With increasing pollutants and obesogens constantly around us, antioxidants have been gaining more and more popularity in the health space. This group of nutrients is known for fighting off the negative effects of toxins and other harmful molecules, and can also help prevent cell damage.
Out of hundreds of different types of antioxidants, polyphenols and tannins are two that are known to be particularly potent and effective. While these two compounds have some similarities, they have different functions in the body, so it’s important to understand why each one is beneficial.
In this article, we’ll break down the differences between the two and let you know the best way to add these nutrients to your diet to reap the benefits for your overall health.
We already know that antioxidants help protect against harmful chemicals. But how do they work exactly?
Antioxidants get their name from their ability to reduce levels of harmful molecules called free radicals. One commonly known type of free radical is called reactive oxygen species. These molecules are unstable oxygen based compounds and can wreak within the body by throwing your body’s natural processes off balance.
When there are high levels of these unstable compounds (or molecules) in the body, a state of increased oxidative stress is created. While some stress can be good in some situations, this type of reaction can lead to negative health consequences like:
This is where antioxidants come in, helping to fight these free radicals and reduce oxidative stress.
Since polyphenols and tannins are both antioxidants, they each have the ability to reduce oxidative stress. However, each compound has a unique role and are only found in certain types of food.
Polyphenols are organic compounds that are found in fruits and vegetables that have a variety of health benefits in humans. Some in vitro research shows that polyphenols may help prevent chronic diseases, reduce the risk of cardiovascular conditions, and can support metabolic health.
Polyphenols can exist as simple molecules called monomers or oligomers, or can be polymers, which are long, repeating chains of molecules. These compounds can also be classified as micronutrients (which are known to have antioxidant properties) and are also a type of phenolic compound.
In order to be characterized within a group of antioxidants, a molecule has to have a specific chemical structure. In the case of polyphenols, the antioxidant molecule is made up of two phenyl rings, and these rings have to have at least one group of oxygen bonded to hydrogen.
Polyphenols are specifically referred to as phytochemicals (chemicals produced by plants), and within this group of phytochemical antioxidants, there are subtypes of polyphenols with unique benefits.
There are several subtypes of polyphenols, including:
Some polyphenols can also be enzymes such as polyphenol oxidase.
The benefits of polyphenols as a group are extensive, but here are some of the most commonly known health benefits of this antioxidant group:
Polyphenols are abundant in fruits and vegetables, and are also found in certain drinks. Here’s where you can find plant polyphenols to add to your diet:
Tannins are a type of polyphenol found all throughout the plant kingdom, including in plants such as willow trees, maple, eucalyptus, and red mangroves. These compounds form part of the flavonoid group of polyphenols.
There are two main types of tannins, which can be classified into hydrolyzable tannins and condensed tannins (or proanthocyanidins). These compounds are made up of multiple ring groups that are similar to gallic acid derivatives (like gallotannins), and like all other polyphenols, they have potent antioxidant properties.
Tannins have been used in medicine due to their astringent properties (or bitter taste), as well as during the fermentation process in wine and beer production. For example, both red wine and white wine contain tannins which come from grape skins and seeds and affect the wine’s color and mouthfeel.
Tannins are known to have a high molecular weight, and can precipitate proteins by forming large complexes (which help to give the alcohol its color). These compounds can even be found in the form of tannic acid, which is commonly used to stain woods and dye cotton.
Tannins provide health benefits such as faster blood clotting, lower risk of cardiovascular disease and certain cancers, lower blood pressure, and helping protect against microbial infections in humans. Other positive effects of tannins include:
Although these compounds have shown promising health benefits, they shouldn’t replace any medications. Always consult with your health practitioner before trying any dietary supplement as a therapeutic alternative to medication.
Tannins give plants a bitter, sour taste which derives from their astringency. This taste acts as a defense mechanism for plants, as it prevents them from being eaten too early by bugs and bees. For example, unripened fruits are high in this phytochemical antioxidant.
Here are some edible plant sources that have a high tannin content:
Let’s review what we’ve discussed about the unique roles and qualities of polyphenols and tannins:
While antioxidants can be incredibly beneficial for health, they’re not always helpful. In fact, there are some situations in which antioxidants can have negative effects on your health.
Tannins have what is called an anti-nutritional effect, which means this antioxidant can reduce digestion and bioavailability of nutrients such as iron. If you’re on an iron supplement or have anemia, you may want to consult with your doctor before adding large amounts of tannins through your diet or supplements.
Some polyphenols may interact with certain pharmaceutical agents or medicines so it's important to consider how much of these foods are being included in your diet.
Tannins can also produce liver necrosis in large amounts, while high amounts of specific polyphenols such as catechins can lead to hepatotoxicity. A 2014 report citing only 20% of liver injuries being due to polyphenol intake.
Overall, it seems that the dosage (or amount) of polyphenols, whether that be tannins specifically or another subgroup, as well as the type of phytochemical is key in whether that compound will lead to an adverse reaction.
Your diet can significantly impact your overall health, quality of life, and risk for developing chronic diseases, so making the right dietary choices for your body is crucial. Phytochemical antioxidants such as polyphenols can help improve blood glucose levels by altering how your body responds to carbohydrates and improving glycemic control.
Using a continuous glucose monitor (CGM) from the NutriSense program is a great way to take a deeper look at how different sources of polyphenols affect your blood sugar and overall health. You’ll be able to access 24/7 data right inside the NutriSense app on how your glucose levels change as you incorporate antioxidants into your diet.
As a NutriSense member, you can also work with a personal dietitian to discuss your health goals and create an individual diet plan to support your unique needs.
See how NutriSense can help you improve your nutrition and stay on top of your health today.