What is Phytic Acid?
Phytic acid is a molecule that occurs naturally in almost all living cells, both plant, and animal. Plant seeds are naturally high in phytic acid because phytic acid is a good source of phosphorus, an essential nutrient for the development of a healthy seedling. When a seed germinates, enzymes within the seed will break down phytic acid molecules to release the stored phosphorus to support the growing seedling.
Phytic acid has gained some notoriety in the media lately because so many of our foods are based on seeds. Most grains, beans, nuts, and other seed-based foods contain high amounts of phytic acid. Phytic acid is also somewhat high in certain tubers, fruits, and vegetables, such as potatoes, cassava, and tomatoes.
The controversy surrounding phytic acid relates to the fact that a phytic acid molecule can bind to certain minerals in your digestive tract, making them difficult to absorb. This binding process is known as chelation, and phytic acid chelates minerals, such as zinc, iron, calcium, and magnesium.
Phytic acid’s chelating properties can cause significant problems with mineral absorption in humans. Particularly in two very specific situations:
- When you eat a primarily plant-based diet, or
- You are malnourished due to inadequate calorie intake, poor quality food, or illness (1).
However, phytic acid has been shown to have many important health benefits, including the prevention of cancer, heart disease, diabetes, kidney stones, and osteoporosis (2).
Can one molecule be both good and bad for you? In the case of phytic acid, yes. And how it affects each of us depends on a few different factors.
Let’s delve a bit deeper into this contradictory molecule.
Deconstructing a Phytic Acid Molecule
An individual phytic acid molecule looks a bit like a snowflake. As you can see in the diagrams below, a phytic acid molecule consists of a central ring with six “branches” coming off of it.
The central ring is made up of a molecule known as inositol. Inositol is a type of sugar that’s abundant in both plant and animal cells. It’s involved in many different biological processes throughout your body. Another name for it is myo-inositol.
You can see that each phytic acid molecule has six groups of phosphates attached to the central inositol ring. A phosphate is simply any chemical compound that contains phosphorus.
And each of those phosphate groups has a negative charge, which will attract positively charged molecules or atoms. Many common mineral atoms, such as zinc, iron, calcium, and magnesium, are positively charged.
The chemical name of phytic acid is myo-inositol hexaphosphate, which is abbreviated as IP6. This chemical name refers to the inositol ring at the center of the phytic acid molecule, surrounded by six (hexa-) phosphate groups.
What Is Phytate?
It is important to understand the difference between Phytic Acid and Phytate. Phytate is the molecule that’s formed when phytic acid binds to a mineral.
In seeds, phytic acid never occurs alone. It’s always bound to a mineral in the form of phytate, and the minerals attached are typically calcium or magnesium (3).
Certain foods will help break down phytates when eaten together. For example, fermented foods, meats, vitamin C, and vitamin D have all been shown to help break down phytates in your digestive tract.
And when the minerals are detached from a phytate molecule, they’re more available for absorption in your gut.
But, if you eat a diet that’s high in phytates and limited in foods that assist their breakdown, the phytates will remain intact and you won’t be able to absorb the minerals contained in them. And phytate will also affect the endogenous pool of zinc. Absorption and reabsorption of zinc are critical to your immune system.
This is why phytic acid is sometimes called an “anti-nutrient”. Its strong negative charge will keep a phytate molecule intact, and the minerals unavailable, unless the conditions are right for the chemical bonds to be broken.
When Do Phytates and Phytic Acid Become a Problem?
If you’re eating a wide variety of natural foods and you’re in good health, it’s unlikely that phytic acid will have any negative impact on your health.
On the other hand, if you eat a more limited diet, particularly a plant-based diet high in grain, beans, and other seeds, or you eat foods that are highly processed or are not nutrient-dense, you’re at an increased risk of phytic acid in your diet impairing your nutrient absorption and potentially developing a micronutrient deficiency.
Now, we’re certainly not suggesting a plant-based diet is a bad thing.
In fact, it’s just the opposite.
Research is mounting that a diet rich in whole, plant-based foods is one of the best diets possible for human health.
In his book The Blue Zones, Dan Buettner examined certain geographic areas throughout the world in which people have the lowest rates of chronic disease and live longer than anywhere else.
In these Blue Zones, Buettner discovered that the local people primarily eat a 95% plant-based diet, including plenty of vegetables, whole grains, legumes, and nuts. Most of these groups are not exclusively vegetarian, although, on average, they tend to only eat meat around five times per month.
Also, keep in mind that phytic acid itself has been linked to a variety of health benefits.
So, going “grain-free” or cutting high-phytate foods out of your diet simply doesn’t make sense. Whole grains, legumes, nuts, and other seeds are nutritious parts of a healthy diet.
But, if you eat a primarily plant-based diet, you need to make sure you take steps to counteract the nutrient-inhibiting properties of phytic acid.
How Do You Break Down Phytates in Food?
This is a lengthy topic, which we’ll cover in much more depth in future blog posts.
But, to get started, the best ways you can break down phytates in your food are:
- Soaking or sprouting your grains, beans, and other seeds before cooking or eating them.
- Eating fermented foods with your meals.
- Taking a phytase supplement with foods high in phytates.
- Including foods high in vitamin C with your meals, such as citrus fruits, broccoli, and red peppers.
- Eating a diet rich in nutrient-dense, whole foods. Being well-nourished is one of the best-proven ways to counteract any of phytic acid’s nutrient-inhibiting action.
Conclusion
If you eat a plant-based diet, or are significantly malnourished, eating foods high in phytate can put you at risk of micronutrient deficiencies.
Soaking and sprouting grains, beans, and other seeds before eating them will help break down phytates and make the nutrients they contain more bioavailable.
Eating a diet that’s rich in nutrient-dense, whole foods is one of the best ways to combat any of phytic acid’s nutrient-inhibiting effects.
Whether you eat meat or a plant-based diet, it’s important to include foods that contain phytates in your diet because phytic acid has a number of important health benefits.
References
(1) Reddy NR, Sathe SK. Food Phytates. Boca Raton, FL: CRC Press; 2002.
(2) Zhou JR, Erdman W Jr. Phytic acid in health and disease. Critical Reviews in Food Science and Nutrition. 1995;35(6):495-508.
(3) Pallauf J, Rimbach G. Nutritional significance of phytic acid and phytase. Arch Tierernahr. 1997;50(4):301-19.