(P42-03-26) Assessment of Systematic Health Properties of Pecan Nut Consumption: Study Protocol for a Randomized Crossover Trial

Objectives: The study objective compares the consumption of pecan nuts to no-nuts, examining the holistic health properties of pecans in healthy adults. Our primary outcome is vascular response. Secondary outcomes include evaluation of the impact on the gut microbiome, gut permeability, cognitive performance, and cardiometabolic markers.

Methods: This is a randomized crossover trial of 40 healthy male and female adults (45-75 years) with a BMI of 20-35 kg/m2.  Participants will be randomly assigned to a 2 oz unsalted pecan nut diet or no-nut diet for 12 weeks, 4–6-weeks washout, and 12 weeks on the diet arm not previously assigned. Pecans will be consumed in a divided dose twice daily. Pre- and post-intervention study visits include collection of biological samples, anthropometrics, cognitive health assessments, and vascular measurements. The primary outcome of vascular response will be measured by carotid-femoral pulse wave velocity (cfPWV). Vascular response will be assessed on day 1 of each diet period at fasting and as an acute post-prandial response 3 hours after nut consumption, and at the end of each 12-week diet period in the fasting state to assess long-term impact. Secondary measures include serum biomarkers of gut permeability (zonulin, LBP, sCD14, LPS), plasma inflammatory cytokines (Luminex bead assay), cardiometabolic markers (lipid panel, hsCRP), circulating endothelial function markers (sVCAM1, sICAM1, sE-selectin, matrix metalloproteinases), and fecal microbiome profiling (16S rRNA). Cognitive health assessments include the use of  Cambridge Neuropsychological Test Automated Battery (CANTAB) and self-report using validated questionnaires (Perceived Stress Scale, Generalized Anxiety Disorder Scale, Pittsburgh Sleep Quality Index, Beck Depression Inventory-II, and World Health Organization Quality of Life-Brief). Statistical tests will include alpha and beta diversity, gut microbial differential abundance, and ANCOVA for vascular response, gut health, clinical, and cardiometabolic biomarkers.

Results: N/A

Conclusions: We hope to demonstrate the effectiveness of pecans to improve vascular function, gut health, metabolism, inflammation, and cognitive function. The study will provide evidence for the role of pecans in supporting healthy aging.

Funding Sources: USDA NIFA CA-D-NTR-6316-H, The American Pecan Board