Green Tea ORAC value

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

Posted by Stephany Morgan

Many health food companies talk about antioxidant levels in their sales copy and brag about high ORAC scores, but if you’re like most people, you probably have no idea what they’re talking about. Sure, you might have gathered that the higher the ORAC number, the greater the antioxidants, but the notion beyond that tends to be quite vague! So what’s a good ORAC score? Does it matter? Can you trust it?

Well, wonder no longer - today I’m going to give you the low-down on:

  • What the ORAC level of a substance actually means
  • Why ORAC values are important for your health
  • How scientists calculate ORAC antioxidant levels
  • Why you can’t always trust companies who brag about ORAC levels (and how to spot the untrustworthy claims)
  • How many ORAC units you need per day
  • The real ORAC values for tea

What do ORAC Levels Mean? Why Are They Important?

First of all, ORAC isn’t a nutrient or substance in its own right. ORAC stands for Oxygen Radical Absorbance Capacity (1) and is a type of test - one of the four main ways to measure antioxidant activity.

It was invented in 1992 at the National Institute of Health and Ageing (part of the NIH) in Baltimore, and is typically used alongside the three other antioxidant tests - Ferric reducing ability of plasma (FRAP), Trolox equivalent antioxidant capacity (TEAC), and Hydroxyl radical antioxidant capacity (HORAC).

These four tests each analyze different aspects of antioxidant activity, with ORAC looking at the total effects of antioxidants in a sample and measuring their collective effects on neutralizing oxygen radicals (ORs).

ORs occur when oxygen molecules split into atoms with unpaired electrons. Desperate to pair their electrons up, ORs scavenge the body for electrons they can steal. This activity damages cells, proteins, and DNA, and can be detrimental to health (2).

Clearly, you want to neutralize as many of those nasty ORs as possible with the help of antioxidants!


Herbal tea has lots of antioxidants

If this discussion of antioxidants and oxygen radicals seems a little dense to you, get up to speed by checking out our articles on how antioxidants work: Part One, which contains the basics, can be found here. Part Two, which goes a little deeper into what antioxidants do, can be found here.

Suffice to say, ORAC is a way to numerically determine how much free radical oxidation the tested plant material is able to inhibit, and how long it will take to inhibit it (3).

This “real world” metric makes ORAC the most effective way to tell you how much a certain food will benefit your body in terms of fighting free radicals. Antioxidants are difficult to measure because they aren’t really “things,” but properties attributed to certain vitamins and compounds. There are so many antioxidants that we don’t even have names for all of them, and botanicals can have thousands! It’d be impossible to measure them all individually.

Other tests may measure only one antioxidant (beta carotene, for example), but they don’t tell you how that relates to what it is doing in the body, nor do these tests account for any synergistic (combined) action between all the other antioxidants in the plant. (Hence why all four tests are usually used in conjunction, to cover all the bases!)

ORAC looks at how the relationships between antioxidants act to neutralize free radical damage (4) - that is, it tells you in practical terms just how much benefit you will get from consuming a substance.


Blackberries are high in antioxidants

    How Do Scientists Calculate ORAC Values?

    The way scientists measure a substance’s ORAC level is pretty straightforward. They set up a test tube which contains:

    • A sample of the plant material that they want to measure
    • Compounds that create free radicals
    • Some molecules that are vulnerable to damage from the free radicals

    By observing the reactions that take place and measuring how many free radicals are left over, the scientist is able to numerically determine how effectively the botanical sample was able to protect the vulnerable molecule from the free radicals (4). And, by extension, this number acts as a guide about how effectively the botanical in question can protect our own cells. 

    Simple enough, right? Well, it’s unfortunately not that simple for a consumer trying to compare products. Here’s why ...

    Why You Can’t Always Trust Companies Who Brag About ORAC Levels

    To put it bluntly, some companies are unethical, and they pit incomparable numbers against others to make it look like their product is healthier than it actually is (or, at best, they simply don’t understand the science). This is due to a lack of standardization. When it comes to ORAC testing, there’s nobody to oversee everyone’s numbers, and that can lead to misleading claims.

    Remember above, when I said that scientists test for ORAC levels using a “sample” of the botanical? Well, some companies will artificially inflate the ORAC scores of their products by testing a large sample and then comparing it to the numerical value of a company who used a smaller sample. And then other companies will quote that number without checking the quality of the study, and voila! Inaccurate information is born…

    That’s how you get claims like this:
    “Come and buy our ‘Company A Super Ultra Antioxidant Juice’! It has an ORAC score of 32,000! Don’t buy Company B’s blueberry juice. They only have an ORAC score of 2,400!” (5).

    Obviously, an ORAC score of 32,000 sounds much better than a score of 2,400, but there’s no way of knowing how much juice each company actually tested to get their numbers. The discrepancy may come from Company A testing a gallon sample and comparing it to Company B’s serving-size sample.

    My personal favorite trick that these companies use is making health claims without thinking about quantities. Ground cloves have the highest level of antioxidants of any food in the world, with an ORAC score of 314,446 (broccoli, for comparison, has a score of 3083). However, this is all based on the same weight: 100 grams / 3.5oz.

    That’s a LOT of ground cloves! You certainly wouldn’t scarf down a plate of them in one sitting. And suddenly, their high score becomes academic, rather than useful.

    Trouble is, how do we sort through all the misleading claims? I get one massive headache trying to compare ORAC scores that are measured in completely different units, not to mention the differing sample sizes discussed above.

    Once, when trying to compare two articles which reported bafflingly different measurements, I reached out to a chemistry professor for some advice about why the studies had such different methodologies. He explained that one measured the volume of liquid (like a brewed tea), and the other looked at the weight of the dried leaf.

    Seriously? This makes any kind of comparison impossible without more information!

    Knowingly or not, companies will often use these discrepancies to their advantage. Clearly, consumers should pay close attention to the science and units behind the sales pitch!


    Rooibos tea next to an open book

      Case in Point: the 137x Matcha Myth  

      There’s an oft-repeated marketing statement among matcha tea companies that matcha contains 137 times more antioxidants than green tea. However, this claim is false, and it’s all thanks to using incomparable numbers like the ones discussed above.

      In the study that produced this result, the matcha in question was measured using alcohol to extract the largest amount of antioxidants possible, while the green tea was:


      1. Extracted with water
      2. Sampled from a teabag, which typically contains fewer antioxidants than loose leaf tea anyway
      3. From a batch that included way fewer antioxidants than USDA estimates

      Lesson learned: it’s important to pay attention to where a company’s statistics come from!

      Click here to read my full post debunking the 137x Matcha Myth, including an explanation of why it would actually kill you if matcha contained that many antioxidants!


      Matcha does not have as many antioxidants as other teas

      What Is a Good ORAC Level? Can I Overdose on Antioxidants?

      The USDA suggests a daily intake of around 5000 ORAC units, while the FDA and the UK’s FSA recommend the classic “five a day” of fruit and vegetables, which works out to around 3500 ORAC units. This is equivalent to about three mugs of green tea. (6)

      Happily, you don’t need to worry about overdoing it with antioxidants - any extra components your body can’t use will be removed by your kidneys.

      HOWEVER, and this is a big caveat, you can overdose and significantly harm your body by taking too many antioxidant supplements, as they often contain enormous levels of ORAC (in the tens or hundreds of thousands in a single pill), which is obviously not good for you. So stick with your naturally antioxidant-rich fruits, vegetables and teas!

      Why Does Use ORAC Levels?

      Back in 2012, the USDA removed their ORAC database of scores for various foods from their website. They cited two reasons for this: 1) the blatant misuse of ORAC levels in commercial industry as we just described, and 2) lack of relevance to human biology.

      Undoubtedly, their first reason was sound; companies did (and still do) use ORAC levels for some pretty shady marketing claims.

      However, I agree with Ronald Prior, PhD, who sent a letter to the USDA refuting their second reason, citing the impact that ORAC scores had on the epidemiology of disease. Thanks to testing ORAC levels, he said, we now know how combined antioxidant activity acts in a disease model, which has important implications for treatment (5). 

      Basically, despite some companies’ questionable use of ORAC scores, these metrics are still very useful when it comes to our health, and ORAC tests are still regularly performed to assess antioxidant activity. And ORAC scores, when used ethically, are incredibly useful for making direct comparisons across teas. This is why uses them - so you actually know what antioxidant levels are in your teas. Saying 'High in antioxidants' simply isn't good enough!

      Because I want my research to be completely transparent, I always make sure to keep those pesky units and sample sizes consistent when researching ORACs for Matcha Alternatives’ teas. Why would I tell you the ORAC level for a liter of tea when you’re only going to drink 8 ounces? *shakes head*

      To help you explore the ORAC levels in various teas, from the very highest ORAC in Honeybush to the rare Purple tea with its anthrocynanins, I’ve created a table which ranks Matcha Alternatives’ pure teas by their ORAC level per 8 ounces, using as consistent a methodology as the available literature research allowed. By comparing apples with apples, I hope it will help you pick a delicious tea that also has a ton of free radical-busting action!

      For reference, matcha has an ORAC score of 1384.


      Tea Type

      Approximate ORAC Level per 8 fluid ounces

      How many cups to get the recommended 3500 ORAC units




      Green tea



      Purple tea



      Red Rooibos



      Moringa tea powder



      Green Yerba Mate



      Green Rooibos



      Tulsi Holy Basil







       MatchaAlternatives Teas and Packaging

      Note from the Herbalist

      This is a seriously science-y piece! However, I hope it has helped demystify what antioxidant scores mean, and you’re now able to spot trustworthy vs sketchy information when food and tea shopping.

      My approach is to eat a diet rich in vegetables and fruits, and drink different types of tea throughout the day. This way, I get a range of antioxidants (as they all do different things), and I am spreading them out over time so my body can continue to absorb and use them.

      If you would like to try this method, these are my go-to all-day-drinking teas for their taste and antioxidant levels:


      "The Purist" Organic Honeybush loose leaf tea

      "The Purist" Organic Honeybush

      The highest ORAC of them all! 

      More antioxidants than all our other teas, and its cleansing lemon, honey, and pepper notes make it a super yummy way to stay healthy.


      Read more:

      What Are Antioxidants
      and How Do They Work?

      Rare Superfood Loose Leaf Tea Trio (Moringa-Tulsi-Purple Tea Bundle)

      Rare Superfood Tea Trio Bundle

      Antioxidants all day long!

      Superior Organic Moringa Powder, Organic Tulsi Holy Basil, and Rare Purple Tea - each of which comes with a mega antioxidant hit.


      Read more:

      Best Substitutes for Matcha Tea...for Concentration, Caffeine & Antioxidants


      Explore our Tea Science & Lifestyle blog | Subscribe to the MA Blog to save $5!

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      FeelGood Musical Notes


      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.

      References on Antioxidants and ORAC Levels

      1. Garrett, Andrew R. et. al. “Measuring Antioxidant Capacity Using the ORAC and TOSC Assays.” Advanced Protocols in Oxidative Stress II, Humana Press, 2010, pp. 251-262.
      2. Szalay, Jessie. “What Are Free Radicals?” LiveScience, May 27, 2016.
      3. Dasgupta, Amitava, and Kimberly Klein. Antioxidants in Food, Vitamins and Supplements. Elsevier, 2014.
      4. Reinagel, Monica. “What Are ORAC Values?” Scientific American, August 14, 2013.
      5. Bowden, Jonny. “ORAC No More!” HuffPost, July 16, 2012.
      6. “How Do We Know Levels of Antioxidants in Foods? The ORAC System.” Natural Balance Foods.

      Further Reading on Antioxidants and ORAC Levels 

      More Matcha Alternatives Resources About Antioxidants and ORAC Levels

      Rooibos vs Honeybush: What's the Difference? 

      Is Milk in Tea Bad for You? Here's Why & Why Not

      The Health Benefits of Teas and Tisanes

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      • Thanks for writing this post! I feel much better informed about ORAC levels (and antioxidants – had to go back and read your antioxidant posts for context!)

        Celeste DeLancey

      • Thank you for this information packed post; thank you for all the research.

        Alison Harada

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