Flavonoids – What Are They? Key Information, Sources, and Properties
Flavonoids are a large group of compounds found in plants. Their multidirectional biological activity makes them the subject of numerous scientific studies today. So far, more than 6,000 different flavonoid compounds have been identified, including flavones, flavonols, isoflavones, chalcones, and anthocyanins, which show strong anti-inflammatory, anticancer, and antioxidant effects.
What are flavonoids and what properties do they have? In which foods can you find the highest amounts of these substances? How does flavonoid consumption affect health? When is it worth considering the use of flavonoid-containing supplements?
Table of Contents
- What Are Flavonoids And What Are Their Health-Promoting Properties?
- Types Of Flavonoids – Characteristics And Chemical Structure
- Flavonoids – Antioxidant, Anti-Inflammatory, And Preventive Properties
- Dietary Sources Of Flavonoids – Where Can You Find The Most?
- How Flavonoid Consumption Affects The Cardiovascular System
- Flavonoids In Cosmetics – Applications, Effects, And Benefits For The Skin
- Flavonoids In Dietary Supplements And Preparations
- How Flavonoids Interact With Vitamins, Minerals, And Medications
- What Research Says About Flavonoids And Their Effects
- Flavonoids – Why It Is Worth Including Them In Diet And Supplementation
What Are Flavonoids And What Are Their Health-Promoting Properties?
Flavonoids are organic chemical compounds most commonly found in the leaves and flowers of plants. They are less frequently present in fruits, bark, wood, and seeds. These compounds act as plant pigments, and their colors can range from light yellow and cream to orange, red, and purple shades. Examples of domestic sources of flavonoids include hawthorn blossoms, wild pansy herb, goldenrod herb, and birch leaves.
The first substances classified as flavonoids were discovered in 1930. At that time, rutin isolated from oranges was thought to belong to a new class of vitamins and was named vitamin P. Over time, it turned out that this compound is a flavonoid. To this day, several thousand flavonoids have been identified, showing protective and preventive effects in many health conditions.
Types Of Flavonoids – Characteristics And Chemical Structure
Flavonoids are a group of compounds with diverse phenolic structures that show broad biological activity. They are built from two aromatic rings connected by a three-carbon bridge, forming a characteristic skeleton called C6-C3-C6. The biogenesis of these substances is a complex process, as they are formed from primary metabolism precursors through two pathways: the malonic acid pathway and the shikimic acid pathway.
Based on structural differences, the following groups of flavonoid compounds can be distinguished:
- flavanones (hesperidin, hesperetin, naringin)
- flavanols (catechin, epicatechin, epigallocatechin)
- flavonols (quercetin, morin, kaempferol)
- flavones (luteolin, apigenin, diosmetin)
- isoflavones (genistein)
- anthocyanins (pelargonidin, cyanidin)
In addition, flavonoid compounds also include chalcones, proanthocyanidins, flavonoid glycoside esters, and biflavonoids (e.g., ginkgetin). In the plant world, flavonoids occur both in free form (as aglycones) and as β-glycosides.
Flavonoids – Antioxidant, Anti-Inflammatory, And Preventive Properties
Flavonoid compounds are pigments that give vegetables and fruits their wide range of colors – from yellow in citrus fruits to purple in black currants and grapes. They also protect plants from harmful UV radiation and act as plant hormones and growth regulators. But how do they affect the human body?
The positive effects of flavonoids come mainly from their antioxidant properties. Scientific studies show that the more hydroxyl groups present in a molecule, the stronger its ability to neutralize free radicals. These compounds can capture and eliminate reactive oxygen species, as well as reduce their formation in cells.
In addition, some flavonoids have anti-inflammatory and anti-allergic properties, influencing immune system cells. The structural similarity of certain flavonoids (especially isoflavones) to estrogens means they can also have estrogen-like effects, helping to reduce symptoms associated with menopause.
Dietary Sources Of Flavonoids – Where Can You Find The Most?
The foods richest in flavonoids include vegetables (onions, peppers, tomatoes, broccoli) and fruits (citrus fruits, apples, berries, chokeberries, grapes). In addition, these compounds are also present in:
- certain grains
- algae (chlorella, spirulina)
- legume seeds (e.g., soy)
- spices
- cocoa
- green tea
- red wine
Flavonoids in the human diet can also come from medicines and supplements, especially those based on hawthorn, elderflower, or citrus extracts (e.g., grapefruit extract). These substances are also ingredients in many preparations used to treat heart and vascular diseases (such as rutin, hesperidin, diosmin).
How Flavonoid Consumption Affects The Cardiovascular System
The biological activity of flavonoids makes them increasingly used as natural support in the therapy of cardiovascular diseases. Together with vitamin C, these compounds make blood vessels more elastic and stronger, lower blood pressure, and inhibit the development of inflammation. They also have a beneficial effect on platelet function. Because of these effects, flavonoids may play an important role in the prevention of cardiovascular diseases.
Flavonoids In Cosmetics – Applications, Effects, And Benefits For The Skin
Flavonoid-rich raw materials are also used in the production of cosmetics. These compounds not only neutralize the harmful effects of free radicals but also help reduce allergic reactions, support the rebuilding of the skin’s natural protective barrier, and slow down aging processes. By counteracting the oxidation of ascorbic acid, they also help prevent fragility and damage to blood vessels.
Flavonoids In Dietary Supplements And Preparations
Flavonoids in dietary supplements, available in tablets or capsules, can be a valuable way to enrich the diet with these biologically active compounds. They can be found, among others, in preparations containing natural plant extracts from ginkgo leaves, elderberry, or hawthorn.
Current scientific analyses suggest that regular supplementation with flavonoid-rich sources may improve overall body function by lowering glucose levels and stabilizing blood pressure, which translates into a reduced risk of developing metabolic syndrome, diabetes, and cardiovascular diseases.
How Flavonoids Interact With Vitamins, Minerals, And Medications
Flavonoids in supplements and preparations are often combined with vitamin C. These compounds work synergistically by strengthening blood vessel walls, improving skin condition, and supporting the prevention and treatment of heart diseases. Such a combination also enhances the antioxidant properties of ascorbic acid, providing better protection against the harmful effects of reactive oxygen species and oxidative stress.
Flavonoid compounds also have a protective effect on vitamin E, increasing its absorption from the digestive tract.
What Research Says About Flavonoids And Their Effects
The current state of knowledge about the biological activity of flavonoid compounds clearly indicates that their beneficial impact on the human body comes mainly from their antioxidant properties. Many studies show that regular consumption of these compounds may help reduce the risk of mortality from cardiovascular diseases.
In addition, these substances may influence processes responsible for allergic reactions by inhibiting the release of histamine from immune cells and stabilizing the body’s allergic response.
Flavonoids – Why It Is Worth Including Them In Diet And Supplementation
The multidirectional action of flavonoids makes them useful not only in prevention but also in the treatment of many different conditions. Fruits and vegetables contain the highest amounts of flavonoids, but valuable sources also include algae, green tea, and red wine. To increase the body’s supply of these compounds, supplementation can be considered.
However, remember that supplements should only complement your daily diet and cannot replace healthy eating. That is why, if you want to enrich your menu with flavonoids, eat as many natural plant-based products as possible – and your body will surely thank you for it.
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