N/A N=29 Randomized Triple-blind Basic Science

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

Healthy

Bottom Line

View on ClinicalTrials.gov: NCT04175106 ↗

Enrolled (actual)

Serious AEs

0.0%

Results posted

Feb 2026

Primary outcome: Primary: Total Urinary Recovery of (Poly)Phenolic Metabolites Across Treatments — 179.50; 142.41; 127.78; 83.15 mg — p=<0.05

Study Design & Population

Study type: Interventional
Phase: N/A
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); a standard commercially available blueberry variety (i.e., cultivar) (Other); a "minimally processed" blueberry-rich protein bar (Other); a control beverage of matched-nutritive content (Other)
Age: Adult, Older Adult · 25+ yrs
Sex: All
Sponsor: North Carolina State University
Primary completion: Oct 2021

Outcome Measures

Outcome	Result	p-value
PRIMARY Total Urinary Recovery of (Poly)Phenolic Metabolites Across Treatments	179.50; 142.41; 127.78; 83.15	<0.05 sig
PRIMARY Serum Area Under the Curve (AUC) of (Poly)Phenolic Metabolites Across Treatments	3889.34; 3049.40; 3515.23; 2704.96	<0.05 sig
SECONDARY Maximum Serum Concentration [Cmax] of (Poly)Phenolic Metabolites Between the Treatments	15.37; 8.44; 11.15; 6.96	<0.05 sig

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.

Eligibility Criteria

Inclusion Criteria

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.

Exclusion Criteria

current smokers (vaping and deeping included), or ex-smokers ceasing 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.

View full record on ClinicalTrials.gov →

Data sourced from ClinicalTrials.gov (NCT04175106). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.