Anti-aging potential of tree nuts with a focus on the phytochemical composition, molecular mechanisms and thermal stability of major bioactive compounds

Tree nuts, complete functional foods, contain macro- and micronutrients of high biological value. These bioactive compounds have a synergistic effect in preventing and delaying many age-related pathologies (e.g. cardiovascular diseases, stroke, type 2 diabetes mellitus, certain types of cancer, and several neurodegenerative diseases). Tree nuts are low in carbohydrates, but they abound in healthy fatty acids, in optimal proportion for a good plasma lipid profile, and are a good source of proteins, rich in proteinogenic amino acids. They contain significant amounts of vitamin E, minerals, polyphenols, and phytosterols. Polyphenols, which are powerful phytochemicals, act as direct and indirect antioxidants, reduce the inflammatory response, improve proteostasis and mitochondrial biogenesis, modulate many cell signaling pathways, have a major role in cytoprotection, are Nrf2/ARE activators, down-regulate the NFB system, promote anticancer potential, and prevent cell senescence. Some of them have senolytic effects, interfere in specific cell signaling pathways modulated by caloric restriction, and protect against UV radiation and photoaging. Moreover, tree nuts are good prebiotics and improve gut microbiota. The stability of polyphenolic compounds and their antioxidant activity can be influenced by cooking techniques, temperature of storage, and post-harvest processing methods. The consumption of tree nuts has been scientifically proven to improve lifespan and healthspan and should be a part of a healthy diet in the elderly.