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

  • End date
    Dec 31, 2023
  • participants needed
  • sponsor
    University of California, Davis
Updated on 23 March 2022
Accepts healthy volunteers


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).


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.

Condition Vascular Dilation
Treatment Freeze Dried Strawberry Powder
Clinical Study IdentifierNCT04763499
SponsorUniversity of California, Davis
Last Modified on23 March 2022


Yes No Not Sure

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 prescreening 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
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