Evaluating the Availability of Berry Phytonutrients Post-consumption of Fresh and Processed Blueberry by Healthy Adults

NCT04175106 | Completed Results

• 1 other identifier: 19138
• Study Type: interventional
• Target: 29
• Locations: 1 country
• Sites: 1

Brief Summary

This study will evaluate the availability of phytonutrients in two blueberry varieties, chosen for their phytonutrient levels. This will be compared to phytonutrient-matched processed protein bar and a macronutrient-matched control meal, in healthy human volunteers. Blueberry phytonutrients will be analyzed in blood and urine over a four-day period, 48h prior to consumption and 48h after. The participants will consume each of the four meals over a 3-month period (4-way crossover design, 4 blocks of 4-day periods). The main objective of this study is to compare the proportions of blueberry phytonutrients recovered in the blood and urine after ingestion of the four treatments. We hypothesize that phytonutrient content will be predictive of human bioavailability and that a berry-enriched processed product will have similar phytonutrient bioavailability to unprocessed berries. The results of this study may establish if the nutritional value of a berry can be predicted or enhanced to provide elevated nutritional quality, with the ultimate goal of maximizing the health benefits of fruit consumption. As it is challenging for many to increase their fruit and vegetable intake to government recommended levels (5+ servings per day), the present proof-of-concept study explores a reasonable approach to help consumers achieve optimal health associated with high fruit and vegetable intakes, within the context of current consumption patterns, through enhancement of the nutritional density and bioavailability of common fruits and consumer products.

Conditions

Healthy

Outcome Measures

Primary Outcomes (2)

• Total Urinary Recovery of (Poly)Phenolic Metabolites Across Treatments

  Concentration of 185 (poly)phenolic metabolites in urine was measured after consumption of the treatments using broad spectrum metabolomic analysis via UPLC-MS/MS (ultra-performance liquid chromatography coupled with tandem mass spectrometry). Recovery of each metabolite was calculated by multiplying the concentration of the metabolite (ng/mL) by the volume of urine (mL) in each collection then converted to milligrams. The total urinary recovery of each (poly)phenolic metabolite was assessed as a measurement of their bioavailability, and it was established as the sum of the recovery from each urine collection (0 h to 48 h postintervention) minus the mean of the 48 h and 24 h baseline collections per participant and treatment. Then, it was averaged across participants per treatment and per metabolite, and further summed across metabolites. Therefore, data reported for each treatment represents the sum of the means of total urinary recovery across (poly)phenolic metabolites.

  4 days of urine collection per intervention; -48, -24, 0-9, 9-24 and 24-48 hours collections of urine.

• Serum Area Under the Curve (AUC) of (Poly)Phenolic Metabolites Across Treatments

  Concentration of 185 (poly)phenolic metabolites in blood was measured after consumption of the treatments using broad spectrum metabolomic analysis via UPLC-MS/MS (ultra-performance liquid chromatography coupled with tandem mass spectrometry). The area under the curve (AUC) of each (poly)phenolic metabolite in serum was assessed as a measurement of the bioavailability of these metabolites per participant and treatment. It was calculated using concentration and time data in the software Phoenix WinNonlin (version 8.3, Certara). Then, AUC was averaged across participants per treatment and per metabolite, and the mean AUCs were further summed across metabolites. Therefore, data reported for each treatment represents the sum of the means of AUC across (poly)phenolic metabolites.

  3 days of blood collection per intervention; 1 baseline collection, followed by 1, 3, 6, 9, 24 and 48 hours post-treatment collections of blood.

Secondary Outcomes (1)

• Maximum Serum Concentration [Cmax] of (Poly)Phenolic Metabolites Between the Treatments

  3 days of blood collection per intervention; 1 baseline collection, followed by 1, 3, 6, 9, 24 and 48 hours post-treatment collections of blood.

Other Outcomes (1)

• Time at Maximum Concentration [Tmax] of (Poly)Phenolic Metabolites in Serum Between the Treatments

  3 days of blood collection per intervention; 1 baseline collection, followed by 1, 3, 6, 9, 24 and 48 hours post-treatment collections of blood.

Study Arms (4)

a phytochemical-rich blueberry variety

EXPERIMENTAL

Single-time consumption of 150 g phytochemical-rich blueberry per participant.

Other: a non-traditional (i.e., not typically available in the supermarket) blueberry cultivar bred using natural plant breeding techniques and established as having enhanced nutritive value

a phytochemical-poor blueberry variety

EXPERIMENTAL

Single-time consumption of 150 g phytochemical-poor blueberry per participant.

Other: a standard commercially available blueberry variety (i.e., cultivar)

a "minimally processed" blueberry-rich protein bar

EXPERIMENTAL

Single-time consumption of blueberry-rich protein bar matched for 150 g blueberry phytochemicals.

Other: a "minimally processed" blueberry-rich protein bar

a blueberry control beverage of matched-nutritive content

PLACEBO COMPARATOR

Single-time consumption of control beverage matched for the macronutrient content of the blueberry-rich protein bar.

Other: a control beverage of matched-nutritive content

Interventions

a non-traditional (i.e., not typically available in the supermarket) blueberry cultivar bred using natural plant breeding techniques and established as having enhanced nutritive value OTHER

150 g of a non-traditional (i.e., not typically available in the supermarket) blueberry cultivar bred using natural plant breeding techniques and established as having enhanced nutritive value. Dietary restrictions will be observed (i.e. avoidance of food or supplements containing berry phytonutrients) for 7 days before each arm visit and throughout the study days.

a phytochemical-rich blueberry variety

a standard commercially available blueberry variety (i.e., cultivar) OTHER

150 g of a standard commercially available blueberry variety (i.e., cultivar). Dietary restrictions will be observed (i.e. avoidance of food or supplements containing berry phytonutrients) for 7 days before each arm visit and throughout the study days.

a phytochemical-poor blueberry variety

a "minimally processed" blueberry-rich protein bar OTHER

A "minimally processed" blueberry-rich protein bar matched to the phytonutrient content of the 150 g of the non-traditional blueberry. Dietary restrictions will be observed (i.e. avoidance of food or supplements containing berry phytonutrients) for 7 days before each arm visit and throughout the study days.

a "minimally processed" blueberry-rich protein bar

a control beverage of matched-nutritive content OTHER

The matched nutritive content of the blueberry-rich protein bar will be dissolved in whey protein Dietary restrictions will be observed (i.e. avoidance of food or supplements containing berry phytonutrients) for 7 days before each arm visit and throughout the study days.

a blueberry control beverage of matched-nutritive content

Eligibility Criteria

• Age: 25 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• male and female adults between 25-65 years;
• non-smokers, non-tobacco users (no vaping nor deeping), or who ceased it ≥ 6 months ago;
• who present no allergies to fruits or vegetables containing polyphenolic (e.g. anthocyanins, flavonoids) and phenolic acids such as blueberries, red apple, strawberry, red orange, purple onion and broccoli;
• who present no allergies to dairy products, specifically whey protein, fructose or salicylates;
• who are generally healthy and without chronic diseases including cancer, type 1 and 2 diabetes;
• who are not prescribed thyroid or hypoglycemic medication or hormone replacement therapy (HRT) (due to the likely concomitant effects that these medications cause on the primary endpoint in the trial);
• who has not been consuming any phytonutrient-containing supplements (e.g. with cocoa, coffee, berry, polyphenol, flavonoid, or anthocyanin extracts) for at least a month before the study and willing to not consume it during the study;
• who lives within 40 miles from the North Carolina Research Campus (NCRC) campus;
• those agreeing to restrict dietary intake of rich sources of phytonutrients targeted on the study during the wash-out and clinical sampling periods, agreeing to comply with a biological sampling protocol involving the collection of urine and blood samples, and to record their additional dietary intake over 2 days before each intervention, and two days after the intake of the intervention treatments;
• who have BMI ≥18.5 and ≤ 30 (lbs/in2x703);
• who have a successful (i.e., within normal range for healthy individuals) biochemical, hematological and urine analyses assessed by the clinical advisor as established during the screening period prior to final enrollment.

You may not qualify if:

• current smokers (vaping and deeping included), or ex-smokers ceasing \< 6 months before recruitment;
• pregnant or breastfeeding;
• subjects with existing or significant past medical history of vascular disease or medical conditions likely to affect the study measures i.e. vascular disease, circulatory (i.e. Reynaud's), diabetes, hepatic, renal, digestive, hematological, cancer, or thyroid disease;
• fructose intolerant subjects or those with known allergy to salicylates, dairy products, specifically whey protein, or to berries;
• those unprepared to adhere to dietary restrictions for 1 week preceding and during each intervention or unwilling to comply with the assessments per protocol;
• who are in parallel participation in another research project involving dietary intervention and/or sampling of biological fluids/material;
• those on therapeutic diets or having experienced substantial weight loss (to be judged by clinical advisor) within 3 months of screening;
• those taking phytonutrient-containing supplements (e.g. with cocoa, coffee, berry, polyphenol, flavonoid, or anthocyanin extracts), unwilling to cease intake during, and 1 month preceding the trial, or unwilling to stop existing intake of other supplements or regular use of large-dose nutrient, herbal, and dietary supplements during the past one to two weeks, or planning to use them during the study;
• prescribed thyroid, hypoglycemic medication or HRT medication -other medications will be assessed for suitability by the clinical advisor;
• those having donated blood in the last month;
• individuals that consume more than 1 and 2 drinks of alcohol per day for women and men, respectively, or more than 7 and 14 drinks per week for women and men, respectively (U.S. Department of Health and Human Services and U.S. Department of Agriculture Dietary guidelines 2015-2020);
• currently on a weight-reducing plan or using weight-loss medications (e.g., selective serotonin reuptake inhibitors, steroids, Ritalin, appetite suppressants such as Diethylpropion or Amfepramone, and weight loss medications such as Alli, Xenical, Qsymia, Belviq, Contrave, and Saxenda), or planning to continue this treatment during the 10-week period of the study;
• who has BMI\<18.5 and \>30 (lbs/in2x703);
• who presents abnormal biochemical, hematological or urinary results, and measurements considered to be counter-indicative for the study, including: kidney and liver function, fasting glucose (especially if indicative of diabetes), lipid abnormalities, full blood count as established during the screening period prior to final enrollment.

Sponsors & Collaborators

• North Carolina State University: lead
• Foundation for Food and Agriculture Research: collaborator

Study Sites (1)

Plants for Human Health Institute, North Carolina State University

Kannapolis, North Carolina, 28081, United States

Location

Related Publications (1)

• Santana MC, Rathore AS, Chandra P, Everhart JL, Schulz H, Granillo CD, Ferruzzi MG, Iorizzo M, Lila MA, Diaz JT, Kay CD. Bioavailability and pharmacokinetics of (poly)phenols following consumption of selected blueberries and a blueberry-rich protein bar by adult males and females: a randomized, crossover, controlled trial. Am J Clin Nutr. 2025 Apr;121(4):779-794. doi: 10.1016/j.ajcnut.2025.01.028. Epub 2025 Jan 31.

  PMID: 39894303 RESULT

Related Links

• Publication of Clinical Study Results

Limitations and Caveats

Some limitations in this study include the lack of a software to evaluate background diet, and lack of measurement of composition of the protein bars. Further, compliance to a diet low in (poly)phenols (but not polyphenol-free) was evaluated through food intake logs and a strictly controlled and (poly)phenol-free diet is only feasible in a metabolic ward/domicile study design, which is relatively rare for (poly)phenol interventions. Also, we cannot account for nonreported noncompliance events.

Results Point of Contact

• Title: Dr. Colin Kay
• Organization: University of Arkansas for Medical Sciences at Arkansas Children's Research Institute

CKay@uams.edu

(501) 364-3147

Study Officials

• Colin D Kay, PhD

  North Carolina State University

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor in Nutrition Science, PhD

Study Record Dates

• First Submitted: November 13, 2019
• First Posted: November 22, 2019
• Study Start: December 13, 2019
• Primary Completion: October 29, 2021
• Study Completion: October 29, 2021
• Last Updated: February 9, 2026
• Results First Posted: February 9, 2026

Record last verified: 2026-02

Locations

US (1)