A Closer Look at Phytic Acid

If you’ve been reading about or following a low-carbohydrate diet lately, chances are you’ve come across the words “phytic acid” and “anti-nutrient.” While the term “anti-nutrient” can sound intimidating, is phytic acid something we actually need to be concerned about in our diets? Let’s take a closer look at what the research has to say!

What is Phytic Acid?

As mentioned above, phytic acid, also known as phytate, is a plant-based substance found mostly in nuts, seeds, grains, and legumes (including beans, lentils, and peanuts). However, small amounts are also present in roots and tubers.

While it’s primary role is phosphorus storage, phytic acid is classified as an anti-nutrient, as it also hinders the absorption of certain nutrients. This brings us to the main argument against this compound: does eating foods high in phytic acid result in nutrient deficiencies? Let’s find out!

Does Phytic Acid Lead to Nutritional Deficiencies?

As we were just discussing, phytic acid binds to metals, many of which are important for human nutrition, including calcium, iron, magnesium, and zinc. By “binding” to these minerals, phytic acid decreases our ability to absorb these nutrients; instead, they are excreted from the body.

Diets, including Paleo and Whole30, argue that by eating foods high in phytic acid, we are stripping our bodies of important minerals.

This could be concerning for those who are iron-deficient or more prone to iron deficiency, such as vegans and vegetarians. As well as potentially problematic for populations that don’t have access to a balanced diet and instead rely on grains and lentils as their main (or sole) food source.

However, there’s currently no evidence that individuals consuming foods high in phytic acid along with a balanced diet are at increased risk for developing mineral deficiencies. The reason for this is likely due to a combination of factors.

One of which is that there are ways to decrease the phytic acid present in foods. Soaking, sprouting, and fermenting can help reduce the amount of phytic acid in these foods, as does cooking, baking, and processing. As we rarely eat raw beans, lentils, or grains, by the time we actually eat phytate-containing foods, the concentration of phytic acid is much lower.

Additionally, research has shown that consuming vitamin C-rich foods or beverages at the same meal as a phytic acid-containing food may significantly reduce these binding effects. Furthermore, vitamin C is known the help improve the absorption of iron. Foods high in vitamin C include oranges, cauliflower, broccoli, brussels sprouts, leafy greens, peppers, tomatoes, and sweet potatoes.

Finally, phytic acid only binds metals in the foods present at that meal, not for the whole day. By eating a balanced, varied diet throughout the day, you’ll be getting these minerals from other food sources, including animal products, fruits, and vegetables.

For vegans and vegetarians who are concerned about iron absorption and likely do eat foods high in phytic acid, it’s important to consume a varied diet, soak beans and lentils prior to eating, and incorporate plenty of vitamin C-rich fruits and vegetables.

Possible Benefits

Phytic acid binds to and inhibits the absorption of all metals, including those that are toxic to our bodies, and thereby may actually protect us from a dangerous accumulation of heavy metals.

Additionally, there’s evidence that phytic acid has antioxidant properties and may play a role in the prevention of chronic disease; however, this relationship is still in need of further research.

More specifically, it’s being looked at as a possible factor for why diets high in whole grains may be protective against colon cancer.

While not specific to phytic acid, foods high in this plant compound are also the foundation of the Mediterranean Diet.

The Mediterranean Diet has been extensively researched and associated with a decreased risk of chronic disease, weight loss, and reduced overall mortality. While animal products are allowed on the Mediterranean Diet in moderation, regular whole grains, legumes, nuts, and seeds are emphasized, in addition to fruits and vegetables.

The Bottom Line

While it’s true that phytic acid inhibits the absorption of important dietary metals, consuming these foods is unlikely to result in nutrient deficiencies. Furthermore, these high phytic acid foods are also rich sources of fiber and vitamins and have been associated with an overall reduced risk of disease and mortality.

If you’re concerned about the amount of phytic acid you’re consuming, there are ways to reduce these amounts through soaking, cooking, and pairing with vitamin C-rich foods.

However, if you already have a mineral deficiency, it’s worth cutting back on high phytic-acid foods and consulting with a dietitian to create a personalized meal plan to best fit your nutritional needs.