Polyphenols are yet another class of compounds that’s become popular. They’re micronutrients, ones that can decrease disease risk and improve health.
There are also many examples of foods high in polyphenols. Some of them may already be a regular part of your diet. Others are great additions that you can try.
In this post, we’re looking at what polyphenols are and how you can get the most benefits from them.
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What are Polyphenols?
The term polyphenols refers to a structural class of compounds.
- There are more than 8,000 individual polyphenols in this class (1).
- They’re present in many different plants and plant-based foods. Polyphenols are often produced to help defend plants.
- Their distinguishing feature is the presence of multiple phenol structures.
- Foods contain a complex mixture of different polyphenols.
- Some types of polyphenols are found in specific foods (e.g., flavanones are present in citrus fruit), while other types are present across multiple types of food.
There are multiple subgroups of polyphenols, including the following:
- Flavonoids. These are common in many plants. They have antioxidant and anti-inflammatory functions. The subgroup also includes anthocyanidins, flavones and flavanols. Flavanols are often discussed, partly because of cocoa flavanols and their implications for health.
- Phenolic acids. These include hydroxybenzoic acids and hydroxycinnamic acids. The former is common in tea, while the latter is found in cinnamon, along with coffee, apples, cherries and some other fruit.
- Stilbenes (like resveratrol). These are most common in peanuts and in red wine.
- Lignans. These are found in seeds and in various grains. They’re also present in red wine, although the levels are much lower.
Each of these subgroups contains many individual compounds, which all play different roles in the body. For example, anthocyanins have been linked to improved cognitive function, decreased heart disease risk and lower inflammation.
Health Benefits of Polyphenols
The term polyphenols covers a very large group of compounds – and research is still examining their exact impacts. In many cases, we know that benefits exist but it’s not clear exactly which compound is causing them. The strength of the effect is often unclear too.
Nevertheless, many advantages and functions have been linked to polyphenols (2), including the following:
- Antioxidants. This role has been linked to many possible health benefits, such as decreasing inflammation and lowering oxidative stress. By doing so, antioxidants may be able to decrease the risk of many diseases.
- Type 2 Diabetes. Polyphenols don’t treat diabetes directly. However, they have been shown to decrease insulin resistance and help stabilize blood sugar (3,4). These effects could improve diabetes management and may even reduce the risk of diabetes.
- Heart Disease. High polyphenol intake has been linked to decreased heart disease risk (5,6). The effect is connected to reducing platelet clumping and decreasing vascular endothelial growth factor (7,8,9).
- Improved Gut Health. Polyphenols may also impact the bacteria in your gut, increasing the levels of good bacteria. Research has focused on the effects of green tea, although chocolate and red wine have been considered as well (10,11,12,13). This is a topic that Mercola considers in more detail.
- Cancer. The antioxidant impacts of polyphenols may decrease cancer risk – as antioxidants protect against free radical damage (14,15,16).
- Neuroprotection. Polyphenols may have neuroprotective effects. This includes reducing the risk of Alzheimer’s disease and delaying its onset (17,18).
- Osteoporosis. Polyphenols may also help decrease the risk of osteoporosis (19).
There are other benefits too, along with much more research. But, this evidence is more than enough to show that polyphenols are good for you. Besides, many polyphenol-rich foods taste great.
Foods High in Polyphenols – Your Best Choices
Polyphenols can be found in many different foods. But, we’re not focusing on all of them. This list looks at the most powerful options for your diet.
These are the foods that offer many other nutrients and plant-based compounds that can promote health – along with ones that have a good combination of polyphenols.
We’re also emphasizing foods that are realistic sources of polyphenols – ones that you can include in your diet each day.
Berries are already well-known as a source of polyphenols. Blackberries, strawberries and raspberries are all particularly powerful choices.
The darker berries (like blackberries and black raspberries) tend to be higher in anthocyanins. Lighter ones are still significant for polyphenols, they just have a different distribution of types.
This means you can include any berries in your diet, including common and obscure ones. In fact, black chokeberries are particularly high in polyphenols (20) – although they won’t always be practical.
Red and white onions both contain polyphenols, although the levels are higher for red onions (21). Red onions are also a source of anthocyanins.
In both cases, there are more polyphenols in the outer layers. This suggests that you shouldn’t peel any more of the onion than you need to.
Dark Chocolate and Cocoa
Cocoa powder is also a powerful polyphenol source – which means that dark chocolate is as well. This isn’t surprising, as the flavanols in dark chocolate have been associated with many health benefits.
Because the compounds come from cocoa powder, chocolate with a higher cocoa percentage will offer more polyphenols. At least 70% cocoa/cacao is the best place to start – but the higher the better.
For cocoa itself, you need to look for brands with no added sugar or other ingredients. You could also consider products like CocoaVia, which focus on maximizing the healthy compounds.
You will still get some polyphenols in less concentrated chocolate – including low cocoa percentages and milk chocolate (but not white chocolate!). However, those types contain much more sugar and aren’t nearly as powerful.
Nuts are popular for their protein content and they’re a good source of healthy fats. But, some also contain polyphenols. The most significant examples are hazelnuts, pecans, walnuts and almonds.
The compounds are present in roasted and unroasted nuts (22), so you can choose whichever style you prefer.
Soy is another interesting source of polyphenols. This includes all forms of soy, like tempeh, soy flour, tofu and soy yogurt.
As Precision Nutrition points out, soy is highly controversial. It was once promoted as extremely healthy and some people still have that opinion. Others feel that it is risky and could even damage health.
But, either way, soy does offer polyphenols. This is valuable for anyone who does consume soy regularly.
Another powerful option is olive oil. The oil is a good addition to your diet anyway – offering various benefits. It also makes a healthy alternative to options like canola oil (Be Brain Fit explains why canola oil is so bad).
As always, it’s best to buy extra virgin olive oil, if you can. This type is created from the first pressing of olives and can contain more compounds from olives as a result.
Coffee contains many healthy compounds. It’s even been shown to lengthen life. Polyphenols are another reason to drink coffee regularly.
The polyphenols are partly why coffee is a good source of antioxidants. In fact, coffee is one of the most prolific sources of antioxidants. Many foods contain more antioxidants (such as berries). But, as a population, we consume more coffee than most other antioxidant-rich foods.
You can safely add milk to coffee without affecting antioxidant activity (23). However, non-dairy creamer and sugar can decrease the availability of some compounds.
Red and white wine both contain polyphenols. However, red wine has more polyphenols – as it is made from the whole grape (24).
Red wine is also famous for the polyphenol resveratrol. The site Self Hacked highlights the many benefits this compound offers and why it is so important.
This doesn’t mean you have to ignore white wine completely. As Livestrong explains, research shows that the antioxidant effects of red and white wine are often similar (despite the differences in polyphenol numbers).
On average, tea, coffee and wine contain around 100 mg per cup or glass (27), which is lower than many fruits. But, these are still good sources, especially if you drink multiple cups of tea or coffee per day.
Flaxseed meal is often used as a type of low carb flour and is another source of polyphenols. Flaxseed is especially good as a source of lignans, which offer various health benefits (28).
Other Sources of Polyphenols
Of course, many other foods contain polyphenols as well, including this list:
- Spices. Rosemary, oregano, peppermint, sage, spearmint, thyme, curry powder, ginger, cinnamon, cumin, vanilla, cloves, celery seed, basil and saffron.
- Other Vegetables. Artichokes, olives, red cabbage, sweet potatoes, broccoli and asparagus.
- Seeds and Legumes. Roasted soybeans, peanuts, chickpeas, snap beans, white beans and black beans.
- Grains. Rye, oat and wheat flour.
As a general rule, these foods are less powerful. Some contain lower levels of polyphenols, while others are less practical in your diet. For example, you’re not going to consume excessive amounts of various spices.
Even so, these sources are still relevant. They are all foods you can add to your diet and can promote health too, even if the levels of polyphenols are lower.
What About the Polyphenol Levels?
We’ve avoided talking about the exact number of polyphenols in the foods because that simply isn’t relevant.
- Polyphenols are a large class of compounds and they don’t all have the same impacts. Polyphenol levels ignore these differences and assume that higher numbers are always healthier.
- Levels are influenced by many factors, including testing and the exact product. For example, two varieties of apples may have different levels of polyphenols. The same is true for apples grown in different locations and even in different seasons.
- More isn’t necessarily better. Some foods with lower levels may have higher antioxidant function.
- Retention and use vary. Our bodies respond to polyphenols in different ways. The specific polyphenols consumed may be more relevant than the total polyphenol levels.
You shouldn’t try to maximize polyphenol levels anyway. Instead, the goal is to include them regularly in your diet – from a wide variety of sources. This gives you access to the largest range of polyphenol types, along with other nutrients.
However, if you do like focusing on numbers, the FDA has improved labeling requirements. As a result, polyphenol claims on product labels should be more accurate (29).
The site Phenol Explorer also offers a comprehensive database on current polyphenol figures. Their information even includes some details about polyphenol retention.
What’s the Ideal Dose?
Polyphenols aren’t essential nutrients. We don’t need them to survive. So, there is no recommended daily dose. With so many different compounds, an ideal dose isn’t realistic anyway.
Even if you found a recommended dose, this wouldn’t be a practical way to increase your polyphenol intake. The types of polyphenols that you’re getting are much more relevant than the numerical dose.
The best way to promote health is a diet that heavily relies on plants and on whole foods. This doesn’t mean you have to be a vegetarian or vegan (meat has its own benefits anyway) but you should include many different types of fruit and vegetables in your diet regularly.
Relying on a diversity of food gives you access to many different types of phytochemicals. Doing that is critical for health. After all, the combination of compounds varies dramatically from one food to the next.
Some people don’t do this. Instead, they might get stuck on the idea of superfoods – such as kale. Most of the superfoods are beneficial in their own right. But, if you focus on these and use the same selection in everything, you’re getting more of some nutrients and much less of others. Relying on just a few foods isn’t nearly as powerful for health.
Besides, many of these polyphenol-containing foods are easy to include in your diet.
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