Afternoon Tea with Book

What Are Antioxidants and How Do They Work? (Antiox Part 1)

Posted by Stephany Morgan

You’ve probably heard about antioxidants: Everyone is talking about superfoods and super-teas with very high antioxidant levels (think blueberries with their anthocyanins, matcha, moringa, Goji berries, etc.), but cutting through all the noise to find trustworthy information about them can be challenging. Basically, their benefits are no secret, yet contradictions abound! 

This series of posts will shed some scientifically-robust light on antioxidants and antioxidants in tea in particular. In this first part, I will delve into what “free-radicals'' are and just how important it is that we have antioxidants available in our body to neutralize them.

In Part Two I examine the health impacts, in Part Three how they are measured, and then we continue the series with investigations on the antioxidants found in specific teas.

In this article, we will cover:


  • Explore our Antioxidant Series: brief descriptions with links to all our articles
  • A quick summary: what are antioxidants? How do they help?
  • What are free-radicals and where do free-radicals come from? The details
  • A closer look at antioxidants and what they do
  • Antioxidant levels in tea & superfood fun facts
  • Your day of antioxidants: 5 superfood teas for the whole day


Explore Our Antioxidant Series

➔  Part 1: What Are Antioxidants and How Do They Work?

You’re already reading it! Just below this series summary you will find the answer to the most important question: What (the heck) are antioxidants?

➔  Part 2: All About Antioxidants: Q&A with the Herbalist

Antioxidants have long been touted as powerfully healthy compounds, yet the specifics remain unclear. Studies that look at the effects of tocopherols, beta carotene and vitamin C (antioxidants) have often found little difference between the antioxidant intervention, and the placebo. But that isn’t the whole story. This post is a Q&A of the big questions about antioxidants and trying to clarify the confusing science, we hope you enjoy!

➔  Part 3: How Are Antioxidants Measured? ORAC Scores and How Much You Need Per Day

ORAC scores can be confusing, but the science behind calculating antioxidant values doesn’t have to be! Discover why ORAC levels are important, what they are, how they are measured, how to watch for misleading claims, and which teas have the highest ORAC levels and health benefits.

➔  Part 4: Busting the Matcha Myth: Does matcha really have 137 times more antioxidants (EGCG) than green tea?

The matcha industry claims that matcha contains 137 times the EGCG levels of green tea, but this is blatantly false. This figure is taken out of context from one flawed study, and if its antioxidants levels were actually that high matcha would be deadly! This article busts this matcha myth once and for all and looks at actual antioxidant levels in matcha and green tea. They can still be superfoods even if this extreme level isn’t true!

➔  Part 5: Antioxidants in Green vs Black Teas: What's the Difference?

Many think that black teas contain no antioxidants because they have been oxidized, but the truth is a bit more complex than that. This post looks at the antioxidant levels and types in green and black teas, their capacity to neutralize free-radicals, how they differ, and their bioavailability (especially when it comes to adding milk to your tea).

➔  Part 6: Antioxidants in Rooibos, Honeybush & Chamomile: What Do They Actually Do?

What antioxidants are found in Honeybush, Rooibos, and Chamomile, and what are their studied health benefits? I look one by one at the key antioxidants and explain how they affect the body. We've all heard that this tea or that is a 'superfood', meaning full of antioxidants, but what do they actually do?! Find out!

➔  Part 7: Antioxidant Benefits of Yerba Mate, Moringa, & Tulsi

The latest and greatest superfood kids on the block! But what are they made of and what do their antioxidants actually do? I demystify the health properties of these three fantastic herbal teas: coffee-replacement Yerba Mate, the ‘miracle tree’ Moringa and the adaptogen Tulsi Holy Basil

➔  Part 8: Most Common Antioxidants in Green Tea

Green tea is famous for its antioxidants, but do you know what they do? This detailed guide to the science behind EGCG, EGC, and Theanine, looks at green tea's anticancer benefits, how it helps reduce anxiety and improve sleep, and how these antioxidants compliment a healthy lifestyle. Plus what lemon does to antioxidants in green tea!

➔  Part 9: Purple Powerhouse: Antioxidants in Purple Tea & Their Health Benefits

What are the antioxidants in purple tea that make it a superfood...err…superdrink? Purple tea has many antioxidants, most famously GHG (unique to purple tea) and anthocyanins (what make blueberries blue). Learn what these antioxidants do, the health benefits of purple tea, purple tea and pregnancy, and so much more!

➔  Part 10: Is Cold Brew Tea Better for You? Antioxidants in Iced Tea vs Hot Brew

Diving into how brewing changes the antioxidant levels of different teas: How does water temperature affect taste? Cold brewing black vs green vs oolong vs white tea: Which has the most antioxidants? And what about antioxidant levels for red vs green rooibos iced tea? How to get the most antioxidants out of your tea, whichever method you try!


Bowl of Berries


A quick summary: what are antioxidants? How do they help?

I am going to explain the process is the briefest possible way first, and then elaborate in the next section, I hope this helps understanding:

Antioxidants are not actually “things” but properties attributed to certain vitamins and compounds. This includes vitamins C and E for example - they have antioxidant “action”.

  1. Antioxidants are compounds, whose electrons in their make-up can be donated where needed in the body
  2. Free-radicals on the other hand are molecules in the body which want to snatch electrons from other molecules in the body (let’s call them the victim here), causing damage in the process
  3. Antioxidants help stop this free-radical damage by donating an electron to that electron-hungry free-radical
  4. This spares the victim from losing one themselves
  5. The victim can merrily go on its way unaffected, doing its job in the body, as the free-radical is satisfied. The antioxidant successfully prevented “oxidative stress” from occurring


Antioxidant action is measured most commonly in ORAC units. This stands for “Oxygen Radical Absorbance Capacity”, which tells us how many free-radicals a substance can “neutralize”. You can read more about ORAC in Part 3.


Fun fact: The term 'superfood' is a non-scientific way to describe foods and drinks high in antioxidants. Although it doesn't have a scientific definition, it makes eating blueberries and cabbages even more fun: SUPER BLUEBERRY!

Antioxidant Tug of War



What are free-radicals and where do free-radicals come from? The details...

Free-radicals, also called Reactive Oxygen Species, can come from the environment such as pollution; foodstuffs such as alcohol, fried food and cigarettes; and UV exposure to name a few. Importantly, they are produced constantly in the body with completely natural and normal internal metabolic processes.

That being said, free-radicals are most famous for causing damage to DNA, RNA, cell membranes, lipids, and protein and more, leading to various cancers and other health issues. For example, they can also oxidize cholesterol which may lead to clogged blood vessels and heart troubles.


How and why do they do this?

Free-radicals is a descriptive term for unstable atoms/molecules which have one or more unpaired electrons, and so in order to become stable, they are eager to ‘grab’ electron(s) from other atoms nearby, so they steal from the nearest molecule (imagine a game of tug-a-war). Of course there is no real “desire” but like how a gas on one side of a room spreads to be equal in all parts of the room in a natural fashion, it is naturally part of physics that molecules want to become stable.

The snatching of electrons is called oxidation and the effect is described as oxidative stress. But what then? You guessed it, the ‘victim’ is now short of an electron too, and now in a more reactive state goes on to steal an electron from another. As you will have worked out by now, this is a chain reaction that goes on and on causing cascading damage to cell functions by affecting more and more molecules.

Oxidative stress alters the structure and function of the molecule that lost the electron. This can result in signs of ageing, increased susceptibility to/progression of disease, and even DNA damage.

It is important to remember that free-radicals are naturally occurring so no scaremongering here, they are not “toxins” being unnatural in any way...however they do cause damage as we have explained.

"As usual, it's a case of everything in moderation. In normal conditions, free-radicals act as important signal substances, but very high levels or long-lasting increases can lead to disease," Professor Håkan Westerblad, who led a study published in the Journal of Physiology concerning how free-radicals do have a purpose in the body.


Red Berries on a Line


A closer look at antioxidants & what they do

As we have said antioxidant is a descriptive term for certain compounds. So that means for you grammar enthusiasts, “antioxidant” is really a verb, not a noun, as they represent a group of compounds which have this action. Molecules that delay or prevent the oxidation of another.

They either reduce the creation of free-radicals or react with them by donating that electron they so desperately want. Due to this, antioxidants are also called free-radical scavengers. This neutralizes the free-radical (makes them stable), and so they will not go on to oxidize other atoms/molecules which are part of the proper running of cells, disrupting them.

While antioxidants protect against free-radical activity, they also play a role in immune system function. Mobilization of various immune reactions as you know involve inflammatory compounds, and this can result in a large production of free-radicals.

In turn, large numbers of antioxidants are needed to modulate this activity. Dietary antioxidants have also been found to modulate the susceptibility and resistance of the host (the person) to infections (caused by infectious pathogens).


Teacup of Blueberries


Can antioxidants prevent disease? Supplements vs diet vs tea

The actions described earlier are fact, that free-radicals damage all sorts of things, and that antioxidants protect the body by in part preventing or stopping this occurring. We know this, but it is difficult to know how important the consumption of antioxidants is towards this process.

It’s been observed that eating a diet rich in fruits and veggies means lower disease incidence, but they don’t know for sure if this is due to the antioxidants or other phytochemicals (that is, compounds that come from plants).

Some studies of antioxidant supplements - which are antioxidants removed from their whole-food context and typically given in large doses in clinical settings - become pro-oxidants. Argh! These increase risk for certain diseases.

Importantly, this reductionist approach is not found in nature, that is, unnaturally high quantities of one specific antioxidant only, in capsule form.

There are theories that this could be the problem with the current studies, that there are synergies between the various and multiple antioxidants (or other compounds) in a particular fruit or vegetable.

So this means isolated high-concentrations of antioxidant supplements are potentially harmful (but not always), so it is a more conservative and sensible approach to get antioxidants from whole food sources. This is the safest approach because they have thousands of other components which interact synergistically as either catalysts or buffers, helping to provide your body with exactly what it needs.

From a holistic point of view and to summarize, antioxidants can become damaging, and may increase disease risk, when they are taken unnaturally. The literature, for example, has shown that huge quantities of various antioxidants, such as Vitamin E, do not benefit overall health.


So what to do? How to safely consume antioxidants

Fruit and vegetables, in a balanced diet, contain lots of antioxidants. By getting antioxidants from plant sources such as tea, you help your body consume what it needs while making sure that you don’t get too much of a good thing.

So for us this means continue loving and drinking tea! In our fun facts section you will also find a list of high-antioxidant foods, which surprise surprise are ones you might expect to be healthy to eat!

Effectively in an unexciting way it comes down to the usual case of a balanced diet. The antioxidants in one tea (or food) are different from the next. Each tea contains a host of different ones, and the rest of this series concerns investigating each tea in this way. We look into what free-radical scavengers are found and check the literature about their effect on the human body.

So that is the big takeaway, antioxidants are a group of compounds, there is no one antioxidant. Eat the rainbow! (To our tea-loving friends outside the USA, that means eat a rich and varied diet with lots of colorful foods and drinks, which of course means lots of tea too...)


Antioxidant Rich Herbal Tea Options


Foods Rich in Antioxidants include...

Apart from teas and herbal teas of course, here are some examples of antioxidants-rich foods:


  • Dark chocolate
  • Nuts like pecans
  • Coffee
  • Blueberries, strawberries, goji berries, raspberries and other red and purple berries
  • Artichokes
  • Kale & spinach
  • Red cabbage
  • Beans
  • Beets


Antioxidant Fun Facts

Teas rich in antioxidants

Here is a handy guide to popular and uncommon teas high in antioxidants:

Some cool facts about antioxidants and tea


  • There are thousands and thousands of different types of antioxidants out there! Plants often produce antioxidants as defence mechanisms against pests and disease. You already know all the vitamin A in the world won’t help you if your body needs Vitamin E, so give your body plenty of everything through a varied and colorful diet so it can pick and choose what it needs.

  • Purple tea has interesting antioxidants - purple anthocyanins, the same antioxidant in blueberries, raspberries, red cabbage etc. that change color when you add lemon juice (seriously fun). Learn more in the purple tea edition of this series
  • Honeybush has an ORAC level of 2750 vs. the 1,283 found in Green tea. Tons! The most of any tea we know!
  • Tulsi Holy Basil - very high in antioxidants (2550 ORAC) and it’s also an adaptogen. Read about adaptogens here
  • Fighting free radicals with antioxidants is only half the battle - seek out ways to stop consuming free radicals to begin with, too! For example, stop smoking, clean your lungs with fresh, unpolluted air, and avoid heavily processed foods. A good place to start!
  • Antioxidants degrade over time. For tea, the speed depends on how hot the water was when brewed, so tea brewed in boiling water will have its antioxidants decay over a few hours, while cold-brew tea’s antioxidants will stick around for even a few days. Bottled iced tea from the store has almost zero antioxidants.
  • Teabags in general have fewer antioxidants than looseleaf, as the tea has more surface area = more exposure to air = the faster the antioxidants are removed.
  • ORAC levels stands for “Oxygen Radical Absorbance Capacity”, which tells us how many free radicals a substance can “neutralize”.



    Stephany Morgan

    A Note From The Herbalist... Your day of antioxidants

    Personally, I love knowing that my cups of tea throughout the day are packed full of a range of antioxidants, so they not only taste good but are good for me. Here's an ideal day of antioxidant-rich tea for me:



    Questions? Thoughts? Let me know in the comments below or on our IG @MatchaAlternatives

    Now, time to try some antioxidant-rich tea!

    First published August 2019. Updated and expanded May 2021.


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    All of the information regarding the herbs, botanicals, minerals, vitamins, etc., is information drawn from traditional use data or academic research and should be regarded as such. If you, the reader, has a health or medical concern, please consult your healthcare professional. The information found here is not meant to diagnose, treat, prescribe or cure and has not been evaluated by the FDA. This information is for educational purposes only. 



    Antioxidants References and Further Reading

    Antioxidants: In Depth, National Center for Complementary and Integrative Health

    U.S. Department of Health and Human Services. Antioxidants: In Depth National Center for Complementary and Integrative Health (NCCIH), accessed 1 August 2019. 

    Ware, M. How can antioxidants benefit our health? Medical New Today, accessed 1 August 2019.

    Harvard School of Publich Health, Antioxidants: Beyond the Hype Harvard TH Chan School of Public Health, accessed 1 August 2019.

    H Nishino, M Murakoshi, Y Satomi. Health Promotion by Antioxidants Functional Foods in Health and Disease. 2011;1(12):574-581,  retrieved April 14, 2019

    Superfoodly. Green Tea - Brewed ORAC Values Superfoodly, accessed 1 August 2019.

    The Alcohol Pharmacology Education Partnership, Formation of Reactive Oxygen Species and Cellular Damage, Duke University, accessed 1 August 2019.

    Karolinska Institutet, free-radicals may be good for you  accessed 23rd May 2021. 

    12 Healthy Foods High in Antioxidants, Healthline accessed 23rd May 2021.

     Aalt Bast. Guido R.M.M. Haenen, Ten misconceptions about antioxidants, July 01, 2013


    MatchaAlternatives' Blogs in this Series

    Part 2: All About Antioxidants: Q&A with the Herbalist

    Part 3: How Are Antioxidants Measured? ORAC Scores and How Much You Need Per Day

    Part 4: Busting the Matcha Myth: Does matcha really have 137 times more antioxidants (EGCG) than green tea?

    Part 5: Antioxidants in Green vs Black Teas: What's the Difference?

    Part 6: Antioxidants in Rooibos, Honeybush & Chamomile: What Do They Actually Do?

    Part 7: Antioxidant Benefits of Yerba Mate, Moringa, & Tulsi

    Part 8: Most Common Antioxidants in Green Tea (Antiox Part 8)

    Part 9: Purple Powerhouse: Antioxidants in Purple Tea & Their Health Benefits

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    • No wonder tea after drinking feels so good!

      Lauren Elizabeth Hirth

    • @Alison Harada – Thank you for your comment, and we are so happy you are enjoying your Matcha Alternatives teas!! Holy Basil is one of my favorites too.

      So, for moringa: my personal favorite is to sprinkle it on my granola, eggs or toast in the mornings, and add it to tuna or egg salad for lunch. For drinking, it’s delicious straight (add boiling water to a teaspoon of moringa powder, stir and job done), and also if you feel like a new twist on the latte: add some hot milk and some honey and YUM. How have you tried it so far?

      Happy drinking!
      Elizabeth Taeed co-founder

      Elizabeth Taeed

    • After my doctor advised me to cut coffee from my diet, I have enjoyed exploring the variety of teas offered by Matcha Alternatives. I have tried the Sencha green tea, Holy Basil tea and now am trying a few Roibus teas. They are all delicious but I think I like the Holy Basil best. I would like to make more use of my Moringa tea and would appreciate some suggestions about how to drink it. Thank you!

      Alison Harada

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