Vitamin P – Bioflavonoids: How They Can Help You & Top 5 Food Sources

In this article, we explore the health benefits of bioflavonoids (sometimes called Vitamin P). The fascinating health benefits of this class of phytochemicals is what makes eating sufficient fruits and vegetables so important. Not only are bioflavonoids essential naturally-occurring antioxidants and anti-inflammatories, but they also function in support of a healthy circulatory system, a healthy immune system, and to promote longevity and well-being. We explore the world’s best food sources for bioflavonoids, as well as top dietary supplements that can be taken in addition to a healthy diet, to boost your flavonoid intake! Anybody who is interested in health, fitness, well-being, or longevity should definitely make sure that they’re getting sufficient bioflavonoids in their diet.

The Bioflavonoids: What is Vitamin P?

Vitamin P is an outdated term that refers to a group of naturally-occurring chemicals called flavonoids, or bioflavonoids. This group of compounds all share a very similar chemical structure and are synthesized by plants for a variety of physiological functions. For example, they are very important for flower pigmentation (giving flowers their colours), as well as in the filtration of UV light and nitrogen fixation.[1] However, their benefits are not restricted to plants. Bioflavonoids have been used for centuries as health-promoting phytochemical ingredients in an incredibly wide range of traditional medicine from around the world. There is now comprehensive clinical evidence to show their vast array of important effects in a variety of biological processes in mammal species, including humans.  Today, bioflavonoids are used to enhance the immune-supporting benefits of vitamin C, to support blood circulation and a healthy circulatory system, and as a means of managing inflammation in the body.[2] There is solid peer-reviewed scientific evidence to support the health-promoting claims made about bioflavonoids. Researchers from around the world are engaged in studies to understand their mechanisms in the human body, as well as how they affect our health in the long-term, through a type of medical research known as epidemiology. More and more research shows that intake of bioflavonoids is associated with better health, longevity, and well-being over long periods of time.[3]  

Top 5 Health Benefits of Bioflavonoids

1.     Antioxidant Effects

Antioxidants are compounds that help to remove reactive chemicals called ‘free-radicals’ or ‘reactive oxygen species (ROS)’ from the body. These are considered to be harmful to the body because they are able to react chemically with processes occurring inside cells, and even with DNA. This is called ‘oxidative stress’ and has the ability to cause cell damage and potentially dangerous DNA mutations. Free-radicals are naturally generated through biological processes and biochemical reactions within the human body. Our bodies have complex and integrated systems to balance the generation of free-radicals. However, there are some environmental and genetic factors that can cause the body to produce excess ROSs. These include living in areas with polluted air, unhealthy diets high in sugar and fat, smoking, drinking, exposure to radiation, inflammation, and exposure to harmful chemical products like pesticides.[4]   Antioxidants are able to interact with free-radicals to prevent them from causing damage to the body. These effects are also known as ‘free-radical scavenging’ benefits. Of the over 8000 individual flavonoid compounds known, many have already demonstrated great antioxidant benefits in vitro.[5] It is more difficult to show antioxidant benefits in living systems (in vivo) because of the inherent complexity of living systems. However, a variety of long-term epidemiological studies have found that people who consume diets rich in antioxidants tend to have a reduced risk of disease.[6]  

2.     Anti-Inflammatory Benefits

It’s important to remember that inflammation is not “bad”, by definition. Inflammation is actually an important process of restoring health in the body. Acute inflammation is what occurs when the immune system kicks into action in response to toxins, infections, or wounds. Redness, swelling, heat, and itchiness are all signs of a healthy inflammatory response of the immune system.[7] Chronic inflammation, however, refers to an ongoing process of the body trying – and failing – to remove unwanted substances from the body. These could include the toxins from cigarette smoke, excess fat in organs, the build-up of plaque in arteries (a condition known as atherosclerosis), and other factors – including genetically inherited diseases of the immune system.[8]   In terms of danger to health, long-term, chronic inflammation is associated with numerous diseases and ailments. There is a medical theory that many, if not most, diseases have inflammation as an underlying cause: including heart disease, diabetes, and others.[9] With this in mind, it's easy to see why managing inflammation in the body is so important. Plant foods are the only natural sources of anti-inflammatory compounds, which is why doctors today recommend eating between 5-10 servings of fruits and vegetables every day.[10]  

3.     Immune System Support

The effects of natural bioflavonoids on the immune system have been well-studied. Plant flavonoids are established as being able to help support a healthy immune system through their regulatory effects. Studies have found, for example, that increased fruit and vegetable consumption improves markers of immune response in elderly people with chronic disease, while others have indicated stimulatory effects on all types of immune cells, including neutrophils, eosinophils, T & B lymphocytes, macrophages, and others.[11] The immune system is your body’s defence system against toxins, bacteria, viruses, and parasites. Flavonoids interact indirectly with the immune system through their actions on biochemical processes in the body.[12] These interactions are highly complex and involve numerous feedback loops. To better understand how this works, below is an example of one of the dozens of interactions between bioflavonoids and the human immune system.   Lymphocytes are a type of white blood cell which either produce antibodies to attack viruses and bacteria (B-Type) or implement a self-destruct mechanism to destroy infected human cells (T-Type).[13] In order to work properly, lymphocytes need to first be activated by antigens, and this process requires the actions of enzymes called tyrosine protein kinases.[14] Flavonoids have been shown to interact significantly with protein kinases and to regulate the activities of lymphocytes and immune response.[15]  

4.     Support a Healthy Circulatory System

Bioflavonoids are important for supporting a healthy circulatory system, and their role in this function has been shown through multiple studies from around the world. Their ability to support a healthy circulatory system is directly related to how they function in the human body in terms of their antioxidant, anti-inflammatory, anti-thrombotic, anti-ischemic, anti-hypertensive, and anti-arrhythmic effects. [15] In one example, a population of over 34’000 post-menopausal women was studied for their food intake and risk of cardiovascular disease. The first data was recorded in 1985. Follow-up questionnaires were mailed and recorded in 1987, 1989, 1992, and 1997. In 2002, 16 years after the study began, the final data was reviewed, including mortality rates and cause of death. The results showed a significant adverse relationship between the number of bioflavonoids in diet and the risk of death from cardiovascular disease or coronary heart disease.[16]   Several smaller studies have been conducted, with similar results. In Finland, over 5100 volunteers participated in a 25-year study which found that low levels of bioflavonoid intake significantly increased the risk of heart disease.[17] In Holland, 4807 people partook in a similar 5.6-year study examining the effects of tea intake (as a proxy for flavonoids). Results again showed a significant inverse relationship between bioflavonoid intake and risk of diseases of the circulatory system.[18]  

5.     Further Research

Further potential uses of bioflavonoids are being studied by researchers around the world. For example, Swiss scientists are exploring the potential use of bioflavonoids found in many plant foods – for protection against radiation. In a recent study, they exposed mice to gamma radiation and later gave them a mixture of bioflavonoids extracted from Quercetin and Rutin. The results showed a significant decrease in radiation-triggered lipid peroxidation, meaning that the bioflavonoids offered a protective effect against oxidative stress from radiation.[19] Some studies have explored the potential links between bioflavonoids in the diet and risk of dementia and Alzheimer’s disease. For example, French scientists conducted a study on a population of 1367 people over the age of 65 years. A questionnaire was used to assess their dietary intake of bioflavonoids, and follow ups were conducted for 5 years after. In that time, 66 cases of dementia were reported among the participants. After accounting for a variety of other possible factors, the results showed a significant adverse relationship between intake of flavonoids and risk of dementia.[20] Finally, researchers are exploring the potential uses of bioflavonoids against microbes like bacteria and fungi. These fascinating compounds have already demonstrated antimicrobial effects in plants, where they are an important line of defence against infection. Scientists are now exploring the potential to develop these traits further, for use by humans.[21]  

Top Food Sources of Vitamin P

There are a few different types of bioflavonoids, all of which are beneficial to your health. These great health-promoting compounds can be found in all fruits and vegetables. Importantly, its far better to aim for a diet that has is both varied and abundant, in terms of fruit and vegetable intake – rather than binging on one ‘top bioflavonoid food source’, for example. Eating a varied diet gives you a wide range of nutrients, vitamins, minerals, and flavonoids.
Anthocyanidins Flavonones Flavones Flavan-3-ols Flavonols Isoflavones
Blueberries Oranges Parsley Black tea Onions Soybeans
Bananas Grapefruits Thyme Green tea Apples Soy products
Strawberries Lemons Celery Cacao Tomatoes Legumes
Cherries Tomatoes Hot peppers Grapes Garbanzo beans
Grapes Watermelon Berries Almonds
Red wine Lettuce Strawberries Kale
Plums Peaches Broccoli
Pears Bananas
[22] [23] According to the most recent research, Americans consume around 200 mg of total bioflavonoids per day, with tea being the greatest source of these compounds.[24] In 2017, researchers at the Imperial College of London found that an estimated 5.6 to 7.8 million premature deaths worldwide could be attributed to a lack of fruits and vegetables in people’s diets. They recommended a daily intake of at least 500 grams of fruits and vegetables, or around 8-10 servings, for optimum health-promoting benefits. [10]  

Top 3 Bioflavonoid Dietary Supplements

In addition to a healthy diet that is rich in fruits and vegetables, dietary supplements are another great way to increase your daily intake of bioflavonoids and promote a healthier body. Below are the Top 3 Bioflavonoids supplements available today:  

1.     Green Tea Extract Catechins

[caption id=""attachment_1220"" align=""alignright"" width=""300""] Click the image to buy Green Tea Extract![/caption] Green Tea is widely regarded as the healthiest drink in the world and is rich in catechins and polyphenols, both of which are great sources of bioflavonoids. In fact, it is established that the health-promoting benefits of Green Tea can be attributed to its high the polyphenol content, particularly flavanols and flavonols, which represent 30% of fresh leaf dry weight.[25]   Green Tea Extract supplements provide a high-potency powder or capsule form of polyphenols and catechins. Studies have indicated that these groups of compounds have several health benefits, including supporting a healthy cardiovascular system, powerful anti-inflammatory effects, antioxidant and neuroprotective benefits, and many more.[26] With the greatest source of flavonoids for Americans being tea, it’s easy to see how Green Tea Extract is a great dietary supplement source for boosting your bioflavonoid intake.  

2.     Quercetin and Rutin

[caption id=""attachment_275"" align=""alignright"" width=""300""] Click the image to buy Quercetin![/caption] Two more great sources of flavonoids are Quercetin and Rutin – with Rutin offering a ‘slow-release’ form of Quercetin, due to the presence of an additional rutinose sugar molecule. These naturally-occurring compounds are found in most fruits and vegetables, with buckwheat, asparagus, apples, figs, black tea, green tea, and elderflower tea being a few great sources.[27] Unlike Green Tea Extract, which is a source of a variety of bioflavonoids, Quercetin itself is a flavonoid compound.   Both Rutin and Quercetin have been the focus of research teams around the world involved in nutrition and the study of natural antioxidants and anti-inflammatories. Many studies assessing the efficacy of bioflavonoids in general for their health-promoting benefits use either Rutin or Quercetin as proxy compounds because they are simply so effective! Like all bioflavonoids, the benefits of these compounds include strong antioxidant effects, potent anti-inflammatory benefits, and support for a healthy circulatory system.[28]  

3.     Baicalin

[caption id=""attachment_1277"" align=""alignright"" width=""279""] Click the image to buy Baicalin![/caption] Like Quercetin, Baicalin is not a source of flavonoids, but rather a bioflavonoid itself. The key active compound found in Scutellaria baicalensis, this amazing health-promoting phytochemical has been found to provide numerous health benefits, both in vitro and in vivo. In one study, researchers found that Baicalin binds to chemokines – a family of small signalling molecules used in the immune system – as a key mechanism of its powerful health benefits.[29]   Unlike Quercetin and Green Tea Extract, Baicalin has additional benefits on top of its bioflavonoid effects. Research has shown that it binds to GABA receptors in the brain, to help promote calm and relaxation, and reduce feelings of stress.[30] It has also been shown to enhance the activation of an enzyme called AMPK, which is responsible for regulating hormone levels in the blood and involved in the metabolism of fat.[31]  


In summary, bioflavonoids are not only beneficial but are actually essential for good health and well-being. Studies now show that the ideal intake of fruits and vegetables is as high as 8-10 servings per day, to support optimum health. One great way of achieving this is by blending a variety of flavonoid-containing foods into a healthy smoothie. Taking additional bioflavonoids in the form of a powder or as capsule supplements is another way to boost your daily intake.   The top bioflavonoid dietary supplements include Green Tea Extract, Quercetin/Rutin, and Baicalin. These are a great way to support good health through their antioxidant, anti-inflammatory, and circulatory-supporting benefits. However, although dietary supplements can certainly be beneficial, they should not be seen as a replacement for a healthy diet. Getting adequate fruits and vegetables in your diet is the best way to ensure good health!


Medical Disclaimer

Not intended to treat, diagnose, or cure any disease or ailment. Please read and fully understand potential adverse effects before using this product. These statements have not been reviewed by the FDA and are not written by a medical professional. Please consult your doctor before using any supplements, especially if you have any medical conditions.


B.Sc. in Molecular Biology and Biochemistry Researched & written by Tristan and verified by the Research Team


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