# Pecan (Carya illinoinensis) Shells as a Source of Antioxidants: Implications for Oxidative Stress-Driven Pathologies

## TL;DR

Pecan shells contain high levels of antioxidants that may help treat diseases caused by oxidative stress, but more research is needed to confirm their effectiveness.

## Contribution

This review highlights the potential of pecan nutshells as a sustainable antioxidant source with therapeutic applications.

## Key findings

- Pecan nutshells contain polyphenols like gallic acid and ellagic acid with high antioxidant activity.
- Preliminary studies suggest protective effects against cardiovascular disease, diabetes, and cancer.
- Variability in extraction methods and bioavailability remains a challenge for clinical use.

## Abstract

Pecan nutshells (PNS), once considered agricultural waste, are now recognized as a sustainable source of natural antioxidants with potential therapeutic benefits against oxidative stress-related diseases. This narrative review synthesized evidence from the last decade, including predominantly in vitro and in vivo studies, with limited clinical evidence. PNS are particularly rich in polyphenols (gallic acid, ellagic acid, vanillic acid, catechins), with phenolic and flavonoid concentrations reported to be 5–20 times higher than those in the edible kernels. Their antioxidant actions involve free radical scavenging, metal chelation, enhancement of enzymatic defenses, and modulation of redox signalling. Preclinical findings suggest protective roles in cardiovascular disease, diabetes, neurodegeneration, and cancer, mediated through reduced lipid peroxidation, improved glucose metabolism, neuroprotection, and anticarcinogenic activity. However, variability in extraction methods, cultivar differences, and bioavailability issues remain major challenges. Standardized clinical studies are needed to validate the therapeutic potential of PNS as a sustainable antioxidant source.