Consuming 2.34 grams of phytate daily in a controlled diet lowers the amount of zinc the body absorbs from about 34% to 17.5%, which is a 48% reduction in zinc uptake.

Pro

Against

Mechanism

Synthesis from 1 study

How it works

Phytate in food binds to zinc in the gut, making it stuck and impossible for the body to absorb. As a result, the zinc passes through the digestive system and leaves the body in stool instead of entering the bloodstream.

Most probable mechanism

In Simple Terms

When phytate is eaten, it binds tightly to zinc in the gut, forming a solid compound that the body cannot absorb. This prevents zinc from entering the bloodstream, so most of it passes out in the stool instead of being used by the body.

Causal chain

Phytate dissociates in the intestinal lumen and binds to free zinc ions, forming an insoluble complex.

Verified by multiple studies

which leads to

The phytate-zinc complex remains stable at physiological pH and cannot be transported across the intestinal epithelial cell membrane.

Verified by multiple studies

which leads to

Reduced zinc uptake by intestinal cells leads to lower zinc concentrations in the bloodstream and decreased renal excretion of zinc.

Verified by multiple studies

Evidence from Studies

Supporting (1)

Community contributions welcome

A stable isotope study of zinc absorption in young men: effects of phytate and alpha-cellulose.

Randomized Controlled Trial

Human

1984 Nov

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

A stable isotope study of zinc absorption in young men: effects of phytate and alpha-cellulose.

Score: 44

DOI: 10.1093/AJCN/40.5.1071

Similar Assertions

Consuming 2.34 grams of phytate daily with a liquid diet lowers the amount of zinc the body absorbs by nearly half, from 34% to 17.5%, when the ratio of phytate to zinc in the diet is 15:1.

99%

When phytate and zinc are consumed together in a 15:1 ratio, zinc absorption decreases in healthy young men. However, this study does not show that this reduction leads to zinc deficiency in real-life eating patterns.

88%

When healthy adults eat diets low in zinc for several weeks and consume foods with little phytate, their bodies absorb a higher percentage of the zinc they eat, up to 92% more than under normal conditions.

88%

Eating large amounts of phytate, a compound found in some plant foods, might reduce how much zinc the body absorbs in the short term under controlled lab conditions, but this does not necessarily mean it causes zinc deficiency in people eating normal diets.

88%

When the ratio of phytate to zinc in food is high (15:1), the body absorbs less zinc than when the ratio is low (near 1:1). This suggests that the relative amounts of phytate and zinc in the diet directly affect how much zinc the body can take up.

86%