The Primary Alternative Name: Free Radical Scavengers
At the most fundamental level, antioxidants are often referred to as free radical scavengers. This name directly describes their core function in the body. Free radicals are unstable molecules produced naturally during metabolism, or by external factors like pollution, radiation, and cigarette smoke. At high concentrations, these highly reactive molecules can cause cellular damage, a process known as oxidative stress. Antioxidants counteract this by interacting with and neutralizing free radicals, essentially 'scavenging' them before they can harm vital components of cells, including DNA and proteins.
The Chemistry of the Scavenging Process
From a chemical perspective, this action is a reduction-oxidation (redox) reaction. A free radical is an oxidizing agent, meaning it steals electrons from other molecules. An antioxidant, therefore, is a reductant or reducing agent, which donates an electron to the free radical. By sacrificing one of its own electrons, the antioxidant stabilizes the free radical and terminates the damaging chain reaction that could otherwise spread through cells.
Categorical Names: How Location and Source Define Antioxidants
Depending on their origin, antioxidants can be categorized using different terminology:
Endogenous vs. Exogenous Antioxidants
- Endogenous Antioxidants: These are the antioxidants that the human body produces internally to neutralize free radicals. Examples include glutathione, ubiquinol (Coenzyme Q10), and uric acid. The body maintains a complex system of these internal defenses.
- Exogenous or Dietary Antioxidants: These are obtained from external sources, primarily through our diet. Fruits, vegetables, and grains are rich sources. Common examples include vitamins C and E, beta-carotene, and lycopene.
Specific Antioxidant Subtypes
Beyond these broad categories, many specific compounds and compound classes are also called antioxidants due to their properties. Some are naturally produced by plants and animals to serve as a defense mechanism, a concept known as xenohormesis.
- Phytochemicals or Phytonutrients: This is a broad term for chemicals produced by plants that have potential health benefits for humans. Many phytochemicals act as antioxidants. Examples include carotenoids, polyphenols, and flavonoids.
- Polyphenols: Found in sources like tea, cocoa, berries, and red wine, polyphenols are a large group of phytochemicals with antioxidant properties.
- Flavonoids: A specific class of polyphenols present in fruits and vegetables, like quercetin found in apples and onions.
- Carotenoids: These are pigments that give color to many plants, fruits, and vegetables. Common carotenoids with antioxidant activity include beta-carotene, lycopene, and lutein.
- Vitamins and Minerals: Many essential nutrients also function as antioxidants, or are essential cofactors for antioxidant enzymes. These include Vitamin C, Vitamin E, Selenium, Zinc, and Manganese.
Understanding Antioxidant Terminology
To help clarify the various terms, this table outlines the different names and their context.
| Term | Context | Examples | Core Function |
|---|---|---|---|
| Free Radical Scavenger | Functional (Popular) | All antioxidants | Neutralizes unstable free radicals. |
| Reductant / Reducing Agent | Chemical (Scientific) | All antioxidants | Donates an electron in a redox reaction. |
| Phytochemical / Phytonutrient | Source (Plant-based) | Carotenoids, Flavonoids, Polyphenols | Plant-derived compounds with antioxidant properties. |
| Endogenous Antioxidant | Origin (Body-produced) | Glutathione, Uric acid | Produced internally to defend against oxidative stress. |
| Exogenous / Dietary Antioxidant | Origin (Food-derived) | Vitamin C, Vitamin E, Selenium | Obtained from external dietary sources. |
| Vitamin A, C, E, etc. | Classification (Specific) | Beta-carotene, Ascorbic Acid, Tocopherol | Nutrients with proven antioxidant activity. |
| Selenium, Zinc, Manganese | Classification (Specific) | Co-factors for antioxidant enzymes | Minerals that assist endogenous antioxidant enzymes. |
The Complexity and Nuances of Antioxidants
It is a common misconception that all substances with antioxidant properties are interchangeable. In fact, each compound has unique chemical behaviors and biological properties. For instance, Vitamin E is fat-soluble and protects cell membranes, while Vitamin C is water-soluble and operates in aqueous environments. Furthermore, in certain high concentrations, some antioxidants can exhibit pro-oxidant activity, causing damage rather than preventing it.
This complexity highlights why it is generally recommended to get antioxidants from a varied diet of whole foods rather than relying on high-dose supplements. Many of the health benefits of a plant-rich diet are attributed to the synergistic action of a wide array of antioxidants working together.
Conclusion
So, what are antioxidants also called? The answer depends on the context, but the most common alternatives are free radical scavengers, which describes their function, and phytonutrients or reductants, which relate to their source and chemical role. These compounds are a diverse group of molecules, including specific vitamins, minerals, and plant-based substances, all playing a critical part in combating the cellular damage caused by oxidative stress.
For more detailed information on antioxidants and their role in preventing disease, consider exploring resources from the National Cancer Institute. https://www.cancer.gov/about-cancer/causes-prevention/risk/diet/antioxidants-fact-sheet
