A long, very comprehensive review. FULL TEXT
MikeV
American Journal of Clinical Nutrition, Vol. 79, No. 5, 727-
747, May 2004 © 2004 American Society for Clinical Nutrition
Polyphenols: food sources and bioavailability
Claudine Manach, Augustin Scalbert, Christine Morand,
Christian Rémésy and Liliana Jiménez From the Unité des
Maladies Métaboliques et Micronutriments, INRA, Saint-Genès
Champanelle, France (CM, AS, CM, and CR), and Danone
Vitapole Research, Palaiseau cedex, France (LJ).
Abstract Polyphenols are abundant micronutrients in our
diet, and evidence for their role in the prevention of
degenerative diseases such as cancer and cardiovascular
diseases is emerging. The health effects of polyphenols
depend on the amount consumed and on their bioavailability.
In this article, the nature and contents of the various
polyphenols present in food sources and the influence of
agricultural practices and industrial processes are
reviewed. Estimates of dietary intakes are given for each
class of polyphenols. The bioavailability of polyphenols is
also reviewed, with particular focus on intestinal
absorption and the influence of chemical structure (eg,
glycosylation, esterification, and polymerization), food
matrix, and excretion back into the intestinal lumen.
Information on the role of microflora in the catabolism of
polyphenols and the production of some active metabolites
is presented. Mechanisms of intestinal and hepatic
conjugation (methylation, glucuronidation, sulfation),
plasma transport, and elimination in bile and urine are
also described. Pharmacokinetic data for the various
polyphenols are compared. Studies on the identification of
circulating metabolites, cellular uptake, intracellular
metabolism with possible deconjugation, biological
properties of the conjugated metabolites, and specific
accumulation in some target tissues are discussed. Finally,
bioavailability appears to differ greatly between the
various polyphenols, and the most abundant polyphenols in
our diet are not necessarily those that have the best
bioavailability profile. A thorough knowledge of the
bioavailability of the hundreds of dietary polyphenols will
help us to identify those that are most likely to exert
protective health effects.