Food With Phytic Acid

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Our blog provides you with information on the importance of phytic acid and how to reduce it in your food. We provide recipes that can help lower phytate levels, thereby promoting healthy digestive function and overall wellness.

Food With Phytic Acid

The highest concentrations of phytic acid are found in raw and unprocessed plant-based foods. 

If your diet lacks nutrition or you have an iron or zinc deficiency, you should reduce the amount of phytic acid you consume. 

Here are four foods high in phytic acid:

1. Beans

Most beans and legumes contain a high amount of phytic acid. However, studies have shown that soaking beans before eating them significantly reduces their phytate levels.

2. Seeds

When a plant is ripening, phytate rapidly accumulates in its seeds. Phytic acid is found in sesame seeds, linseeds, and sunflower seeds.

3. Nuts

Nuts naturally contain a high amount of phytic acid. The process of “activating” nuts by soaking them in water and then dehydrating them at a low temperature breaks down some of the phytic acid. 

However, many people think this laborious process is not worth the end result, as it gets rid of only a small amount of phytates.

4. Grains

Grains contain phytic acid, but only if they haven’t been processed. Whole grains also contain lectins and saponins, which are two more anti-nutrients. However, products made with processed grains contain fewer healthy nutrients.

Why You Should Avoid Phytic Acid

People sometimes refer to phytic acid as an anti-nutrient, because it blocks the absorption of certain minerals into the body. 

When you eat foods high in phytic acid, the molecules bind with certain minerals in your digestive tract, including: 

  • Calcium
  • Magnesium
  • Iron
  • Zinc
  • Chromium
  • Manganese 

Once this occurs, your body no longer has access to these nutrients.

Generally, the more phytic acid you eat, the more minerals are blocked from your body.

However, recent studies have shown that phytic acid’s anti-nutrient effect occurs only when large amounts of phytates are consumed within a diet that is already lacking nutrition. It also only affects the absorption of nutrients eaten at the same meal. 

Phytates and phytic acid.
Here’s what you need to know.


Phytic acid – the storage form of phosphorus – is one of those pesky “anti-nutrients” the Paleo community keeps telling you to avoid.

It’s often considered an anti-nutrient because it binds minerals in the digestive tract, making them less available to our bodies.

Yet these same anti-nutrient properties can also help in the prevention of chronic disease.

What is phytic acid?

Seeds — such as nuts, edible seeds, beans/legumes, and grains — store phosphorus as phytic acid. When phytic acid is bound to a mineral in the seed, it’s known as phytate.

The tables below compare various seed types according to their phytic acid/phytate content.

Whole grains

phytic-acid-whole-grains

Source: Schlemmer U, et al. Phytate in foods and significance for humans: Food sources, intake, processing, bioavailability, protective role and analysis. Mol Nutr Food res 2009;53:S330-S375.

Legumes

phytic-acid-beans

Source: Schlemmer U, et al. Phytate in foods and significance for humans: Food sources, intake, processing, bioavailability, protective role and analysis. Mol Nutr Food res 2009;53:S330-S375.

Nuts

phytic-acid-nuts

Source: Schlemmer U, et al. Phytate in foods and significance for humans: Food sources, intake, processing, bioavailability, protective role and analysis. Mol Nutr Food res 2009;53:S330-S375.

Oil seeds

phytic-acid-oils

Source: Schlemmer U, et al. Phytate in foods and significance for humans: Food sources, intake, processing, bioavailability, protective role and analysis. Mol Nutr Food res 2009;53:S330-S375

As you can see, phytic acid content varies greatly among plants.  This is due to the type of seed, environmental condition, climate, soil quality, how phytate is measured in the lab, and so forth.

Roots, tubers, and other vegetables may also contain phytic acid, but usually in lower amounts.

The most concentrated sources tend to be whole grains and beans. Phytic acid is isolated in the aleurone layer in most grains, making it more concentrated in the bran.  In legumes, it’s found in the cotyledon layer (where the protein is).

Phytate = phytic acid bound to a mineral

Phytates perform an essential role in plants, as they are an energy source for the sprouting seed. When a seed sprouts, phytase enzymes break down the stored phytates.

When we eat the plant, phytates are hydrolyzed during digestion to myo-inositol-1,2,3,4,5,6-hexkisphosphate (IP6) and lower inositol polyphosphates including IP1 through IP5 (these are phytate degradation products).

Who’s eating phytic acid?

Everyone who eats plants consumes some phytic acid. It’s all a question of degree.

As you can imagine, intake tends to be much higher among those who follow non-Westernized diets.  In developing countries, plants are staple foods, which means people eat more of them, and therefore get more phytic acid.

In developed countries, plant-based or vegetarian eaters tend to consume more phytic acid than omnivores.  Further, males usually consume more phytic acid than females, simply because they eat more food.

Phytate digestion

Most phytate (37-66%) is degraded in the stomach and small intestines.

Ordinarily, our bodies regulate phytate levels pretty well, adjusting uptake in the gut and excretion until body levels come into balance.

Vitamin D status in the body seems to influence how much phytate is actually retained.  The more vitamin D, the more phytate retained; the less vitamin D, the less phytate retained.

Potential problems with phytic acid

Phytic acid can bind minerals in the gut before they are absorbed and influence digestive enzymes.  Phytates also reduce the digestibility of starches, proteins, and fats.

Here’s an example.

Vegan eaters often consume more iron than omnivores.  Yet, they also consume more anti-nutrients, including phytates, and these reduce the amount of iron available to their bodies. Consuming 5-10 mg of phytic acid can reduce iron absorption by 50%.

This is why vegetarian eaters should eat more iron than omnivores (33 mg for veg eaters vs. 18 mg for omnivores).

Daily iron loss for men & women

  • Adult men lose ~1 mg of iron per day
  • Adult menstruating women lose ~1.4 mg/day
  • Postmenopausal women lose ~0.8 mg/day
  • Lactating women lose ~1.1 mg/day

While in the intestines, phytic acid can bind the minerals iron, zinc, and manganese. Once bound, they are then excreted in waste.

This can be a good or bad thing, depending on the condition.  It’s a bad thing if you’re having trouble building up iron stores in the body and have developed iron-deficiency anemia.

When is it a good thing?  Keep reading – you’ll find potential benefits of phytic acid below.

Potential benefits of phytic acid

Despite its potential drawbacks, phytic acid is similar in some ways to a vitamin, and metabolites of phytic acid may have secondary messenger roles in cells.

Some experts even suggest that it’s the phytic acid in whole grains and beans that lends them their apparent protective properties against cardiovascular disease, cancer, and diabetes.

(Remember, the grains with little to no phytic acid are the refined ones.)

The supplement industry has caught on to this.  Have you even seen a bottle of inositol hexaphosphate, or IP6?  That’s simply a supplemental source of phytic acid.

When phytic acid binds minerals in the gut, it prevents the formation of free radicals, thus making it an antioxidant. Not only that, but it seems to bind heavy metals (e.g., cadmium, lead) helping to prevent their accumulation in the body

Phytic acid’s preventative properties

Cancer

Foods higher in phytic acid seem to enhance the activity of natural killer cells and inhibit tumor growth.

Those who consume more phytic acid are less likely to succumb to breast and prostate cancer. Exposing the colon to less iron seems to decrease the risk of colon cancer.  And phytic acid might reduce the side effects of chemotherapy.

Mode of action - anticancer properties

Source: Vucenik I & Shamsuddin AM. Protection against cancer by dietary IP6 and inositol. Nutrition and Cancer 2006;55:109-125.

Cardiovascular disease

Phytic acid helps prevent hardening of the arteries and platelet formation.

Kidney stones

With some phytate being excreted in the urine, this may improve kidney health and prevent stones.

Insulin resistance

Phytic acid plays a role in pancreatic function and insulin secretion. And it may reduce the glycemic response from meals, meaning you feel full for longer.

Hemochromatosis

Hemochromatosis, or iron overload, is a common genetic disorder that phytic acid’s iron-binding properties can protect against or reduce.

In the balance

Is phytic acid worth worrying about?  Maybe not, for most of us.

One study showed that subjects consuming a Mediterranean-style diet that included 1000-2000 mg of phytic acid per day did not suffer from reduced mineral bioavailability.

At the same time, certain people might have to be more wary.

In particular, iron intake and absorption can be critical for infants nearing six months of age. So when plants are added to infants’ diets, it may be important to adopt strategies to reduce phytic acid and enhance iron absorption.

Overcoming phytic acid as an antinutrient

Luckily, it’s possible to overcome the anti-nutrient effects of phytic acid in our foods while still getting the benefits of a plant-rich diet. Here are a few strategies that my be more or less helpful depending on the specific situation:

Heat

Heating foods can destroy small amounts of phytic acid. (Note: heat can also destroy phytase and vitamin C.)

Processing

Milling grains and removing the bran decreases phytic acid.  Unfortunately, milling also tends to remove many of the minerals! Removing the bran and then enriching a food with minerals might allow for enhanced nutrient absorption in the body.

Soaking

Soaking beans and grains can reduce phytic acid (and other antinutrients).

Fermenting

Fermentation and bread leavening (using yeast) can help to break down phytic acid due to the activation of native phytase enzymes, reducing the number of phosphate groups.

This is big stuff since myo-inositol phosphates with fewer than five phosphate groups don’t inhibit zinc absorption (IP1 to IP4).  And those with fewer than three phosphate groups don’t inhibit iron absorption (IP3 to IP2).

Also, some of the acids produced during fermentation might actually boost absorption of certain minerals.

Sprouting

Sprouting and malting enhances native phytase activity in plants and thus decreases phytic acid.

Vitamin C

Vitamin C appears strong enough to overcome phytic acid.  In one study, adding 50 mg of vitamin C counteracted the phytic acid load of a meal.  In another study, 80 mg of ascorbic acid (vitamin C) counteracted 25 mg of phytic acid.

Protein powders

During processing of plant-based protein powders, it’s possible to de-phytinize (via addition of microbial phytase). Also, protein isolates and concentrates can be treated with dialysis or ultrafiltration to remove phytic acid.

Seed breeding

Scientists are working on seed breeds containing less phytic acid.  There are modern seed hybrids of grain and legume plants that contain less phytic acid.

Animal protein

Animal protein may enhance absorption of zinc, iron, and copper. Adding small amounts of animal protein might increase the absorption of these minerals in the body.   (Well, except for dairy/casein, as it also seems to hinder iron and zinc absorption.)

Gut health

A low pH in the gut enhances iron absorption.  Balancing the level of beneficial bacteria in the GI tract might help with this.   See All About Probiotics.

Phytates and sprouts

Sprouting enhances native phytase activity in plants and thus decreases phytic acid.

Bonus: Can other animals digest phytic acid?

Ruminant animals (e.g., cattle, sheep, goats, buffalo) possess phytase producing flora for digesting phytic acid.

Non-ruminant animals (e.g., pigs, chickens, dogs, cats) don’t have phytase producing flora, so phytic acid passes through them undigested and makes its way into the soil.

Feeding livestock too much grain can inhibit mineral absorption and increase phosphorus excretion, leading to pollution.  Ever heard of the Dead Zone in the Gulf of Mexico?

Summary and recommendations

In healthy people eating balanced diets, phytic acid’s effects on iron, zinc, and manganese status is minimal and it doesn’t seem to cause nutrient deficiencies.

To argue that some plant foods are “unhealthy” because of their phytic acid content seems mistaken, especially when phytic acid’s potential negative effects on mineral assimilation may be offset by its health benefits.

So we should aim to reduce phytic acid rather than eliminate it.

To reduce the anti-nutrient effects of phytic acid in foods, try the following:

  • Soak, sprout, ferment, and cook plant foods.
  • Consume vitamin C-rich foods with meals that contain phytic acid.  Dense source of vitamin C include guava, bell pepper, kiwi, oranges, grapefruit, strawberries, Brussels sprouts, cantaloupe, papaya, broccoli, sweet potato, pineapple, cauliflower, kale, lemon juice, and parsley.
  • Use vinegar in salad dressings and cooking to enhance mineral absorption and offset phytic acid.
  • Supplement with phytase enzymes if necessary.
  • Eat mineral fortified foods if necessary
  • Supplement minerals if there is still a shortfall in your diet.
  • If you’re eating a plant-based diet and have confirmed nutrient deficiencies, and you’ve tried all the above strategies with no success, adding small amounts of animal foods on occasion might boost stores of necessary minerals in your body.

vitamin-c

Consume vitamin C rich foods with meals that contain phytic acid to offset the effects.

What Are Phytates?

Foods high in phytic acid: nuts and legumes
iStock.com/thananya

Plant seeds store the mineral phosphorus in a naturally occurring compound called phytic acid. When you eat plant foods with phytic acid, it binds to other minerals in your digestive tract, like calcium and iron, and creates what are known as phytates.

The main types of foods that contain phytic acid include:

  • Beans
  • Lentils
  • Whole grains
  • Nuts
  • Seeds

You may be looking at that list and wondering, “Hey, but aren’t those foods typically recommended as part of a whole foods, plant-based diet? What’s the deal? Are phytic-acid-rich foods leaching important minerals out of my body? Should I cut back, or stop eating them entirely?”

The Controversy Over Phytates

woman holding bowl of walnuts in shells
iStock.com/AaronAmat

The key to the phytic acid controversy revolves around its chelating properties. “Chelation” just means the binding of a metal ion to an organic molecule. When you eat food that contains a mineral like zinc, iron, or calcium, and you also consume phytic acid, the phytic acid will bind to — or chelate — the mineral, forming one of the phytates. Phytic acid and phytate are sometimes used interchangeably to refer to this chelation process.

The human body lacks the phytase enzyme that can break down phytates, so we can’t digest and absorb the nutrients bound up in them very well. That’s the basis of the “antinutrient” label. For example, one study showed 13% of magnesium and 23% of zinc were absorbed in the presence of phytic acid, as opposed to 30% without.

A diet high in phytic acid could, detractors argue, lead to nutritional deficiencies over time. At least, that’s the theory. The question is, does it?

Let’s examine the science.

What the Science Says About “Antinutrients”

biologist making notes while inspecting legumes and grains
iStock.com/Motortion

So-called antinutrients are naturally found in many plant-based foods. Some other common plant compounds that fall into this category include tannins, lectins, and oxalates.

Phytic acid’s primary purpose in plants is to protect them from bacterial infections and insects. In the human diet, phytates can affect the absorption of important nutrients, such as zinc, iron, and calcium, if they’re eaten in the same meal. 

But how much nutrient loss actually occurs in our diets as a result of “antinutrients”? The answer is: it depends. The degree of chelation depends on factors like pH and the proportion of phytate to metal ions. Plus, the effects of phytates likely vary among individuals, based on their metabolism and how the food in question is cooked and prepared.

So, the amount of nutrient loss depends on a variety of factors. But in any case, it’s not much of a loss. A 1994 review of trace elements in vegetarian diets from around the world didn’t find iron or zinc deficiencies in those people eating high concentrations of foods containing phytic acid.

Could the human body be adapting to the presence of antinutrients by increasing the absorption of these minerals in the gut? Maybe. And if so, this could be a remarkable example of intelligent dietary evolution.

But, as we’ll discuss a little later, by the time most foods high in phytic acid get to our plate, they may no longer contain enough to cause problems. And phytates may actually bring you significant health benefits, too.

Health Benefits of Phytates

Wooden spoons holding foods high in phytic acid that converts to phytates
iStock.com/kireewongfoto

Calling phytic acid an “antinutrient” is unfair and misleading because the foods that tend to be high in phytic acid bring enormous health benefits. And it’s not just that these foods are so good for us that their benefits “outweigh the harms” of phytic acid. Phytates themselves — despite reducing the absorption of certain nutrients — offer significant health benefits.

1. Phytates may reduce the risk for cancer.

Phytates show impressive anticancer activity by inhibiting the growth and spread of cancer cells. They also appear to have immune-boosting effects by amplifying the activity of natural killer cells that target harmful cancer cells in the body. Additionally, phytates can prevent the formation of new blood vessels that would otherwise feed tumors, causing them to either die or return to normal, healthy cells.

2. They may prevent heavy metal toxicity.

The chelation effect of phytate isn’t all negative. In fact, one study showed that phytic acid was able to absorb cadmium, copper, lead, nickel, and zinc heavy metal ions from an aqueous solution. Many scientists believe that phytic acid can bind to toxic heavy metals and help your body to excrete them. And some research suggests that phytic acid could help prevent neurodegenerative diseases, largely by binding heavy metals that are toxic to the brain.

3. They may act as an antioxidant.

Antioxidants are compounds found in plant foods that fight off harmful free radicals that can damage your cells and lead to disease. When phytic acid binds to minerals in the gut, it creates phytates, which turn out to be potent antioxidants. Animal studies have found that phytic acid added to drinking water may offer a promising therapeutic option for Alzheimer’s disease by protecting the brain from oxidative damage. Specifically, this treatment offered complete protection against amyloid plaque precursors that could harm rats’ brains.

4. They may protect against kidney stones.

Phytates may also prevent calcification in bodily fluids and inhibit the crystallization of calcium oxalate and calcium phosphate into kidney stones. The effects are so promising that some researchers suggest using phytate to treat kidney stones. In fact, some large observational epidemiological studies have shown an inverse association between phytate intake and kidney stone formation among women.

5. Phytic acid helps your body produce inositol.

When phytic acid reaches your digestive tract, it interacts with bacteria and produces a substance called inositol. Inositol helps your liver process fats and has a role in muscle function. In addition, it may help to lower blood triglyceride levels, blood pressure, and blood sugar.

The bottom line is that foods high in phytic acid are some of the healthiest and most nutritious foods you can eat. They’re high in vitamins, minerals, antioxidants, and fiber. And when you include nuts, seeds, whole grains, and legumes as part of a varied and balanced diet, they contribute to your overall health and help prevent disease.

Who Should Avoid or Limit Phytic Acid Intake

Phytic acid occurs naturally in healthy, whole plant foods, so it doesn’t make much sense to stop eating it altogether. Still, there may be certain groups of people who would benefit from knowing where phytic acid is most present in their diet and understanding how to limit it or minimize unwanted effects.

People who may want to limit phytic acid intake include:

1. Individuals who are at high risk for nutritional deficiencies and related disorders.

Conditions like osteoporosis with calcium deficiency, anemia with iron deficiency, or zinc deficiency could worsen if phytates are allowed to further reduce mineral bioavailability. People who fall into this category should diversify their diets and not include high-phytate foods in all meals, consider supplementation of key minerals, and prepare foods with phytic acid in ways that minimize its effect. See the next section for details.

2. Individuals who have malabsorption disorders.

Malabsorption disorders make it harder to absorb nutrients to begin with. And a high-phytate diet could make this challenge worse. If you fall into this category, you may want to reduce phytic acid intake in your diet and increase your overall intake of minerals. Your healthcare provider may advise you to take mineral supplements as well.

3. Individuals who are at a higher risk of malnutrition.

This may include people who suffer from an eating disorder or who lack access to adequate food. A diet that is based mostly on calories from limited food sources like rice and beans, without much variety, can be very high in phytic acid and low in other nutrients that could otherwise help prevent malnutrition.

How to Reduce Phytic Acid in Food

Pouring rice and beans into boiling water
iStock.com/PixelCatchers

Sprouting, cooking, baking, processing, soaking, fermenting, and yeast leavening all help to destroy phytic acid and allow for increased mineral availability. So for many foods containing phytates, the way you would regularly prepare them is often enough to eliminate or significantly reduce phytic acid content. For example, one study on green cowpea pods found that pressure cooking them for three minutes and then boiling them for 15 minutes improved nutrient absorption and reduced antinutrient effects by over 90%.

But, if, for any reason, you want to deliberately reduce your phytic acid intake, there are some simple steps you can take (without having to stop eating some of the healthiest foods on the planet). Some of these steps are health-promoting for other reasons, too.

One study found that pre-soaking reduced the phytic acid concentration in quinoa by about 70%, while more than doubling iron solubility. Other research indicates that the use of sprouting and lactic acid fermentation can almost completely eliminate phytic acid from white sorghum and maize. Other studies also tell us that soaking beans for at least 12 hours, then rinsing them and cooking them in fresh water, reduces phytic acid levels by 60%.

If you’re a fan of homemade bread or fermented foods, phytate levels in wheat drop dramatically when it’s made into leavened bread. In one study, yeast fermentation brought phytate levels down by 32%, while sourdough fermentation brought them down by 62%.

Food combining is also another way to mitigate the effects of phytic acid. For example, mineral-absorbing enhancers, such as garlic and onions, can increase the bioavailability of iron and zinc in plant foods. And by including sources of vitamin C with your high-phytate meals, you can boost iron absorption and negate the iron-inhibiting effects of phytates.

Don’t Fear the Phytates

Pouring almonds and hazelnuts out of a glass jar into hands
iStock.com/turk_stock_photographer

So although phytic acid can chelate with important minerals in your digestive system, the impact of phytates is mostly minimal. When included with a variety of other whole plant foods, there’s little reason to avoid foods high in phytic acid. If you have concerns about zinc, iron, or calcium, you may want to increase your intake of these minerals or not ingest them with high-phytate foods. Or you may want to make nutrients more bioavailable by cooking or fermenting phytic acid-containing foods. In some cases, mineral supplementation may become necessary. But one thing you probably don’t want to do is to eat fewer legumes, whole grains, nuts, or seeds. After all, thousands of studies have shown that for most people, these are among the healthiest foods on the planet.

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