The fruit of guava (Psidium guajava L.) comes from a tropical plant with both edible and health-beneficial values. Guava leaves are often processed into guava leaf tea for consumption. Its fruit and leaves contain polysaccharides, phenolic acids, flavonoids, terpenoids, vitamins, and minerals, but the strength of evidence varies markedly across preparations and outcomes. This review critically evaluates studies published mainly during the past five years and links organ-specific composition, extraction conditions, mechanisms, preclinical outcomes, clinical evidence, and product development. Reported guava leaf total phenolic contents range from 53.24 to 438.80 mg gallic acid equivalents/g, while guava leaf polysaccharides showed a DPPH-scavenging rate of 65.43 ± 2.56% and α-glucosidase IC₅₀ values of 790–904.67 μg/mL in preclinical assays. Mechanistically, phenolic compounds and polysaccharides may directly scavenge radicals and modulate Keap1–Nrf2–ARE, PI3K–Akt–GLUT4, NF-κB, and carbohydrate-hydrolyzing enzymes; guajadial and guaijaverin provide compound-level examples, although most causal evidence remains biochemical, cellular, or animal-based. Four randomized studies (n = 31–120) reported changes in postprandial glucose, blood lipids, blood pressure, inflammatory indices, or viral-clearance time, but heterogeneity, short follow-up, incomplete blinding, and predominantly healthy or mildly affected populations preclude firm clinical conclusions. Compared with earlier descriptive reviews, this review integrates fruit–leaf similarities and differences, explicitly appraises evidence strength and study limitations, and connects composition and processing to biological function and translation. Standardized extracts, exposure–response studies, and adequately powered multicenter trials are priorities for determining efficacy, safety, and practical value.

Aging is a pathophysiological process driven by genetic, environmental, dietary and behavioral factors, contributing to the development of cancer, cardiovascular diseases, metabolic disorders, and neurodegenerative conditions. This study primarily explores the anti-aging effects of dietary bioactive components to promote healthy aging. Dietary bioactive components, including polyphenols, carotenoids, and essential polyunsaturated fatty acids, have become significant agents in reducing age-related decline and promoting longevity. The anti-aging effects of these components are associated with various modes of action, including enhanced immune function, modulation of gene expression associated with aging, modulation of apoptosis, alteration of intestinal microbial diversity, regulation of cellular autophagy, suppression of cellular senescence, telomere protection, and mitochondrial health. However, additional studies are required to comprehensively uncover the complex interactions between dietary bioactive components and aging processes.

Cancer remains a significant global health challenge, necessitating the exploration of novel therapeutic strategies. Natural compounds have emerged as promising candidates for cancer treatment due to their diverse pharmacological activities and relatively low toxicity. Among these, pterostilbene, a natural stilbenoid found mostly in blueberries and grapes, has garnered increasing attention for its potential anti-cancer properties. Pterostilbene has been shown to modulate multiple molecular mechanisms involved in cell proliferation, apoptosis, autophagy, angiogenesis, and metastasis by targeting multiple signaling pathways, including PI3K/Akt/mTOR, AMPK, MAPK/ERK, JAK/STAT, and NF-κB. Evidence from studies on various cancer types highlights its capability to suppress tumor growth, modulate oxidative stress, and inhibit inflammation. Furthermore, preclinical studies have demonstrated the ability of pterostilbene to inhibit tumor growth, induce apoptosis, and enhance the efficacy of conventional chemotherapy drugs. Overall, pterostilbene holds promise as a novel therapeutic agent for cancer treatment, offering potential benefits for improving patient outcomes and quality of life. So, this review provides a comprehensive overview of the molecular mechanisms underlying pterostilbene’s anti-cancer effects and evaluates its role as a potential therapeutic agent in cancer treatment.