What do phytates do in the human body? Benefits, Risks, and How to Manage Them

December 10, 2025 •

4 min read

A significant portion of the world relies on diets rich in plant foods, meaning they also consume phytates. Understanding what do phytates do in the human body involves exploring their dual role as both mineral binders and potent health-promoting compounds found in grains, legumes, and nuts.

Quick Summary

Phytates, or phytic acid, are compounds in plant seeds that can bind minerals, limiting their absorption. However, they also possess antioxidant and anti-inflammatory properties, offering significant health benefits for most people.

Key Points

Mineral Binding: Phytates can bind to minerals like iron, zinc, and calcium in the gut, potentially reducing their absorption, though this is primarily a concern in nutrient-poor diets.
Potent Antioxidant: Phytates act as powerful antioxidants by chelating iron, which helps prevent oxidative damage and reduces inflammation throughout the body.
Prevents Calcification: Phytates inhibit the crystallization of calcium salts, which is a key mechanism in preventing kidney stones, dental calculus, and dangerous vascular calcifications.
Anticancer Potential: Research suggests that phytates have anti-cancer effects, inhibiting the growth of various cancer cells and potentially reducing the risk of cancers like colon cancer.
Culinary Management: Simple food preparation methods such as soaking, sprouting, and fermentation can significantly reduce the phytic acid content in grains, nuts, and legumes.
Supports Bone Health: Despite concerns over calcium absorption, a diet high in phytates is associated with greater bone mineral density and a lower risk of osteoporosis.

Phytates, also known as phytic acid (IP6), are naturally occurring compounds found in the seeds of all plants, including grains, legumes, nuts, and seeds. Historically, they've been labeled as 'anti-nutrients' due to their ability to bind with minerals in the digestive tract, which can interfere with absorption. However, modern research reveals a more complex picture, showing that phytates also possess impressive health-promoting properties that, for most individuals on a balanced diet, far outweigh their inhibitory effects.

The Dual Nature of Phytates: "Antinutrient" vs. Health Promoter

Phytates play a dual role in human nutrition, affecting both mineral bioavailability and providing a range of therapeutic benefits.

Phytates and Mineral Absorption

As a storage form of phosphorus in plants, phytic acid has a high affinity for positively charged minerals. In the digestive tract, it binds to essential minerals such as iron, zinc, calcium, and magnesium, forming insoluble compounds called phytates. Because humans lack the necessary enzymes (phytases) to break down these complexes efficiently, the bound minerals cannot be absorbed and are instead excreted as waste.

This mineral-binding effect is a primary concern for populations with predominantly plant-based diets, low mineral intake, or malabsorption issues. For the majority of people consuming a varied and balanced diet, however, this effect is considered minimal. Dietary modifications and proper food preparation techniques can further mitigate any potential negative impact.

Health-Promoting Roles

Beyond their perceived 'antinutrient' status, phytates act as powerful health promoters in the human body:

Antioxidant and Anti-inflammatory effects: Phytates are potent antioxidants that combat oxidative stress and have anti-inflammatory actions. This is partly achieved by chelating iron, which reduces the formation of harmful free radicals.
Cardiovascular Health: Studies suggest phytate intake is linked to improved cardiovascular health by helping to lower blood lipids, triglycerides, and blood glucose response.
Anti-cancer Properties: Research has demonstrated phytates' anticancer activity, with studies showing they can inhibit the growth and spread of certain cancer cells, particularly those related to the colon and breast.
Neuroprotection: Their antioxidant and anti-inflammatory actions help protect against neuronal damage and loss, showing promise for preventing neurodegenerative diseases.
Prevention of Pathological Calcification: Phytates inhibit calcium salt crystallization, which can help prevent the formation of kidney stones, dental calculus, and vascular calcifications.
Bone Health: Contrary to concerns about calcium absorption, long-term consumption of phytate-rich foods is associated with increased bone mineral density and reduced risk of osteoporosis.

Managing Phytate Intake

For those who wish to reduce the phytate content of their food, various preparation methods can significantly lower levels and increase mineral bioavailability without needing to eliminate healthy foods.

Culinary Techniques to Reduce Phytates

Soaking: Soaking grains, legumes, nuts, and seeds in water for several hours or overnight can significantly reduce phytate content. Soaking also activates endogenous enzymes that help break down phytic acid.
Sprouting (Germination): The sprouting process naturally breaks down phytates to liberate phosphorus for the growing plant. Sprouting seeds and grains before use can be a highly effective strategy.
Fermentation: The organic acids produced during fermentation, such as in sourdough bread, promote the breakdown of phytic acid. Lactic acid fermentation can lower phytate levels by 12-51%.
Cooking: Longer cooking times, particularly for legumes, can also help degrade phytic acid content.
Combining Methods: Using a combination of these techniques, like soaking followed by cooking, is most effective.

Comparison of Phytate Effects


Feature	Antinutrient Perspective	Health-Promoting Perspective
Mineral Binding	Strong binding of iron, zinc, and calcium, reducing their intestinal absorption and potentially causing deficiencies in vulnerable populations.	Binds and helps remove toxic heavy metals like lead and cadmium from the body.
Nutrient Impact	Inhibits absorption of minerals consumed in the same meal, especially for those with low overall nutrient intake.	Overall, part of nutrient-dense foods (legumes, nuts, whole grains), whose health benefits often outweigh the minor mineral loss for most people.
Cellular Effects	Can inhibit some digestive enzymes, like pepsin and amylase, though the clinical significance is debated.	Functions as a powerful antioxidant and anti-inflammatory agent, protecting cells from damage and disease.
Long-Term Health	High intake without mineral compensation can pose a risk for deficiencies, particularly for vegans and those with malnutrition.	Associated with a lower risk of chronic diseases, including cancer, diabetes, and osteoporosis, especially in well-nourished individuals.

Conclusion

Understanding what do phytates do in the human body reveals they are not simply harmful 'antinutrients' but complex compounds with diverse physiological impacts. While they do inhibit the absorption of some minerals, their potent antioxidant, anti-inflammatory, and anti-cancer properties provide considerable health benefits. For most people on a balanced diet, the inclusion of phytate-rich foods like whole grains, nuts, seeds, and legumes is a vital part of a healthy eating pattern. For those with specific concerns or risk factors, simple culinary preparations like soaking and sprouting can effectively reduce phytate content. Ultimately, the best approach is not to fear phytates, but to appreciate their nuanced role in whole-food nutrition.

Learn more about preparing plant-based foods to maximize nutrient absorption from sources like the Harvard T.H. Chan School of Public Health.(https://nutritionsource.hsph.harvard.edu/anti-nutrients/)

Frequently Asked Questions

No, phytates are not inherently bad for you. While they can inhibit mineral absorption, they also provide significant health benefits as antioxidants and anti-inflammatory agents. The risks of mineral deficiency are primarily a concern for those on highly restrictive or poor-quality diets.

Phytates are found in a variety of plant-based foods, particularly the seeds, shells, and outer layers. Common sources include whole grains (e.g., wheat, rice), legumes (e.g., beans, lentils), nuts (e.g., almonds, walnuts), and seeds (e.g., flaxseeds, sesame seeds).

You can significantly reduce phytate levels through preparation methods like soaking grains and legumes overnight, sprouting (germinating) seeds, and fermentation (e.g., making sourdough bread). Cooking, especially for longer periods, also helps.

The mineral-binding effect of phytates occurs only during the meal in which they are consumed and does not carry over to subsequent meals. This is why eating a varied and balanced diet throughout the day is so effective at offsetting any minor impact.

Yes, research indicates that phytates can be beneficial for bone health. They have been shown to help prevent bone mass loss, with studies linking higher phytate intake to greater bone mineral density and reduced osteoporosis risk.

Evidence suggests that phytates may help prevent certain chronic diseases. Their antioxidant and anti-inflammatory properties are linked to a reduced risk of some cancers, diabetes, and cardiovascular disease.

Vegans and vegetarians, who typically consume high-phytate, plant-based diets, may be at a higher risk of developing mineral deficiencies like iron and zinc insufficiency. They can address this by increasing mineral intake, utilizing food preparation techniques to reduce phytates, and ensuring dietary diversity.