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(OR12-05-26) Enhancing Blueberry Polyphenol Bioavailability and Functionality With Dietary Proteins: Results From a Randomized Controlled Crossover Pilot Trial

Sunday, July 26, 2026
3:06 PM - 3:18 PM ET
Location: Maryland Ballroom D
Disclosure(s):
Sylvia Y. Lee, PhD: No relevant financial relationship(s) with ineligible companies to disclose.
Sarah A. Johnson, PhD, RDN, FASN: No relevant financial relationship(s) with ineligible companies to disclose.
Objectives: Consumption of polyphenol-rich foods is associated with reduced risk of numerous chronic diseases. However, consumption of fruit and vegetables, the primary source of dietary polyphenols, is low in the US. Polyphenols also have limited bioavailability, in part, due to their instability in the gastrointestinal (GI) tract. Dietary proteins can interact with polyphenols through intermolecular electrostatic interactions, potentially impacting their bioavailability. This study evaluated whether co-consumption of blueberries, a polyphenol-rich food, with different dietary proteins would increase circulating polyphenol metabolites.

Methods: We performed a randomized, single-blind, controlled, crossover pilot trial to examine the effects of co-consuming whey, hemp, and pea protein and blueberries on plasma polyphenol metabolites in healthy adults. Participants consumed four treatments in random order on separate test days with one-week washout periods between test days: 15 g of whey, pea, or hemp protein powder with 22 g freeze-dried blueberry powder and 300 ml of water or blueberry powder alone with 300 ml of water. On test days, blood draws and hemodynamics measurements were performed at baseline (0 hours) and 1, 2, 4, and 6 hours postprandially, with a final blood draw at 24 hours. Plasma blueberry polyphenol metabolites were quantified using targeted UHPLC-MS/MS.

Results: There were significant global differences in plasma polyphenol metabolites and co-consumption of blueberries with hemp protein significantly increased concentrations of certain plasma polyphenol metabolites 2 hours postprandially compared to whey protein with blueberry, including chlorogenic acid, 3-hydroxybenzaldehyde, ferulic acid derivatives, among others. Blueberry with hemp protein also significantly increased plasma 2,5-dihydroxybenzoic acid at 6- and 24-hour time points compared to all other treatments, including blueberries alone. No major differential effects were observed across treatment groups for hemodynamic measurements or plasma nitric oxide metabolites.

Conclusions: These findings suggest that hemp protein may enhance blueberry polyphenol absorption in the upper GI tract and gut microbial metabolism in the lower GI tract. Further research is needed to evaluate health implications.

Funding Sources: Colorado Agricultural Experiment Station