Kitchen Stewardship | A Baby Steps Approach to Balanced Nutrition

Exploring Soaking Grains: What are Phytates and Phytic Acid?

February 18th, 2010 · 32 Comments · Science of Nutrition

I feel a little like Jeff Probst sometimes:  “Next time on..Kitchen Stewardship!”

I hope no one feels like I’m stringing you along with all these promises of soaking grain research and then more posts telling you other things with “research coming later”.

Disclosure:  Research posts intimidate me a little.

They’re hard to pull together, especially when my blogging time is at the end of the day and I’m distracted by checking comments, email, etc.  I need to spend some time during the day on a weekend putting focused effort into this stuff!

That said, I’m going to share some of what I have so far with you today.  “Some” because no blog post should be as long as it could get if I write it all, and “so far” because I’m still hoping to hear from a real live scientist who can answer some of my questions.  It’s time to send a follow-up email!

image For today, I’m going to try to start with the basics:  What are phytates and phytic acid?

If you’re familiar at all with the concept of soaking grains put forth by Nourishing Traditions, you’ll know that the prime evildoer in the battle is called phytates, often used synonymously with phytic acid.

Phytates and phytic acid are not the same thing. They are related and work together, but one cannot speak of them interchangeably.

Within the bran layer of a grain/seed, we find phosphorus bound up and unavailable, along with calcium, magnesium, iron and zinc.

Phytic acid is billed as both an antioxidant and an anti-nutrient, clouding the issue from the get-go.  It’s technically called a hexaphosphoinositol and is a powerful chelator, which means it binds with other minerals and takes them out of your system.  This could be positive, toxin-reducing, and cancer-fighting, or negative, prohibiting your system from absorbing minerals.

That is, if phytic acid can get free in the first place.

Phytates are the bond holding phytic acid.  They are officially the “salt of the phytic acid,” which can be broken in a number of ways.

  1. in the gut with stomach acid
  2. via germination
  3. under the enzyme phytase

Unfortunately, this is all assuming one would want to break down their phytates.  Doing so releases free phytic acid into the system, which is looking for something to fulfill it.  That something could be your iron reserve.

During germination, the phytate is “hydrolyzed”, which is a fancy way of saying broken into compounds by reacting with water. This is much like when salt is dissolved into water. Phosphorus, magnesium, iron and calcium are made available for the development of seedlings (and you, too!).  Like salt, however, which can return to it solid state if the water is evaporated, phytates can potentially bond back to the minerals because its electron needs are not fulfilled.

Stomach acid is a pH of 1, whereas the vinegar, lemon juice, etc. recommended by Sally Fallon and crew ranges from 3.5-4.5, about 1000-10,000 times weaker than the digestive juices.  If an acid at that pH could affect the phytate bond, the grain would have to be cracked for it to happen, as the bran itself is too tough to digest and too tough for mild acids.

Germination only begins when the seed is intact or cracked, not ground.  It’s possible that more nutrients are made available through germination, and that’s what soaking purports to do: begin the growing process of a seed.

Two procedural questions quickly arise from the two paragraphs above:

  1. If the grain has to be cracked for acidulated liquid to potentially affect it, what does soaking whole rice, barley, or dry beans do?
  2. If germination is the key, how can one soak flour, which is way beyond the ability to germinate?

UPDATE: Part of the answers lies in understanding the goal of the acid in the water. The enzyme phytase is the key to understanding a lot of what happens when grains are soaked in an acidic medium. You can read about how phytase works to learn more.

Questions one and two are sort of diametrically opposed, yet answer each other. The goal in soaking whole seeds is often to begin germination, which doesn’t need an acid medium, and the goal of soaking flour is to activate the phytase, not germinate the seed. There are still more details to be nailed down, but I’m not ruling out that soaking does something and has a genuinely possible goal.

Other question that need to be addressed:

  1. Is phytic acid good or bad?
  2. Do we want to release phytic acid in the first place?
  3. If phytic acid is released into the soak water, does it need to be rinsed off before cooking so that the phytic acid doesn’t bond back up with the minerals you’re trying to release?

That’s all for today.  As much as I’d like to pretend I’m a real researcher in uncharted territory, let’s keep it real: I’m just a mom with a computer and a yen for knowledge.  I’m just going to be conversational about all this until I feel like I can say something more definitive (or run out of research to share).  You’ll know when you’ve reached the last “grains information post” when it’s titled “To Soak or Not to Soak”…

Sources:

    • Personal emails with Dr. Teri O’Brien, a PhD biologist who researches plants.
    • Phytate in foods and significance for humans: Food sources, intake, processing, bioavailability, protective role and analysis
      Ulrich Schlemmer, Wenche Frølich, Rafel M. Prieto and Felix Grases: Mol. Nutr. Food Res. 2009, 53, S330 –S375.
    • Phytates and the inhibitory effect of bran on iron absorption in man.

Hallberg L, Rossander L, Skånberg AB.  Am J Clin Nutr. 1987 May;45(5):988-96.

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32 Comments so far ↓

  • Kathy

    I’m really enjoying all this. I’ve been a Sue Becker follower long before I learned about Nourishing Traditions. Because I have Crone’s, I’m also familiar with the Maker’s Diet. I’m just not convinced soaking is that important. I’ve been blessed to be able to eat my grains without soaking. But I so appreciate the time and research you are putting into all this. Homeschooling 3 kids with a deployed husband doesn’t leave me much time to research. I just hop on and read what you’re learning. Thank you very much!

  • Nicole Handfield

    Thank you so much for all the work you are putting into this! I have been wondering how the time required for soaking affects the availability of the vitamins that disappear/oxidize??? so many hours after the flour has been milled. That’s why we bought our grain mill but now that we soak, I wonder if we are losing some of the nutrition in order to deal with the phytate issue? Does that make sense? Thanks again!

    Katie Reply:

    Nicole,
    I will definitely try to address that next week when I talk fresh-milled grains!
    Thanks – Katie

  • Aubree Cherie

    I’m so happy you’re doing this. Mostly because its an interesting topic, but also because you’re creating an amazing summary of what I wouldn’t have the mental energy to tackle. But reading the information on your blog is easy! And I’m really enjoying learning about grains : )
    .-= Aubree Cherie´s last blog ..German Chocolate Brownies =-.

  • Amy @ Homestead Revival

    I’m so glad you are taking the time to do these posts. I’ve wondered about this for a couple of years! I’m pushing forward and taking the eCourse from GNOWFGLINS, but I need convincing in my mind that this IS the best method (soaking grains). I’ve emailed a friend in Jerusalem and asked her to go to the Hebrew University there or the Institute of Biblical Studies and find someone there who would be able to tell us if the Israelites actually practiced these methods in Biblical times or not (since this is part of Sally Fallon or Weston Price’s argument that cultures have practiced this for generation upon generation. I’m particularly interested in what the Israelites did, because God often set them apart not only spiritually, but in practical ways that allowed them to experience better health (thus many of the levitical laws and health measures outlined in Numbers). I don’t want to know what every culture did, I want to know what God’s people did.

    Please keep posting this stuff. I’m just a mom like you, and I really want to understand it!

    mackytack Reply:

    hi…i wonder if you ever learned anything from your friend in Israel…
    this whole thing has me stumped…wanting to do what’s ‘right’ for my family…
    and once soaked, to rinse, or not to rinse?
    thanks for taking the time…
    m

  • nopinkhere

    Thank you for taking the time to outline what you’re finding out. I feel like a lot of the information about this is contradictory and I’m glad I’m not the only one.
    .-= nopinkhere´s last blog ..This Stuff Ain’t Bad =-.

  • Sarah W

    As far as the first procedural question… don’t we soak beans for a different reason? (i.e. not b/c of phytic acid). I thought it was to leach out the indigestible complex sugars? (oligosaccharides?)
    And what about nuts? NT calls for a different soaking method there as well (salt water.) I understand if you can’t answer these questions now… but perhaps you will look into the other “soaking” processes in the future? :)

    Katie Reply:

    Sarah,
    I marked down your questions! I think nuts are for phytic acid, but you’re right, beans may be different. Good thoughts! :) Katie

  • Naomi

    Amazing work, Katie!
    A few questions and thoiughts from a nonsciencey person (so excuse me if I’m totally off)
    To your procedural questions, it seems it would be enough to soak whole seeds in just water to get the germination process started, but flours, which are not capable of germinating but the bran has been broken up, would require an acidic soak.
    Once the germination process has begun, could the changes in the grain/seed inhibit the phytic acid reconnecting with minerals? Or cooking? Or adding salt (as salt stops the phytates from breaking up)?

  • Naomi

    Another question…are enzyme inhibitors and phytates different or the same? Because if they are different than there seems to be an answer to the nuts and beans question.

    Katie Reply:

    Naomi,
    They are different, although I don’t really understand the enzyme inhibitors as I’ve been focusing so much on the phytates. Great questions above! They’re copied into my notes… :) Katie

  • Marianne

    I’ve just discovered your blog through Fight Back Friday and was excited because I have been hoping to get to the bottom of this very question. Several friends have been asking me about phytates since Ann Marie’s interview with Rami Nagel and one friend recently sent me an article by Sue Becker raising these these same questions about the potential benefit of not soaking.

    I love research, but usually lack the time. I’ll probably be linking back to this series once I put my own post together to answer my friends’ questions!
    .-= Marianne´s last blog ..Menu Plan Monday =-.

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  • Julie S

    Thank you for investigating this issue, Katie!

    When I first looked into soaking grains, I also came across dissenting material which was no less a rational, scientific-sounding argument, so I wasn’t automatically sold on soaking. Having a background in biology, I need a little more to go on than “because Dr. Price says so”.

    In the end, we may find out that soaking is essential to proper grain digestion (if grains are even essential at all!), but it doesn’t seem like many food bloggers have even looked into the other side of the argument. On the other hand, why has mainstream nutritional science ignored this issue?

    In my experience, the truth never lies at either extreme, but somewhere in the middle. I am very gratified to see some effort to reconcile the extremes.

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  • Rachel Wisdom

    Thank you so much for all of your research Katie! I’ve been trying to learn more about these things for quite a while as my husband has Crohn’s disease and I’d like to figure out what we can do to help him from a dietary standpoint. It’s difficult though because so much of what I read is conflicting and/or just sounds like hype or bunk.
    One specific thing I am wondering. Have you seen anything in your research about taking a phytase supplement? My dh’s digestive enzyme supplement has some, and I am wondering if all the angst surrounding this stuff (to soak or not to soak, does it actually do anything anyway if there’s little to no phytase left in my flour, etc. ) is pointless.
    That’s the long way of saying, what about a phytase supplement?

    Katie Reply:

    Rachel,
    I haven’t heard much about supplements, but my husband has Crohn’s, too, so I understand your angst! Sounds like phytase is the key to unlocking all the goodness, so it can’t hurt to supplement in my opinion. There are studies on adding phytase to animal feed, and usually the results are better digested food. I wonder what would happen if you put the phytase supplement into the soak water! See, I am such a science geek! ;) Katie

    Rachel Wisdom Reply:

    Heehee. I have wondered the same thing.

  • Rachel Wisdom

    PS – right on Julie.

    I also wonder how we can reconcile what we read in Scripture to what NT/WPF/paleo people say. I find it hard to believe that God would encourage His people eat such “bad” things in the OT and use it in His imagery in the NT.

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  • Katie

    Just in case anyone is subscribed to this old soaking grains post, I wanted to let you know that I’ve reopened the issue with the goal of closing it at KS this Friday. There’s also a little Nutrimill grain mill giveaway going on.

    Last fall we tested our grains, I did a recap post on soaking grains, measured pH, and have a soaked recipe ebook coming out for free in about a month.

    If you’ve been away, come on back to the party! :) Katie

  • sandra

    Hi again!

    I was wondering what you would prefer between a soaked whole wheat recipe and a sourdough whole wheat recipe. and also why, of course :)

    Katie Reply:

    Sandra,
    Always sourdough, for health benefits! Sourdough is much more well-researched. See here: http://www.kitchenstewardship.com/2010/03/05/food-for-thought-health-benefits-of-sourdough/

    : Katie

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  • mackytack

    in reference to ‘rinsing’ after the lemon juice/yogurt, etc…
    it is my understanding, that it does not need to be rinsed, because the phytates have not necessarily been ‘removed’, but rather, neutralized…

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  • John

    Interesting article, but a correction needs to be addressed.

    Phytate is Phytic Acid in it’s salt form (salts are minerals and vis versa). Or, Phytic Acid after it has chelated minerals.

    Phytase is an Enzyme that is capable of breaking the bonds of Phytic Acid (Phytate) releasing the Phosphorus bound up in Phytic Acid and/or Phosphorus and any minerals bound up in Phytate.

    Phytates are not chemical bonds. Phytates are Phytic Acid that has bound up (chelated) minerals (salts). Hence it is Phytic Acid in it’s salt (mineral) form.

    Google is your friend. (not really but hey, it still works)

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I embrace butter. I make homemade yogurt. I eat traditional real food – plants and animals that God created, not products of plants where food scientists work. Here at Kitchen Stewardship, I share how I strive to be a good steward of my family's nutrition, the environment, and our budget, all without spending every second in the kitchen. Learn more about the mission of KS here.

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