Flavonoids are molecules that serve to regulate cell activity and help fight free radicals that cause oxidative stress in the body.
In simpler terms, flavonoids help your body function more efficiently while protecting you against toxins and everyday stressors.
According to research, a daily intake of 500 mg of flavonoids reduces the risk of cancer by 17% and cardiovascular disease by 15%. (1,2) This figure increases for smokers, alcohol users and also in overweight people.
This article describes what exactly flavonoids are, what they are for, and examples of foods in which you can find large amounts of these substances.
Flavonoids: what are they?
Flavonoids are the largest class of plant polyphenols, there are more than 6,000 chemicals that belong to this group. The most studied subclasses are anthocyanidins, flavones, flavonols, flavonones and isoflavones. Many flavonoids are pigments that give plants their bright colors.
The first flavonoid in history was isolated from the sweet pepper or bell pepper in 1936; the main benefit found at that time was to strengthen the walls of the blood vessels. However, interest in this topic took off only in the 1990s, after the discovery of the antioxidant properties of flavonoids, that is, their ability to neutralize free radicals.
The most beneficial flavonoids for health are the class flavan-3-ol (flavonoids), mainly epicatechin and catechin. In turn, catechin is a powerful antioxidant found in tea, Brazilian acai berries, and cocoa.
Foods containing flavonoids by type
Quercetin is one of the most abundant flavonoids in nature. It is found in red or purple plants, some types of honey, walnuts, broccoli, cauliflower and cabbage, olive oil, and acorns. For example, talking about the benefits of red wine boils down to talking about the benefits of the flavonoid quercetin that black grapes contain.
This flavonoid helps reduce the risk of chronic vascular disease by normalizing vascular permeability. Additionally, quercetin protects the brain from damage associated with local circulatory disorders, preventing the development of neurodegenerative diseases. (2)
Similar substances are found in most purple-colored fruits, vegetables, and berries, from eggplant to blueberries to red onions.
Foods with quercetin – content per 100 g:
- alcaparras – 170-230 mg
- alforfón – 90 mg
- accessed – 86 mg
- radish leaves – 70 mg
- algarroba – 58 mg
- eneldo – 55 mg
- bell pepper – 50 mg
- red onion – 32 mg
- kale – 23 mg
- blueberries – 15 mg
- black plums – 12 mg
Catechins – the flavonoids in tea
Catechins are flavonoids of the flavan-3-ol classification found in tea, cocoa, and some fruits and vegetables. These substances are useful for the body to reorganize the capillary network and optimize the processes of renewal of dead cells, improving the state of the cardiovascular system. (3)
Foods with catechins – Content per 100 g:
- green tea – 10-80 mg
- black tea – 6-50 mg
- chocolate – 40-60 mg
- vino tinto – 8-30 mg
- apples – 10-43 mg
- apricot – 10-23 mg
- strawberries – 5-50 mg
- legumes – 35-55 mg
Anthocyanin – a purple flavonoid
Anthocyanins are plant glycosides related to flavonoids. They are found in plants and are the ones that give red, purple and blue colors to fruits and leaves. Its use is associated with the normalization of blood pressure , as well as a decreased risk of developing diabetes and cancer.
Foods with anthocyanin – content per 100 g:
- bayas de acai – 410 mg
- black currant – 190-270 mg
- raspberries – 365 mg
- grapes – 326 mg
- moras – 317 mg
- cherries – 122 mg
- black rice – 60 mg
Benefits and Contraindications
Since flavonoids are an extremely broad class of substances found in plants, it is impossible to unequivocally summarize their benefits and contraindications. Some flavonoids help optimize cell metabolism, while others are toxic and not recommended.
Flavonoids with scientifically proven health benefits include catechin (the antioxidant found in tea), quercetin (a pigment that gives it a red color), and anthocyanin (a pigment that gives it a purple or violet color). Other flavonoids are considered much less often beneficial and may even have certain contraindications.
Should I Take Flavonoid Supplements?
Although scientific studies support the beneficial properties of certain flavonoids, it is not about taking a specific dose in the form of dietary supplements. In addition, plants often contain several flavonoids combined, and it is not yet known exactly what the effect of isolating one of them is.
The study mentioned above¹, which recommended a 500mg dose of flavonoids, looked at purely natural foods, noting that adherence to a healthy diet itself was clearly correlated with an increase in daily flavonoid intake.
In other words, it is enough to include green tea, natural dark chocolate, buckwheat in the daily diet, and also try to consume more vegetables, fruits and purple berries. In a balanced diet, supplements are not necessary.
Flavonoids are a class of plant polyphenols responsible for the coloring of fruits and vegetables. There are over 6,000 different flavonoids found in various foods. The greatest health benefits come from the catechin (an antioxidant in tea) and the pigments found in purple fruits.