Re: Green Tea Extract (iron deficiency)

[Guest guest]

How do you know green tea is related to iron deficiency?

> Hello all,

> I confess to being a green tea addict, but would like to say that

drinking a

> lot of tea before and after mealtimes has given me an iron

deficiency. Now I

> make sure tea consumption is at least 1 hour from meal times. It

seems that

> cocoa and coffee also have this effect, though a bit less. So

perhaps

> extracts of green tea should also be far from meals if you are at

all iron

> deficient.

> On the other hand one of the benefits of green tea is its ability

to absorb

> iron in those people who build it up as excess iron is thought to

be a major

> cause of free radical damage.

>

> my two cents worth..

> best wishes to all

> MM

>

> _________________________________________________________________

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[Guest guest]

Dear ,

Thank you, here are some papers that I found on pubmed and google (easy to

do!) on tea and iron absorption. Again thanks and

best wishes,

MM

Green tea or rosemary extract added to foods reduces nonheme-iron

absorption.

Samman S, Sandstrom B, Toft MB, Bukhave K, Jensen M, Sorensen SS, Hansen M.

Research Department of Human Nutrition, LMC Centre for Advanced Food

Studies, The Royal Veterinary and Agricultural University, Frederiksberg,

Denmark. s.samman@...

BACKGROUND: Phenolic compounds act as food antioxidants. One of the

postulated mechanisms of action is chelation of prooxidant metals, such as

iron. Although the antioxidative effect is desirable, this mechanism may

impair the utilization of dietary iron. OBJECTIVE: We sought to determine

the effect of phenolic-rich extracts obtained from green tea or rosemary on

nonheme-iron absorption. DESIGN: Young women aged 19-39 y consumed test

meals on 4 separate occasions. The meals were identical except for the

absence (meal A) or presence (meal of a phenolic-rich extract from green

tea (study 1; n = 10) or rosemary (study 2; n = 14). The extracts (0.1 mmol)

were added to the meat component of the test meals. The meals were

extrinsically labeled with either 55Fe or 59Fe and were consumed on 4

consecutive days in the order ABBA or BAAB. Iron absorption was determined

by measuring whole-body retention of 59Fe and the ratio of 55Fe to 59Fe

activity in blood samples. RESULTS: The presence of the phenolic-rich

extracts resulted in decreased nonheme-iron absorption. Mean (+/-SD) iron

absorption decreased from 12.1 +/- 4.5% to 8.9 +/- 5.2% (P < 0.01) in the

presence of green tea extract and from 7.5 +/- 4.0% to 6.4 +/- 4.7% (P <

0.05) in the presence of rosemary extract. CONCLUSION: Phenolic-rich

extracts used as antioxidants in foods reduce the utilization of dietary

iron.

PMID: 11237939 [PubMed - indexed for MEDLINE]

Natural polyphenols-iron interaction: its biological importance.

Anghileri LJ, Thouvenot P.

Biophysics Laboratory, Medicine Faculty, University of , Vandoeuvre les

, France.

The iron-binding capacity of different fractions of natural polyphenols

extracts was determined by chromatographic and electrophoretic methods.

Their effects on iron-induced calcium homeostasis changes in liver tissue

suspension showed that mate tea and green tea extracts provoke a very

significant inhibition of the iron effects, whereas it is much less

significant with red wine extract. The biological importance of this

phenomenon is discussed.

PMID: 11049215 [PubMed - indexed for MEDLINE]

GUT 1998;43:699-704 ( November )

Clinical trial on the effect of regular tea drinking on iron accumulation in

genetic haemochromatosis

J P Kaltwasser,a E Werner,b K Schalk,a C Hansen,b R Gottschalk,a C

Seidlc

a Medizinische Klinik III, Zentrum der Inneren Medizin, der Johann Wolfgang

Goethe-Universität, Theodor-Stern-Kai 7, D-60596 furt am Main, Germany,

b Institute of Radiation Protection, GSF-National Research Center for

Environment and Health, Ingolstädter Landstr. 1, D-85764 Oberschleiheim,

Germany, c Institut für Transfusionsmedizin und Immunhämatologie

Blutspendedienst des DRK Hessen, Sandhofstrasse 1, D-60528 furt am Main

Correspondence to: Professor J P Kaltwasser.

BackgroundBlack tea is known to be a potent inhibitor of intestinal

absorption of non-haem iron at least in healthy subjects.

AimsTo investigate this effect in patients with genetic haemochromatosis,

and, more importantly, the effect of regular tea drinking on the

accumulation of storage iron in these patients over one year.

PatientsInvestigations were carried out on 18 patients with clinically

proven genetic haemochromatosis. For the study of storage iron

accumulation, they were separated into a group instructed to drink a

particularly tannin rich tea regularly with meals and a control group.

MethodsIntestinal iron absorption from a test meal was measured using whole

body counting. Body iron stores were evaluated quantitatively by exhaustive

phlebotomy, using haemoglobin, saturation of serum iron binding capacity,

and serum ferritin for the assessment of body iron status.

ResultsA significant reduction in iron absorption was observed when the

test meal was accompanied by drinks of tea instead of water. In the tea

drinking group, the increase in storage iron was reduced by about one third

compared with that of the control group.

ConclusionsRegular tea drinking with meals reduces the frequency of

phlebotomies required in the management of patients with haemochromatosis.

(GUT 1998;43:699-704

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