Tags

Type your tag names separated by a space and hit enter

Iron absorption and phenolic compounds: importance of different phenolic structures.
Eur J Clin Nutr 1989; 43(8):547-57EJ

Abstract

The phenolic compounds (phenolic monomers, polyphenols, tannins) are considered to interfere with iron absorption by complex formation with iron in the gastro-intestinal lumen, making the iron less available for absorption. Very little is known about the extent to which different types of phenolic compounds of different size and chemical structure inhibit iron absorption. The relationship between iron absorption and the amount and type of phenolic compounds was studied by the extrinsic tag method. The aims of the studies were as follows: (i) To study the effect of small phenolic compounds with different hydroxylation patterns (gallic acid, catechin, chlorogenic acid) on iron absorption, (ii) To study the effect of different amounts of a hydrolysable tannin containing ten gallic acid residues (tannic acid) on iron absorption. (iii) To study the degree of inhibition of iron absorption by some foods and beverages (oregano, spinach, coffee and tea) in relation to their respective content of iron-binding phenolic groups, measured by a newly developed method. The inhibition of iron absorption by tannic acid was strongly dose-related. The smallest amount (5 mg) inhibited absorption by 20 per cent, 25 mg by 67 per cent and 100 mg by 88 per cent. Gallic acid inhibited iron absorption to the same extent as tannic acid, per mol galloyl groups, whereas no inhibition was observed when catechin was added to the test meal. Chlorogenic acid inhibited iron absorption to a lesser extent. Oregano and tea inhibited iron absorption in proportion to their respective content of galloyl groups, whereas the inhibitory effect of spinach was less marked. The inhibiting effect of coffee was explained mainly by its content of galloyl groups, but also by some other factor, probably chlorogenic acid. It is concluded that the content of iron-binding galloyl groups might be a major determinant of the inhibitory effect of phenolic compounds on iron absorption from the diet, whereas the phenolic catechol groups seem to be of minor importance. The results further suggest that the group of condensed tannins do not interfere with iron absorption.

Authors+Show Affiliations

Department of Medicine II, University of Göteborg, Sweden.No affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

2598894

Citation

Brune, M, et al. "Iron Absorption and Phenolic Compounds: Importance of Different Phenolic Structures." European Journal of Clinical Nutrition, vol. 43, no. 8, 1989, pp. 547-57.
Brune M, Rossander L, Hallberg L. Iron absorption and phenolic compounds: importance of different phenolic structures. Eur J Clin Nutr. 1989;43(8):547-57.
Brune, M., Rossander, L., & Hallberg, L. (1989). Iron absorption and phenolic compounds: importance of different phenolic structures. European Journal of Clinical Nutrition, 43(8), pp. 547-57.
Brune M, Rossander L, Hallberg L. Iron Absorption and Phenolic Compounds: Importance of Different Phenolic Structures. Eur J Clin Nutr. 1989;43(8):547-57. PubMed PMID: 2598894.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Iron absorption and phenolic compounds: importance of different phenolic structures. AU - Brune,M, AU - Rossander,L, AU - Hallberg,L, PY - 1989/8/1/pubmed PY - 1989/8/1/medline PY - 1989/8/1/entrez SP - 547 EP - 57 JF - European journal of clinical nutrition JO - Eur J Clin Nutr VL - 43 IS - 8 N2 - The phenolic compounds (phenolic monomers, polyphenols, tannins) are considered to interfere with iron absorption by complex formation with iron in the gastro-intestinal lumen, making the iron less available for absorption. Very little is known about the extent to which different types of phenolic compounds of different size and chemical structure inhibit iron absorption. The relationship between iron absorption and the amount and type of phenolic compounds was studied by the extrinsic tag method. The aims of the studies were as follows: (i) To study the effect of small phenolic compounds with different hydroxylation patterns (gallic acid, catechin, chlorogenic acid) on iron absorption, (ii) To study the effect of different amounts of a hydrolysable tannin containing ten gallic acid residues (tannic acid) on iron absorption. (iii) To study the degree of inhibition of iron absorption by some foods and beverages (oregano, spinach, coffee and tea) in relation to their respective content of iron-binding phenolic groups, measured by a newly developed method. The inhibition of iron absorption by tannic acid was strongly dose-related. The smallest amount (5 mg) inhibited absorption by 20 per cent, 25 mg by 67 per cent and 100 mg by 88 per cent. Gallic acid inhibited iron absorption to the same extent as tannic acid, per mol galloyl groups, whereas no inhibition was observed when catechin was added to the test meal. Chlorogenic acid inhibited iron absorption to a lesser extent. Oregano and tea inhibited iron absorption in proportion to their respective content of galloyl groups, whereas the inhibitory effect of spinach was less marked. The inhibiting effect of coffee was explained mainly by its content of galloyl groups, but also by some other factor, probably chlorogenic acid. It is concluded that the content of iron-binding galloyl groups might be a major determinant of the inhibitory effect of phenolic compounds on iron absorption from the diet, whereas the phenolic catechol groups seem to be of minor importance. The results further suggest that the group of condensed tannins do not interfere with iron absorption. SN - 0954-3007 UR - https://www.unboundmedicine.com/medline/citation/2598894/Iron_absorption_and_phenolic_compounds:_importance_of_different_phenolic_structures_ L2 - https://ClinicalTrials.gov/search/term=2598894 [PUBMED-IDS] DB - PRIME DP - Unbound Medicine ER -