Dietary Flavonoids for Immunoregulation and Cancer: Food Design for Targeting Disease
Antioxidants doi: 10.3390/antiox8070202
Authors: Ahn-Jarvis Parihar Doseff
Flavonoids, one of the most abundant phytochemicals in a diet rich in fruits and vegetables, have been recognized as possessing anti-proliferative, antioxidant, anti-inflammatory, and estrogenic activities. Numerous cellular and animal-based studies show that flavonoids can function as antioxidants by preventing DNA damage and scavenging reactive oxygen radicals, inhibiting formation of DNA adducts, enhancing DNA repair, interfering with chemical damage by induction of Phase II enzymes, and modifying signaling pathways. Recent evidence also shows their ability to regulate the immune system. However, findings from clinical trials have been mixed with no clear consensus on dose, frequency, or type of flavonoids best suited to elicit many of the beneficial effects. Delivery of these bioactive compounds to their biological targets through “targeted designed” food processing strategies is critical to reach effective concentration in vivo. Thus, the identification of novel approaches that optimize flavonoid bioavailability is essential for their successful clinical application. In this review, we discuss the relevance of increasing flavonoid bioavailability, by agricultural engineering and “targeted food design” in the context of the immune system and cancer.
Some examples of foods that contain flavonoids are described below: Citrus fruits Citrus fruits such as lemons and oranges contain flavonoids such as hesperidin, quercitrin and rutin. Hesperidin is a glycoside of hesperetin which is a flavanone, and quercitrin and rutin are glycosides of quercetin, which is a flavonol. Another flavonoid found in citrus fruits is tangeritin. Green and white tea Green tea is rich in flavonoids that posses antioxidant properties, which can protect against heart disease and cancer. Some of the important flavonoids in green tea include kaempferol and catechins such as epicatechin, epicatechin gallate, and epigallocatechin gallate. When oolong tea or black tea is prepared, the leaves are allowed to oxidize. This causes conversion of some or all of the catechins to larger molecules and reduces the flavonoid content. White tea is tea that has undergone even less processing than green tea and therefore provides the highest catechin content. Red wine Wine is prepared from grapes, the skins of which are known to contain significant amounts of flavonoids and other polyphenols. The flavonoids are mainly stripped from the stems, skins and seeds of the grape during the wine making process. Red and white wine both contain flavonoids but red wine contains more flavonoids since less contact is made with the skins of white grapes during winemaking. Dark chocolate Flavonoids occur naturally in chocolate but are often extracted because they can taste bitter. Flavonoids are also present in both dark and milk chocolate, although milk can disrupt their absorption. Some examples of other foods that contain flavonoids include: Seabuckthorn Berries, particularly blueberries Onions Parsley Ginkgo biloba Lentils and pulses Sources http://mimoza.marmara.edu.tr/~ozan.deveoglu/A11.pdf http://www.fc.up.pt/pessoas/lfguido/Design/Assets/Flavonoids.pdf http://www.ipharmsciencia.com/Dacuments/1/4.pdf http://ajcn.nutrition.org/content/74/4/418.abstract