Polyphenols are natural compounds found in plants with various biological activities, including antioxidant, anti-inflammatory, and anti-cancer properties. They play a crucial role in mitigating oxidative stress and inflammation, which are linked to chronic diseases. Oxidative stress arises from an imbalance between reactive oxygen species (ROS) and the body's antioxidant defenses, leading to cellular damage and chronic inflammation. Polyphenols combat this by scavenging free radicals, inhibiting enzymes involved in ROS production, and modulating inflammatory pathways. They also influence transcription factors like NF-κB and AP-1, which are critical in inflammatory responses. Polyphenols inhibit the production of pro-inflammatory cytokines such as TNF-α and IL-6, and reduce the expression of inflammatory molecules like VCAM-1 and ICAM-1. They also modulate the arachidonic acid pathway, which is central to inflammation. In addition, polyphenols can protect against oxidative damage in the brain, reducing neuroinflammation and neurodegeneration. Polyphenols have been shown to benefit cardiovascular health by improving vascular function through mechanisms involving nitric oxide synthase (eNOS) and reducing oxidative stress. They also exhibit protective effects against neurological diseases by modulating neuronal and glial signaling. In cancer prevention, polyphenols may inhibit tumor growth by inducing apoptosis, modulating cell cycle progression, and reducing the activity of enzymes involved in carcinogenesis. Despite their potential, the bioavailability of polyphenols is influenced by factors such as digestion, absorption, and metabolism. While they are abundant in the diet, their absorption is limited, and they are often metabolized by the gut microbiota. However, their antioxidant and anti-inflammatory properties make them promising candidates for the development of new therapeutic strategies for chronic diseases. Further research is needed to fully understand their mechanisms and to translate these findings into effective clinical applications.Polyphenols are natural compounds found in plants with various biological activities, including antioxidant, anti-inflammatory, and anti-cancer properties. They play a crucial role in mitigating oxidative stress and inflammation, which are linked to chronic diseases. Oxidative stress arises from an imbalance between reactive oxygen species (ROS) and the body's antioxidant defenses, leading to cellular damage and chronic inflammation. Polyphenols combat this by scavenging free radicals, inhibiting enzymes involved in ROS production, and modulating inflammatory pathways. They also influence transcription factors like NF-κB and AP-1, which are critical in inflammatory responses. Polyphenols inhibit the production of pro-inflammatory cytokines such as TNF-α and IL-6, and reduce the expression of inflammatory molecules like VCAM-1 and ICAM-1. They also modulate the arachidonic acid pathway, which is central to inflammation. In addition, polyphenols can protect against oxidative damage in the brain, reducing neuroinflammation and neurodegeneration. Polyphenols have been shown to benefit cardiovascular health by improving vascular function through mechanisms involving nitric oxide synthase (eNOS) and reducing oxidative stress. They also exhibit protective effects against neurological diseases by modulating neuronal and glial signaling. In cancer prevention, polyphenols may inhibit tumor growth by inducing apoptosis, modulating cell cycle progression, and reducing the activity of enzymes involved in carcinogenesis. Despite their potential, the bioavailability of polyphenols is influenced by factors such as digestion, absorption, and metabolism. While they are abundant in the diet, their absorption is limited, and they are often metabolized by the gut microbiota. However, their antioxidant and anti-inflammatory properties make them promising candidates for the development of new therapeutic strategies for chronic diseases. Further research is needed to fully understand their mechanisms and to translate these findings into effective clinical applications.