MuscleScience

You see a lot about anti-oxidants and how you should eat fruits and veggies and take vitamins to get your anti-oxidants. But what exactly does that mean, what do they do. I hope to help those who are confused about what all they hype about its is.

The body creates free radicals as part of its normal metabolism.

The body uses oxygen in many reactions of normal metabolism. Oxygen is actually a toxic substance. As part of normal metabolism free radicals are generated from these varies reactions. For the purpose of this discussion I will talk only about oxygen containing compounds that are reactive, these are called Reactive Oxygen Species (ROS).

A free radical or ROS are terms that are used interchangably. A free radical is basically a ROS that floats around and interacts with other molecules and cause them to be chemically altered.

Free radicals are bad because???

Free radicals are bad when they interact with parts of cells that are sensitive to chemical alteration. These include such things as cell membranes, proteins, organelles and of most importance DNA.

Why is DNA damage from free radicals a concern

This is actually very simple to answer. The DNA of the cell controls all the functions of the cell. Free radicals when they interact with the cells DNA can change or alter the coding units. This is not of much concern normally because free radicals usually don't do damage in the short term that cause much effect because of the inherite repair mechanisms for DNA.

You just said that DNA damage from free radicals is bad

Over time the damage from free radicals can become cumulitive. As a cell ages it repair mechanisms for DNA start to decline. Also the mechanisms to control free radicals start to decline which will be discussed later. Without getting into way to much cell physiology. Free radicals are basically a major factor in the aging process.

How does the body combat free radicals?

There are natural processes in the body that are used to combat free radical generation. Probably the most recognize is the effects of the enzyme catalase. If you have ever cut yourself and put hydrogen peroxide and seen it bubble up, you have seen the action of catalase. This enzyme is used to convert hydrogen peroxide in the body to water and oxygen. Most believe this is cause by the killing of bacteria in the wound. The bubbles are cause when the Peroxide comes into contact with bodily fluids which contain catalase.

The second important anti-oxidant made in the body is called superoxide dismutase. This converts the very toxic superoxide into oxygen and hydrogen peroxide. There are three known forms in humans described so far and all have very similar functions.

Dietary anti-oxidants

Dietary anti-oxidants work somewhat different in most cases than the enzymatic anti-oxidant compounds produced by the body. For example I will use vitamin E. Vitamin E basically prevents free radicals from damaging the cell membranes of cells by coming into contact with a free radical and rendering it inert. They usually do not convert the free radicals into different compounds, what they do is cause the charged molecule to became a neutrally charge molecule that will not react with with other compounds.


To briefly summarize, anti-oxidants render free radicals incapable of causing damage to cellular structures by rendering the free radicals chemically inert or changing them to a lower reactive state.