Phytic acid
A natural plant extract that inhibits mineral absorption.
- Category
- Preservatives
- Vegan
- Yes
- Vegetarian
- Yes
What it is
A natural acid found in plant seeds and bran, functioning as an antioxidant but famously known as an "anti-nutrient".
How it is used in food
Phytic acid is the principal phosphorus store in seeds, nuts and whole grains, and its strong metal-chelating ability makes it an effective antioxidant and preservative: by binding free iron it blocks the Fenton reaction that drives fat rancidity and colour loss. The same chelation is being studied for genuine health benefits, including reduced kidney-stone formation and possible anticancer activity in the colon.
Commonly found in- Historically as a food additive
Health and safety
Safe but inhibits the body's absorption of essential minerals like iron, zinc, and calcium. Not officially authorised as an EU E-number.
Phytic acid is not authorised as an E-number additive in the EU; it is present in food naturally rather than added. Its best-documented effect is inhibition of non-haem iron and zinc absorption — WHO/FAO and EFSA both treat the phytate:mineral molar ratio as a key determinant of mineral bioavailability, which matters most for populations relying heavily on unrefined cereals and legumes with little meat or vitamin C. Reviews (for example Schlemmer et al., 2009) describe it as a double-edged compound: an antinutrient for mineral status but with plausible antioxidant and chemopreventive roles, and no evidence of toxicity.
Regulatory status
| Region | Status | Notes |
|---|---|---|
| Australia & New Zealand FSANZ |
Permitted | Permitted under the FSANZ Food Standards Code. |
| European Union EFSA / European Commission |
Not approved | Not on the EU authorised list of food additives (Annex II). |
| United States FDA (Food and Drug Administration) |
Permitted | Authorised for food use by the FDA (often GRAS for standard additives). |
Identification on labels
- E-number
- E391
Worth knowing
Traditional food preparation evolved around phytic acid long before it was identified: soaking, sprouting, sourdough fermentation and nixtamalisation all activate phytase enzymes or acidic conditions that break it down, which is one reason long-fermented sourdough bread delivers more absorbable minerals than quick-risen wholemeal bread.
Conclusion
A natural plant extract that inhibits mineral absorption.
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Open the appEntry last reviewed 2026-07-28.
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