Understanding Dose Related Effects of Strawberry

NCT06173765 | Active Not Recruiting

• 1 other identifier: IRB-2021-98
• Study Type: interventional
• Target: 66
• Locations: 1 country
• Sites: 1

Brief Summary

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

Outcome Measures

Primary Outcomes (2)

• Changes in plasma biomarkers and measures of inflammation: NF-κB activation/suppression

  The dose related change in measures of inflammation by analyzing NF-κB activation/suppression in monocytes among participants after 4 weeks of strawberry intake (1 cup or 3 cup FWeq) vs control (0 cup strawberry).

  Baseline to 4 weeks

• Change in primary clinical marker of inflammation IL-6

  The dose related change in blood level of IL-6 among participants after 4 weeks of strawberry intake (1 cup or 3 cup FWeq) vs control (0 cup strawberry). Cellular evaluation of inflammatory status, collected plasma samples will be analyzed for selected inflammatory markers (IL-6) using standard ELISA.

  Baseline to 4 weeks

Secondary Outcomes (8)

• Change flow mediated dilation (FMD) before and after four weeks strawberry intake compared to control

  Baseline to 4 weeks

• Change in Insulin sensitivity index using Liquid Meal Tolerance Test (LMTT).

  Baseline to 4 weeks

• Change in Beta cell function using Liquid Meal Tolerance Test (LMTT).

  Baseline to 4 weeks

• Change in Insulin Disposition index using Liquid Meal Tolerance Test (LMTT).

  Baseline to 4 weeks

• Change in Insulin Fractional disappearance rate of plasma glucose using Liquid Meal Tolerance Test (LMTT).

  Baseline to 4 weeks

Study Arms (3)

36g of strawberry

EXPERIMENTAL

High dose intervention

Other: freeze-dried whole strawberry powder 36 g powder

12g of strawberry

EXPERIMENTAL

Low dose intervention

Other: freeze-dried whole strawberry powder 12 g

0g of strawberry

PLACEBO COMPARATOR

Control

Other: freeze-dried control powder 0 g strawberry

Interventions

freeze-dried whole strawberry powder 36 g powder OTHER

After day 1 measurements, subjects will be given their first intervention drink (powder plus water) according to their randomization to 3 cup FW equivalent of strawberries. The freeze-dried whole strawberry powder (36 g powder) requested from the California Strawberry Commission. All drinks will be standardized to 41 g powder to match USDA Control arm.

36g of strawberry

freeze-dried whole strawberry powder 12 g OTHER

After day 1 measurements, subjects will be given their first intervention drink (powder plus water) according to their randomization to 1 cup FW equivalent of strawberries. The freeze-dried whole strawberry powder (12 g powder) requested from the California Strawberry Commission. All drinks will be standardized to 41 g powder to match USDA Control arm.

12g of strawberry

freeze-dried control powder 0 g strawberry OTHER

After day 1 measurements, subjects will be given their first intervention drink (powder plus water) according to their randomization to 0 cup FW equivalent of strawberries. The freeze-dried powder is used as a control. All drinks will be standardized to 41 g powder to match USDA Control arm.

0g of strawberry

Eligibility Criteria

• Age: 20 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Clinical Nutrition Research Center, Illinois Institute of Technology: lead

Study Sites (1)

Clinical Nutrition Research Center

Chicago, Illinois, 60616, United States

Location

MeSH Terms

Conditions

Glucose Intolerance; Insulin Resistance; Inflammation

Interventions

Powders

Condition Hierarchy (Ancestors)

Hyperglycemia; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Hyperinsulinism; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Dosage Forms; Pharmaceutical Preparations

Study Officials

• Britt Burton-Freeman, PhD

  Illinois Institute of Technology

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: a 3 arm, randomized, controlled parallel design using the control arm from the USDA parallel study.

Study Record Dates

• First Submitted: May 22, 2023
• First Posted: December 18, 2023
• Study Start: August 31, 2022
• Primary Completion: March 30, 2023
• Study Completion: January 28, 2026
• Last Updated: July 11, 2025

Record last verified: 2025-07

Locations

US (1)