Inhibition of food iron absorption by coffee.
Dual isotope studies were performed in iron replete human subjects to evaluate the effect of coffee on nonheme iron absorption. A cup of coffee reduced iron absorption from a hamburger meal by 39% as compared to a 64% decrease with tea, which is known to be a potent inhibitor of iron absorption. When a cup of drip coffee or instant coffee was ingested with a meal composed of semipurified ingredients, absorption was reduced from 5.88% to 1.64 and 0.97%, respectively, and when the strength of the instant coffee was doubled, percentage iron absorption fell to 0.53%. No decrease in iron absorption occurred when coffee was consumed 1 h before a meal, but the same degree of inhibition as with simultaneous ingestion was seen when coffee was taken 1 h later. In tests containing no food items, iron absorption from NaFeEDTA was diminished to the same extent as that from ferric chloride when each was added to a cup of coffee. These studies demonstrate that coffee inhibits iron absorption in a concentration-dependent fashion.
D000293:Adolescent; D000328:Adult; D000740:Anemia / Q000209:etiology; D002712:Chlorides; D003069:Coffee / Q000009:adverse effects*; D004492:Edetic Acid / Q000494:pharmacology; D005260:Female; D005290:Ferric Compounds / Q000494:pharmacology; D005293:Ferritins / Q000097:blood; D006400:Hematocrit; D006801:Humans; D007408:Intestinal Absorption; D007501:Iron / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D013997:Time Factors
D002712:Chlorides; D003069:Coffee; D005290:Ferric Compounds; D005293:Ferritins; D004492:Edetic Acid; D007501:Iron; C019179:Fe(III)-EDTA; C024555:ferric chloride