The article discusses the role of free radicals and reactive oxygen species (ROS) in human health and disease. Free radicals, such as superoxide (O2-) and hydrogen peroxide (H2O2), are produced in the body and can cause oxidative stress, leading to tissue damage. Antioxidant defenses, including superoxide dismutases (SOD), catalases, and glutathione peroxidases, help to remove these ROS. However, when ROS levels exceed the body's ability to neutralize them, they can cause significant damage. The article highlights the importance of assessing oxidative damage to biomolecules, such as DNA, lipids, and proteins, to understand the underlying mechanisms of diseases like cancer, atherosclerosis, and neurodegenerative disorders. It also emphasizes the potential of antioxidant supplementation as a therapeutic strategy, supported by emerging technologies for measuring oxidative damage. The article concludes by discussing the complex interplay between ROS generation and tissue injury, and the need for further research to optimize the use of antioxidants in disease prevention and treatment.The article discusses the role of free radicals and reactive oxygen species (ROS) in human health and disease. Free radicals, such as superoxide (O2-) and hydrogen peroxide (H2O2), are produced in the body and can cause oxidative stress, leading to tissue damage. Antioxidant defenses, including superoxide dismutases (SOD), catalases, and glutathione peroxidases, help to remove these ROS. However, when ROS levels exceed the body's ability to neutralize them, they can cause significant damage. The article highlights the importance of assessing oxidative damage to biomolecules, such as DNA, lipids, and proteins, to understand the underlying mechanisms of diseases like cancer, atherosclerosis, and neurodegenerative disorders. It also emphasizes the potential of antioxidant supplementation as a therapeutic strategy, supported by emerging technologies for measuring oxidative damage. The article concludes by discussing the complex interplay between ROS generation and tissue injury, and the need for further research to optimize the use of antioxidants in disease prevention and treatment.