Polyphenols: what they are, which foods contain them and what the evidence says

What are polyphenols and what are their main groups?

Polyphenols are a broad group of substances produced by plants. Phenol-Explorer brings together published measurements of their content in many different foods [1]. They are not a vitamin or an essential nutrient with a required daily intake.

Flavonoids include anthocyanins, which give many berries their colour, and the flavanols found in cocoa. Phenolic acids occur in foods including coffee [1].

Stilbenes are a less abundant group in the usual diet. Lignans are found in some seeds and nuts [1]. These groups help organise the terminology; they do not, by themselves, predict a health benefit.

Which foods contain polyphenols?

The Phenol-Explorer database records compounds in plant foods [1]. This table is for guidance. The actual amount varies by variety and preparation. You also cannot add up the figures in the table to calculate a “healthy dose”.

Group	Easy-to-use examples	Common groups
Berries	Blueberries, strawberries, blackberries and raspberries	Anthocyanins and other flavonoids
Cocoa	Unsweetened cocoa and dark chocolate	Flavanols
Tea	Green or black tea	Catechins and other flavonoids
Coffee	Black coffee or coffee with milk	Phenolic acids
Extra-virgin olive oil	For dressings or everyday cooking	Oil phenols
Pulses	Lentils, beans and chickpeas	Different groups depending on the variety
Nuts and seeds	Walnuts, hazelnuts and linseeds	Flavonoids and lignans
Spices and herbs	Cinnamon, cloves and oregano	Different polyphenols; used in small amounts

Tea catechins raise specific questions about caffeine and safety. We cover them in our tea guide.

What does the evidence say about polyphenols?

Population studies find an association between higher polyphenol intake and lower mortality [2]. These are observational data. People who eat more of these foods may also have other health-supporting habits. The finding does not prove that an isolated substance prevents disease.

The European Union has authorised health claims for products that meet specific conditions. The claim for olive oil polyphenols concerns the protection of blood lipids from oxidative damage [3]. It may be used only if the oil provides at least 5 mg (5,000 µg) of hydroxytyrosol and its derivatives per 20 g of oil [3]. The label must state that the claim is linked to a daily intake of 20 g of oil [3].

The claim for cocoa flavanols refers to maintaining the elasticity of blood vessels and supporting normal blood flow [4]. The label must state a daily intake of 200 mg (200,000 µg) of cocoa flavanols [4]. The product must provide that amount and meet the other conditions in the regulation [4].

For cocoa drinks and dark chocolate, the regulation specifies flavanols with a degree of polymerisation from 1 to 10 [4]. A high cocoa percentage does not guarantee that the conditions for the claim are met. None of these compounds is expressed in international units (IU). The cited regulations do not set different conditions by age [3][4]; these figures are labelling requirements, not a recommended dose for an individual.

These claims have a limited scope. They do not prove that any olive oil or chocolate reduces heart attacks. For more context about the food itself, read our guide to dark chocolate. The Mediterranean diet shows how to combine these foods with pulses, vegetables and nuts.

Can polyphenols help with recovery or sports performance?

Drinks, foods and products rich in polyphenols have been studied in sport. A review in team-sport athletes found indications of improved muscle function and performance, and reduced discomfort after exercise-induced muscle damage. The certainty of the evidence ranged from moderate to very low, depending on the outcome [5]. The authors call for more research on amounts and duration; these findings do not establish a plan for every athlete [5].

If you are preparing for an event, first make sure you eat enough and have suitable fluids, training and rest. Findings about a supplement do not mean that eating a particular fruit will make you run faster. Nor do they mean you need to remove berries from your menu.

Why choose foods instead of extracts?

A piece of fruit, a pulse or olive oil provides more than its polyphenols. These foods can also be part of meals you enjoy and want to repeat. An extract may concentrate substances and change how they are consumed. Drinking green tea as an infusion is generally safe, but concentrated extracts may be associated with liver injury [6]. Avoid taking them on your own. If a supplement is being considered, it should be recommended by your doctor or dietitian-nutritionist.

If you take medication or have a health condition, discuss any product with your doctor before using it. In a consultation, we can help you organise your eating pattern without promising an extract’s effects.

What does “antioxidant” mean on a package?

A chemical test can show antioxidant activity in a sample. This does not prove that eating it has the same effect in your body or prevents disease [7]. Digestion and metabolism change compounds before they reach tissues.

The word on the package tells you little unless you look at the food as a whole. If a product contains a lot of sugar and promotes its cocoa content, it is still useful to read the ingredients. The European flavanol claim does not make chocolate a treatment either [4].

What we see in consultations

We see people replace fruit they usually eat with an expensive product making a big polyphenol claim. Others give up coffee they enjoy because they think only berries count. The table shows there are more options. The choice depends on your preferences, tolerance and overall diet.

People also ask whether cooking “destroys” all polyphenols. Phenol-Explorer gathers results from published food analyses [1]; it does not show how much a person will absorb from a meal. That is why we avoid presenting a laboratory figure as a guarantee. For an overall eating pattern, see our guide to eating with high cholesterol.