Phytic Acid: What it is, Where it’s Found, and Should You Be Concerned?
If you’ve ever listened to any debates about what the healthiest diet to follow is, you might have heard proponents of paleo and carnivore diets warn against so-called ‘antinutrients’ found in plants, such as phytic acid. But what exactly is phytic acid, and is it something you should be concerned about?
What is phytic acid?
Plants, such as nuts, beans, and legumes, store phosphorous in their seeds in the form of phytic acid. Phytic acid, when bound to minerals found in plant seeds, is known as a phytate. Phytates act as an energy source for sprouting seeds and young plants. As plants ripen, phytic acid accumulates in the seeds. When the seeds sprout, the phytate is broken down, releasing the phosphorous for the young plant to use to grow.
Where does phytic acid come from?
Phytic acid is found in all plant-based foods in varying amounts. Foods that are particularly high in phytic acid include legumes, nuts, and whole grains. Small amounts are also found in roots and tubers. Phytic acid is found in the seed portion of these plants. For instance, in whole grains, the phytic acid is most concentrated in the bran, and in legumes, the phytic acid is concentrated in the protein-containing layer.
How does phytic acid affect us?
When we eat plant foods with phytic acid, we consume the phytic acid found in the seed portion of the plant. However, humans lack the enzyme necessary to break down phytic acid, meaning that we can’t readily absorb the phosphorous (an important mineral in bones and teeth) from these plants. Phytic acid is also considered an antinutrient, meaning it inhibits the absorption of other nutrients from your diet. Phytic acid forms insoluble compounds with other minerals, such as iron, zinc, calcium, and magnesium, preventing these nutrients from dissolving and being absorbed in your gastrointestinal tract when consumed at the same time. Phytic acid has been shown to reduce zinc absorption by up to 65%, and iron absorption by 82%. The insoluble phytate complexes can also reduce the digestibility of starches, proteins, and fats in the diet. Phytic acid inhibits digestive enzymes such as pepsin and trypsin, needed to breakdown proteins in the stomach and small intestine, and amylase, which is necessary for the breakdown of starches.
However, phytic acid isn’t all bad. Phytic acid can also act as an antioxidant by binding to iron to block the formation of free radicals. Phytic acid can also bind to heavy metals to prevent their accumulation in the body. In addition, phytic acid may provide protective properties against cardiovascular disease, cancer, and diabetes by protecting against the hardening of arteries, enhancing the activity of natural killer cells to inhibit tumor growth, and preventing against insulin resistance.
Should I be concerned about phytic acid?
Although phytic acid limits the absorption of certain minerals, the average diet usually has enough nutrients and variety to protect from deficiencies. However, those who have mineral deficiencies or eat diet low in meat and high in phytic acid-rich foods, such as vegans or vegetarians, may benefit from limiting foods high in phytic acid. Whereas animal proteins contain heme-iron, which can still be absorbed even when consumed with phytic acid, plant-based foods contain non-heme iron, which is largely affected by phytic acid. In addition, since vegans and vegetarians are often at risk for iron and zinc deficiencies, paying attention to your phytic acid content may be especially important to protect yourself against micronutrient deficiencies.
Hidden sources of phytic acid:
Although you may be thinking that you don’t consume a large about of nuts, legumes, seeds, or grains containing phytates, phytates can actually be hiding in many plant-based protein powders. Since phytic acid is found in plant seeds where a majority of the plant protein is concentrated, many plant-based protein powders, including soy, pea, and brown rice protein, often contain high levels of phytic acid. In addition, phytic acid accumulates when a plant goes into storage mode, meaning that the dried plants used to make protein powder, are even higher in phytic acid than the fresh plants. Since phytic acid reduces the absorption of protein, your body may actually be getting much less protein from these powders than you think! Many plant-based protein powder companies don’t test their products for phytic acid. So even though you might not be getting a high amount of phytates from whole foods in your diet, consuming protein powders with high quantities of phytic acid may put you at risk for nutrient deficiencies. However, there are some plant-based proteins which test for levels of phytic acid! CorePerform protein is third-party tested for phytic acid, meaning that the plant-based protein powder has gone through rigorous testing to ensure that the level of phytic acid is low enough to safely consume without inhibiting absorption of important nutrients and causing GI upset!
Concluding Remarks and Recommendations:
Although phytic acid isn’t a major concern if you eat a varied diet with plenty of nutrients, you may want to be mindful of limiting high sources of phytic acid. This is particularly important for vegans and vegetarians, who are at greater risk for mineral deficiencies. Here are a few practical recommendations for being mindful of phytic acid in your diet:
- Use a plant-based protein powder such as CorePerform which uses third party testing for phytic acid
- Soak, sprout, or ferment plant foods. These methods enhance the activity of phytases, enzymes which breaks down phytic acid in plants
- Consume vitamin C-rich foods with meals high in phytic acid-rich foods. Vitamin C has been shown to counteract the effects of phytic acid. Foods. High in vitamin C include oranges, kiwi, bell peppers, tomatoes, brussel sprouts, and white potatoes
- Pay attention to mineral deficiencies and supplement as necessary
References:
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Gupta, R. K., Gangoliya, S. S., & Singh, N. K. (2013). Reduction of phytic acid and enhancement of bioavailable micronutrients in food grains. Journal of Food Science and Technology, 52(2), 676–684. https://doi.org/10.1007/s13197-013-0978-y
Prynne, C. J., McCarron, A., Wadsworth, M. E., & Stephen, A. M. (2009). Dietary fibre and phytate – a balancing act: Results from three time points in a British birth cohort. British Journal of Nutrition, 103(2), 274–280. https://doi.org/10.1017/s0007114509991644
Péneau, S., Dauchet, L., Vergnaud, A.-C., Estaquio, C., Kesse-Guyot, E., Bertrais, S., Latino-Martel, P., Hercberg, S., & Galan, P. (2008). Relationship between iron status and dietary fruit and vegetables based on their vitamin C and fiber content. The American Journal of Clinical Nutrition, 87(5), 1298–1305. https://doi.org/10.1093/ajcn/87.5.1298
Singh, M., & Krikorian, A. D. (1982). Inhibition of trypsin activity in vitro by phytate. Journal of Agricultural and Food Chemistry, 30(4), 799–800. https://doi.org/10.1021/jf00112a049