Adding phytic acid, a compound naturally present in brown bread, to white bread lowers the amount of magnesium the body can absorb from that bread, reducing absorption from about 32% to 24% in...
Mechanism
Synthesis from 1 study
Phytic acid in bread grabs onto magnesium in your gut and locks it into a form your body can't absorb. The magnesium then leaves your body in poop instead of entering your bloodstream.
Most probable mechanism
When phytic acid is eaten with food, it binds tightly to magnesium in the gut, forming a solid compound that the body cannot absorb. This bound magnesium passes through the digestive tract and leaves the body in stool instead of entering the bloodstream.
Phytic acid dissociates from food matrix in the intestinal lumen under physiological pH conditions
Phytic acid chelates free magnesium ions to form insoluble phytate-magnesium complexes
The insoluble complexes remain in the intestinal lumen and are excreted in feces, preventing magnesium uptake by enterocytes
Evidence from Studies
Supporting (1)
Community contributions welcome
Phytic acid added to white-wheat bread inhibits fractional apparent magnesium absorption in humans.
Contradicting (0)
Community contributions welcome
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.