Phytic acid in wheat bread reduces how much magnesium the body absorbs, even when the bread contains the same amount of magnesium, because phytic acid binds directly to magnesium and prevents its...

Pro

Against

Mechanism

Synthesis from 1 study

How it works

Phytic acid in bread grabs onto magnesium in your gut and locks it into a form your body can't absorb. Even if the bread has plenty of magnesium, it all ends up being flushed out instead of being used, because it's stuck to the phytic acid.

Most probable mechanism

In Simple Terms

When phytic acid is present in food, it binds tightly to magnesium in the gut, creating a solid compound that the body cannot absorb. This bound magnesium passes through the digestive tract and is removed in stool, so even if there's plenty of magnesium in the food, the body can't take it in because it's locked up by phytic acid.

Causal chain

Phytic acid dissociates from food matrix in the intestinal lumen under physiological pH conditions

Supported by evidence

which leads to

Phytic acid chelates free magnesium ions to form insoluble phytate-magnesium complexes

Verified by multiple studies

which leads to

The insoluble complexes remain in the intestinal lumen and are not transported across the intestinal epithelium

Verified by multiple studies

which leads to

Magnesium contained in the complexes is excreted in feces without entering systemic circulation

Verified by multiple studies

Evidence from Studies

Supporting (1)

Community contributions welcome

Phytic acid added to white-wheat bread inhibits fractional apparent magnesium absorption in humans.

Randomized Controlled Trial

Human

2004 Mar

Contradicting (0)

Community contributions welcome

No contradicting evidence found

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.

Source Study

Phytic acid added to white-wheat bread inhibits fractional apparent magnesium absorption in humans.

Score: 55

DOI: 10.1093/AJCN/79.3.418

Similar Assertions

Phytic acid, a compound naturally found in whole-grain breads, reduces how much magnesium the body can absorb from those breads, meaning the total magnesium listed on nutrition labels may overestimate how much is actually usable.

89%

Consuming phytic acid with white bread reduces the amount of magnesium the body absorbs, with higher amounts of phytic acid leading to greater reductions in absorption.

89%

Adding a specific amount of phytic acid to white-wheat bread lowers how much magnesium the body can absorb from the bread, which may reduce the availability of this mineral in diets that rely heavily on cereal products.

87%

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 healthy people.

87%

PK0-28011 is a chemical that lowers phytic acid levels in rice and wheat grains by up to 47% without changing the amount of minerals like iron and zinc, which allows the body to absorb more of these minerals relative to phytic acid.

71%