- Antioxidants are a diverse group of molecules that play a crucial role in protecting biological systems from oxidative stress by neutralizing free radicals and reactive oxygen species (ROS).
- Free radicals are highly reactive molecules with unpaired electrons that can damage cellular components such as DNA, proteins, and lipids. If left unchecked, this oxidative damage contributes to aging, inflammation, and the development of chronic diseases including cancer, cardiovascular disorders, neurodegenerative conditions, and diabetes. Antioxidants act as the body’s defense mechanism against these potentially harmful processes, maintaining cellular homeostasis and promoting health.
- There are two broad categories of antioxidants: enzymatic and non-enzymatic. Enzymatic antioxidants, such as superoxide dismutase (SOD), catalase, and glutathione peroxidase, are produced naturally within cells and work by catalyzing reactions that convert reactive oxygen species into less harmful molecules like water and oxygen. Non-enzymatic antioxidants, which include vitamins C and E, carotenoids, flavonoids, and glutathione, can be obtained both from endogenous synthesis and from dietary sources such as fruits, vegetables, nuts, and whole grains. These compounds act by directly scavenging free radicals, chelating transition metals that promote oxidative reactions, or regenerating other antioxidants in a synergistic network.
- Beyond their role in basic cellular defense, antioxidants have significant implications in medicine, nutrition, and pharmacology. In clinical settings, antioxidant therapy is investigated for its potential in slowing the progression of diseases such as Alzheimer’s, Parkinson’s, and atherosclerosis, where oxidative stress plays a central role. In nutrition, a diet rich in antioxidant-containing foods is strongly associated with reduced risk of chronic disease and improved overall health. In the pharmaceutical and cosmetic industries, antioxidants are incorporated into formulations to protect products from oxidation and to reduce skin aging caused by ultraviolet radiation.
- Despite their well-documented benefits, antioxidant research has revealed complexities. While antioxidants can protect against oxidative stress, excessive supplementation may disrupt redox balance and interfere with physiological processes where ROS act as signaling molecules. Clinical trials on antioxidant supplementation have produced mixed results, suggesting that natural dietary intake may be more beneficial than high-dose supplements. This has shifted the scientific perspective toward maintaining a balanced antioxidant defense system, rather than relying on single compounds.
