What are Antioxidants?

bowl of blueberries

What is an antioxidant?

Antioxidants are believed to protect the body from damage caused by harmful molecules called free radicals. They are found in foods, specifically fruits, and vegetables, but have also been made into dietary supplements.

It’s not surprising that we often feel good when we eat antioxidants as they are found in many healthy fruits and vegetables. We also get the added health bonus of feeling like we are warding off Alzheimer’s, some cancers, arthritis, and even some eye diseases by eating antioxidants. But, is this too good to be true? How do antioxidants work inside your body?

Antioxidants > Free Radicals

We cannot discuss antioxidants without talking about free radicals. Our bodies are composed of trillions of cells working hard to keep us strong and healthy. One of the biggest hypothesized threats to our healthy cells is free radicals.

There are a few ways in which your body can ingest free radicals. Environmental contaminants like pollution, cigarette smoke, and chemicals create free radicals can be absorbed by your skin or inhaled through your lungs. Additionally, your body can also create free radicals. This happens naturally when your body turns food into energy. If your diet is deficient in fresh fruits and vegetables and you are not sleeping enough, your body can create free radicals which also attack healthy cells. Whether they are inhaled, absorbed, or created internally, the chain reaction of free radicals compromising healthy cells is called oxidative stress.

Free radicals are unstable atoms or molecules containing an unpaired electron that rapidly stabilize by bonding with an electron in another atom or molecule. As a consequence, free radicals are extremely reactive and if they bond with a molecule in a healthy cell, the healthy cell will be damaged.

Some in vitro scientific research indicates that if radicals are created faster than they are neutralized by antioxidants, healthy cells may be compromised. However, this research has only been proven in simple laboratory systems (these systems are usually isolated cells in a synthetic medium). Because of this, antioxidants have been touted as the “antidote” to eliminate these free radicals and keep the healthy cells intact.

Unfortunately, the ability for antioxidants to prevent oxidative stress and stabilize free radicals has not been proven in complex systems, like the human body. And while this research is often extrapolated to be true in humans— this is incorrect.

Therefore, we cannot definitively make a claim that consuming antioxidants neutralizes free radicals or prevents oxidative stress in your body.

Some recent health claims have drawn a correlation between the findings in the lab, but the human body is extremely complex, and scientific evidence for an antioxidant effect is lacking. Products that claim to have the ability for antioxidants help prevent disease, fight cancer-causing free radicals, and maintain overall body health do not have scientific research that supports these claims in humans.

For example, we recently discussed the antioxidant findings in chocolate from the MARS Center for Health Science chocolate in our article, “Crazy for Cocoa.” While the understanding of antioxidants (specifically flavanols) in the cocoa bean is understood; how the human body uses these antioxidants is highly speculative. (The FDA required Mars to withdraw CocoaVia because they were making an unapproved health claim in a food ineligible for such a claim [too much saturated fat]). So, while we encourage you to eat foods that have a dense nutrient profile, do not fall victim to the marketing claims that try to lure you with false promises based on unsubstantiated research.

This is not to say that you should scrap the healthy food! There are thousands of different types of antioxidants and their abilities are extremely complex. While we do not know exactly how they react inside the human body, antioxidant-rich foods like blueberries, dark chocolate, kale, and green tea, are all known to have a strong vitamin and mineral profile that also support a healthy body.

Ultimately, foods containing antioxidants can help support a healthy, well-balanced diet, but antioxidants by themselves have not been proven to be the universal antidote for curing disease.

So, while the research is inconclusive, it is still beneficial to understand how to provide your body with a balanced diet that also includes antioxidant-rich foods.

How do we know which foods are high in antioxidants?

The USDA has developed a test called the Oxygen Radical Absorbance Capacity (ORAC) test which measures the antioxidant capacity of certain foods. This measurement can help you determine which fruits and veggies with high antioxidant content to incorporate into your diet.

With the use of the ORAC test, the USDA tested many of the fruits, nuts, vegetables, and spices to determine their antioxidant capacity.

The ORAC test is reliable when testing the antioxidant content in fruit or vegetables in vitro (in the lab), however, this test is unreliable when testing antioxidants abilities in vivo (in your body).

“Led by Ronald Prior, an ARS chemist who works at the Arkansas Children’s Nutrition Center in Little Rock, researchers investigated how the consumption of different fruits affected volunteers’ antioxidant status.

They did this by measuring the plasma (blood) antioxidant capacity (AOC) of volunteers who’d just ingested blueberries, cherries, dried plums, dried-plum juice, grapes, kiwis or strawberries.

The series of ARS studies confirmed what many antioxidant experts have long suspected: that the free-radical-busting compounds found in foods are quite complex, with some apparently being easier to absorb and utilize than others.

For instance, the researchers found that despite their high antioxidant content, plums did not raise plasma AOC levels in volunteers. According to Prior, one of the major phytochemicals in plums is chlorogenic acid, a compound not readily absorbed by humans.

As for the wild blueberry, a larger-than-average serving of this much-heralded antioxidant source was needed to boost plasma AOC levels. A noticeable climb in AOC wasn’t detected until volunteers consumed at least a half-cup serving of the berries.”

Data on antioxidants provided by the U.S. Department of Agriculture.

Again, human research in this field is limited. There have been a few animal-based studies that demonstrated a correlation between increased consumption of antioxidants and a decreased level of free radicals.

Additionally, the understanding that free radicals inside your body are causing disease has yet to be definitively proven. While free radicals have been proven to cause oxidative stress in the lab, which can affect healthy cells, how an individuals body responds to free radicals and oxidative stress is different. There is also some promising research regarding the role of antioxidants and the effects of aging.

According to the American Journal of Clinical Nutrition, Early findings suggest that eating plenty of high-ORAC fruits and vegetables—such as spinach and blueberries—may help slow the processes associated with aging in both body and brain. Two human studies show that eating high-ORAC fruits and vegetables or simply doubling intake of fruits and vegetables—both naturally high in antioxidants—raises the antioxidant power of the blood between 13 and 25 percent.” 

However, it should also be stated that many of these studies specified that human participants take an antioxidant supplement as opposed to whole foods that have a natural high antioxidant component. It has been hypothesized that the antioxidants in foods may be more effective than antioxidant supplements. Unfortunately, there is no way to determine the relationship between antioxidants and free radicals. More extensive, long term human trials must be performed.

Do You Matcha?

matcha powder and tea

Green tea has been acclaimed as a healthy source of antioxidants for centuries. But, recently, the health benefits of green tea have been overshadowed by matcha. And while matcha has always been a staple in Asian culture, the weight-loss movement in the United States has made this product mainstream.

Some of the marketing claims and possible health benefits of matcha include: 

Aids in weight loss by boosting metabolism.
Naturally detoxifies.
Calms the mind and promotes concentration.
Antioxidants may have anti-cancerous properties.
Lowers cholesterol and blood sugar.

However, while matcha, and green tea, have a compliment of health benefits, there is a limited amount of research that proves these expansive claims.

Human clinical evidence is still limited. Future research needs to define the actual magnitude of health benefits and establish the safe range of tea consumption.”
(2010 Literature Review of Green Tea)

Unlike traditional green tea, which is typically steeped in hot water and enjoyed, matcha is made from tencha green tea leaves and is ground into a powder, making matcha the more potent of the two. Thus rather than drinking just the steeped water, you are consuming the leaves themselves.

A 2010 literature review of green tea research indicated that “the health-promoting effects of green tea are mainly attributed to its polyphenol content [particularly flavanols and flavonols] which represent 30% of fresh leaf dry weight.” For matcha products, this antioxidant content is intensified because the leaves are consumed directly.

These matcha tea leaves are ready to be picked. Image Source

An ORAC test, or oxygen radical absorbance capacity, measures the antioxidant content of foods. According to the USDA, “early findings suggest that eating plenty of high-ORAC fruits and vegetables–such as spinach and blueberries–may help slow the processes associated with aging in both body and brain.”

Matcha is often served as a tea or latte but preparing it is much more arduous than simply brewing a cup of tea. Cultivating matcha is bit different as well. To cultivate the tea leaves, farmers cover the tencha plant and keep it in the shade for about four weeks before harvest. This forces the plant to compensate for the lack of sunlight and in turn the plant produces a greater amount of an antioxidant called chlorophyll. This provides matcha tea with a dense of amino acid profile.

Plant-based catechins are antioxidants that are often found in tea as well as a diverse mix of foods like chocolate, berries, and fava beans. This shading process for growing matcha does reduce the amount of catechins found specifically in matcha— making traditional green tea a stronger source for this particular antioxidant.The decreased level of catechin’s in green tea is also said to decrease the traditionally bitter flavor of brewed green tea leaves.

Chlorophyll is the pigment that gives green plants their color. It is also an antioxidant that supports detoxification, specifically aiding in the cleansing of your liver. It is also believed to help support digestion and possess antiviral properties that can protect against bacteria entering your body. A 2012 study performed at Oregon State University found that chlorophyll may also help protect your body against cancer.

One of the most prevailing amino acids that is present in matcha is L-theanine. New research on this amino acid indicates that it can help to control stress. In fact, Buddhist monks are known to have consumed matcha tea before meditating to help concentration. This amino acid helps regulate the digestion of caffeine present in matcha. Rather than a quick burst of energy, L-theanine slows the rate of absorption. According to Mintel market research, “the elevated levels of theanine in matcha help control the caffeine ‘hit’ and provide a more sustained energy boost for a longer period of time.” (Mintel). Additionally, and perhaps most importantly, a 2009 study indicated that L-theanine may “help in the prevention and treatment of Alzheimer’s disease.”

Nutrient profile of matcha powder from Matcha Source

The process of harvesting and creating matcha makes the final product much stronger than traditional tea blends. The elevated caffeine levels and powerful vitamin, mineral, and antioxidant component has made this “ingredient” into a very popular product.

The food and drink industry has responded to the many recognized health benefits of matcha tea. According to Mintel market research, “the number of global food and drink launches containing matcha has more than doubled between 2012 and 2014.” And it continues to climb— making matcha more and more mainstream. In the U.S., matcha lattes are available at almost every coffee and tea chain, including Starbucks and Coffee Bean & Tea Leaf. In Asia, you can even find matcha in Kit-Kat and Crunch bars! But be wary, while these candy bars and latte’s may be tasty, they are often packed with sugar and do not provide the same health benefits as a pure matcha powder.

And while tea is certainly good for you, there are two things to be aware of with regards to matcha products:

  1. Caffeine
  2. False marketing claims

Source: Spoonacular

A single serving (8oz) of matcha tea as roughly 70mg of caffeine, whereas the average green tea has roughly 25mg per 8oz serving. Black tea has more caffeine than green tea with roughly 45mg per serving. However, an 8oz Starbucks (“tall”) contains roughly 165 mg of caffeine.

3 cups of green tea = 2 cups of black tea =
1 matcha latte = 1/2 cup of coffee

But if you are adding the additional caffeine into your routine, could you be negatively affecting your health?

As with all foods, the negative effects of overconsumption does exist— even with green tea. In a 2005 study on hamsters, researchers found that a high consumption of green tea negatively affected the animal’s liver.

According to the 2005 literature review, “green tea should not be taken by patients suffering from heart conditions or major cardiovascular problems.” Additionally, the U.S. Dietary Guidelines recommends no more than 300-400 milligrams of caffeine per day.  Keep in mind, caffeine is a drug and its intake should be carefully monitored. Meaning, if you are already a coffee drinker, you might want to use discretion when adding matcha to your diet.

Essentially, you have to be a mindful consumer. Every diet is individualistic, and while matcha is a good source of antioxidants, amino acids, vitamins and minerals, if you are sensitive to caffeine or you suffer from a heart condition, consume matcha with caution.

As matcha becomes more mainstream, food processing companies will use its understood health value to sell products that might not be as healthy as you may think. For example, the average matcha latte has anywhere from 18-26 grams of sugar. As matcha’s health benefits become yet another marketing claim, it is important to make sure you are putting the cleanest form of this product into your body.

To that end, some recent studies found that metals, such as aluminum and lead, as well as pesticides can be found in tea. The literature review of green tea also noted the “presence of aluminum” as one of the harmful effects of tea overconsumption. Moreover, if there are contaminants in the soil, they can be present on the tea leaves as well. This is particularly concerning with matcha as you are consuming the leaf itself. With green tea, for example, steeping the leaves helps filter the metal from the leaf. If there is pesticide residue on the leaf, your body is directly ingesting it. So, when buying your matcha, make sure you are confident in the farming practices of the supplier.