New book in Dutch

Eet vet word slank

Eet vet word slank gepubliceerd januari 2013

In dit boek lees je o.a.: * heel veel informatie ter bevordering van je gezondheid; * hoe je door de juiste vetten te eten en te drinken kan afvallen; * hoe de overheid en de voedingsindustrie ons, uit financieel belang, verkeerd voorlichten; * dat je van bewerkte vetten ziek kan worden.

Trick and Treat:
How 'healthy eating' is making us ill
Trick and Treat cover

"A great book that shatters so many of the nutritional fantasies and fads of the last twenty years. Read it and prolong your life."
Clarissa Dickson Wright

Natural Health & Weight Loss cover

"NH&WL may be the best non-technical book on diet ever written"
Joel Kauffman, PhD, Professor Emeritus, University of the Sciences, Philadelphia, PA

Soy Online Service

Soy protein, phytate, and iron absorption

Search for nutritional confounding factors in the relationship between iron deficiency and brain function

Hallberg L

Am J Clin Nutr 1989 Sep 50:3 Suppl 598-604; discussion 604-6


This paper on confounding factors in the relationship between iron deficiency and brain function is mainly limited to nutritional factors, primarily factors that can contribute to the development of iron deficiency and that may have an independent direct action on brain function.

Three theoretically possible confounders were found in a systematic search for dietary factors: 1) low intake of ascorbic acid, 2) excess of phytates, and 3) increased absorption of lead.

Ascorbic acid has a marked effect on the bioavailability of dietary iron and is also known to directly influence various metabolic processes in the brain. Phytates inhibit the absorption not only of iron but also of zinc. An iron deficiency may thus be accompanied by a zinc deficiency which may affect mental performance.

A state of iron deficiency may increase the absorption of lead from the diet, which in turn may affect brain function.

Soy protein, phytate, and iron absorption in humans.

Hurrell RF, Juillerat MA, Reddy MB, Lynch SR, Dassenko SA, Cook JD

Am J Clin Nutr 1992 Sep 56:3 573-8


The effect of reducing the phytate in soy-protein isolates on nonheme-iron absorption was examined in 32 human subjects.

Iron absorption was measured by using an extrinsic radioiron label in liquid-formula meals containing hydrolyzed corn starch, corn oil, and either egg white or one of a series of soy-protein isolates with different phytate contents.

Iron absorption increased four- to fivefold when phytic acid was reduced from its native amount of 4.9-8.4 to less than 0.01 mg/g of isolate.

Even relatively small quantities of residual phytate were strongly inhibitory and phytic acid had to be reduced to less than 0.3 mg/g of isolate (corresponding to less than 10 mg phytic acid/meal) before a meaningful increase in iron absorption was observed.

However, even after removal of virtually all the phytic acid, iron absorption from the soy-protein meal was still only half that of the egg white control.

It is concluded that phytic acid is a major inhibitory factor of iron absorption in soy-protein isolates but that other factors contribute to the poor bioavailability of iron from these products.

Iron bioavailability studied in infants: the influence of phytic acid and ascorbic acid in infant formulas based on soy isolate.

Davidsson L, Galan P, Kastenmayer P, Cherouvrier F, Juillerat MA, Hercberg S, Hurrell RF

Pediatr Res 1994 Dec 36:6 816-22


The influence of phytic acid and ascorbic acid content of soy formula on iron (Fe) bioavailability was investigated in infants by analysis of the incorporation of stable isotopes of Fe into red blood cells 14 d after administration using a double stable isotope technique.

Paired comparisons were made with each infant acting as his or her own control.

The geometric mean fractional Fe incorporation into red blood cells increased from 5.5 to 6.8% (p < 0.05) when soy formula with the native content of phytic acid was compared with a 83% dephytinized formula. A more pronounced effect was shown with soy formula containing no phytic acid; the mean fractional Fe incorporation increased from 3.9 (native phytic acid) to 8.7% (zero phytic acid; p < 0.001).

A significant (p < 0.01) effect was also demonstrated when the Fe:ascorbic acid molar ratio in the native phytate-containing formula was increased from 1:2.1 to 1:4.2; mean fractional Fe incorporation increased from 5.9 to 9.6%.

These results demonstrate that the Fe bioavailability from soy-based infant formulas can be similarly increased by either removing phytic acid or increasing the ascorbic acid content.

A comparison of iron absorption in adults and infants consuming identical infant formulas.

Hurrell RF, Davidsson L, Reddy M, Kastenmayer P, Cook JD

Br J Nutr 1998 Jan 79:1 31-6


Fe absorption was estimated in adults and infants from the erythrocyte incorporation of Fe isotopes added to infant formula.

Fe absorption was measured in adults using radioisotopes, and in infants with a stable-isotope technique.

In adults, the geometric mean Fe absorption from a ready-to-feed soya formula with its native phytic acid content was 2.4%. This increased to 6.0% (P < 0.05) after almost complete dephytinization.

In infants, mean Fe absorption values were 3.9 and 8.7% respectively from the same products (P < 0.05). In adults, mean Fe absorption from a spray-dried soya formula containing 110 mg ascorbic acid/l was 4.1%, increasing to 5.3% (P < 0.05) when ascorbic acid was doubled to 220 mg/l. In infants, mean Fe absorption values were 5.7 and 9.5% (P < 0.05) from the same products.

Mean Fe absorption from a milk-based formula was 6.5% in adults compared with 6.7% in infants. All meals in the adult and infant studies were fed using an identical meal size of 217 g. Increasing the meal size threefold in adults did not change fractional Fe absorption.

Mean Fe absorption values for each meal were lower in adults than in infants but the relative inhibitory effect of phytic acid and the enhancing effect of ascorbic acid were similar.

We conclude that Fe absorption studies in adults can be used to assess the influence of enhancers and inhibitors of Fe absorption in infant formulas fed to infants. Further studies, however, are required to extend these findings to weaning foods and complete meals.



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