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What Is Oxidative Stress (OS) and Role of Antioxidant

What Is Oxidative Stress and Role of Antioxidant
What Is Oxidative Stress and Role of Antioxidant

What Is Oxidative Stress (OS) and Role of Antioxidant

Oxidative Stress

An imbalance among free radicals and antioxidants in your body is Oxidative stress. Free radicals are oxygen-containing molecules with an uneven number of electrons, making it highly reactive with other molecules. On the other hand, it is a phenomenon caused by an imbalance between the production and accumulation of ROS.

What is ROS?

ROS means reactive oxygen species. Oxygen in a molecular form O2 is not a reactive form of oxygen. Free radicals converted to oxygen molecule into reactive forms.

These are an unstable form of oxygen which generates the OS in our body. This is a chain reaction.

Types of ROS:
Endogenous ROS:

Endogenous free radicals/ROS are produced in our body due to inflammation, mental stress, infection etc.

Exogenous ROS:

Exogenous free radicals /ROS are produced due to smoking, pollution, radiation, alcohol, some drugs, heavy metals etc.

What is Antioxidants?

Antioxidants are molecules which can donate an electron to a free radical without making themselves unstable. This will cause free radical to stabilise and become less reactive and prevent OS. It acts as free-radical scavengers.

Types of Antioxidants:

Antioxidants produced endogenously or some form of exogenous sources.


Antioxidants which are produced in our body called Endogenous Antioxidants. Endogenous include enzymes like superoxide dismutase, catalase and glutathione peroxidase

(Enzyme that functions to remove hydrogen peroxide) and glutathione reductase.


Antioxidants are naturally occurring plant substances that protect the body from damage caused by free radicals. Some vitamins or minerals act as antioxidants like vitamin C, vitamin E, beta-carotene, selenium, Zn etc. Fruits and vegetables are the best sources of antioxidants, including:

citrus fruits
dark leafy greens

Effects of Oxidative Stress(OS):

The effects of oxidative stress(OS) vary and are not always harmful. It is either beneficial or harmful for our body. Oxidative stress(OS) that results from physical activity may have beneficial, regulatory effects on the body. Exercise increases free radical formation, which can cause temporary oxidative stress(OS) in the muscles. However, the free radicals formed during physical activity regulate tissue growth and stimulate the production of antioxidants.

Beneficial Effects:

There is a fixed ratio of “total body oxidative stress(OS) Vs antioxidant capacity” in our body. If this ratio is maintained, then it has beneficial effects on the body like it helps in several physiological activities (i.e. cell signalling). They are needed to synthesise some cellular structures and to be used by the host defence system to fight pathogens.

Harmful Effects:

On the other hand, if this ratio is imbalanced, then it has adverse effects on the body. When there are more free radicals present in our body, it can damage cells, DNA and protein. So, this damage can lead to a vast number of diseases like cancer, heart attack, neurological disorders and other diseases.

Harmful Effects and Role of Antioxidants:

When the level of ROS becomes high, which increase the oxidative stress(OS) and leads to many diseases including;


Oxidative stress is a causative agent of cancer. When the number of free radicals increases in our body, then it can increase the number of ROS, which ultimately increases the level of oxidative stress(OS). The increased level of ROS damaged the DNA and stimulated the cell division. When a cell with a damaged DNA strand divides, it gives rise to disturbed and deformed clusters of cells that form cancer.

The antioxidant can donate its one electron and stabilise the free radical and prevent cancer by reducing the level of oxidative stress(OS) and maintains its ratio. Due to which the chances of cancer will reduce.

Heart Attack:

Heart disease risk is raised by several factors, including high cholesterol levels, high blood pressure, smoking, and diabetes. These promote atherosclerosis. Atherosclerosis refers to the formation of hardened walls of the arteries that impair blood flow to the heart. The increased level of ROS injured the epithelial cells as well as oxidised the LDL (Bad Cholesterol). This oxidised LDL starts to deposit on the damaged epithelial cell, which causes plaque formation. The formation of plaque hinders the blood flow and leads to Heart Attack.

The antioxidant can stabilise and maintain the level of ROS and oxidative stress(OS) and protect from epithelial injury and can prevent from Heart Attack (Myocardial Infection).

Neural Disorders:

Free radicals also damage the nerves and the brain. If the level of oxidative stress(OS) increase, it may damage the nerves, which lead to neurological disorders like Parkinson’s disease and Alzheimer’s disease, seizure disorders etc.

Other Diseases:

Due to the high level of ROS and OS, many diseases like diabetes, inflammatory disorders, infertility, ageing etc. Antioxidants reduce the chances of risks of these all diseases, and it considers as antiaging.

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Managing and Preventing Oxidative Stress(OS)

It’s impossible to altogether avoid free radical exposure and oxidative stress(OS). However, there are things you can do to minimise the effects of oxidative stress(OS) on your body. The main thing you can do is to increase your levels of antioxidants and decrease your formation of free radicals.

So, our lifestyle and dietary measures that may help reduce oxidative stress(OS) in the body include:

eating a balanced, healthful diet rich in fruits and vegetables
exercising regularly
quitting smoking
reducing stress
avoiding or reducing exposure to pollution
Maintaining a healthy body weight may help reduce oxidative stress(OS)