Antioxidants: What Do They Do?

Do you ever wonder why a sliced apple turns brown, why a fish becomes rancid or why a cut on your skin is raw and inflamed? These results are caused by a natural process called oxidation. It occurs to all cells, including the ones in your body. To help protect your body from oxidation, antioxidants, which are found in many foods including fruits and vegetables, play a role in putting up defense, especially in today’s environment.


Antioxidants are substances that may prevent or delay some types of cell damage. They are found in fruits, vegetables, whole grains, nuts and legumes. Antioxidants can also be man-made as dietary supplements.

Plant foods are rich sources of antioxidants. They are found in fruits, vegetables, nuts and whole grains. Some meats, poultry and fish also have antioxidants. The most well known antioxidants include vitamin A, vitamin C, vitamin E and the minerals zinc and selenium.

Oxidation and Free Radicals

Oxygen is an essential component for living. All living organisms need it for metabolizing and using dietary nutrients to produce energy needed to survive. Oxygen meditates chemical reactions that metabolize carbohydrates, proteins and fats to create energy.

While it is one of the most vital components of life, oxygen does have a dark side. Oxygen is a highly reactive atom capable of becoming part of potentially damaging molecules we also know as free radicals. Aside from our bodies, they can also be found everywhere, in the air, the food we eat, and the materials around us.

Free radicals have the potential to harm cells. At high concentrations, they can be hazardous to the body and damage all major components of cells including DNA, proteins and cell membranes, creating a seed for disease. In time, it can lead to a host of chronic diseases, including cancer, heart disease, Alzheimer’s disease and Parkinson’s disease.

How Antioxidants May Prevent Against Free Radical Damage

Antioxidants neutralize free radicals by donating one of their own electrons. They work in two ways: chain-breaking and preventive.

Chain breaking – Free radicals generate more unstable products. It happens when a free radical releases or steals an electron and a second radical is formed. This process goes on until it decays into a harmless product or a chain-breaking antioxidant such as beta-carotene and vitamins C and E stabilize the radical.

Preventive – Antioxidant enzymes prevent oxidative process by reducing the rate of chain initiation. They act as scavengers that prevent the oxidation chain from taking place. They also stabilize transition metal radicals such as copper and iron to prevent oxidation.

Three Major Antioxidant Vitamins


Beta-carotene is a fat soluble vitamin naturally synthesized by plants. The antioxidant capacity of beta-carotene has a role in preventing harmful cancerous tumor growth. It prevents a cell from turning into a cancerous growth and increase the amount and functioning of cancer-fighting enzymes in the cells.

Vitamin C

Vitamin C is the best-known antioxidant, offering a wide variety of health benefits such as protecting from infection and damage to body cells, helping produce collagen, strengthening capillary walls and blood vessels and increasing absorption rate of iron and folate.

Vitamin E

Vitamin E is a fat-soluble vitamin that helps protect the cell’s outer protective barrier from free radicals. The protective barrier is the first line of defense against damage from free radicals as well as bacteria and viruses, helping with the prevention of cancer, heart disease and other degenerative diseases.

Other antioxidants that can keep you healthy include zinc and selenium. Zinc plays roles in immune function, protein synthesis, cell division and wound healing. Selenium is important for reproduction, thyroid function, DNA synthesis and protection from oxidative damage and infection.

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