What are polyphenols and flavonoids?
There are over 8000 different phenols and there are many as 14 classes. Over 2/3 of these polyphenols are in the class called flavonoids or bioflavonoids
by S. C.
One large class of phytonutrients is called polyphenols. There has been a lot of interest in these compounds in the recent few years even though they have been used for centuries by healers. There are over 8000 different phenols and there are many as 14 classes. Some of the common ones are coumarins, flavonoids, phenolic acids, simple phenols, lignans, quinines, and xanthones. Over 2/3 of these polyphenols are in the class called flavonoids or bioflavonoids.
Flavonoids or bioflavonoids (the old name was “tannins”) are compounds that give vegetables, fruits, grains, leaves, flowers and bark their color. The colors include the deep red, purple, mauve, blue and red. These compounds also protect the plants from disease, UV light and from predators. There are many types of flavonoids—flavanols or flavan-3-ols (myricetin, catechin and epicatechin), flavanones, flavones, flavonols, anthocyanins, and isoflavanoes—each with health-promoting benefits. If you look at all the studies, these compounds have antibacterial, anti-inflammatory, antiallergic, antimutagenic (anticancer), antiviral, antithrombotic (anti platelet formation), hormone-like, liver-protective, and vasodilatory (relax blood vessel walls) actions.
Flavonoids can increase energy levels, lower blood pressures, and decrease Parkinson’s symptoms. They can help stop motor nerve deterioration and help improve cognition, memory function, and dementia. Flavonoids have been found to help with allergies through decreasing inflammation (antihistamine); inhibiting the growth of cancer cells in breast, colon, prostate, and lungs; improving stomach ulcers; and improving the health of the cardiovascular system by reducing platelet aggregation, strengthening vascular walls, making the vessels more flexible, preventing further damage to the vessel walls, and reducing the plaques in all blood vessels. Flavonoids also have antimicrobial actions which help prevent dental caries, oral diseases and other infections. Flavonoids are strong antioxidants which neutralize many free radicals like the hydroxyl radical (HORAC), singlet oxygen, superoxide radical and peroxynitrate. This action helps stop damage to most of the body’s functions. The bioflavonoids inhibit COX-2 enzymes in your body, the same strong anti-inflammatory action that many prescription drugs have. By blocking COX-2 enzymes your immune system works better, decreases pain in your joints, and stops further production of free radicals.
Another type of flavonoid, anthocyanins, is a powerful antioxidant and has strong anti-inflammatory properties. It gives fruits and vegetables their dark color. The darker the color of a berry, the stronger antioxidant properties it has. Anthocyanins are also hypoglycemic agents which lower blood sugar levels and help the body use sugars effectively. By lowering sugar loads and using antioxidant properties they can stop the free-radical damage of eyes and extremities, where diabetes likes to attack. They not only prevent small blood vessel damage; they also start to repair and clean up the damage. They also stop small blood vessels from leaking in the eye and causing eye damage, and they repair the damage once it happens. They are also very effective histamine blockers and can stop the inflammation associated with allergies, cardiovascular disease, arthritis, and stomach ulcers.
Another powerful antioxidant group of flavonoids are called proanthocyanidins (condensed tannins or oligometric proanthocyanidins (OPCs)). They are very powerful and help other antioxidants work better and more effectively. They inhibit the oxidation of LDL-C, preventing heart vessel damage.
A cousin of the flavonoids is xanthones. Xanthones are a bitter compound (tannic) that prevent predators from eating the plants. In a few studies they have been shown to be also an antioxidant and anti-inflammatory. They have been found to reduce diarrhea, curb appetites, reduce insulin resistance, and improve moods. The richest source is found in gentian root nectar. There are over 200 types of xanthones identified with limited studies on which types are beneficial.
Flavonoids and phytonutrients are just starting to be studied. There are thousands of flavonoids which need to be researched in the future. The research is just starting to explode in trying to help us learn how these compounds can benefit us.