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Immunity

Antioxidants. What they are and how they support our immune system health

Dr Jane Winter
Written by Dr Jane Winter | Dietitian, Science Communication Manager
Antioxidant rich brunch food

Recently, the Swisse Squad community told us that they wanted to learn more about antioxidants. We’re often told to eat more antioxidants to support general health and wellbeing. But do you understand what antioxidants are, the role of antioxidants in the body and how they can support our bodies to thrive? Let us share our findings and research with you now.

What are antioxidants?

Antioxidants are any substances that can prevent damage to cells caused by free radicals. They can be found naturally in the body, or in food or supplements. Vitamin C, vitamin E and beta-carotene are all examples of nutrients that are classified as antioxidants.

What role do antioxidants play in the body?

Antioxidants play a starring role in warding off free radicals in the body before they damage our cells. Free radicals are highly unstable molecules that are generated naturally when we exercise or when our body converts food into energy.

Environmental factors like stress, UV exposure and pollutants as well as ageing, can also contribute to the increase of free radicals. When we have an overload of free radicals in the body, it can create oxidative stress which stops important processes working as they should[1].

Similar to how fibre cleans up waste in the intestines, antioxidants clean up free radical waste in the cells[2]. They keep the free radicals in check by preventing them from taking electrons from the cells which converts them into more free radicals. They are able to give the free radicals an electron themselves without becoming destabilised, which stops the chain reaction that damages our cells[3].


How can antioxidants support our immune system?

Antioxidants play an important role as a line of defence against cell damage. Given this, antioxidants are an important part of many processes in the body, including our immune system. In fact, the immune system is particularly sensitive to oxidative stress, which happens when there’s an imbalance between free radicals and low antioxidant levels[4].

To function at its best, the immune system is extremely reliant on accurate communication between the cells. Oxidative stress can impact the signaling systems involved in this communication, which can lead to an impaired immune system.[5] Research shows that dietary antioxidants can improve immune system function, providing an important protective role for us.[6]

How to get antioxidants through diet to support a healthy immune system response

While the body produces some antioxidants on its own, this isn’t enough to keep free radical damage at bay. The good news is, you can support this through a healthy diet.


Vitamins and minerals

Vitamin C, vitamin E and β-carotene are antioxidants that have been found to have an impact on the immune system. Minerals such as selenium, copper, zinc and iron are also essential as they help antioxidants perform their role in the body.

Fruits and vegetables

Most fruits and vegetables are rich in antioxidants and generally, the more colourful, the better. Great dietary sources include berries, tomatoes, broccoli, carrots and spinach[7]. Antioxidants are also abundant in green tea and nuts. Walnuts, pecans, chestnuts and peanuts have the highest antioxidant content of all nuts[8].

Polyphenols

Polyphenols are antioxidants that have been found to play a particularly important role in immune health[9], and these are naturally found in apples, red wine, olive oil and turmeric, along with other plant-based food.[10]

Can you tell if you're low on antioxidants?

There is currently no accurate test to determine whether you are eating enough antioxidants or if oxidative stress is occurring in the body. Thus, it’s important to eat an antioxidant-rich diet all year round, to ensure you’re getting adequate amounts.

References:

[1]Maria A. Puertollano, Elena Puertollano, Gerardo Alvarez de Cienfuegos and Manuel A. de Pablo, “ Dietary Antioxidants: Immunity and Host Defense”, Current Topics in Medicinal Chemistry (2011) 11: 1752. https://doi.org/10.2174/156802611796235107

[2] https://www.livescience.com/54901-free-radicals.html

[3] https://www.livescience.com/54901-free-radicals.html

[4] Maria A. Puertollano, Elena Puertollano, Gerardo Alvarez de Cienfuegos and Manuel A. de Pablo, “ Dietary Antioxidants: Immunity and Host Defense”, Current Topics in Medicinal Chemistry (2011) 11: 1752. https://doi.org/10.2174/156802611796235107

[5] https://www.ncbi.nlm.nih.gov/pubmed/10343344

[6] https://www.ingentaconnect.com/content/ben/ctmc/2011/00000011/00000014/art00002

[7] https://www.livescience.com/54901-free-radicals.html

[8] https://www.ncbi.nlm.nih.gov/pubmed/17125534

[9] Maria A. Puertollano, Elena Puertollano, Gerardo Alvarez de Cienfuegos and Manuel A. de Pablo, “ Dietary Antioxidants: Immunity and Host Defense”, Current Topics in Medicinal Chemistry (2011) 11: 1752. https://doi.org/10.2174/156802611796235107

[10]https://utswmed.org/medblog/polyphenols/