Antioxidants
Antioxidants and free radicals
Oxidative Stress caused by free radicals
Free radicals can cause oxidative Stress in the body. Oxidative Stress refers to an imbalance in any cell, tissue, or organ between the amount of free radicals and the capabilities of the detoxifying and repair systems in the body. Free radicals can attack body cells and tissues. However, our bodies can repair these damages when the number of free radicals is under reasonable control within the body's self-defense capabilities. On the other hand, if the free radical-induced damage is left unrepaired, the damage caused by free radical attacks can impair lipids, proteins, RNA, and DNA in cells, leading to inflammations and diseases.
Antioxidants from foods
Vitamins A, C, E, and the mineral selenium are the four significant antioxidants in our foods. In addition, other nutrients from plant-based foods, called phytonutrients, such as carotenoids, lipoic acid, and phenolic acids, also perform antioxidant functions guarding body cells against attacks by free radicals.
Vitamins A and E are essential vitamins required by our bodies, and they are also important antioxidants protecting cells from being damaged by free radicals. Vitamins A and E also help spare another antioxidant, glutathione. Glutathione can protect cellular components from damage caused by reactive oxygen species, such as free radicals, peroxides, lipid peroxides, and heavy metals. In addition, vitamin C and other phytonutrients such as carotenoids, lipoic acid, and phenolic acids all have antioxidant functions. The following table summarizes the significant antioxidants existing in our foods.
Free radicals, the oxidants in the human bodies
Free radicals are produced in our bodies when our food is converted to the energy we rely on. Factors from the environment can also trigger the generation of free radicals.
Energy sources and environmental substances can add to or accelerate the production of free radicals within the body. For example, exposure to excessive sunlight, smoke, heavy metals, ozone, asbestos, other toxic chemicals, and ionizing radiation increases the number of free radicals in the body. These factors trigger the formation of free radicals in the body.
Excessive exposure to environmental sources of free radicals can contribute to some related diseases by overwhelming bodies' detoxifying systems to eliminate excess free radicals and repair the oxidative damage caused by free radicals.
The body’s balanced defense, the two sides of free radicals; Free radicals have positive effects required by the body’s immune system.
Free radicals can benefit the human body as they can kill pathogens. Free radicals are not always as harmful as attacking healthy body cells. However, they are also required by the immune system for the body’s defense. Immune cells engulf an invading pathogen, such as bacteria; the pathogen is then exposed to free radicals, such as hydrogen peroxide, which destroys the pathogen. Scientific studies also suggest free radicals such as hydrogen peroxide can act as a signaling molecule that calls immune cells to injury sites and aid with tissue repair when the body gets cut.
Free radicals are necessary for many other bodily functions as well. For example, the thyroid gland synthesizes its free radical, hydrogen peroxide, which is required to synthesize thyroid hormone. In addition, reactive oxygen and reactive nitrogen species (free radicals containing nitrogen) interact with proteins in cells to produce signaling molecules. Some free radicals control their synthesis by acting as signaling molecules and regulating cell growth, development, reproduction, death, metabolism, and stress responses. Therefore, everything has two sides; we need a self-balancing body system.
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