If you eat a plant-based, vegan or vegetarian diet, you have probably heard the criticism that this way of eating is unhealthy because of the phytic acid found in most plant foods. The problem is that some of the nutrients in plant foods cannot be absorbed because of this phytic acid. Is this really a hidden danger when eating a vegetarian diet? At the same time, there are also studies that find phytic acid to be a healthy substance with many health-giving properties.
This is just one of many vegan or plant-based myths, that the foods we eat are unhealthy because of one thing or another. In this case, it is phytic acids in plant foods.
Phytic acid is called the anti-nutrient because it is believed that they can inhibit our body’s ability to absorb certain nutrients and that those eating a plant-based diet will end up deficient in certain nutrients.
What is Phytic Acid?
Phytic acid (also called phytate, inositol hexaphosphate, or IP6) is the storage form of phosphorus. Phytic acid is found naturally in plant foods, and phosphorus is the second most abundant mineral in our body.
The main source of phosphorus for vegetarians is grains, soy, beans, nuts, and seeds. As you can see in the following list, those same foods are also highest in phytic acid. The following foods are high in phytic acid [1]:
- Rice bran: 2.65 to 8.7 grams of phytic acid per 100 grams dry weight
- Sunflower meal: 3.9 - 4.3 grams
- Wheat bran: 2.1 - 7.3 gram
- Wheat germ: 1.14 - 3.91 grams
- Sesame seeds: 1.44 - 5.36 grams
- Soybeans: 1.0 - 2.22 grams
- Kidney beans: 0.61 - 2.38 grams
- Oats: 0.42 - 1.16 grams
- Peas, chickpeas, lentils: 0.22 to 1.60 grams
- Peanuts, almonds, walnuts, cashew nuts: 0.17 to 9.42 with almonds having the highest amount
The Hidden Dangers of Phytic Acid
Phytic acid has been called the anti-nutrient because it can inhibit our body from absorbing certain nutrients like phosphorus, zinc, iron, calcium, and magnesium. This is because the phytic acid binds to these minerals in the gut, preventing them from being utilized by our body and are excreted undigested.
Phytic acid also inhibits the following enzymes:
- Peptise, needed for the digestion of proteins in the stomach
- Trypsin, needed for the breakdown of proteins into amino acids in the small intestine
- Amylase, needed for the digestion of starches
This is why phytic acid is called an anti-nutrient or a hidden danger in a vegetarian diet and why some say that those that eat a vegetarian diet will end up deficient in these minerals.
And to make it worse, because phytic acid also inhibits the digestive enzymes for absorbing protein, vegetarians could end up deficient in protein as well, though that is unlikely.
What Can Vegetarians Do About Phytic Acid?
There are a number of ways that vegetarians can solve the problem of phytic acid and mineral absorption. The following remedies to reduce phytic acid in foods can help.
- Soaking beans overnight is a great way to reduce the amount of phytic acids in beans.
- Sprouting beans and legumes will lower the amount of phytic acid.
- Fermenting.
- The milling and baking of bread removes phytic acid.
- Having a little vitamin C with your meals can also help mineral absorption. As little as 50 mg of vitamin C, such as a one-half cup of red bell peppers or tomatoes.
- Taking a digestive enzyme that includes phytase will help you break down the phytic acid and absorb the minerals and nutrients.
The problem is that we cannot produce enough of the phytase enzyme in our gut in order to release these minerals.
The good news is that studies have found our gut bacteria can start making phytase enzymes the more we eat phytic acid containing foods. And once our gut bacteria start making phytase, we can then digest and absorb the iron, calcium, phosphorus, manganese, and magnesium [2].
Another study found that eating a vegetarian diet can degrade 100% of phytic acid [3]. In other words, eating a vegetarian diet will create the proper enzymes in your gut so you can digest all of the nutrients in phytic acid containing foods.
Having good gut bacteria will also help your body’s ability to absorb all of the minerals and nutrients from the foods you eat, including the minerals in plant foods with phytic acid.
The Health Benefits of Phytic Acid
With all of the talk about how bad a vegetarian diet is because of the phytic acid, it is often overlooked that there are health benefits with phytic acid, and instead should be looked at as a healthy substance in our food. Phytic acid is considered an antioxidant with numerous health benefits.
Phytic Acid Inhibits Cancer
Foods high in phytic acid can inhibit tumor growth and enhance the action of natural cancer killer cells. One study found that phytate (phytic acid) is a natural constituent possessing moderate anticancer activity, and as an antioxidant also enhances the immune system contributing to tumor cell destruction [4].
Another study found that the phytic acid in rice bran induced cancer cell death in colorectal cancer [5].
In a separate study, it was found that phytic acid may have a role in both the prevention and treatment of many forms of cancer including bone, prostate, ovarian, breast, liver, leukemia, sarcomas and skin cancers [6].
Phytic Acid Protects Against Parkinson’s
Another healthy benefit of phytic acid is that it has a neuroprotective effect on the brain. Phytic acid is a naturally occurring iron chelator that can rid the body and the brain of excess iron. Studies have found that this chelating action can protect us againstParkinson’s disease [7].
Phytic Acid Prevents Kidney Stones
Phytic acid is one of the best natural preventatives for calcium-based kidney stones. Phytic acid prevents kidney stones by preventing the crystallization of calcium salts whether of the calcium oxalate or calcium phosphate type of kidney stone [8, 9].
Phytic Acid Prevents Osteoporosis
A 2008 study found that bone mineral density increased with an increase in phytic acid containing foods in the diet. The analysis found that a low phytate diet was among the greatest risk factors for developing osteoporosis [10].
Phytic Acid is Part of a Healthy Diet
The foods you might be told to avoid because of phytic acid are also some of the healthiest foods we can eat. It’s not just the phytic acid, it is all of the foods that work in combination that makes a plant-based diet so healthy.
- Beans and legumes are a nutrient dense food that has a good amount of protein, folate, zinc, iron, magnesium, and fiber. Beans are also an antioxidant, good for the heart and can reduce the risk of diseases like cancer, diabetes, and fatty liver disease.
- Soy is a complete protein, which means it contains all nine essential amino acids. Soy is also a great source of B-vitamins, iron, zinc, antioxidants, and phytochemicals.
- Flax seeds are high in the omega-3 fatty acid, alpha-linolenic acid (ALA), high in the anti-cancer nutrient, lignans, and high in healthy fiber.
- Oats and barley are high in beta-glucan, a healthy form of soluble fiber, plus vitamins and nutrients. Beta-glucan can lower blood cholesterol levels, help regulate blood glucose levels, and decrease the risk of developing certain types of cancer.
The Bottom Line
Phytic acid is a healthy substance in our food, and anyone that eats a vegetarian, vegan or plant-based diet shouldn’t be concerned about phytic acid in their diet.
Eating a well rounded plant-based diet will ensure you get plenty of vitamins and nutrients despite the fact that phytic acid diminishes the absorption of certain nutrients.
The longer you eat a plant-based diet, the more your gut bacteria will be able to break down phytic acid.
It looks like the health benefits far outweigh any negatives. As someone who also eats a plant-based diet, I eat all of the plant foods without worrying about phytic acid.
About the Author
Sam Montana is a certified Food Over Medicine instructor from the Wellness Forum Health Center and certified in optimal nutrition from the Harvard T.H. Chan School of Public Health.
© 2019 Sam Montana/Healthy Food and Life
Resources:
The longer you eat a plant-based diet, the more your gut bacteria will be able to break down phytic acid.
It looks like the health benefits far outweigh any negatives. As someone who also eats a plant-based diet, I eat all of the plant foods without worrying about phytic acid.
About the Author
Sam Montana is a certified Food Over Medicine instructor from the Wellness Forum Health Center and certified in optimal nutrition from the Harvard T.H. Chan School of Public Health.
© 2019 Sam Montana/Healthy Food and Life
Resources:
[1] PubMed: List of phytic acid amounts in food
[2] PubMed: Regular Consumption of a High-Phytate Diet Reduces the Inhibitory Effect of Phytate…
[3] PubMed - Journal of Applied Microbiology - Diet shapes the ability of human intestinal microbiota to degrade phytate
[4] PubMed - Cancer inhibition by inositol hexaphosphate (IP6)
[5] PubMed - Pro-apoptotic effect of rice bran inositol hexaphosphate (IP6) on HT-29 colorectal cancer cells
[6] PubMed - Phytic acid (IP6), novel broad spectrum anti-neoplastic agent
[7] PubMed - Neuroprotective effect of the natural iron chelator, phytic acid in a cell culture model of Parkinson's disease
[9] PubMed - Phytate (IP6) is a powerful agent for preventing calcifications in biological fluids
