What Do Phytates Do to Your Body? The Complete Guide

December 24, 2025 •

4 min read

Phytates, or phytic acid, are natural compounds found in the seeds of plants, including grains, legumes, and nuts. Historically labeled as "anti-nutrients," they are now recognized for both their mineral-binding properties and significant health benefits, challenging the long-held negative perception.

Quick Summary

Phytates can inhibit mineral absorption, but research reveals they also possess potent antioxidant, anti-inflammatory, and anti-cancer properties. Understanding this dual role, combined with proper food preparation, allows for maximizing health benefits.

Key Points

Dual Action: Phytates act as both mineral-absorption inhibitors and powerful health-promoting compounds with antioxidant and anti-cancer effects.
Mineral Binding: They bind to essential minerals like iron, zinc, and calcium in the gut, reducing their absorption from plant-based foods.
Antioxidant and Anti-inflammatory: Phytates are potent antioxidants that combat oxidative stress and inflammation, contributing to disease prevention.
Cancer Protection: The IP6 form of phytates has shown promise in inhibiting the growth and spread of various cancer cells, potentially turning them back into normal cells.
Kidney Stone Prevention: Phytates inhibit the formation of calcium salt crystals, which is key to preventing kidney stones and pathological calcifications.
Mitigation Strategies: Soaking, sprouting, and fermentation are effective and traditional methods for reducing the phytate content in foods.
Dietary Context is Key: For those with a balanced diet, phytates pose little risk, but individuals with heavy plant-based diets or existing deficiencies should pay closer attention to food preparation.

The Dual Nature of Phytates: Anti-Nutrient and Bioactive Compound

Phytates, also known as inositol hexaphosphate or IP6, exist as the main storage form of phosphorus in many plant seeds. In their natural state, they are crucial for a plant's development. For humans, however, their strong chelating (binding) ability has given them a dual reputation. On one hand, they bind to minerals in the digestive tract, potentially reducing their absorption. On the other, these same binding properties and potent antioxidant effects are responsible for a range of health-promoting actions in the body.

The Anti-Nutrient Effect: Inhibiting Mineral Absorption

When consumed, phytates can bind to positively charged minerals in the digestive system, forming insoluble complexes that the body cannot easily absorb. The primary minerals affected by this chelating process include:

Iron: Phytates significantly reduce the absorption of non-heme iron, the type found in plant foods. Heme iron from animal sources is not affected.
Zinc: A potent inhibitor of zinc absorption, which can be a concern for those with heavy plant-based diets.
Calcium: Phytates bind to calcium, which can impact its bioavailability, especially from plant-based sources.
Magnesium and Manganese: The absorption of these minerals can also be affected, though often to a lesser extent.

For the average person consuming a varied diet, the risk of developing a mineral deficiency from phytates is low. The effect is typically limited to the meal in which high-phytate foods are consumed and does not significantly impact overall mineral status over the long term. However, for individuals with poor iron or zinc stores, or those whose diets consist almost exclusively of unprocessed grains and legumes, the inhibitory effects can be more pronounced.

The Protective Effect: Health Benefits of Phytates

Despite their anti-nutrient reputation, phytates are not all bad. Research has illuminated a wide array of powerful health benefits:

Antioxidant Powerhouse: Phytates are strong antioxidants that help neutralize free radicals in the body, reducing oxidative stress and fighting inflammation.
Anti-Cancer Potential: The inositol hexaphosphate (IP6) molecule has been studied for its ability to inhibit cancer cell growth, and in some cases, induce cancerous cells to revert to a normal state. It is believed to act as a "Trojan horse," being absorbed by cancer cells and then causing their destruction. IP6's effects have been studied in relation to colon, breast, prostate, and liver cancers, among others.
Cardiovascular Health: Research suggests phytate consumption may protect against atherosclerosis and coronary heart disease by preventing pathological calcification in blood vessels.
Prevents Kidney Stones: By inhibiting the crystallization of calcium salts, phytates can help prevent the formation of kidney stones.
Diabetes Management: Some studies suggest phytates can assist with blood sugar control by delaying starch digestion and improving insulin sensitivity.
Bone Health: Contrary to concerns about calcium absorption, studies link higher phytate consumption to increased bone mineral density and a lower risk of osteoporosis. It inhibits the breakdown of bone mineral complexes.
Detoxification: Phytates can bind to and remove toxic heavy metals like lead and cadmium from the body.

Mitigating Phytates: Enhancing Mineral Absorption

For those concerned about mineral absorption, simple food preparation methods can significantly reduce phytate levels and enhance nutrient bioavailability.

Effective Phytate Reduction Methods

Soaking: Submerging grains, legumes, and nuts in water for several hours activates the naturally occurring enzyme phytase, which breaks down phytic acid. Discarding the soaking water is key.
Sprouting: Also known as germination, this process triggers a higher level of phytase activity, leading to a substantial breakdown of phytates.
Fermentation: Lactic acid fermentation, as used in sourdough bread, effectively degrades phytic acid.
Cooking: Extended cooking, especially after soaking, can further break down phytates.

A Comparison of Phytate Reduction Techniques


Method	Effectiveness	Best For	Considerations
Soaking	Moderate reduction; activates phytase	Grains, legumes, nuts	Simple, but requires planning; discard water
Sprouting	High reduction; significant phytase activation	Grains, legumes, seeds	Requires more time and attention; ideal for high-mineral foods
Fermentation	High reduction; beneficial bacteria produce acids	Sourdough bread, fermented foods	Good for grains and legumes; alters flavor
Cooking	Varies; high heat can degrade phytase	Legumes, grains	Often used in combination with soaking for maximum effect

Who Needs to Worry About Phytates?

For most people eating a balanced diet, the benefits of including phytate-rich whole foods far outweigh the potential negative effects on mineral absorption. The minerals lost are typically a small fraction of the total daily intake. However, special attention may be needed for:

Vegans and Vegetarians: Rely heavily on plant-based food, increasing phytate intake while potentially reducing intake of easily-absorbed heme iron. They should focus on preparation methods and consume Vitamin C with meals.
Individuals with Mineral Deficiencies: Those with pre-existing iron, zinc, or calcium deficiencies should monitor their intake and use preparation methods that reduce phytate content.
Populations with Food Insecurity: In regions where the diet is monotonous and centered on unprocessed, phytate-rich grains, mineral deficiencies are a real concern.

Conclusion

Phytates occupy a fascinating place in nutrition, being both a minor mineral absorption inhibitor and a powerful bioactive compound with significant health benefits. The narrative surrounding them has shifted from a one-sided negative view to a more balanced understanding that recognizes their protective, antioxidant, and anti-cancer properties. For a healthy, varied diet, there is little cause for concern, and the inclusion of whole grains, legumes, nuts, and seeds is highly recommended. For those who consume large quantities of these foods or have specific nutritional needs, simple, traditional food preparation techniques like soaking, sprouting, and fermentation are effective tools for enhancing mineral bioavailability. Ultimately, the presence of phytates is not a reason to avoid nutrient-dense plant foods but rather to appreciate their complex role in promoting overall health. For further reading on other common anti-nutrients and their effects, you can visit Harvard's T.H. Chan School of Public Health Nutrition Source.

Frequently Asked Questions

Foods high in phytates include whole grains like wheat, rice, and oats; legumes such as beans, lentils, and chickpeas; nuts like almonds and walnuts; and seeds such as sesame and flaxseeds.

Phytates can contribute to mineral deficiencies, particularly in iron and zinc, but this is rarely a concern for people with a balanced diet. It is more of an issue for those whose diet is heavily reliant on unprocessed, phytate-rich foods and who may have existing low mineral stores.

You can reduce phytate content through methods like soaking, sprouting (germination), and fermentation. Soaking grains and legumes for several hours before cooking can significantly lower phytic acid levels, as can sprouting seeds.

Yes, extensive research shows that the IP6 component of phytates has significant anti-cancer properties. It works by inhibiting cancer cell growth and inducing apoptosis (cell death) in various types of cancer, including colon, breast, and prostate.

No. The impact of phytates is context-dependent. It poses a greater risk for individuals following restrictive plant-based diets (vegan, vegetarian) and those suffering from malnutrition, compared to individuals consuming a diverse, mixed diet.

For most people, a low-phytate diet is not necessary or recommended. The benefits of consuming whole foods rich in fiber, vitamins, and minerals—despite their phytate content—typically outweigh the risks. The focus should be on a varied diet and proper food preparation.

Cooking, particularly prolonged methods like boiling and pressure cooking, can reduce phytate levels. Its effectiveness is often increased when combined with prior soaking or fermentation, which breaks down phytic acid further.