Polyphenols – what are they and in which products can they be found?

Polyphenols are chemical compounds with a wide range of health-promoting properties. Regular consumption can bring numerous health benefits, including protection against oxidative stress, reduction of inflammation, and support for heart, brain, immune and digestive health. Including polyphenol-rich foods such as fruits, vegetables, legumes, nuts, seeds, tea, coffee and spices in your diet can contribute to improving your overall health and well-being.

What are polyphenols?

Polyphenols are a group of chemical compounds found naturally in plants, characterised by the presence of more than one phenolic group per molecule. These compounds are known for their antioxidant and health-promoting properties. Polyphenols play a key role in protecting plants from the harmful effects of UV radiation, pathogens and insects. For people who consume plants rich in polyphenols, these compounds can have numerous health benefits, such as reducing the risk of chronic diseases, including heart disease, type 2 diabetes and cancer.

Classification of polyphenols: flavonoids, phenolic acids, lignans, stilbenes

Polyphenols can be divided into several main groups:

• Flavonoids - are the largest group of polyphenols and include several subcategories such as flavonols, flavones, isoflavones, flavan-3-ols and anthocyanins. They are found in many fruits, vegetables, teas, wine and chocolate. Flavonoids have strong antioxidant, anti-inflammatory and anti-cancer properties.

• Phenolic acids - such as gallic acid, caffeic acid, ferulic acid and rosmarinic acid, are found mainly in cereal grains, fruits, vegetables and spices. They have antioxidant and anti-inflammatory properties and may also support heart and cardiovascular health.

• Lignans - are polyphenolic compounds found in flaxseed, sesame seeds, whole grains and certain vegetables. Lignans can affect the body's hormonal balance, making them beneficial for hormonal health and reducing the risk of breast and prostate cancer.

• Stylbenes - the best-known representative of stylbenes is resveratrol, found mainly in grape skins, red wine and berries. Resveratrol is known for its potential benefits for heart health, anti-inflammatory and anti-cancer effects.

Polyphenolic compounds and the effects of polyphenols in the body

Polyphenols have a variety of effects in the body, which contribute to their health-promoting properties. Here are some of the mechanisms by which polyphenols work in the body:

• Neutralisation of free radicals - polyphenols are powerful antioxidants, which means they can neutralise free radicals and protect cells from oxidative stress. This action helps to protect cells from damage and reduces the risk of chronic diseases.

• Regulation of inflammation - polyphenols can affect various signalling pathways in the body that are associated with the inflammatory process. As a result, they can help reduce inflammation and improve overall health.

• Impact on the gut microbiome - polyphenols can affect the composition and functioning of the gut microbiome, which is beneficial for digestive and overall health. These compounds can support the growth of beneficial gut bacteria and inhibit the growth of pathogens.

What are the health benefits of polyphenols?

Polyphenols (chemical compounds naturally found in plants) have a number of health-promoting properties that contribute to improving overall health. They are being studied for their numerous health benefits, including antioxidant, anti-inflammatory, antibacterial and antiviral effects. Here is a detailed overview of their health-promoting properties:

1. Antioxidant activity

Polyphenols are powerful antioxidants that help neutralise free radicals - unstable molecules that can damage cells and DNA, leading to the development of various chronic diseases. The antioxidant activity of polyphenols contributes to:

• Protecting cells from oxidative stress – polyphenols protect cells from damage caused by free radicals, reducing the risk of heart disease, type 2 diabetes and cancer.

• Slowing down the ageing process - by neutralising free radicals, polyphenols can help delay the ageing process of the skin and other tissues.

2. Anti-inflammatory effect

Chronic inflammation is associated with the development of many diseases such as heart disease, diabetes, arthritis and cancer. Polyphenols can have an anti-inflammatory effect by:

• Reducing inflammation markers - polyphenols can lower levels of inflammation markers such as C-reactive protein (CRP) and interleukin-6 (IL-6), which contributes to reducing inflammation in the body.

• Modulating inflammatory pathways - polyphenolic compounds affect various signalling pathways involved in inflammatory processes, which can lead to their reduction.

3. Support for heart health

Polyphenols have a beneficial effect on cardiovascular health. Regular consumption of foods rich in polyphenols may contribute to:

• Lowering blood pressure – certain polyphenols, such as flavonoids, can improve blood vessel function and lead to lower blood pressure.
• Reduction of the risk of atherosclerosis - polyphenols may prevent the oxidation of LDL cholesterol, which is a key factor in the development of atherosclerosis.
• Improvement of blood vessel function - polyphenols may improve the elasticity of blood vessels and support healthy blood flow, which reduces the risk of cardiovascular disease.

4. Supporting brain health

Research suggests that polyphenols may support brain health and improve cognitive function. They may help protect neurons from oxidative stress and inflammation, which may contribute to:

• Reducing the risk of neurodegenerative diseases - polyphenols may protect against diseases such as Alzheimer's and Parkinson's due to their antioxidant and anti-inflammatory properties.

• Improving memory and cognitive function - regular consumption of polyphenols, especially those found in berries, green tea and red wine, can improve memory and cognitive function.

5. Antibacterial and antiviral effects

Polyphenols have antibacterial and antiviral properties, which may contribute to:

• Strengthening the immune system - polyphenols can support the immune system by helping to fight bacterial and viral infections.

• Inhibiting the growth of pathogens - some polyphenols can inhibit the growth and development of harmful bacteria and viruses, which may reduce the risk of infection.

6. Support for gut health

Polyphenols may also affect digestive health by:

• Supporting a healthy gut microbiome - polyphenols may promote the growth of beneficial bacteria in the gut and inhibit the growth of pathogens, which improves gut health.

• Reducing inflammation in the gut - thanks to their anti-inflammatory properties, polyphenols can help reduce inflammation in the digestive system.

Sources of polyphenols in food - legume seeds and other products rich in phenolic compounds

Polyphenols are found in a wide range of foods. Below is a detailed overview of various sources of polyphenols that are worth including in your daily diet.

Legume seeds

Legume seeds are not only rich in protein and fibre, but also contain significant amounts of polyphenols, which have many health benefits:

• Lentils: contain phenolic acids and flavonoids, which can support heart health and reduce inflammation.

• Chickpeas: are rich in phenolic acids and isoflavones, which have antioxidant and anti-inflammatory effects.

• Beans: various types of beans, such as black beans, red beans and mung beans, contain flavonoids, phenolic acids and anthocyanins.

• Peas: rich in phenolic acids and flavonoids, they support cardiovascular and digestive health.

• Broad beans: they contain polyphenols such as chlorogenic acid and ferulic acid, which have antioxidant properties.

Fruits

Fruits are one of the best sources of polyphenols and contain various types of these compounds, which have powerful antioxidant effects:

• Berries: blueberries, raspberries, blackberries, strawberries and cranberries are rich in anthocyanins, flavonoids and phenolic acids.

• Grapes: contain resveratrol, which is a stilbene with strong antioxidant properties.

• Apples: rich in flavonoids such as quercetin and phenolic acids.

• Pomegranates: contain punicalagins and other phenolic acids.

• Citrus fruits: oranges, lemons and grapefruit contain flavonoids such as hesperidin and naringenin.

Vegetables

Vegetables are also an excellent source of polyphenols, which support health in various ways:

• Broccoli: contains flavonoids and phenolic acids such as ferulic acid.

• Spinach: rich in phenolic acids and flavonoids.

• Onions: contain quercetin, a powerful antioxidant.

• Cabbage: contains various flavonoids and phenolic acids.

• Carrots: rich in phenolic acids and carotenoids.

Nuts and seeds

Nuts and seeds are rich in healthy fats and polyphenols:

• Walnuts: contain ellagic acid and other polyphenols.

• Almonds: rich in flavonoids and phenolic acids.

• Flaxseed: contains lignans, which are beneficial for hormonal health.

• Chia seeds: rich in phenolic acids and antioxidants.

• Sesame seeds: contain lignans such as sesamin.

Beverages

Beverages such as tea and coffee are excellent sources of polyphenols:

• Green tea: contains catechins such as EGCG, which have powerful antioxidant properties.

• Black tea: rich in theaflavins and thearubigins.

• Coffee: contains chlorogenic acid, which is a powerful antioxidant.

• Red wine: contains resveratrol and other polyphenols that may support heart health.

Spices and herbs

Spices and herbs are a concentrated source of polyphenols:

• Cinnamon: contains cinnamic acid and other phenols.

• Turmeric: rich in curcumin, which has powerful anti-inflammatory properties.

• Rosemary: contains rosmarinic acid and other polyphenols.

• Oregano: rich in flavonoids and phenols.

Chocolate

• Dark chocolate: contains flavonoids such as catechins and epicatechins, which have antioxidant properties and may support heart health.

Supplementation or a healthy diet – how to increase your intake of polyphenols?

Polyphenol supplementation may be an option for people who find it difficult to achieve adequate intake of these compounds through diet alone. Supplements can provide concentrated doses of polyphenols, which may be beneficial in some cases. However, it is important to remember that supplementation should be used in moderation and under the supervision of a specialist.

The best way to increase your intake of polyphenols is to eat a healthy and balanced diet rich in a variety of plant-based foods. Eating fruits, vegetables, legumes, nuts, tea and coffee can provide natural sources of polyphenols and numerous health benefits.

A polyphenol-rich diet - tips and advice

A diet rich in polyphenols can have numerous health benefits, including protection against chronic diseases, improved heart health, and support for cognitive function. Here are some tips and advice on how to incorporate more polyphenols into your daily diet:

1. Choose colourful fruits and vegetables such as berries, grapes, apples, broccoli, carrots, and spinach. A variety of colours on your plate ensures a wide range of polyphenols. Opt for seasonal fruits and vegetables that are fresh and full of nutrients.
2. Add legumes such as lentils, chickpeas, beans and peas to soups, salads and one-pot dishes. You can also make chickpea hummus as a healthy snack rich in polyphenols.
3. Almonds, walnuts, flaxseed and chia seeds are excellent sources of polyphenols. Add them to salads, yoghurts, smoothies and baked goods. Flaxseed and chia seeds can also be added to your morning porridge or yoghurt to increase your lignan intake.
4. Green tea is rich in catechins, which have strong antioxidant properties, so it is worth drinking it regularly. Coffee contains chlorogenic acid, which also has antioxidant properties - consume it in moderation.
5. Choose dark chocolate with a cocoa content of over 70%, which is rich in flavonoids. Consume it in moderation as a healthy snack that supports heart health.
6. Add spices and herbs such as cinnamon, turmeric, rosemary and oregano to various dishes. They are rich in polyphenols and can provide additional health benefits.
7. Prepare fresh juices and smoothies from fruits and vegetables rich in polyphenols such as berries, citrus fruits, spinach and beetroot. This is a great way to quickly and easily increase your intake of these compounds.
8. Choose whole grains such as brown rice, wholemeal bread and porridge. They are rich in polyphenols and fibre, which supports digestive health and overall health.

Lifestyle and meal preparation tips

1. Planning healthy meals in advance will help you incorporate a variety of polyphenol sources into your daily diet. Try to include at least one source of polyphenols in each meal.

2. Try to eat as many fresh and natural products as possible, avoiding processed foods, which often contain fewer polyphenols. Fresh fruit, vegetables, nuts, seeds and spices are the best sources of these compounds.

3. Cooking at home gives you complete control over what you eat and allows you to easily incorporate polyphenol-rich foods into your diet. Prepare healthy meals using a variety of recipes that include these ingredients.

Incorporating these tips into your daily life will help increase your polyphenol intake and contribute to improved health and well-being. Remember that a balanced diet rich in a variety of polyphenol sources is the key to health and longevity.