Phytate and refugees
Phytate and refugees André Briend 18.04.97
Re: Phytate and refugees Michael H.N. Golden 22.04.97


Fri, 18 Apr 1997 13:40:50 +0100 (BST)

From: briendatext.jussieu.fr (Andre' BRIEND)

Subject: Phytate and refugees

 

I leave Mike comment on the phytate content of food given to refugees.

Let me point out that food given to moderately malnourished kids (CSB type) is almost always cooked by extrusion. The references below suggest that it may reduce phytate disgestion. Clearly, 'more research is needs to be done on the subject'.

TI : Extrusion cooking of a high-fibre cereal product. 2. Effects on apparent absorption of zinc, iron, calcium, magnesium and phosphorus in humans. AU : Kivisto B; Andersson H; Cederblad G; Sandberg AS; Sandstrom B AF : Department of Clinical Nutrition, Gothenburg University, Sweden.

LP : ENGLAND,

SO : Br J Nutr; 1986 Mar: 55(2): 255-60

DEA : Absorption; Adult; Calcium/Pharmacokinetics; Cookery*; Dietary Fiber*/Pharmacokinetics; Female; Human; Iron/Pharmacokinetics; Magnesium/Pharmacokinetics; Male; Middle Age; Minerals/*Pharmacokinetics; Phosphorus/Pharmacokinetics; Support, Non-U.S. Gov't; Zinc/Pharmacokinetics PTA :

JOURNAL ARTICLE

RN : 0 (Minerals); 7439-89-6 (Iron); 7439-95-4 (Magnesium); 7440-66-6 (Zinc); 7440-70-2 (Calcium); 7723-14-0 (Phosphorus);

RES :

1.The effect of extrusion cooking, using mild conditions, of a high-fibre cereal product on apparent small bowel absorption of zinc, iron, calcium, magnesium and phosphorus was studied.

2.Seven ileostomy subjects were studied during two periods (each of 4 d), on a constant low-fibre diet supplemented with either 54 g/d of a bran-gluten-starch mixture or the corresponding extruded product.

3.The apparent absorption of Zn, Mg and P was significantly decreased (P less than 0.05) during the period with extruded product compared with the period with bran-gluten-starch.No difference was found for Fe and Ca.

4.The negative effect of extrusion cooking of a product containing phytic acid on availability of Zn, Mg and P was small but could be of nutritional relevance in foodstuffs that are consumed frequently and in infant formulas.

 

TI : Degradation products of bran phytate formed during digestion in the human small intestine: effect of extrusion cooking on digestibility. LA : Eng AU : Sandberg AS; Andersson H; Carlsson NG; Sandstrom B AF : Department of Food Science, Chalmers University of Technology, Goteborg, Sweden.

LP : UNITED STATES

SO : J Nutr; 1987 Dec: 117(12): 2061-5

DEA : Cereals; Cookery*; Dietary Fiber/Administration & dosage; Digestion*; Energy Intake; Female; Human; Intestine, Small/*Metabolism; Male; Phytic Acid/Analysis/*Metabolism; Support, Non-U.S. Gov't

PTA : JOURNAL ARTICLE

RN : 83-86-3 (Phytic Acid);

RES : To investigate the digestion of phytate in the stomach and small intestine in humans, studies were performed in subjects with established ileostomy.A recently developed high performance liquid chromatography method made it possible to analyze phytate and its degradation products in food and digesta.The digestibility of phytate in raw bran and extruded bran was investigated in seven ileostomy patients.Each subject was studied for two 4-d periods while consuming a constant low fiber diet with the addition of either 54 g/d of a bran-gluten-starch mixture or the corresponding extruded product.During passage through the subject's stomach and small intestine 58%, on average, of the phytate in unprocessed bran was hydrolyzed to inositol penta-, tetra- and triphosphates.When bran was subjected to extrusion cooking, 25% of the inositol hexaphosphate was hydrolyzed to penta- and tetraphosphate and the phytase activity ceased.Essentially no phytate digestion occurred when the ileostomy subjects consumed the extruded product.The reduced digestibility might be due to the lost phytase activity or to formation of indigestible phytate complexes during extrusion cooking.

 

Dr. André Briend


Subject: Re: Phytate and refugees

Date: Tue, 22 Apr 1997 10:42:57 +0100 (BST)

From: "Michael H.N. Golden" <m.goldenatabdn.ac.uk>

 

The phytate content of the refugee foods that I measured (see list distributed with message last week) were all from foods that were collected in the field. All the samples of CSB were from refugee camps in Africa. Thus, the levels were still high AFTER extrusion cooking.

There are no regulations or standards at all for the levels of anti-nutrients that can be in foods distributed to relief programs and none of the weanign foods that were produced within the third world had the levels of anti-nutrients measured or even considered before they are given to children. We did find that they were very variable. Several of the foods had saponins and quite high levels of lectins. The concentrations of anti-trypsin, anti-chymotrypsin and anti-alpha-amylase were frequently surprisingly high and they all had appreciable levels of phytate in them.

Codex Alimetarius is silent on anti-nutrients. It is unclear what the tolerable levels should be in healthy children. There is an urgent need for the Codex commission to convene an expert meeting to make recommendations about these components of food.

The level of antinutrient tolerable by the child with severe malnutrition, who already has pancreatic atrophy and major problems with absorption, is likely to be much lower than that for a healthy child.

If anyone has experience with the induction of malabsorption when porridges are introduced we would be very interested to hear from them. If anyone else has data on the anti-nutrient levels of diets/foods used in the management of malnourished people I would love to hear from them.

Best wishes,

 

Prof. Michael H.N.Golden