Phytic acid, a compound found in plant foods, binds to iron, calcium, zinc, and magnesium in the digestive tract, which decreases how much of these minerals the body can take up.
Mechanism
Synthesis from 4 studies
Phytic acid in plant foods binds to minerals like iron, zinc, calcium, and magnesium in the gut, turning them into solid clumps that the body can't absorb. These clumps just pass through and leave the body in stool, so less of these important minerals get into the bloodstream.
Most probable mechanism
When phytic acid is eaten with food, it binds tightly to minerals like iron, zinc, calcium, and magnesium in the gut, turning them into solid clumps that the body can't absorb. These clumps pass through the intestine and are pooped out instead of being taken into the bloodstream.
Phytic acid dissociates from food matrices in the gastrointestinal lumen under physiological pH conditions and becomes available to interact with free mineral ions.
Phytic acid forms insoluble, high-affinity complexes with divalent cations including iron, magnesium, zinc, and calcium, rendering them bio-unavailable.
These insoluble mineral-phytate complexes remain in the intestinal lumen and are not transported across the intestinal epithelium by known mineral uptake pathways.
The unabsorbed mineral-phytate complexes are excreted in feces, resulting in reduced systemic mineral availability.
Evidence from Studies
Supporting (4)
Community contributions welcome
Phytic acid added to white-wheat bread inhibits fractional apparent magnesium absorption in humans.
Degradation of phytic acid in cereal porridges improves iron absorption by human subjects.
The influence of different protein sources on phytate inhibition of nonheme-iron absorption in humans.
Contradicting (0)
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