Effect of dietary phytate on growth and selenium status of chicks fed selenite or selenomethionine.
Level 5 - mechanism / opinion, no new human data
Animal experiment (chick model)
PubMed 7719737 · doi:10.1080/00071669408417738
What was done
Chicks were fed semi-purified diets with or without dietary phytate, combined with or without selenium supplementation (200 µg Se/kg as sodium selenite or selenomethionine). Investigators evaluated chick growth, feed intake, food conversion efficiency, glutathione peroxidase (GSHPx) activity, and specific selenium fractions (selenide-Se, reducible-Se, and non-reducible-Se) across blood, liver, kidney, heart, and muscle tissue.
What was found
The abstract reports directions and statistical significance without numerical values. Dietary phytate significantly reduced chick growth, feed consumption, and feed conversion efficiency. Supplemental selenium did not affect growth but significantly increased GSHPx activity across all tested tissues, with selenomethionine yielding greater tissue selenium deposition than selenite. Phytate increased GSHPx activity in blood and heart (and in muscle when supplemental selenium was absent), but reduced activity in kidney. Phytate also increased total selenium in all tissues except muscle, raising reducible selenium in blood, liver, and heart, and non-reducible selenium in blood and kidney.
Why it matters
While phytate is well known as an anti-nutrient that impairs growth and mineral absorption, these findings indicate it may unexpectedly enhance tissue selenium retention or alter selenium metabolism in poultry.
Limits
The abstract reports no sample sizes, specific quantitative means, or confidence intervals. The physiological mechanism driving increased tissue selenium (whether enhanced absorption or reduced excretion) was not determined, and findings in growing chicks on semi-purified diets cannot be directly generalized to humans or other species.
Cited by
- contradicts Phytic acid found in legumes and whole grains binds to divalent cations including zinc, copper, magnesium, and selenium, inhibiting their absorption.