polyphenols
9 interactions related to polyphenols
black tea + iron
Polyphenols (tannins) in black tea bind non-heme iron in the gut lumen to form insoluble iron-tannate complexes, blocking absorption. Inhibition of non-heme iron uptake from a meal can reach 79-94% when black tea is consumed with food.
black tea + thiamine
Black tea contains antithiamine factors - polyphenols such as tannins and chlorogenic acid - that oxidise thiamine (vitamin B1) into thiochrome-negative, biologically inactive forms in the gut. High habitual tea consumption has been linked to reduced thiamine status, especially in populations with marginal B1 intake.
green tea + iron
Green tea catechins, especially epigallocatechin-3-gallate (EGCG), chelate non-heme iron in the gut and form insoluble complexes that reduce intestinal absorption. The effect is dose-related and most pronounced when tea is consumed with iron-containing meals or supplements.
resveratrol + quercetin
Quercetin inhibits the sulfotransferase and UDP-glucuronosyltransferase enzymes that rapidly clear resveratrol, prolonging its plasma half-life and free fraction. The two polyphenols also act synergistically on antioxidant and SIRT1-related longevity pathways in cell and animal studies.
peppermint tea + iron
Peppermint tea is rich in polyphenols (particularly rosmarinic acid) and tannins that bind non-heme iron in the gut, forming insoluble complexes that cannot be absorbed. Controlled studies show peppermint tea can reduce non-heme iron absorption from a meal by up to 84%.
coffee + vitamin b1
Some early studies suggested coffee contains compounds with antithiamine activity, but follow-up work showed chlorogenic and caffeic acids are not active antithiamine agents under physiological conditions. Heavy coffee or tea intake on a marginal thiamine diet can still modestly worsen thiamine status.
curcumin + quercetin
Quercetin inhibits the same UDP-glucuronosyltransferase and CYP3A4 enzymes that rapidly metabolize curcumin, raising its plasma exposure, and both polyphenols share complementary anti-inflammatory and antioxidant pathways. In vitro intestinal models and animal studies show the combination increases apical-to-basal uptake of curcumin and amplifies NF-kB pathway suppression.
oolong tea + iron
Oolong tea sits between green and black tea in polyphenol oxidation and contains substantial tannins and catechins that bind non-heme iron in the gut to form insoluble iron-polyphenol complexes. Drinking oolong tea with meals reduces absorption of dietary and supplemental non-heme iron.
coffee + iron
Coffee contains chlorogenic acid and other polyphenols with galloyl groups that chelate non-heme iron in the gut lumen, forming insoluble complexes. A cup of coffee taken with a meal can reduce non-heme iron absorption by roughly 39% to 60%.