FHN Complementary Medicine Monthly Newsletter January 2002
Last November we had a wonderful CME by UW on the flavonoids in red wine and the effects on cardiovascular health. We thought we would expand on that topic as there are more biologically active flavonoids in foods. As a matter of fact flavonoids may account for the difference in studies using "natural"( those derived from foods and processed intact) vitamins and their synthetic counter parts. We have all seen the studies that seem to counteract one another.
So lets discuss bioflavonoids!
Bioflavonoids are sometimes considered vitamins because they possess the properties of a vitamin and were referred to as the vitamin P. They cannot be produced by the body and have to be taken as supplements or found in food in diet. Bioflavonoids are natural compounds and are often pigments and occur in high concentrations in all fruits(especially found in peel of citrus fruits), peppers, buckwheat and black currants. Other sources include apricots, cherries, grape fruit, grapes, grape seed, lemons, oranges, prunes, rose hips. Herbs that contain bioflavonoids include chervil, elderberries, hawthorn, berry, horsetail, rose hips and sheperd’s purse, as well as in vegetables( including onions),and tea. Different bioflavinoids have different properties and activities. Let's look at some of the more common:
Quercetin is found in red wine, grapefruit, onions, apples, black tea and, in lesser amounts, in leafy green vegetables and beans. However, to get a therapeutic dosage, a supplement is needed. Quercetin supplements are available in pill and tablet form. Quercetin acts on the mast and basil cell to reduce the histamine production at the source. As such it does not have the side effects of histamine blocking type agents.
Proanthocyanidins can be found in many plants, most notably pine bark, grape seed, and grape skin. However, bilberry, cranberry, black currant, green tea, black tea, and other plants also contain these flavonoids. Nutritional supplements containing extracts of proanthocyanidins from various plant sources are available, alone or in combination with other nutrients, in herbal extracts, capsules, and tablets. These are very powerful antioxidant substances.
Lycopene is an open-chain unsaturated carotenoid that imparts red color to tomatoes and several other fruits, but unlike the other carotenoids, lycopene does not convert into vitamin A. It is also one of the most abundant carotenoids in human blood serum and is the most abundant carotene in prostate tissue. It helps bolster the body's defense mechanisms, resulting in greater protection of the body's enzymes, DNA and cellular lipids.
Lycopene is a powerful antioxidant that has shown remarkable fighting power against degenerative diseases. It eliminates a particularly destructive form of oxidation called free radicals and is more than twice as powerful as beta-carotene at quenching free radicals. Lycopene is found in many red foods, like tomatoes and tomato products like tomato sauce, tomato paste and ketchup. It is also found in pink grapefruit, watermelon, guava, palm oil, and to a lesser extent in lobster and crab.
Daidzein is one of the primary isoflavones of soy, a staple food in many Asian countries. The term "soy" is used to refer to many products derived from the soybean. The isoflavones are dietary supplements derived from soybeans as isolated/concentrated soy proteins and soy extracts. Daidzein are believed to have hormonal balancing activity. Please note that the more processed the soy the less daidzein. Rendering most commercial soy products very poor in this area.
Silymarin /Milk thistle is commonly found growing wild in a variety of settings, including roadsides. The seeds of the dried flower are used. Milk thistle extract may protect the cells of the liver by blocking the entrance of harmful toxins and helping remove these toxins from the liver cells. As with other bioflavonoids, silymarin is a powerful antioxidant. Milk thistle also regenerates injured liver cells. Milk thistle extract is most commonly recommended to counteract the harmful actions of alcohol on the liver.
Long-term placebo-controlled, double blind studies have shown milk thistle extracts to be effective in patients with liver cirrhosis, chronic hepatitis, and even diabetes due to cirrhosis. However, there have also been studies that have shown no effect in cirrhosis patients. Milk thistle alters bile makeup, thereby potentially reducing risk of gallstones. Combination of milk thistle with potentially liver-damaging drugs has been shown to protect the liver.
There are many more bioflavonoids some of the more common include:
Anthcyanin – found in black berries, blueberries, raspberries
Ellagic Acid – found in strawberries, grapes, apples, cranberries
Catechin – found in green tea, black tea
Tannin – found in green tea, black tea
Kaempferol – found in strawberries, leeks, kale, broccoli, radishes
Hesperdin and Rutin- Found in buckwheat and citrus
When combined in a comprehensive therapeutic approach biofavonoids are a powerful tool. They may help mitigate some of the side effects of drug/chemotherapy, helping to make it more effective and less toxic.
Dr. Julie Smith
Dr. Glenn Smith