Understanding Dose Related Effects of Strawberry
The proposed research is designed to extend previous research findings building on the knowledge of strawberries as fruits that support a healthy immune and vascular system. The proposed research leverages a recently funded proposal by the USDA to study in greater depth inflammation, glucoregulation and oxidative stress defense and their relation to improving endothelial function and insulin sensitivity. Before and after strawberry intake, blood samples will be collected for monocyte (immune cells and source of inflammatory cytokines) isolation and activation via changes in cellular NF-κB and Nrf-2 (key transcription factors of inflammation/oxidative stress defense) status along with products of their activation (ie., plasma cytokines). Because inflammation and oxidative stress impairs endothelial function and insulin sensitivity, acutely and chronically, investigators will also study changes in vascular and insulin sensitivity status, assessing changes in vascular adhesion molecules, endothelial responsiveness through flow mediated vasodilation (ie., FMD) and insulin sensitivity using the Liquid Meal Tolerance (LMTT) if intravenous glucose tolerance test (IVGTT) method cannot be used due to supply chain issues of sterile Dextrose. Glucoregulation will be assessed by placing a Continuous Glucose monitoring (CGM) machine (Dexcom-6) to participants for 10 days at the beginning and at the end of the study period of intervention. The study will be a randomized, double-blinded, 3-arm parallel, 4-week, dose-response study. Individuals with chronic low grade inflammation will be sought to test the anti-inflammation - vaso-relaxing - insulin sensitivity effects of strawberry.
Conditions:
🦠 Pre-diabetes 🦠 Insulin Sensitivity 🦠 Insulin Resistance 🦠 Inflammation
🗓️ Study Start (Actual) 31 August 2022
🗓️ Primary Completion (Estimated) 30 March 2023
✅ Study Completion (Estimated) 28 February 2024
👥 Enrollment (Estimated) 66
🔬 Study Type INTERVENTIONAL
📊 Phase NA
Locations:
📍 Chicago, Illinois, United States

📋 Eligibility Criteria

Description

  • Inclusion Criteria
  • * Men or women 20-60 years of age
  • * High sensitivity C-Reactive Protein (hs-CRP), a global marker of inflammation, \>1.0 and ≤10 ng/L
  • * BMI ≥ 25 kg/m2
  • * Nonsmokers (Past smokers can be allowed if they have abstinence for minimum of 1 years). Occasional smoker may be allowed at investigator discretion
  • * Judged to be in good health on the basis of the medical history ie., no clinical evidence of cardiovascular, metabolic, respiratory, renal, gastrointestinal or hepatic disease
  • * Not taking any medications that would interfere with outcomes of the study, i.e. lipid lowering medications, anti-inflammatory drugs, dietary supplements, etc.
  • * Able to provide informed consent
  • * Able to comply and perform the procedures requested by the protocol (including dietary restrictions, consumption of study treatments, records of food diary and study visit schedule)
  • * Able to maintain usual physical activity pattern
  • * Able to abstain from alcohol consumption and avoid vigorous physical activity for 24 hours prior to and during study visit

Exclusion Criteria:

  • * Men and women who smoke regularly
  • * Men and women with known or suspected intolerance, allergies or hypersensitivity to study foods or treatments
  • * Men and women who have blood pressure \>160 mmHg (systolic)/100 mmHg (diastolic) at screening visit
  • * Men and women who have fasting blood glucose concentration \>125 mg/dL at screening visit
  • * Men and women with documented vascular disease, e.g., heart failure, myocardial infarction, stroke, angina, related surgeries, etc. that, in the opinion of the investigator, could interfere with the interpretation of the study results
  • * Men and women with cancer other than non-melanoma skin cancer in previous 5 years
  • * Men and women diagnosed with chronic constipation, diarrhea or other chronic gastrointestinal complaint (e.g. irritable bowel syndrome)
  • * Women who are known to be pregnant or who are intending to become pregnant over the course of the study
  • * Women who are lactating
  • * Taking medication or dietary supplements that may interfere with the outcomes of the study; e.g., antioxidant supplement, anti-inflammation, lipid lowering medication, blood pressure lowering medication, etc... Subjects may choose to go off dietary supplements (requires 30-day washout); e.g., fish oil, probiotics, etc...
  • * Men and women who has participated in prebiotics or laxative trial within 3 months prior to enrollment or any other clinical trial within 1 month
  • * Major trauma or a surgical event within 2 months or longer depending on trauma or event and after consultation with PI.
  • * Vegan or other extreme dietary regimens (e.g., Atkins diet, etc.) as judged by the investigator.
  • * Has a known intolerance or sensitivity to any ingredients in the study products
  • * Has used antibiotics within the previous 2 months
  • * History of an eating disorder (e.g., anorexia nervosa, bulimia nervosa, or binge eating) diagnosed by a health professional
  • * Substance (alcohol or drug) abuse within the last 2 years
  • * Excessive coffee and tea consumers (\> 4 cups/d)
  • * Donated blood within last 3 months
  • * Men and women who do excessive exercise regularly or are an athlete
  • * Unstable weight: gained or lost weight +/- 5 kg (11 lbs) in previous 2 months
  • * Women who are taking unstable dose and brand of hormonal contraceptives and/or stable dose and brand less than 6 months
  • * Unusual working hours i.e., working overnight (e.g. 3rd shift)
Ages Eligible for Study: 20 Years to 60 Years (ADULT)
Sexes Eligible for Study: ALL
Accepts Healthy Volunteers: Yes

🗓️ Study Record Dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Registration Dates

  • First Submitted 22 May 2023
  • First Submitted that Met QC Criteria 13 December 2023
  • First Posted 18 December 2023

Study Record Updates

  • Last Update Submitted that Met QC Criteria 13 December 2023
  • Last Update Posted 18 December 2023
  • Last Verified December 2023