Phytate, a compound found in plant-based foods like beans and whole grains, reduces how much iron the body can absorb from food. Even small amounts, such as 2 milligrams, can lower iron absorption by...
Mechanism
Synthesis from 1 study
Phytate in food binds tightly to iron from plants, making it impossible for the gut to absorb. Even a tiny amount can block nearly one-fifth of the iron, and more phytate means even less iron gets in. This is why foods like whole grains can reduce how much iron your body actually uses.
Most probable mechanism
When phytate is present in the gut, it grabs onto iron from plant foods and locks it into a solid clump that the body can't absorb. This happens even with very small amounts of phytate, and the more phytate there is, the more iron gets trapped. As a result, less iron enters the bloodstream, reducing the body's ability to use it.
Phytic acid binds to dietary non-heme iron through its multiple phosphate groups, forming a stable, insoluble complex in the intestinal lumen.
The phytate-iron complex remains undissolved under physiological intestinal pH, preventing interaction with the divalent metal transporter 1 (DMT1) on the surface of intestinal cells.
Reduced iron uptake into intestinal cells decreases the amount of iron available for transport into the bloodstream via transferrin.
Evidence from Studies
Supporting (1)
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Iron absorption in man: ascorbic acid and dose-dependent inhibition by phytate.
Contradicting (0)
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