Health Benefits of Polyphenols, Types and Major Food Sources

Polyphenols are a large group of nutrients found naturally in various plant foods, such as herbs, spices, fruits, vegetables, chocolate, cocoa, and even beverages such as coffee, hot chocolate, tea and wine.

They have renowned health benefits. They function as powerful antioxidants, which means they can act to neutralize harmful free radicals that would otherwise damage your cells and organs. Free radicals in your body increase your risks of conditions such as diabetes, cancer and heart disease.

Polyphenols have a number of other health benefits, particularly reducing inflammation and repairing damaged skin. Regular consumption of polyphenols in your diet is known to aid digestion and improve brain health.

This article reviews everything there is to know about polyphenols: the various types, their health benefits and foods with the highest natural levels.

 Types of Polyphenols
Types of Polyphenols. Source: Pixabay Free Images; Public Domain

Types of polyphenols

Over 7,000 types of polyphenols have been identified. They can be grouped and categorized into four main types:

Flavonoids - These account for around 60% of all polyphenols. Examples include quercetin, catechins, kaempferol and anthocyanins. These types of compounds which are found in foods like onions, dark chocolate, apples and red cabbage.

Phenolic acids - This group accounts for around 30% of all polyphenols. Examples include lignans and stilbenes, which are commonly found in vegetables, fruits, seeds and whole grains.

Polyphenolic amides - This group includes the capsaicinoids, which are found in chili peppers. Another type is avenanthramides, which is found in oats and other grains.

Other polyphenols - This large and diverse group includes resveratrol, which is found in red wine. Another type is ellagic acid, which is found in berries. Curcumin is found in in turmeric. Then there is the lignans which are found in flax seeds, some whole grains and sesame seeds.

The quantity and type of polyphenols found in foods depend on the food substance. Factors which affect polyphenols id food include origin and source, ripeness, and how the food was grown, how it was transported, stored, and prepared and cooked.

 Types of Polyphenols in various food
Types of Polyphenols in various foods. Source: Pixabay Free Images; Public Domain

Effects of Cooking on Polyphenols

Detailed research studies on the affects of various types of cooking show that the total amount of carotenoids, polyphenols and overall antioxidant capacity in green leafy vegetables were significantly reduced by common cooking method. Boiling, steaming, and frying all affected the polyphenol levels. Frying was found to reduces the levels of flavonoids, polyphenols, carotenoids, and antioxidant activities in all leafy vegetables studied. However, boiling and steaming had  varying effects on the carotenoids, polyphenols and antioxidant properties, depending on the leafy green vegetable type. In some vegetables boiling and steaming increased the levels possibly by breaking cell walls so that the contents were more available.  

Effects of cooking on polyphenols in 4 green vegetables compared amounts in with fresh leaves
Effects of cooking on polyphenols in 4 green vegetables compared amounts in with fresh leaves. Source: Pixabay Free Images; Public Domain
Effects of cooking methods on polyphenols in vegetables. Note: does not include frying that reduces levels substantially
Effects of cooking methods on polyphenols in vegetables. Note: does not include frying that reduces levels substantially. Source: Pixabay Free Images; Public Domain

Health Benefits of Polyphenols

Helps lower blood sugar levels - Polyphenols have been shown to help lower blood sugar levels, and may also help stimulate the secretion of insulin to help keep your blood sugar levels in equilibrium.

Helps reduce the risk of heart disease - Studies have shown that this benefit largely due to the antioxidant properties of polyphenols, which help reduce chronic inflammation, which is a risk factor for heart disease.

Helps reduce the risk of blood clots - In animal studies, polyphenols appeared to reduce the platelet aggregation process, thereby reducing the risk of forming blood clots.

May help protect against cancer - Polyphenols have strong anti-inflammatory and antioxidant effects, both of which help in cancer prevention

Improves digestion and gut health - Polyphenols improve digestion by promoting the growth of beneficial gut bacteria. Polyphenols also help probiotic processing bacteria to thrive and survive. These bacteria occur in fermented foods and help provide their health benefits.

May improve brain function - Various studies have shown that eating Polyphenol-rich foods may boost memory and improve the blood flow to the brain. Extracts from Ginkgo biloba and cocoa, which are rich in polyphenols, have been shown to boost memory, learning, and concentration.

Foods Rich in Polyphenols

A definitive study in 2010 identified the top 100 foods richest in polyphenols and antioxidants.

The table below show the foods in various categories that had the highest levels in terms of mg of polyphenols per 100 g serving. Below that table is another one that lists the top 100 foods containing antioxidants.

Herbs and Seasonings

Cloves had the highest level or any food, with a total of 15,188 mg polyphenols per 100 g. Many other dried herbs had amongst the highest levels. Dried peppermint, ranked second with 11,960 mg polyphenols. Star anise, ranked third with 5,460 mg.

The top 10 highest ranking herbs and seasonings are:

Cloves => 15,188 mg
Peppermint, dried 11,960 mg
Star anise => 5,460 mg
Mexican oregano, dried => 2,319 mg
Celery seed => 2,094 mg
Common sage, dried => 1,207 mg
Rosemary, dried => 1,018 mg
Spearmint, dried => 956 mg
Common thyme, dried => 878 mg
Capers => 654 mg
Sweet basil, dried 322 mg

Cocoa Products and Chocolate

Cocoa powder was the fourth richest food identified, with 3,448 mg polyphenols per 100 g of the powder. Dark and milk chocolate are rich sources of polyphenols. Hot chocolate was one of the highest beverages with polyphenols.

The top 3 Cocoa Products were:

Cocoa powder => 3,448 mg
Dark chocolate => 1,664 mg
Milk chocolate => 236 mg


Many berries are rich in polyphenols. These include popular and easily available berries:

Black chokeberry => 1,756 mg
Black elderberry => 1,359 mg
Low bush blueberry => 836 mg
Blackcurrant => 758 mg
High bush blueberry => 560 mg
Blackberry => 260 mg
Strawberry => 235 mg
Red raspberry => 215 mg

Non-Berry Fruits

A large number of fruits contain moderate level polyphenols, less than most berries, but more than most vegetables. These include:

Black currants, => 758 mg
Plums => 377 mg
Sweet cherries => 274 mg
Apples, => 136 mg

Fruit juices such as pomegranate and apple juice also contain high levels of polyphenols per 100 ml.

Pure apple juice => 68 mg
Pure pomegranate juice => 66 mg
Pure blood orange juice => 56 mg
Pure grapefruit juice => 53 mg
Pure blond orange juice => 46 mg

Beans and Soybean Products

Beans and soybeans are naturally rich in polyphenols. The top 7 products are:

Roasted soybean => 246 mg
Soy, tempeh => 148 mg
Soy yogurt => 84 mg
Soy meat => 73 mg
Black bean => 59 mg
White bean => 51 mg
Soy tofu => 42 mg


A wide range of nuts have moderate levels of polyphenols in both raw and roasted nuts. The top 5 ranking nuts are:

Chestnut => 1,215 mg
Hazelnut => 495 mg
Pecan nut => 493 mg
Almond => 187 mg
Walnut => 28 mg


Many vegetables that contain polyphenols. However, vegetables generally have less than nuts and fruit. The top 12 ranking vegetables are:

Black olive => 569 mg
Green olive => 346 mg
Globe artichoke heads => 260 mg
Red chicory => 235 mg
Red onion => 168 mg
Green chicory => 166 mg
Spinach => 119 mg
Shallot => 113 mg
Yellow onion => 74 mg
Broccoli => 45 mg
Asparagus => 29 mg
Potato => 28 mg

Soy and Soy Products

Soy, in all its various forms and products, contains moderate levels of polyphenols:

Soy tempeh => 148 mg
Soy flour => 466 mg
Tofu => 42 mg
Soy yogurt => 84 mg
Soybean sprouts => 15 mg

Coffee, Black and Green tea, Wine and Other Beverages

Many beverages are a good source of polyphenols. Amounts are shown for a 100 ml serving.

Coffee, filter => 214 mg
Black tea => 102 mg
Red wine => 101 mg
Green tea => 89 mg
Chocolate beverage => 21 mg
Soy milk => 18 mg
White wine => 10 mg
Rose wine => 10 mg

Grains and Cereals

Grains and cereals have moderate to low levels of polyphenols

Whole wheat flour => 201 mg
Refined maize flour => 153 mg
Whole rye flour grain => 143 mg
Refined rye flour => 31 mg

Common Seeds

Many seeds have moderate levels of polyphenols

Flaxseed meal => 1,528 mg
Sunflower seeds => 1,400 mg
Pistachios => 642 mg
Peanuts => 460 mg
Pumpkin seeds => 149 mg
Soybean sprout => 15 mg
Soy cheese => 12 mg

Table 1. Foods with Highest Total Polyphenols per 100 g serving, Grouped by Food Type

Food Group Polyphenols
Coffee, filter Beverages 214
Black tea Beverages 102
Red wine Beverages 101
Green tea Beverages 89
Pure apple Beverages 68
Pure pomegranate Beverages 66
Pure blood orange juice Beverages 56
Pure grapefruit Beverages 53
Pure blond orange juice Beverages 46
Pure lemon Beverages 42
Chocolate beverage Beverages 21
Soy milk Beverages 18
Pure pummelo juice Beverages 18
White wine Beverages 10
Rose´ wine Beverages 10
Whole wheat flour Cereals 201
Refined maize flour Cereals 153
Whole rye flour grain Cereals 143
Whole wheat flour Cereals 71
Refined rye flour Cereals 31
Cocoa powder Cocoa products 3448
Dark chocolate Cocoa products 1664
Milk chocolate Cocoa products 236
Black chokeberry Fruits 1756
Black elderberry Fruits 1359
Low bush blueberry Fruits 836
Blackcurrant Fruits 758
High bush blueberry Fruits 560
Plum Fruits 377
Sweet cherry Fruits 274
Blackberry Fruits 260
Strawberry Fruits 235
Red raspberry Fruits 215
Prune Fruits 194
Black grape Fruits 169
Apple Fruits 136
Peach Fruits 59
Redcurrant Fruits 43
Apricot Fruits 34
Nectarine Fruits 25
Quince Fruits 19
Pear Fruits 17
Green grape Fruits 15
Extra-virgin olive oil Oils 62
Rapeseed oil Oils 17
Cloves Seasonings 15188
Peppermint, dried Seasonings 11960
Star anise Seasonings 5460
Mexican oregano, dried Seasonings 2319
Celery seed Seasonings 2094
Common sage, dried Seasonings 1207
Rosemary, dried Seasonings 1018
Spearmint, dried Seasonings 956
Common thyme, dried Seasonings 878
Capers Seasonings 654
Sweet basil, dried Seasonings 322
Curry, powder Seasonings 285
Ginger, dried Seasonings 202
Common thyme, fresh Seasonings 163
Lemon verbena, dried Seasonings 106
Cumin Seasonings 55
Chinese cinnamon Seasonings 48
Caraway Seasonings 33
Ceylan cinnamon Seasonings 27
Parsley, dried Seasonings 25
Marjoram, dried Seasonings 23
Vinegar Seasonings 13
Flaxseed meal Seeds 1528
Chestnut Seeds 1215
Hazelnut Seeds 495
Pecan nut Seeds 493
Soy flour Seeds 466
Roasted soybean Seeds 246
Almond Seeds 187
Soy, tempeh Seeds 148
Soy yogurt Seeds 84
Soy meat Seeds 73
Black bean Seeds 59
White bean Seeds 51
Soy tofu Seeds 42
Walnut Seeds 28
Soybean sprout Seeds 15
Soy cheese Seeds 12
Black olive Vegetables 569
Green olive Vegetables 346
Globe artichoke heads Vegetables 260
Red chicory Vegetables 235
Red onion Vegetables 168
Green chicory Vegetables 166
Spinach Vegetables 119
Shallot Vegetables 113
Yellow onion Vegetables 74
Broccoli Vegetables 45
Asparagus Vegetables 29
Potato Vegetables 28
Curly endive Vegetables 24
Red lettuce Vegetables 23
Endive (Escarole) Vegetables 18
Carrot Vegetables 14

Table 2. Foods with Highest Antioxidants per 100 g serving, Grouped by Food Type

Food Group Antioxidants
Coffee, filter Beverages 267
Red wine Beverages 215
Pure pomegranate Beverages 204
Black tea Beverages 104
Rose´ wine Beverages 82
Pure blood orange juice Beverages 72
Green tea Beverages 62
Pure grapefruit Beverages 54
Pure apple Beverages 34
White wine Beverages 32
Whole wheat flour Cereals 186
Refined maize flour Cereals 102
Whole wheat flour Cereals 90
Whole rye flour grain Cereals 72
Refined rye flour Cereals 45
Dark chocolate Cocoa products 1860
Cocoa powder Cocoa products 1104
Milk chocolate Cocoa products 854
Black elderberry Fruits 1950
Black chokeberry Fruits 1752
Prune Fruits 1195
Red raspberry Fruits 980
Blackcurrant Fruits 821
Blackberry Fruits 570
Lowbush blueberry Fruits 471
Redcurrant Fruits 448
Plum Fruits 411
Strawberry Fruits 268
Highbush blueberry Fruits 205
Black grape Fruits 205
Apple Fruits 205
Sweet cherry Fruits 144
Apricot Fruits 133
Green grape Fruits 122
Pear Fruits 108
Peach Fruits 107
Nectarine Fruits 55
Extra-virgin olive oil Oils 55
Rapeseed oil Oils 18
Cloves Seasonings 16047
Ceylan cinnamon Seasonings 9070
Spearmint, dried Seasonings 6575
Mexican oregano, dried Seasonings 5452
Sweet basil, dried Seasonings 4317
Marjoram, dried Seasonings 3846
Capers Seasonings 3600
Common sage, dried Seasonings 2920
Caraway Seasonings 2913
Rosemary, dried Seasonings 2519
Cumin Seasonings 2038
Common thyme, dried Seasonings 1815
Star anise Seasonings 1810
Parsley, dried Seasonings 1584
Common thyme, fresh Seasonings 1173
Curry, powder Seasonings 1075
Peppermint, dried Seasonings 980
Ginger, dried Seasonings 473
Chestnut Seeds 2757
Pecan nut Seeds 1816
Walnut Seeds 1576
Black bean Seeds 1390
Hazelnut Seeds 687
Almond Seeds 191
White bean Seeds 138
Globe artichoke heads Vegetables 1142
Spinach Vegetables 248
Broccoli Vegetables 198
Green olive Vegetables 161
Red chicory Vegetables 129
Black olive Vegetables 117
Shallot Vegetables 115
Red lettuce Vegetables 114
Red onion Vegetables 91
Yellow onion Vegetables 75
Asparagus Vegetables 75
Carrot Vegetables 58
Potato Vegetables 54