What are Free Radicals?

Going by dictionary meaning, a free radical can be defined as an atom or group of atoms having at least one unpaired electron which makes it unstable and highly reactive. In animal tissues, free radicals can damage cells. They can also accelerate the progression of cancer, cardiovascular disease, and other age-related diseases.

Free Radical Theory of Aging

Free radical theory of aging was first proposed by Denham Harman in the 1950s. FRTA or the Free Radical Theory of Aging says that any organism ages because cells accumulate free radical damage over time. Few free radicals like melanin are not chemically reactive. However, most of the biologically-relevant free radicals are highly reactive. Free radical damage is closely associated with oxidative damage which can be controlled by antioxidants. As antioxidants are reducing agents, they can limit oxidative damage by making free radicals passive.

How Free Radicals Accelerate Aging?

Free RadicalsThe term ‘Free Radical’ is composed of two words- Free + Radicals. They are “free” as they keep on floating around till the time they get stabilized. They ar called “radicals” because they are capable of taking an electron from a wide variety of molecules. As mentioned earlier, free radicals are ‘unstable’ molecules without an even number of electrons. They always look for an extra electron and ‘steal’ it to become stable. This results in unwanted damage to body cells. This ‘stealing’ of electron from other molecules lead to a chain formation of free radicals. For example, when a free radical steals an electron from a cell wall, this cell too become a free radical as it also has a missing electron now. This gradually damages the healthy tissues leading to various diseases and aging too.

What Causes Free Radicals?

Free radicals are, in the first place, the result of our being alive! Various chemical reactions are going on in human body. As a result of the side effects of bodily chemical reactions, free radicals are produced. Thus, we cannot prevent forming of free radicals altogather because our bodies produce them naturally.

Our immune system too produces free radicals to fight off diseases. Free radicals are one of the important elements when white blood cells called phagocytes are working. These white cells fight off the bacteria and other pathogens in our bodies to keep us free of diseases. In fact, free radicals are also believed to be involved in the process known as redox signaling, where they act as cellular messengers.

Thus, not all free radicals are bad. They only create problems when produced in very high amounts- the amount that cannot be managed by our bodies. Free radicals are produced in greater amounts due to certain environmental factors some of which are listed below.

Emotional and physical stress

Ozone depletion

Air pollution

Cigarette smoking


Radiations including UV sunrays

Industrial chemicals

Processed foods

Recreational and prescription drugs

Antioxidant Therapy to Reduce Free Radicals

Antioxidants come to our body’s help when free radicals damage the tissues to make us look old. Antioxidants like vitamin A, vitamin C, vitamin E, and Superoxide dismutase slow down the process of aging by stopping free radicals from oxidizing sensitive biological molecules. In other words, antioxidants help in reducing the formation of free radicals. Any anti-oxidant can supply a replacement for its missing electron to a free radical.

Antioxidants and Free Radicals

You might also like to read Antioxidants and Aging- Facts and Review

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