Flavonoids are polyphenol antioxidants that can be found in plants, herbs and other aliments. They function as powerful antioxidants having a very important role in our metabolism.
"An apple a day keeps the doctor away", I don't remember any longer when was the first time I heard that proverb, but now I guess I know where it comes from and why. Apples are rich in quercetin, a flavonol from the group of flavonoids, which where discovered in 1938 by the Hungarian scientist Albert Szent Byorgyi.
Quercetin is believed to have several benefits for the human body, among which we can mention the anti-inflammatory, anti-allergic and antioxidant. Quercetin has indeed about four times the antioxidant properties of Vitamin C.
Flavonoids are part of a larger group of molecules, the phenols. Some phenols, which are naturally occurring in many herbs and other natural sources are used by plants as a deterrent for herbivores.
Flavonoids have been documented as a cancer preventive agent and a very useful active constituent of herbs and plants responsible for many beneficial properties of those ones, as their anti-ageing effect (Ginkgo biloba, Calendula...etc.) and their free radical scavenging action (antioxidant), preventing cancer occurrence.
Flavonoids are part of a larger group of molecules, the phenols. Some phenols, which are naturally occurring in many herbs and other natural sources are used by plants as a deterrent for herbivores.
Flavonoids have been documented as a cancer preventive agent and a very useful active constituent of herbs and plants responsible for many beneficial properties of those ones, as their anti-ageing effect (Ginkgo biloba, Calendula...etc.) and their free radical scavenging action (antioxidant), preventing cancer occurrence.
Apart from the antioxidant properties of flavonoids, they are also anti-inflammatory and anti-allergic, being also able to decrease capillary fragility [3].
The capabilities of flavonoids to absorb UV radiation [2] make flavonoids a very remedy against the damage caused to our DNA by sunlight and other UV light sources. This could help preventing skin cancer and other skin disorders related to the damage caused on our DNA by the UV radiation.
1. Anthocyanidins
Anthocyanidins are the most abundant type of flavonoid [4] and they are responsible for the blue or purple colour present in blueberries, cherries, grapes, blackberries and others[1]. Actually a little bit more than 500 anthocyanidins have been found [5] in different herbs, plants and natural sources.
2. Flavanols
Onions are a great source of flavonols [1]. Quercetin, a well known flavanol, is used to treat allergies [1]. Cacao is another source of flavanols, containing other types of flavanols as chatechins and epicatechins [11], which have been reported to have a very effective vasodilatory effect due to the effects on the mechanisms of Nitric Oxide [14], increasing the synthesis of this one and the blood flow as a consequence of this.
In two clinical studies flavanols were found to have a very positive effect on the increase of blood flow in certain parts of the brain, showing its potential effect as a possible treatment for dementia and strokes [14]. Apples, tea (specially fresh tea leaves [12]) and red wine are also rich in flavanols. Green tea contains almost double amount of flavanols than black tea.
3. Flavanones
Flavanones are present in many herbs and fruits, but among all the plant kingdom the species where flavanones are most commonly found are citrus. Citrus contain a significantly big amount of flavanones[2], being the riches source of flavanones, specially when they are still immature.
4. Flavonols
Flavonols are the most commonly found type of flavonoids. They are widely spread in nature and can be found as plant pigments and also in the leaves of those ones. These are the two main groups of flavonols found in nature:
3-hydroxyflavone, Azaleatin, Fisetin, Galangin, Gossypetin, Kaempferide, Kaempferol, Isorhamnetin, Morin, Myricetin, Natsudaidain, Pachypodol, Quercetin, Rhamnazin, Rhamnetin.
Astragalin, Azalein, Hyperoside, Isoquercetin, Kaempferitrin, Myricitrin, Quercitrin, Robinin, Rutin, Spiraeoside, Zanthorhamnin, Amurensin, Icariin and Troxerutin.
5. Flavones
Not as widespread as Flavonols, Flavones can be found in some herbs and plants but their amounts and occurrence is far from being close to that of Flavonols. We can find Flavones in the leaves of Carya cathayensis, where it was found to exert certain anti-tumor properties [.
6. Isoflavones
Isoflavones are mainly present in the Leguminosae family, being soy bean sprouts a very good source of isoflavones [6].
7. Catechins
Cathechins are another type of flavonoids that can be found in apples, cherries, pears, tea and even in wine [2].
8. Chalcones
Chalcones have been reported as having important antibacterial, anti-fungal, anti-tumour and anti-inflammatory properties [7]. Chalcones are also responsible for the yellow pigmentation of petals and anthers [8] in certain flowers as Petunia on its early stages, but converted to colourless flavanones late on [10]. This type of flavonoids are less frequent, and they occurrence in nature is not so common, only about 24 different types of chalcones are known to occur in nature [9].
Flavonoids are polyphenol antioxidants that can be found in plants, herbs and other aliments. They function as powerful antioxidants having a very important role in our metabolism.
"An apple a day keeps the doctor away", I don't remember any longer when was the first time I heard that proverb, but now I guess I know where it comes from and why. Apples are rich in quercetin, a flavonol from the group of flavonoids, which where discovered in 1938 by the Hungarian scientist Albert Szent Byorgyi.
Quercetin is believed to have several benefits for the human body, among which we can mention the anti-inflammatory, anti-allergic and antioxidant. Quercetin has indeed about four times the antioxidant properties of Vitamin C.
This type flavonoid is known for its anti-inflammatory and antioxidant properties but it has also many other benefits for our bodies. It isn't then strange that apples got such a good name and were known for its positive effects, but the question is, are those the only ones that contain flavonoids? Where else can we find flavonoids? Do flavonoids have any other benefits for our bodies?
Flavonoids are known to be very powerful antioxidants, they avoid the degradation caused to body cells by the free radicals, therefore thought to be positive for our health. Flavonoids were also named vitamin P, but nowadays with the increase of studies in the field of flavonoids they are mostly simply known as flavonoids. It goes without saying that the use of vitamin P as a remedy for bleeding gums is widely known.
There are many herbs, fruits and aliments rich in flavonoids, among which we can mention green tea, onion, basil, lettuce, cranberry, spinach, asparagus, soy, lime bean, basil, cayenne, coriander, peppermint, chamomile and anise. Green tea contains catechins, another type of flavonoids. It is important to realize that flavonoids are not always preserved, flavonoids may, depending on the type of food and the way it’s prepared, part of the content of flavonoids, disappear after preparation.
There are also many herbal remedies recurring to flavonoids, or more exactly to fruits, vegetables and beverages that contain flavonoids, as possible solutions for very well known problems and we will treat some of them in further articles.
We should have a proverb similar to the apple one to cover the benefits of chocolate, because cocoa is also rich in flavonoids, and these flavonoids in cocoa are the flavonoids responsible for the benefits attributed to chocolate. But not all chocolate is rich in flavonoids, as we said before the cocoa beans are the ones containing a big quantity of flavonoids and therefore dark chocolate, rich in cocoa concentration is the richest one in flavonoids.
If we think tea is rich in flavonoids we should mention that there are other types of flavonoids found in chocolate or more exactly in cocoa that haven't been found in tea. There are many different types of flavonoids in fruits, for example quercetin, the flavonoid found in apples, or more exactly on apple peals, is one of the flavonoids also used as an ingredient in supplements, certain types of aliments and drinks.
The flavonoid quercetin has reported to have also anti-inflammatory supplement. It is not very strange that many herbs and fruits are known to contain flavonoids because there are already more than 5000 different types of those ones found in nature. One of the benefits of the flavonoids that we can found in apples, the quercetin, are its anti-inflammatory properties.
Another curiosity about flavonoids refers to their function in the colour of the aliments that contain flavonoids. Flavonoids are the responsible for the colour of some fruits and vegetables rich in flavonoids.
Nutritionists recommend having a diet containing aliments rich in flavonoids rather than having an intake of dietary supplements to supply that element, which in general should contain the fruits, vegetables and beverages that are rich on flavonoids, but which fruits or drinks contain flavonoids? Well, there are plenty of them and we could start by naming those with a higher quantity of flavonoids.
The dark berries are known to be rich in flavonoids, as well the already mentioned apple, the strawberries and black tea or blue berries. It seems that those flavonoids found in berries may have a positive effect and protect against Parkinson's disease.
Flavonoids contained in berries may have a positive effect and protect against Parkinson's disease
In prepared foods sometimes the content of flavonoids may be lower as those are refined by the companies in charge of its commercialization and some times reduced considerably, trying to avoid the bitter flavour that those flavonoids are giving to the food. It is even believed that the flavonoids contained in the blueberries may help to improve memory in elderly people.
Flavonoids contained in the blueberries may help to improve memory in elderly people
If what we are looking for are drinks rich in flavonoids then we can choose grape juice, but of course we shall pay attention because maybe the content in sugar of those grape juices are to be taken into account. Another solution to obtain flavonoids from grapes will be to liquefy the juice ourselves and of course get rid that way of the additional added sugars.
