What are polyphenols?
Polyphenols are micronutrients that we get through certain plant-based foods. They’re packed with antioxidants and potential health benefits. It’s thought that polyphenols can improve or help treat digestion issues, weight management difficulties, diabetes, neurodegenerative disease, and cardiovascular diseases.
You can get polyphenols by eating foods containing them. You can also take supplements, which come in powder and capsule forms.
Polyphenols may have several unwanted side effects, however. These are most common when taking polyphenol supplements instead of getting them naturally through food. The most common side effect with the strongest scientific evidence is the potential for polyphenols to interfere with or limit iron absorption.
Factors that influence activity of polyphenols in the body include metabolism, intestinal absorption, and the bioavailability of the polyphenol. Although some foods may have higher polyphenol levels than others, this does not necessarily mean that they are absorbed and used at higher rates.
Read on to learn the polyphenol content of many foods. Unless otherwise stated, all numbers are given in milligrams (mg) per 100 grams (g) of food.
1. Cloves and other seasonings
In a 2010 study that identified the 100 foods richest in polyphenols, cloves came out on top. Cloves had a total of 15,188 mg polyphenols per 100 g of cloves. There were a number of other seasonings with high rankings, too. These included dried peppermint, which ranked second with 11,960 mg polyphenols, and star anise, which came in third with 5,460 mg.
2. Cocoa powder and dark chocolate
Cocoa powder was the fourth richest polyphenol food identified, with 3,448 mg polyphenols per 100 g of the powder. It’s not a surprise that dark chocolate fell close behind on the list and was ranked eighth with 1,664 mg. Milk chocolate is also on the list, but due to its lower cocoa content, falls much further down the list at number 32.
A number of different types of berries are rich in polyphenols. These include popular and easily accessible berries like:
- highbush blueberries, with 560 mg polyphenols
- blackberries, with 260 mg polyphenols
- strawberries, with 235 mg polyphenols
- red raspberries, with 215 mg polyphenols
The berry with the most polyphenols? Black chokeberry, which has more than 1,700 mg polyphenols per 100 g.
4. Non-berry fruits
Berries aren’t the only fruits with plenty of polyphenols. According to the American Journal of Clinical Nutrition, a large number of fruits contain high numbers of polyphenols. These include:
- black currants, with 758 mg polyphenols
- plums, with 377 mg polyphenols
- sweet cherries, with 274 mg polyphenols
- apples, with 136 mg polyphenols
Fruit juices like apple juice and pomegranate juice also contain high numbers of this micronutrient.
Beans contain a large number of nutritional benefits, so it’s no surprise that they naturally have hefty doses of polyphenols. Black beans and white beans in particular have the highest number of polyphenols. Black beans have 59 mg per 100 g, and white beans have 51 mg.
Nuts can be high in caloric value, but they pack a powerful nutritional punch. Not only are they full of protein; some nuts also have high polyphenol content.
One 2012 study found significant levels of polyphenols in a number of both raw and roasted nuts. Nuts high in polyphenols include:
- hazelnuts, with 495 mg polyphenols
- walnuts, with 28 mg polyphenols
- almonds, with 187 mg polyphenols
- pecans, with 493 mg polyphenols
There are many vegetables that contain polyphenols, though they usually have less than fruit. Vegetables with high numbers of polyphenols include:
- artichokes, with 260 mg polyphenols
- chicory, with 166–235 mg polyphenols
- red onions, with 168 mg polyphenols
- spinach, with 119 mg polyphenols
Soy, in all its various forms and stages, contains large numbers of this valuable micronutrient. These forms include:
- soy tempeh, with 148 mg polyphenols
- soy flour, with 466 mg polyphenols
- tofu, with 42 mg polyphenols
- soy yogurt, with 84 mg polyphenols
- soybean sprouts, with 15 mg polyphenols
9. Black and green tea
Want to shake it up? In addition to high-fiber fruits, nuts, and vegetables, black and green teas both contain ample amounts of polyphenols. Black tea clocks in with 102 mg polyphenols per 100 milliliters (mL), and green tea has 89 mg.
10. Red wine
Many people drink a glass of red wine every night for the antioxidants. The high number of polyphenols in red wine contributes to that antioxidant count. Red wine has a total of 101 mg polyphenols per 100 mL. Rosé and white wine, while not as beneficial, still have a decent chunk of polyphenols, with 100 mL of each having about 10 mg polyphenols.
Potential risks and complications
There are some risks and complications associated with polyphenols. These seem to be most heavily associated with taking polyphenol supplements. More research is needed to evaluate the actual risk of these complications, which include:
- carcinogenic effects
- thyroid issues
- estrogenic activity in isoflavones
- interactions with other prescription medications
Polyphenols are powerful micronutrients that our body needs. They have numerous health benefits that may offer protection from the development of cancers, cardiovascular disease, osteoporosis, and diabetes. It’s best to consume polyphenols through foods naturally containing them, instead of through artificially made supplements, which may come with more side effects. If you take supplements, make sure they are made from a reputable company with high quality sourcing.