(P25-021-25) Dose-Response Effect of Strawberry Intake Over 4-Weeks on Plasma (Poly)phenolic Metabolites in Individuals With Chronic Low-Grade Inflammation.

Objectives: Strawberry is a rich source of pelargonidin and ellagitannins. This study aims to evaluate the effects of daily consumption of strawberries at two dosage levels on (poly)phenol metabolites in human circulation over a 4-week period.

Methods: Plasma samples were taken from a 3-arm parallel, placebo-controlled study approved by IRB (ClinicalTrail.gov NCT06173765). Participants (n=67, age; 33 ± 6 years, BMI; 29.8 ± 4.8 kg/m², mean ± SD) were randomized to consume a strawberry smoothie daily (41 g powder with/without freeze-dried strawberry, FDS) at low-dose (LD, 12 g FDS, n=22), high-dose (HD, 36 g FDS, n=23), or control (0 g FDS, n=22) for 4 weeks. Fasting plasma samples collected on day 0 and day 28 were quantified for (poly)phenol metabolites using ultra-high performance liquid chromatography coupled with triple quadrupole. Statistical analyses were conducted using generalized linear mixed model on SAS-studio, version 3.8.

Results: A total of 71 (poly)phenol metabolites were quantified from plasma samples, including conjugated pelargonidin, urolithins, valerolactones, and various phenolic acids. Pelargonidin-3-O-glucoside and pelargonidin glucuronide were detected in 41% and 73% of participants in the HD group and 48% and 78% of participants in the LD group, respectively (both treatment effect: p < 0.01). Urolithin A glucuronides were detected in 55% and 35% of participants in HD and LD groups, respectively (treatment effect: p > 0.05). No pelargonidin or other anthocyanins were detected in fasting plasma samples of the control group (n=22). Urolithin B glucuronide was significantly increased after 4-week intake of HD smoothie compared to 4-week intake of control smoothie (2.6±2 nmol/L vs. 0.2±0.1 nmol/L, p = 0.02).

Conclusions: Strawberry (poly)phenols are absorbed, metabolized, and elevated after 4-weeks consumption in most people. Pelargonidin and its conjugated metabolites present in human circulation could serve as potential biomarkers of strawberry intake in humans.

Funding Sources: This work is supported by the California Strawberry Commission.