What do we not know about free radicals?

What are free radicals?

Free radicals are atoms, groups of atoms, or molecules which contain at least one free electron in their external orbit. Electrons are negatively charged particles which usually go in pairs, forming chemically stable bonds. If an electron is free, another atom or molecule may easily bind to it and cause a specific chemical reaction. Due to its chemical instability, each free radical may easily bind to other compounds. It attacks the closest molecule and takes an electron out of it, so, in turn, this molecule becomes a free radical itself. Once the process has started, it may escalate in a chain reaction which is difficult to be taken control of and may cause serious changes in the body, followed by numerous mutations.

It is normal for free radicals to be present in the body and the existence of each of them spans a fraction of a second only. The mutations they leave behind however are irreversible. It is believed that around 10 thousand free radicals are produced daily in each cell of the body.

Factors leading to an excess of free radicals

There is a range of different factors which may lead to an excess of free radicals. Radiation exposure – sunlight or X-ray, tobacco smoke, exhaust fumes, and last but not least – nutrition. A fat-rich diet may enhance the activity of free radicals as the oxidation of fats is easier than that of carbohydrates and proteins. The presence of dangerously high number of free radicals changes the way in which cells code genetic material. The formation of mutated proteins damages the immune system and leads to the development of various oncological diseases. As time goes by, the body starts producing more and more free radicals – a fact which serves as a basis for one of the theories of aging as a process on a molecular level. Radicals are unstable due to the presence of an unpaired electron in the formed free pair. That is why, each free radical easily binds to other compounds. It is always in search of another atom or molecule to find an electron from and bind to it. Due to their high reactivity, free radicals are considered to cause degenerative diseases and cancer. Once they end up in a living cell, they may cause mutations or damage the DNA.

A cause for cell aging

In the mid-1950s, Denham Harman MD, PhD at the University of Nebraska was the first to develop the thesis that free radicals are an essential, if not the main, cause of aging and damage on a cellular level.

Each organism has the ability to protect itself from free radicals with the help of enzymes which neutralise free radicals and make them harmless. In essence, these enzymes are different antioxidants, which bond with highly reactive agents and neutralise them before they are able to attack a free molecule. Antioxidants play the important role of a target and aim at protecting their own cellular structures.

Antioxidants have the ability of deactivating free radicals.

When the body is in normal condition, it controls the number of free radicals on its own. A normal cell produces free radicals and antioxidants simultaneously and this process is managed and controlled by the information in the DNA. The task of each antioxidant is to prevent the damage caused by free radicals long before they affect the body. Antioxidants are substances which protect and help neutralise the harmful effect of oxidative intracellular reactions. Free radicals are atoms with a missing electron in the electron shell. They are highly reactive and are ready to form a new electron pair by adding an electron from the surrounding atoms. This is the mechanism in which they involve the electrons of the healthy cells, damage their integrity and turn them into free radicals. The division of radicals may be terminated only if the body has antioxidants which neutralise radicals. Cells which die and cells which multiply when they have already been impaired are the cause of premature aging, decreased immunity, and development of diseases like cancer, cardiac diseases, osteoporosis, and many others. Antioxidants neutralise the harmful effect of oxidative reactions. All antioxidants work more successfully in conjunction with other antioxidants, their synergic effect is enhanced, and becomes more effective. If levels of antioxidants are maintained high enough, most free radicals may be neutralised before causing harm to the body.