Flavanol or Flavonol?bio1
January 25th, 2012
What’s the difference between a flavanol and a flavonol? It almost looks the same, but the difference in their molecular structure and functions is critically important. Lets learn together.
After this week’s Forward Thinking we’ll definitely know
what flavanols are, and their powerful health benefits. Next week we’ll bring into the picture the flavonols.
Flavanols are also called flavan-3-ols. They’re flavonoids that use the 2-phenyl-3, 4-dihydro-2H-chromen-3-ol skeleton. There are five basic molecules that form the building blocks for this class of flavonoids: catchin, epicatechin, epigallocatechin, epicatechin gallate and epigallocatechin gallate (EGCG). These are called monomers. When two of the five flavan-3-ols are joined together they are called dimers; and when two to five are linked they are called proanthocyanidins (OPCs).
The molcule to the right is a catechin. An epicatechin has a OH at the R1 place on this molecule instead of an H like the catechin actually has. Epigallocatechin and epicatechin gallate and EGCG have the same basic structures with changes at the R1 and OH location on the middle phenolic molecule. Each of these structural differences provides our bodies with a variety of differing molecular functions for the preservation of our good health.
Finally, when the monomeric flavan-3-ols are joined together as 6 or more units, they are called tannins. If you refer back to my Phytochemical Flow Diagram from a couple of newsletters ago you will see that I put the tannins and the OPCs in the wrong place. They should appear as a subgrouping within the Flavonoids category, and placed under the Flavanols in the following succession: catechins to OPCs to tannins. OK, now that that’s all cleared up, let’s look at some health benefits of the Flavanols.
Health Benefits of the Flavanols
Flavan-3-ols exhibit several health beneficial effects by acting as antioxidants, anticarcingens, cardiopreventives, antimicrobials, antivirals and neuro-protective agents. Flavanols are found in fruits, green tea, wine and cocoa. Their presence in food also affects quality parameters such as astringency, bitterness ,sourness, sweet-ness and aroma.
Epicatechins: There has been a wide amount of research on the beneficial effects of the abundance of epicatchins in natural cocoa. In a very interesting study regarding the healthful Kuna Indians who live on the San Blas islands off the coast of Panama, high blood pressure and other signs of cardiovascular disease are rare. The research found that epicatechins are directly linked to improved circulation and other hallmarks of cardiovascular health. The Kuna consume large amounts of flavanol-rich cocoa—three to four cups a day. They also showed in old age very little cognitive dysfunction. Their cocoa boosted blood flow to key areas of the brain. Flavanols have been shown to increase the formation of endothelial nitric oxide, which promotes vasodilation and consequently increases blood flow and lowers blood pressure.
EGCG: Epigallocatechin gallate is a profound anti-oxidant, found mostly in green tea. On average a cup of green tea will have roughly 100 mg per 8 ounces. Of course, the amount varies with the variety of tea, the age of the leave, and the amount of brewing time. High levels of EGCG is believed to be responsible for much of green tea’s promise in the prevention of cardiovascular disease, obesity, Alzheimer’s disease, cancer and periodontal disease.
EGCG and related catechins have the ability to bind to the signaling molecules that either block or activate transcription factors. For example, they can block NF-kB, and thereby stop the expression of pro-inflammatory cytokines and chemokines; and they can upregulate the Antioxidant Defense System by binding to transcription factor NRF2.
Proanthocyanidins (OPCs): Chief among the benefits of OPCs is antioxidant protection against heart disease and cancer. Proanthocyanidins are found in many woody plants, the two most common sources are grape seeds and white pine. OPCs are also abundant in apples, berries ,barley, bean hulls, chocolate, ruhbarb, rosehips and sorghum.
Epidemiological research leads us to believe that proanthocyanidins may help explain the French Paradox. Red wine could be considered an alcohol tincture of several potent flavonoids, including proanthocyanidins from grape seed.
Next week we’ll talk about the Flavonols, also called Flavonoids (not to be confused with the larger category of Phenols also called the Flavonoid). I’ll explain this next week.
Cinnamon contains a variety of phytonutrients, including the flavan-3-ols similiar to those found in grapes, berries, cocoa and green tea (OPCs and catechins). This class of antioxidants boosts the stablilizing effect of insulin on blood sugar. At the same time, these antioxidants inhibit insulin resistance. Just a few of the benefits of these phytonutrients are as follows:
The Last Quiz Answer:
This is our friend from a couple of weeks ago, close up, the Kudu. Couldn’t pass up showing you this beautiful creature once again. Greater kudu may be active throughout the 24-hour day. The large ears are extremely sensitive to noise, making these shy antelope difficult to approach. Under normal circumstance, kudu will sneak away and hide from potential enemies. When startled, however, they flee with large jumps with their tails rolled upwards and forwards. Kudu often stop and look back after a running for a short distance - a frequently fatal habit. Despite their large size, kudu are accomplished jumpers, with records of heights of over 2.5 meters / 8.25 feet being cleared with ease. (ultimateungulate.com/…/Tragelaphus_strepsiceros)