Over the last several years, whole grains, legumes, nuts, and seeds have been the subject of intense scrutiny by certain dietary camps. While there may be multiple explanations, one of the most frequently provided is that they contain phytic acid.
You see, phytic acid is referred to as an “antinutrient” because it can bind to and may prevent the absorption of certain minerals. This includes iron, copper, zinc, and calcium.1 Because of this, some even refer to it as the “mineral reducer.”
True as that may be, is there more to this vilified “antinutrient”? Is this “mineral reducer” so dangerous it’s worth eliminating potentially healthful, nutrient-dense foods and food groups, such as nuts, seeds, beans, oats, and other whole grains?
To borrow the famous words from legendary radio broadcaster Paul Harvey, “And now, the rest of the story…”
What is Phytic Acid?
Phytic acid is also referred to as inositol-6-phosphate or phytate. It’s the primary storage form of the mineral phosphorus in many plants. This includes whole grains, legumes, potatoes, nuts, and seeds. Phytic acid has earned notoriety because of its strong ability to bind to certain minerals and metals (a process called chelation) as mentioned above.
Unlike plants, humans lack the phytate-degrading enzyme phytase, which liberates minerals bound to phytate. As a result, we cannot effectively break down dietary phytates. So, phytates essentially interfere with the absorption of certain minerals. Critics of phytic acid are outspoken about this potential. Interestingly, there’s some evidence that phytic acid may have an exclusive effect on binding to iron.2 Of course, iron deficiency is a real problem, particularly among infants and women. However, as you’ll see, this effect may also be advantageous.
An Antinutrient that is an Antioxidant?
In the mainstream, phytic acid is most popular for being an antinutrient or mineral reducer. Yet in the scientific community, “It may exert its greatest biological effect through its antioxidant properties.” Yep, this often vilified compound is a well-known antioxidant with various beneficial effects.2
In fact, it’s actually the antinutrient properties of phytic acid that contribute to its antioxidant prowess. You see, with its ability to bind to iron, phytic acid inhibits the formation of free radicals by preventing an iron-mediated process called the Fenton reaction.3
Don’t worry, you don’t need to break out your high school chemistry textbook. You can think of it this way… it essentially helps prevent the oxidation of iron, which is akin to a nail rusting or fruit turning brown.
In addition, phytic acid has been shown to reduce inflammation and boost immune function. How? By enhancing the production of natural killer cells.2,4
The Health Benefits of Phytic Acid
The ways that phytic acid boosts your health is:
• Heart Health: Along with its antioxidant prowess, which has heart health written all over it, animal studies have shown phytic acid reduces triglycerides and increases HDL (or “good”) cholesterol.6,7 What’s more, researchers have found it may protect heart vessels from calcification.8
• Brain Health: In addition to preventing the formation of iron-induced free radicals, phytic acid also inhibits a process known as lipid peroxidation. Say what? Our cell membranes are made up largely of fats, also called lipids. Free radicals can oxidize these fats, which generates peroxides (and aldehydes). Lipid peroxidation leads to highly reactive products with pronounced biological effects. They can cause alterations in cell signaling, protein and DNA damage, and more.9
• Fighting Free Radicals: With its ability to inhibit free radical production, phytic acid has been shown to limit DNA damage and prevent tumor growth. In addition, zinc and magnesium—which both bind to phytic acid—are critical for tumor cell proliferation. Animal studies have shown it can inhibit the progression of multiple types of cancer. It may also prevent cancer by activating a process known as apoptosis, which is science speak for cell death.11 According to Dr. Aaron Katz, Chairman of Urology at NYU Winthrop Hospital, “Studies have found that phytic acid has remarkable anticancer effects.”12
• Eliminating Heavy Metals: Another way this antinutrient can be beneficial to health is by chelating potentially toxic heavy metals, such as mercury, arsenic, and lead.13 This strong bond with heavy metals limits their bioavailability, and ultimately, their accumulation in your body.
Not Just Phytic Acid
Of course, you don’t eat phytic acid. You eat food. By and large, when you eat foods that contain phytic acid, you’re also getting a cornucopia of other healthful nutrients. This includes antioxidants, vitamins, essential fats, and fiber. Take oats, for example. While they contain phytic acid, they’re well-known for beneficial effects on heart health, weight management, gut health, and blood sugar management. Of course, beans and nuts are associated with a similar variety of health benefits and overall diet quality.
Or, consider a Mediterranean-style diet, which is characterized by high consumption of whole grains, legumes, nuts, and seeds. The very same antinutrient containing foods that are often written off. A Mediterranean-style diet is associated with a laundry list of benefits, ranging from heart health to weight management to brain health to healthy aging to blood sugar management and more.
…And Now You Know the Rest of the Story
Taken together, if you’re eating a diverse, whole-foods-based diet, it’s unlikely dietary phytates should be a concern. In fact, they may actually be health promoting. Dietary phytates may pose the greatest concern for folks who rely heavily on phytate-containing foods as part of a relatively nutrient-poor diet (e.g., developing countries). That being said, if you are concerned about the phytic acid content in certain foods, you can naturally increase the activity of phytase through sprouting, soaking, and fermentation.14 What’s more, you can also supplement with phytase.