL. Fluency. The length of the battery is approximately 1 hour and 15 minutes.Fatigue (as assessed by PROMIS-Fatigue Scale, Short Form 8 items) The NIH-developed Patient Reported Outcomes Measurement Information System (PROMIS®). The PROMIS Fatigue scale assess a range of self-reported symptoms, from mild subjective feelings of tiredness to an overwhelming, debilitating, and sustained sense of exhaustion that likely decreases one's ability to execute daily activities and function normally in family or social roles. Fatigue is divided into the experience of fatigue (frequency, duration, and intensity) and the impact of fatigue on physical, mental, and social activities. The fatigue short forms are universal rather than disease-specific. All assess fatigue over the past seven days.Depression (measured by PROMIS- Depressive symptoms, 8 item short formThe PROMIS depression scales are reliable and valid measures that have exten.sive normative data in general population samples The items in the PROMIS negative affect banks use a 7-day time frame and a 5-point rating scale that ranges from 1 ("Never") to 5 ("Always"). Each item bank was developed using comprehensive mixed (qualitative and quantitative) methods. The PROMIS Depression bank focuses on affective and cognitive manifestations of depression rather than somatic symptoms such as appetite, fatigue and sleep.The PROMIS depression scale is sensitive to changes in emotional distress in longitudinal studies and has comparable sensitivity when compared to legacy scales. (Kroenke et al., 2021).Secondary OutcomesClinical parameters vital signs, body weight and body composition: Body weight and composition analysis will be performed using the Tanita-BC418 body-fat analyzer (Tanita Corp., Tokyo, Japan) to estimate body weight and body fat, based on the principles of bioelectrical impedance at baseline, week 12.24 hour diet recall: Dietary energy and macronutrient intake will be assessed at baseline, and every two weeks throughout the study. For the 24 hr dietary recall we will be using the Automated Self-Administered 24-hour Dietary Recall (ASA24™) tool (https://asa24.nci.nih.gov/).Quality of life SF-36: The SF-36 is a multi-purpose survey designed to capture adult patients' perceptions of their own health and well-being. It measures each of the following eight health domains: physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional, and mental health. SF-36 questionnaires will be recorded at baseline, 4, 8 and 12 weeks.Dietary intake and physical activity: Subjects in both groups will be instructed to use digital food registration online platform via smartphone app MyFitnessPal [33]. Subjects will be encouraged to track dietary intake as often as possible and mandated to complete 3-day dietary record 2 times every 4 weeks. Activity/exercise and sleep time will be monitored by MyFitnessPal application on iPhone or android phone. We will take advantage that UCLA Health has mature patient portal to capture those data from smart phone via MyUCLAHealth. Subjects will sync MyFitnessPal via Apple Health Kit or Google Fit to sync with myUCLAHealth patient portal every 4 weeks.Cognitive Functions, measured by the NIH Toolbox Cognitive Battery (NIHTB-CB) (Weintraub et al., 2013). The NIHTB-CB was designed for use in epidemiologic studies and clinical trials for ages 3 to 85.The NIHTB-CB contains seven computer-based measures assessing five cognitive sub-domains: Language, Executive Function, Episodic Memory, Processing Speed, and Working Memory. We will analyze two composite scores derived from the NIHTB-CB: The Fluid Intelligence score (subtests of Episodic Memory, Processing Speed, Executive Function, and Working Memory) and Crystallized Intelligence used as an index of pre-morbid cognitive functioning (Language subtests of Reading and Vocabulary) (Heaton et al., 2014). NIH Toolbox-CB takes about 45 minutes to administer. Responses are recorded on an ipad.Tertiary Outcomes:Retention rate: attendance of all study visit activity at baseline, week 4, 8 and 12 will be recorded.Blood fatty acid, ellagic acid and urolithin: blood fatty acid analysis will be done by GC. Urine ellagic acid and urolithin metabolites by LC-MS/MS at the UCLA Center for Human Nutrition Analytical Laboratory.Exploratory Outcomes:Plasma hsCRP will be measured using the Luminex MagPix® analyzer (Luminex, Austin TX)Plasma serotonin and IPA will be measured using LC-MS as previously described [29]. Stool microbiome: stool will be collected at baseline and end of intervention for future microbiome analysis.Statistical Analysis: Preliminary analyses will include graphical methods for checking for outliers to identify errors and highly unusual values, and for checking assumptions needed for analysis such as normality or symmetry of independent and outcome measures. Transformations of these variables to normality or substitution of non-parametric procedures will be done as appropriate. Descriptive statistics will be computed and reported overall and by group. Primary analyses will be carried out on an intent-to-treat basis. The primary outcome of the pilot study will be improvement of Episodic Memory and Executive Function (as detailed in Sec X.X) as well as fatigue and mood at week 12 compared to baseline. The primary statistical model will be a linear mixed effects model which utilizes all available data points for each individual, with the baseline score as a covariate. The primary statistical test is then whether the mean slope in the walnut group differs from the mean slope in the usual care group (group*time interaction). Analysis of the secondary outcomes including blood hsCRP, fatty acids, and urine metabolites will again use linear mixed effects models to assess the relationship of treatment and demographic factors on the secondary outcomes over time.Recruitment and retention rates will be monitored and compared between groups at the end of the study. Adverse events will be monitored throughout the course of the study.Power analysis: We intend to enroll a total of 76 participants, such that with an anticipated 20% drop out rate, we will have 60 completers. With 30 subjects per arm, we can detect an effect size (Cohen's d) of 0.73 SDs, with 80% power. (Note that this is a conservative estimate, since we plan to analyze our data using the general linear mixed model framework that will utilize all observed data collected from all subjects, irrespective of drop-out). While this pilot trial is not designed or powered to detect statistically significant differences between the treatment arms, we believe that these preliminary data will be critical to designing an appropriately powered subsequent trial to assess for meaningful clinical outcomes. We will therefore focus on estimating the effect size between treatment arms in this population of interest.