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Can Phytates be a good thing? Are anti-nutrients as bad as we think?

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  • Can Phytates be a good thing? Are anti-nutrients as bad as we think?

    So I've recently a few articles claiming that phytates can be a good thing, even help in cancer-fighting properties. I've also read that anti-nutrients don't totally block nutrient absorption, just a minimal amount.

    Now, don't jump on me because I clearly understand the harmful effects of refined grains and I can't argue with how I feel without grains and the progress others have seen.

    Just purely from a scientific source, can anyone point me to contradictory studies? Basically, Mark's book has great information but I can't find the sources for his claims. I'm not saying they're wrong, but I'd really like to see some empirical studies abotut this for myself, not just read Dr.'s and nutrition expert's rendition of them.

    Does that make sense? I hope you all understand that I'm not attacking the PB (I'm a follower, and have been for almost a year now) nor am I criticizing the wonderful resources I've read (such as Mark and others). I'm really just wondering if anyone has specific, scientific, empirical sources demonstrating that phytates are not a good thing and explains exactly how severely grains hinder vitamin and mineral absorption.

    Thanks!

  • #2
    Interesting question. I was wondering that myself.

    Apparently, phytates are also an antiozidant, and found in nuts, so legumes and grains are not the only source.

    This study Iron absorption: no intestinal adaptation to a hig... [Am J Clin Nutr. 1989] - PubMed result shows that phytates reduced iron absorbtion by 92-93%, which is significant.
    This study Iron absorption in man: ascorbic acid and dose-dep... [Am J Clin Nutr. 1989] - PubMed result indicates that the more phytates, the more iron absorbtion issues, but that vitamin C definitely increased iron absorption (which it does anyways) and meat did only when there was a very high level of phytates
    This study Bioavailability of minerals in legumes. [Br J Nutr. 2002] - PubMed result says that iron and zinc are significantly inhibited by the phytates in legumes and therefore, not very bioavailable
    A review of phytate, iron, zinc, and calcium conce... [Food Nutr Bull. 2010] - PubMed result This one is a review of iron, zinc and calcium levels as well as phytate levels in a number of foods. Phytates can impair calcium absorbtion too, but this study doesn't show how much.
    The effect of food processing on phytate hydrolysi... [Adv Exp Med Biol. 1991] - PubMed result Soaking, germinating and fermenting reduces phytate levels

    As little as 5-10 mg phytate phosphorus added to a wheat roll containing 3 mg iron inhibited iron absorption by 50 per cent. Ascorbic acid as well as meat strongly counteracted this inhibition. It was concluded that if bran is used to increase the dietary fiber intake that would interfere with the absorption of iron. However, if the intake of ascorbic acid and/or meat are sufficiently increased in the bran containing meals that would effectively counteract the inhibition of the iron absorption by the phytates in bran (wheat fiber).Wheat fiber, phytates and iron absorption. [Scand J Gastroenterol Suppl. 1987] - PubMed result (from this abstract)

    There is also a lady with a phytic acid website and a white paper for sale if you want it: Phytic Acid Good or Bad? A Review of Food Science

    It looks to me like there are some significant mineral absorbtion issues with phytates. I was not so certain myself, but the degree to which the phytates impair absorbtion is greater than I first would have thought.

    I hope this is the sort of information you were looking for.
    Karin

    A joyful heart is good medicine

    He is no fool who gives what he cannot keep to gain what he cannot lose. - Jim Elliot

    Mmmmm. Real food is good.

    My Journal: http://www.marksdailyapple.com/forum/thread29685.html

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    • #3
      Phytase activity in the human and rat small intestine: Phytase activity in the human and rat small intestine.

      We are clearly equipped to cope with very small amounts of phytic acid. An occasional, small handful of nuts, seeds, or properly prepared grains would, in my opinion, best approximate the amount we are designed to ingest. Keep in mind that phytic acid is one of many anti-nutrients found in nuts, seeds, legumes, and grains -- lectins, gluten, insoluble fiber, and enzyme inhibitors are usually also present therein.

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      • #4
        I think it's a really good question.
        Antioxidants in produce are a good example.
        And look at all the peop that swear that nitrites are curative. (and we're talking the concentrated kind used in meat processing not the natural occurring sm amt in vegies.

        It is important to ask these questions since peop following any alternative woe tend to have blinders on.

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        • #5
          as a scientific source, the mentioned information is so useful. good luck with you.

          Comment


          • #6
            Originally posted by tarek View Post
            Phytase activity in the human and rat small intestine: Phytase activity in the human and rat small intestine.

            We are clearly equipped to cope with very small amounts of phytic acid. An occasional, small handful of nuts, seeds, or properly prepared grains would, in my opinion, best approximate the amount we are designed to ingest. Keep in mind that phytic acid is one of many anti-nutrients found in nuts, seeds, legumes, and grains -- lectins, gluten, insoluble fiber, and enzyme inhibitors are usually also present therein.
            Why are nuts primal then? This is something that really confuses me.
            The more I see the less I know for sure.
            -John Lennon

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            • #7
              Small amounts of nuts are primal, or larger amounts of soaked nuts. Gorging on nuts year round is not primal.

              The above links demonstrate why "antioxidant" is not always a good thing. Of the many different mechanisms that an antioxidant can work on, the chelating versions are antioxidants in that they bind up metals that both a) react with unsaturated bonds in fats promoting rancidity in processed products, and b) are required by our body for healthy functioning. While these chelating antioxidants will help extend the shelf life of foods (that we primals don't eat anyways) they rob our body of necessary nutrients.
              Last edited by ProtoAlex; 05-02-2011, 10:48 PM.
              "You can demonstrate the purpose and limits of human digestion with a simple experiment: eat a steak with some whole corn kernels, and see what comes out the other end. It won’t be the steak."
              -J.Stanton

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              • #8
                Thanks so much for the input/articles! They wil be really helpful for me. Keep them coming for those that have more to contribute. I'll keep you posted as I continue with my research!

                Also, lil_earthmomma, I've wondered that too about nuts. The argument always seems to be "a small amount is ok" but I'm curious about how small is ok? Is "small" amounts of sprouted grain bread ok? You see my logic? Why nuts?

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                • #9
                  I think why nuts is that nuts are far more nutritionally dense than legumes and grains, so the tradeoff is that a small amount of nuts is ok - just my guess.
                  Karin

                  A joyful heart is good medicine

                  He is no fool who gives what he cannot keep to gain what he cannot lose. - Jim Elliot

                  Mmmmm. Real food is good.

                  My Journal: http://www.marksdailyapple.com/forum/thread29685.html

                  Comment


                  • #10
                    Originally posted by jem51 View Post
                    It is important to ask these questions since peop following any alternative woe tend to have blinders on.
                    I think you'll find ALL people tend to have blinders on, but thanks for the comment.

                    Comment

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