| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
DIETARY POLYPHENOLS AND HEALTH: PROCEEDINGS OF THE 1ST INTERNATIONAL CONFERENCE ON POLYPHENOLS AND HEALTH |
1 From the Department of Biochemistry, Faculty of Medicine, Singapore (BH, AJ), and the Department of Medical Nutrition, Karolinska Institute, Huddinge, Sweden (JR)
ABSTRACT
Foods and beverages rich in phenolic compounds, especially flavonoids, have often been associated with decreased risk of developing several diseases. However, it remains unclear whether this protective effect is attributable to the phenols or to other agents in the diet. Alleged health-promoting effects of flavonoids are usually attributed to their powerful antioxidant activities, but evidence for in vivo antioxidant effects of flavonoids is confusing and equivocal. This may be because maximal plasma concentrations, even after extensive flavonoid intake, may be low (insufficient to exert significant systemic antioxidant effects) and because flavonoid metabolites tend to have decreased antioxidant activity. Reports of substantial increases in plasma total antioxidant activity after flavonoid intake must be interpreted with caution; findings may be attributable to changes in urate concentrations. However, phenols might exert direct effects within the gastrointestinal tract, because of the high concentrations present. These effects could include binding of prooxidant iron, scavenging of reactive nitrogen, chlorine, and oxygen species, and perhaps inhibition of cyclooxygenases and lipoxygenases. Our measurements of flavonoids and other phenols in human fecal water are consistent with this concept. We argue that tocopherols and tocotrienols may also exert direct beneficial effects in the gastrointestinal tract and that their return to the gastrointestinal tract by the liver through the bile may be physiologically advantageous.
Key Words: Flavonoid • polyphenol • antioxidant • gastrointestinal tract • tocopherols • free radicals • iron • cancer
This article has been cited by other articles:
|
|
 |
|
  T. A. Barringer, L. Hatcher, and H. C. Sasser Potential Benefits on Impairment of Endothelial Function after a High-fat Meal of 4 weeks of Flavonoid Supplementation Evid. Based Complement. Altern. Med., July 3, 2008; (2008) nen048v1. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Taubert, R. Roesen, C. Lehmann, N. Jung, and E. Schomig Effects of Low Habitual Cocoa Intake on Blood Pressure and Bioactive Nitric Oxide: A Randomized Controlled Trial JAMA, July 4, 2007; 298(1): 49 - 60. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Halliwell Dietary polyphenols: Good, bad, or indifferent for your health? Cardiovasc Res, January 15, 2007; 73(2): 341 - 347. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. R. Ferguson, M. Philpott, and N. Karunasinghe Oxidative DNA Damage and Repair: Significance and Biomarkers J. Nutr., October 1, 2006; 136(10): 2687S - 2689S. [Full Text] [PDF]
|
|
|
|
|
|
P. Brat, S. George, A. Bellamy, L. D. Chaffaut, A. Scalbert, L. Mennen, N. Arnault, and M. J. Amiot Daily Polyphenol Intake in France from Fruit and Vegetables J. Nutr., September 1, 2006; 136(9): 2368 - 2373. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. C. Karlsson, U. Huss, A. Jenner, B. Halliwell, L. Bohlin, and J. J. Rafter Human Fecal Water Inhibits COX-2 in Colonic HT-29 Cells: Role of Phenolic Compounds J. Nutr., October 1, 2005; 135(10): 2343 - 2349. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Ahmed, N. Wang, B. B. Hafeez, V. K. Cheruvu, and T. M. Haqqi Punica granatum L. Extract Inhibits IL-1{beta}-Induced Expression of Matrix Metalloproteinases by Inhibiting the Activation of MAP Kinases and NF-{kappa}B in Human Chondrocytes In Vitro J. Nutr., September 1, 2005; 135(9): 2096 - 2102. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
