Effect of beef and soy proteins on the absorption of non-heme iron and inorganic zinc in children.
BACKGROUND
Iron and zinc deficiency remain substantial problems in small children in both developed and developing nations. Optimizing mineral absorption is an important strategy in minimizing this problem.


OBJECTIVE
To assess the effects of beef and soy proteins on the bioavailability of non-heme iron and zinc in children.


METHODS
We measured iron (n = 26) and zinc (n = 36) absorption in 4-8 y old children from meals differing only in protein source (beef or a low-phytate soy protein concentrate). Iron and zinc absorption were measured using multi-tracer stable isotope techniques. Iron absorption was calculated from the red blood cell iron incorporation measured after 14 days and zinc absorption from the ratio of the oral and intravenous excretion of the zinc tracers 48 hours after dosing.


RESULTS
Iron absorption from the beef meal was significantly greater (geometric mean, 7.6%) than from the soy meal (3.5%, p = 0.0015). Zinc absorption from the beef meal was greater (mean +/- SD, 13.7 +/- 6.0%) than from the soy meal (10.1 +/- 4.1%, p = 0.047).


CONCLUSIONS
These findings indicate that beef protein increases both non-heme iron and zinc absorption compared to soy protein. The effect of protein source on non-heme iron and inorganic zinc absorption should be one of the factors taken into account when designing diets for children. The inhibitory effect of the soy based meal on iron and zinc absorption could be overcome by fortifying the soy protein with these minerals during the production process.
Etcheverry
Paz
P
USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, 1100 Bates Street, Houston, Texas 77030, USA.
Hawthorne
Keli M
KM
Liang
Lily K
LK
Abrams
Steven A
SA
Griffin
Ian J
IJ
D001682:Biological Availability; D002648:Child; D002675:Child, Preschool; D004044:Dietary Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007408:Intestinal Absorption; D019266:Iron, Dietary / Q000493:pharmacokinetics*; D008297:Male; D008460:Meat; D011865:Radioisotope Dilution Technique; D030262:Soybean Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D014131:Trace Elements / Q000493:pharmacokinetics*; D015032:Zinc / Q000493:pharmacokinetics* / Q000652:urine
D004044:Dietary Proteins; D006454:Hemoglobins; D019266:Iron, Dietary; D030262:Soybean Proteins; D014131:Trace Elements; D015032:Zinc