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The Influence of Daily Strawberry Intake on Vascular Health in Elderly Men

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ClinicalTrials.gov Identifier: NCT04763499
Recruitment Status : Recruiting
First Posted : February 21, 2021
Last Update Posted : February 18, 2022
Information provided by (Responsible Party):
University of California, Davis

Brief Summary:
The overall objective of this proposed trial is to examine the vascular protective effects provided by the daily consumption of 39g of freeze dried strawberry powder (FDSP) for four weeks. The study population will be older men (60-80 years of age).

Condition or disease Intervention/treatment Phase
Vascular Dilation Other: freeze dried strawberry powder Not Applicable

Detailed Description:
The proposed project will determine the influence of short-term FDSP intake on microvascular function in older men (60-80 years of age). The Framingham reactive hyperemia index (fRHI) will be used as a measure of microvascular function, and will be measured using peripheral arterial tonometry (PAT; EndoPAT200). Secondary outcomes will assess circulating levels of nitrate and nitrite, insulin-like growth factor (IGF), inflammatory cytokines, NADPH oxidase, platelet aggregation, plasma lipids and blood pressure. This suite of markers will provide insight on physiological outcomes and risk factors associated with CVD development, and the metabolic and signaling pathways that influence them. To accomplish the above, after a 4 week run in period of no powder intake, twenty men (60-80 years of age) will be randomly assigned to consume 39 g of FDSP or a control powder for four weeks in a randomized, double-blind, controlled crossover study. This study design will compare the short-term (four week) response of FDSP intake to an isocaloric control powder that provides no polyphenols, as well as to their habitual diet where no powder was consumed.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 20 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Intervention Model Description: A randomized, double-blind, crossover dietary intervention trial.
Masking: Double (Participant, Investigator)
Masking Description: both the control and freeze dried strawberry powders are package with only a code as the identifier
Primary Purpose: Prevention
Official Title: The Influence of Daily Strawberry Intake on Vascular Health in Elderly Men
Actual Study Start Date : December 1, 2021
Estimated Primary Completion Date : March 31, 2023
Estimated Study Completion Date : December 31, 2023

Arm Intervention/treatment
Experimental: Freeze dried strawberry powder

39g of freeze dried strawberry powder, which represents three daily servings of strawberries.

The powder will be mixed in one cup of water.

Other: freeze dried strawberry powder
approximately 24 strawberries that have been freeze dried into a powder

Placebo Comparator: control powder
39 g of a powder that matches the sugar and caloric content of the experimental powder. The powder will be mixed in one cup of water.
Other: freeze dried strawberry powder
approximately 24 strawberries that have been freeze dried into a powder

Primary Outcome Measures :
  1. Framingham Reactive Hyperemia Index (fRHI) [ Time Frame: 4 weeks ]
    fRHI as a measure of microvascular function will be measured by peripheral arterial tonometry (PAT).

Secondary Outcome Measures :
  1. platelet aggregation [ Time Frame: 4 weeks ]
    optimal platelet aggregometry using collagen and adp as agonist

  2. Th17 cytokines [ Time Frame: 4 weeks ]
    TH17 Luminex panel: Interleukin (IL)-1b, IL-4, IL-6, IL-10, IL-17a, IL-21, IL-22, IL-23, IL-31, IL-33, IFNgamma, TNFalpha, IL-17f.

  3. insulin like growth factor (IGF) and binding proteins (IGFBP) [ Time Frame: 4 weeks ]
    Luminex panel: IGF-1, -2 and IGFBP 1-7

  4. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase [ Time Frame: 4 weeks ]
    soluble form marker of oxidative stress

  5. total nitrate and nitrite [ Time Frame: 4 weeks ]
    plasma total nitrate and nitrite

Other Outcome Measures:
  1. blood pressure [ Time Frame: 4 weeks ]
    systolic and diastolic blood pressure

  2. plasma lipids [ Time Frame: 4 weeks ]
    clinical lipid panel

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Ages Eligible for Study:   60 Years to 80 Years   (Adult, Older Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Subject is willing and able to comply with the study protocols.
  • Subject is willing to participate in all study procedures
  • BMI 25.0 - 35 kg/m2

Exclusion Criteria:

  • BMI ≥ 35 kg/m2
  • Visit 1 Reactive Hyperemia Index (RHI; EndoPAT 2000) ≥ 2.8
  • Dislike or allergy strawberries
  • Self-reported use of daily anticoagulation agents including aspirin, NSAIDs
  • Prescription medications other than on a 6 month self-reported stable dose of medications for lipid lowering and/or hypertension.
  • Vegan, Vegetarians, food faddists or those consuming a non-traditional diet
  • Fruit consumption ≥ 3 cups/day
  • Regular consumption of strawberries (2-3 servings/week)
  • Vegetable consumption ≥ 4 cups/day
  • Coffee/tea ≥ 3 cups/day
  • Dark chocolate ≥ 3 oz/day
  • Self-reported restriction of physical activity due to a chronic health condition
  • Self-reported chronic/routine high intensity exercise
  • Self-reported diabetes
  • Blood pressure ≥ 140/90 mm Hg
  • Self-reported renal or liver disease
  • Self-reported heart disease, which includes cardiovascular events and stroke
  • Peripheral artery disease Raynaud's syndrome or disease
  • Inability to properly place or wear the PAT probes or abnormal measurements on pre- screening PAT
  • Abnormal Metabolic or CBC panels (laboratory values outside the reference range) if determined to be clinically significant by the study physician.
  • Self-reported cancer within past 5 years
  • Self-reported malabsorption
  • Supplement use other than a general formula of vitamins and minerals that meet the RDA
  • Not willing to stop any supplement use, including herbal, plant or botanical, fish oil, oil supplements a month prior to study enrollment.
  • Indications of substance or alcohol abuse within the last 3 years
  • Cannabis use
  • Current enrollee in a clinical research study.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04763499

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Contact: Roberta R Holt, PhD 530-400-5952 rrholt@ucdavis.edu

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United States, California
University of California, Davis; Department of Nutrition Recruiting
Davis, California, United States, 95616
Contact: Roberta Holt, PhD    530-752-4950    rrholt@ucdavis.edu   
Sponsors and Collaborators
University of California, Davis
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Principal Investigator: Carl L Keen, PhD Professor of Nutrition and Internal Medicine
Additional Information:
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Responsible Party: University of California, Davis
ClinicalTrials.gov Identifier: NCT04763499    
Other Study ID Numbers: 1567320
First Posted: February 21, 2021    Key Record Dates
Last Update Posted: February 18, 2022
Last Verified: February 2022
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by University of California, Davis:
strawberry, diet, vascular function, inflammation
Additional relevant MeSH terms:
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Dilatation, Pathologic
Pathological Conditions, Anatomical