The body requires a balanced amount of oxidants and antioxidants. Oxidative stress refers to an imbalance caused by an increase in oxidants and/or a significant reduction in antioxidants. This condition leads to irreversible damage to cellular macromolecules, contributing to various diseases, cancer, and aging. Strategies to mitigate oxidative damage and prevent oxidative stress include inhibiting excessive free radical production and supplementing antioxidants.
What are antioxidants?
Oxidants include free radicals and reactive oxygen species (ROS), which are essential for the body’s normal functioning. However, an excess of free radicals and ROS can damage surrounding tissues, trigger inflammatory reactions, and lead to oxidative damage to molecules, cells, and tissues, resulting in disease and aging.
Antioxidants are molecules that slow down or inhibit oxidation caused by oxidants. They are considered free radical scavengers and can be categorized into two groups:
- Enzymatic Antioxidants: Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), thioredoxin reductase, paraoxonase, heme oxygenase.
- Non-Enzymatic Antioxidants: (1) Nutritional antioxidants: Carotenoids, vitamins C and E, selenium; (2) Metabolic antioxidants: Glutathione, uric acid, bilirubin, ceruloplasmin, ubiquinone, ferritin, transferrin, albumin, thioredoxin.
Benefits of antioxidants:
Under normal circumstances, the body maintains a balance between the production of oxidants and antioxidants. A deficiency in antioxidants can lead to oxidative stress.
Oxidative stress is not always harmful. Mild oxidative stress from light physical activity can be beneficial, regulating various physiological effects in the body and protecting it from infections and diseases. However, chronic oxidative stress can significantly impact biological molecules, damaging cells and contributing to diseases and aging, such as: Neurological disorders, cancer, cardiovascular diseases, bone, muscle, and joint diseases, metabolic disorders, chronic inflammation, skin diseases, eye diseases.
The benefits of antioxidants include reducing the risks and damage caused by oxidative stress through several mechanisms: (1) Inhibiting the formation of free radicals; (2) Breaking down oxidizing agents; (3) Transforming toxic free radicals into less toxic substances; (4) Inhibiting the production of secondary toxic metabolites and inflammatory mediators; (5) Suppressing secondary oxidative processes; (6) Repairing oxidatively damaged molecules; (7) Activating and enhancing endogenous antioxidant defense systems.
Foods and beverages rich in antioxidants:
- Foods: Green vegetables, oranges, lemons, apples, pears, cherries, raspberries, honey, nuts, spices, herbs, dark chocolate, etc, …
- Beverages: Green tea, natural fruit juices, red wine.
In addition, regular exercise induces temporary oxidative stress and free radical production in muscles. These free radicals regulate tissue growth and stimulate antioxidant production.
ThS.BSCK2. Nguyễn Chí Thành
References:
- Lê Thị Mai (2016), “Study on Oxidative Stress in Colorectal Cancer Patients,” Master’s Thesis in Science, Vietnam National University, Hanoi.
- Nguyễn Công Khanh, Nguyễn Hoàng Nam (2022). Oxidative Stress and Diseases. Pediatrics Journal; 15(1):1-7.
