Why has ‘antioxidant’ become a buzzword in the world of immunity?

Antioxidants are important because of what they can do to control free radicals. What are these free radicals? These are molecules that have an unpaired number of electrons. They are highly reactive and they interact with other molecules by taking an electron or by donating an electron. 

The reaction generally involves free radicals taking an electron from other molecule’s structure making the molecule weak and unstable(1).

So what? 

Free radicals are not always bad, they are released during normal processes in the body. But the problem starts when the levels of free radicals increase in the body and they start accumulating in tissues which might result in the development of degenerative diseases such as diabetes, osteoporosis, cancer etc. 

And this is where antioxidants enter the scene. Antioxidants are like arsenal that our body uses to keep free radicals in control and protect us. 

How do antioxidants neutralise the harmful impact of free radicals?

When the levels of free radicals increase in the body, it leads to oxidative stress; this is one of the leading causes for chronic and degenerative illnesses such as cancer, autoimmune disorders, rheumatoid arthritis, cardiovascular and neurodegenerative diseases(2). 

Antioxidants combat oxidative stress caused by the build-up of free radicals. Antioxidants prevent the free radicals from grabbing the electrons from other molecules and making them unstable; they quench the free radical’s thirst for electrons by donating their own electrons. These antioxidants have the ability to remain stable even after giving away electrons, and they keep free radicals from causing any type of harm to the important components of cells.

What are the different types of antioxidants?

There are two types of antioxidants – the kind our body produces, which are called endogenous antioxidants, and the antioxidants supplied by our food and supplements, which are exogenous antioxidants. Antioxidants play the part of natural free radical scavengers(1). 

What are dietary antioxidants?

Some components in food, because of their unique structure, display the antioxidant mechanism in the body. The antioxidants provided by our diet, along with the endogenous antioxidants released by our body, perform a crucial role in neutralising the oxidative stress caused by free radicals.

Our daily diet is the source of several bioactive compounds. A majority of these bioactive components are found in plants and they are clubbed under the term phytochemicals, which means ‘plant chemicals’. Plant foods are the primary sources of antioxidants; they are found in foods such as fruits, vegetables, nuts, herbs and spices.

Most of these phytochemicals are redox active molecules and display antioxidant properties(3). Certain vitamins and minerals also exhibit antioxidant activity. 

Here are a few dietary antioxidants:

  • Vitamin E 
  • Vitamin C
  • Iron
  • Zinc 
  • Selenium
  • Copper
  • Beta carotene
  • Flavonoids
  • Lycopene
  • Lutein
  • Zeaxanthin

Do dietary antioxidants have any role to play in the immune function?

We have explored immunity and its importance in this article, and why some people have a weak immune system here.  The immune system is essentially our defence mechanism that consists of an entire network of cells and tissues that guard us against any harm from outside or inside the body. 

Immune system cells, like any other cells in the body, require oxygen radicals for metabolic and physiological processes. The production and neutralisation of free radicals via antioxidants has to be balanced for good health. 

If our diet provides an adequate amount of antioxidants, it prevents the build-up of free radicals/oxidative stress in the immune cells. If there is an imbalance because of a lack of antioxidants, it may lead to deterioration in the immune cells because of oxidative stress(4).

Cells that use oxygen for their functions and release reactive oxygen species also develop an intricate antioxidant-linked defence system to counteract the free radicals. Due to ageing, or for any other reason, if the free radical concentration increases, then the immune function may be affected.


Simply put-

A strong immune system is an indicator of good health and predictor of longevity. Therefore, adequate amounts of dietary antioxidants supplementation would have beneficial effects in correcting or preventing the imbalance of free radicals and antioxidants in the immune system cells (4, 5). Along with other measures we have highlighted in this article to boost immune system, a sufficient amounts of vitamins and antioxidant elements seem to be necessary for the effective functioning of immune system (6) as antioxidants can enhance the immune function(2, 7).