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Phytic Acid (Inositol Hexaphosphate)

What is phytic acid?

Phytic acid or inositol hexaphosphate (IP-6) is a phosphorus-containing acid found mainly in grains, nuts and legumes [7]. It can inhibit the absorption of certain minerals, so it is considered an “antinutrient.”

Absorption and Functions of Phytic Acid in the Human Body

  • Phytic acid (inositol hexaphosphate or IP6) is poorly absorbed [7]. Phytic acid consumed along with calcium, iron, magnesium, manganese, potassium and zinc inhibits the absorption of both phytic acid and the minerals but it is not clear if it can contribute to any significant deficiency of these minerals [7,9].
  • The absorbed phytic acid is partly metabolized to inositol and partly excreted in the urine [7].

Foods High in Phytic Acid

  • PLANT FOODS: wheat bran, wheat germ, rice bran, whole grains, corn, nuts, legumes (beans, peas, lentils), seeds (linseed, sunflower seeds) [7]

In foods, phytic acid occurs in the form of phytic acid salts, for example, calcium, magnesium or potassium phytate [7]. The amount of phytates in foods, such as beans, can be greatly reduced by soaking and cooking [10].

Diet high in phytic acid is POSSIBLY EFFECTIVE in reducing the risk of kidney stones, since it inhibits crystalization of calcium in the urine [2,4,5,6].

Phytic Acid as a Food Additive

Phytic acid can be added to certain beverages as a preservative. It is Generally Recognized As Safe (GRAS) by the U.S. Food and Drug Administration (FDA) [7].

Phytic Acid Supplements

Health Benefits

There is NO EVIDENCE about the effectiveness of phytic acid supplements in the prevention and treatment of cancer [3,8] or heart attack.

Phytic Acid Safety: Side Effects, Toxicity

No side effects of phytic acid are known [7].

Not enough is known about the safety of phytic acid supplements during pregnancy and breastfeeding, so women in these periods should avoid them [2].

Phytic Acid-Drug Interactions

  • Phytic acid may reduce the absorption of calcium and iron from the foods [7,9] and supplements [2].
  • IP-6 nicotinate may slow down blood clotting, so it may increase the risk of bleeding when taken together with medications that slow down clotting: aspirin, clopidogrel, diclofenac, ibuprofen, naproxen, dalteparin, heparin and warfarin.

  1. Phytic acid  PubChem
  2. IP-6  WebMD
  3. Fake cancer “cures” consumers should avoid  US Food and Drug Administration
  4. Grases F et al, 1999, Phytate (IP6) is a powerful agent for preventing calcifications in biological fluids: usefulness in renal lithiasis treatment  PubMed
  5. Saxena A et al, 2010, Nutritional aspect of nephrolithiasis  PubMed Central
  6. Curhan GC et al, 2004, Dietary factors and the risk of incident kidney stones in younger women: Nurses’ Health Study II  PubMed
  7. 2011, GRAS Notification for Phytic Acid (50% Solution)  US Food and Drug Administration
  8. Fox CH et al, 2002, Phytic acid (IP6), novel broad spectrum anti-neoplastic agent: a systematic review  PubMed
  9. Bohn L et al, 2008, Phytate: impact on environment and human nutrition. A challenge for molecular breeding  PubMed Central
  10. Nakitto AM et al, 2015, Effects of combined traditional processing methods on the nutritional quality of beans  PubMed Central

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