Archive

Research Nut: Pecans

Pecan (Carya illinoinensis) shells as a source of antioxidants: implications for oxidative stress-driven pathologies. 

Ezeanolue, I.R., J. George, P.A. Ohioze, O.O. Oyeniyi, J.O.G. Elechi, M.R. Loizzo, P. Plastina, 2026. Pecan (Carya illinoinensis) shells as a source of antioxidants: implications for oxidative stress-driven pathologies. Molecules. 31(6):993. https://doi.org/10.3390/molecules31060993

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 signaling. 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.

pecan nutshell; oxidative stress; antioxidants; chronic disease; bioavailability

Consuming tree nuts daily as between-meal snacks reduces food cravings and improves diet quality in American young adults at high metabolic syndrome risk.

Lillegard, K., A. Widmer, J.R. Koethe, H.J. Silver, 2025. Consuming tree nuts daily as between-meal snacks reduces food cravings and improves diet quality in American young adults at high metabolic syndrome risk. Nutrients. 17, 3778. https://doi.org/10.3390/nu17233778.

Background: Daily energy intake from snacking behaviors has increased over the past few decades, during which the prevalence of obesity and metabolic syndrome has risen to epidemic proportions. There remains considerable room for improvement in the overall quality of dietary intakes of the U.S. population when compared to national recommendations. Food cravings may contribute to the types of snacks chosen for consumption, and thus, the frequency of foods and food groups consumed, and the overall nutritional quality of the diet. Methods: Eighty-four young (28.5 ± 4.3 years) adults with at least one metabolic syndrome risk factor participated in a parallel-arm single-blind randomized trial designed to compare effects of consuming a mix of tree nuts versus typical high-carbohydrate food items as between-meal snacks for 16 weeks. Cravings for 28 common foods via the Food Craving Inventory, short-term dietary intakes via 24 h multi-pass methodology, food group frequency via the Rapid Eating Assessment for Participants, usual hunger and fullness via visual analog scales, appetite-regulating hormones, and diet quality via the Healthy Eating Index-2015 were measured at baseline and end of study. Results: Participants in the TNsnack group had significant decreases in cravings for high sweet items and fast-food items, which were associated with decreased frequency of desserts and salty foods along with increased intake of higher protein items. In contrast, no significant reductions in food cravings or preference for sweets were observed in the CHOsnack group. Decreased cravings for sweets by TNsnack participants were associated with increased total GLP-1 levels: cake (r = −0.35, p = 0.03), brownies (r = −0.44, p = 0.02), candy (r = −0.36, p = 0.03) and ice cream (r = −0.33, p = 0.04). Overall, the total diet quality score improved by 19% among TNsnack participants. Conclusions: Replacing more typical between-meal snacks with tree nuts may reduce food cravings, particularly for sweeter food items that are likely to be nutrient poor and energy dense. By reducing cravings and frequency of intake, consuming tree nuts as snacks could facilitate having a higher quality, more nutrient-dense diet and mitigate potential negative effects of snacking on metabolic health in young adults.

Pecans and human health: distinctive benefits of an American nut.

Sandhu, A.K., I. Edirisinghe, B. Burton-Freeman, 2025. Pecans and human health: distinctive benefits of an American nut. Nutrients. 17, 3686. https://doi.org/10.3390/nu17233686

Pecans are a tree nut native to America with a rich content of unsaturated fatty acids, minerals, fiber, and a diverse array of bioactive components, including polyphenols, tocopherols, and phytosterols. This review summarizes variations in the phenolic composition of pecans from various parts of the world based on cultivar, maturity stage, postharvest storage, and processing. Additionally, the review delves into the bio-accessibility and bioavailability of bioactive components from pecans and their potential influence on diet quality, body weight, satiety, cardiometabolic, brain and gut health. Data from human clinical trials suggest that replacing foods/snacks with pecans improves overall diet quality and lipid profiles. However, inconsistent effects are observed on vascular function, glycemia, and inflammation. Body weight changes after pecan intake are reported as neutral, with promising results on satiety peptides and appetite regulation. Cognition and gut health are emerging areas of research with very limited data from both human and preclinical models, warranting further investigation. Overall, the current literature supports the cardiometabolic benefits of pecans within healthy dietary patterns. Future research should focus on well-controlled studies targeting at-risk populations to understand mechanistic endpoints such as metabolomics, microbiome, and vascular function assessments to substantiate the role of pecans in dietary guidance.

Upcycling commercial nut byproducts for food, nutraceutical, and pharmaceutical applications: A comprehensive review.

Alasalvar, C., G. Huang, B.W. Bolling, P.A. Jantip, R.B. Pegg, X.K. Wong, S.K. Chang, E. Pelvan, A.C. de Camargo, G. Mandalari, A. Hossain, F. Shahidi, 2025. Upcycling commercial nut byproducts for food, nutraceutical, and pharmaceutical applications: A comprehensive review. Food Chem. 467:142222. https://doi.org/10.1016/j.foodchem.2024.142222

This article presents a comprehensive overview of upcycling commercial nut byproducts (such as almond, Brazil nut, cashew, hazelnut, macadamia, peanut (also known as a legume), pecan, pine nut, pistachio, and walnut) for food, nutraceutical, and pharmaceutical applications. Upcycling nut byproducts, namely husk/hull, hard shell, brown skin, defatted flour/meal/cake, pine cone, cashew nut shell liquid, cashew apple, walnut septum, and dreg/okara, has great potential, not only to reduce/minimise waste, but also to fit within the circular economy concept. Each byproduct has its own unique functional properties, which can bring significant value. These byproducts can be used as value-added ingredients to promote better health and well-being, due to their rich sources of diverse bioactive components/phytochemicals, polysaccharides, fibre, lignin, prebiotics, oils, proteins, bioactive peptides, minerals, and vitamins, among other components. This comprehensive review provides a basis for future research and development of product applications for nut byproducts. More studies are needed on novel product development to valorise nut byproducts.