The Phytic Acid Thread

[guestmama9910]

I've been fascinated by the phytic acid = antinutrient in untreated whole grains aspect of canonical (ie Nourishing Traditions based) Traditional Foods diets, so I'm off to compile all the information I can find on the subject, on how necessary intervention is in order to increase bioavailability of minerals and nutrients such as niacin and zinc, and whether there are alternate traditional methods to break down phytic acid when it is called for. I figured that there might be others interested in this subject on a Traditional Foods forum, so here we are. A word of warning, unfortunately, most of the sources I have access to for research materials are copyrighted and I won't be able to quote lengthy sections that might be relevant, I'll be forced to cite and summarize.

Anyway, for a starting point, I suggest the Wikipedia article on Phytic Acid, which bears all kinds of signs of an editing struggle between pro and con phytic acid in the diet forces. I'll be posting articles as I continue my research, mostly from the nutritional science angle, but it would be interested to include research on what traditional cultures actually ate. Case in point: beans are also high in phytic acid, as are other plant foods, yet we don't discuss soaking or sprouting our legumes and lettuces, and neither did our forebears.

I think there's a lot of interesting material to mine in this subject and would love to see if anyone else is as curious as I am.
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AnnaArcturus

[guestmama9910]

Oily fish increases iron bioavailability of a phytate rich meal in young iron deficient women.

Oily fish increases iron bioavailability of a phytate rich meal in young iron deficient women.

J Am Coll Nutr. 2008 Feb;27(1):96-101. (PMID: 18460487 [PubMed - indexed for MEDLINE])

In brief, this study determined that serving oily fish, in this case salmon, increased iron absorption in humans who were fed a high phytic acid bean meal diet. No research was done on whether or not it increased absorption of other key minerals and nutrients affected by phytate, such as zinc or niacin, but I would imagine they were.

Interpretations? Mine are that fat soluble nutrients need fats to be absorbed.
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AnnaArcturus

[eastkygal]

I am interested. As not having many organic or non already ground flour options available to me, I've been wondering if I need to soak all my flour in yogurt or buttermilk. Also, if I need to soak all my beans to sprouting. NT says yes. Now, traditionally in my culture we eat alot of soupbeans which is pinto beans cooked until a little passed soft with lots of bacon fat and onions, salt and pepper. It's so yummy! We serve it with cornbread and fried potatoes. Anyway, traditionally we soak the beans overnight. My grandmothers called it soaking the gas out of them. They were never soaked to sprouting as far as I have seen.
I just made black eyed peas last night and didn't soak them at all. :

[guestmama9910]

High prevalence of low dietary calcium, high phytate consumption, and vitamin D deficiency in healthy south Indians.

High prevalence of low dietary calcium, high phytate consumption, and vitamin D deficiency in healthy south Indians.

American Journal of Clinical Nutrition, Vol. 85, No. 4, 1062-1067, April 2007
© 2007 American Society for Nutrition

ORIGINAL RESEARCH COMMUNICATION
High prevalence of low dietary calcium, high phytate consumption, and vitamin D deficiency in healthy south Indians1,2
Chittari V Harinarayan, Tirupati Ramalakshmi, Upadrasta V Prasad, Desineni Sudhakar, Pemmaraju VLN Srinivasarao, Kadainti VS Sarma and Ethamakula G Tiruvenkata Kumar

1 From the Departments of Endocrinology and Metabolism (CVH, TR, UVP, DS, and EGTVK), Biochemistry (PVLNS), and Statistics (KVSS), Sri Venkateswara Institute of Medical Sciences, Tirupati, India

Background: Data on the vitamin D status of the population in a tropical country such as India have seldom been documented. Vitamin D deficiency is presumed to be rare.

Objective:The objective was to document the dietary habits and concentrations of serum calcium, 25-hydroxyvitamin D [25(OH)D], and parathyroid hormone of Indian urban and rural populations.

Design:Healthy urban (n = 943) and rural (n = 205) subjects were studied for their dietary pattern and concentrations of serum calcium, phosphorus, alkaline phosphatase, 25(OH)D, and immunoreactive parathyroid hormone.

Results:The daily dietary calcium intake of both the urban and rural populations was low compared with the recommended dietary allowances issued by the Indian Council of Medical Research. Dietary calcium and phosphorous were significantly lower in rural adults than in urban adults (P < 0.0001). The dietary phytate-to-calcium ratio was higher in rural subjects than in urban subjects (P < 0.0001). The 25(OH)D concentrations of the rural subjects were higher than those of urban subjects (P < 0.001), both men and women. In the rural subjects, 25(OH)D-deficient (<20 ng/mL), -insufficient (20–30 ng/mL), and -sufficient (>30 ng/mL) states were observed in 44%, 39.5%, and 16.5% of the men and 70%, 29%, and 1% of the women, respectively. In the urban subjects, 25(OH)D-deficient, -insufficient, and -sufficient states were observed in 62%, 26%, and 12% of the men and 75%, 19%, and 6% of the women, respectively.

Conclusions:Low dietary calcium intake and 25(OH)D concentrations were associated with deleterious effects on bone mineral homeostasis. Prospective longitudinal studies are required to assess the effect on bone mineral density, a surrogate marker for fracture risk and fracture rates.

Key Words: Dietary calcium • phytate consumption • vitamin D insufficiency • bone mineral density • Indians • high prevalence

((Abstract was free. I'm sorry, I was unable to link to this article.))

Interpretations? Here is an example of a traditional population, that is apparently healthy, which is eating a high phytate diet. They happen to have low dietary calcium and low vitamin D concentrations, which is correlated with bone problems, but so far do not appear to be suffering too much for it. Or, at any rate, this is a rather confusingly worded abstract and the full article is no better. (Ok, they're healthy, but they're not?)
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AnnaArcturus

[quietserena]

Gale Force has a phytic acid email course on her site that will give you some practical info too.

[guestmama9910]

Soaking Beans

Eastkygal, I soak my beans as well, though not my peas and lentils, although I do this more as a convenience than anything else, it saves me a little time the next day. Truth be told, the long, low cooking used in your average bean dish will probably remove most of the phytate without the need for soaking, and the tradition of cooking the beans with some fat would increase absorption of what was there.
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AnnaArcturus

[guestmama9910]

Low zinc, iron, and calcium intakes of Northeast Thai school children consuming glutinous rice-based diets are not exacerbated by high phytate.

Low zinc, iron, and calcium intakes of Northeast Thai school children consuming glutinous rice-based diets are not exacerbated by high phytate.

Int J Food Sci Nutr. 2006 Nov-Dec;57(7-8):520-8.

Krittaphol W, Bailey KB, Pongcharoen T, Winichagoon P, Gibson RS.

Department of Human Nutrition, University of Otago, Dunedin, New Zealand.

Clearly, phytate will not compromise mineral absorption from these diets. Instead, low zinc intakes are probably primarily responsible for the low zinc status of these children. In contrast, although intakes of dietary iron appear low, the prevalence of biochemical iron deficiency was also low, suggesting that iron absorption may have been higher than previously assumed.

Summary: A comparison study between two populations of Thai school children, one given low phytate rice and the other given their traditional high phytate rice, then each was checked for mineral and vitamin concentrations in their blood. As it turns out, the school children consuming the traditional high phytate glutinous rice were no worse off than the children consuming the low phytate rice. Both had lower than "healthy" concentrations of zinc, iron, and calcium concentrations, despite being apparently healthy.

However, I thought this throwaway line would be of particular interest to us:

The inositol penta-phosphate and hexa-phosphate levels were so low they were below the detection limit, attributed in part to leaching of water-soluble potassium and magnesium phytate from glutinous rice after soaking overnight before cooking.

The above indicates to me that we have another instance of grain soaking up in Thailand, although in this case no acid is mentioned or implied. (I will see if I can find Thai instructions for rice preparation to append to this.)

Of other interest to me is a common trend I'm seeing in research on traditional, or at least more traditional, diets: the mineral and vitamin concentrations in the tested individuals are routinely lower than deemed healthy while they remain apparently, outwardly, healthy. I'm curious if there are comparative statistics on bone breakage among nations, but I suppose it would be impossible to control for the compounding variable of differing lifestyle and daily occupations.

Addendum: How to Prepare Thai Rice Indeed, the Thai traditionally soak their high-phytate glutinous rice overnight without benefit of an acid, and that appears to reduce the phytate content all on its own, just as it does with the beans.
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AnnaArcturus

[guestmama9910]

Low-phytate barley cultivars improve the utilization of phosphorus, calcium, nitrogen, energy, and dry matter in diets fed to young swine.

Low-phytate barley cultivars improve the utilization of phosphorus, calcium, nitrogen, energy, and dry matter in diets fed to young swine.

J Anim Sci. 2007 Apr;85(4):961-71. Epub 2006 Dec 18.

Veum TL, Ledoux DR, Raboy V.
Department of Animal Sciences, University of Missouri, Columbia 65211, USA. [e-mail]

Low-phytate barley cultivars improve the utilization of phosphorus, calcium, nitrogen, energy, and dry matter in diets fed to young swine1
T. L. Veum*,2, D. R. Ledoux* and V. Raboy{dagger}

* Department of Animal Sciences, University of Missouri, Columbia 65211; and and {dagger} USDA-ARS, National Small Grains Germplasm Research Facility, Aberdeen, ID 83210

2 Corresponding author: [e-mail]

A 28-d experiment was conducted using 45 crossbred barrows with an average initial BW of 9.5 kg and age of 35 d to evaluate low-phytate barley (LPB) mutants (M) M422, M635, and M955, which were hulled, near-isogenic progeny of the normal barley (NB) Harrington and had 47, 66, and 80% less phytic acid, respectively, than NB. A hull-less LPB, M422-H, which was not near-isogenic to the other cultivars, was also evaluated. Apparent nutrient balance, bone measurements, and growth performance were the response criteria evaluated. The barrows were fed the diets to appetite in meal form in individual metabolism crates. Barley and soybean meal were the only sources of phytic acid. Dietary protein supplementation and ME/kg were equalized in all diets. The treatments were diets containing NB, M422, M635, or M422-H without or with added inorganic P (iP), or M955 without added iP. Diets with added iP contained 0.30% available P (aP), the same concentration of aP provided by the diet containing M955 without added iP. There were linear increases (P ≤ 0.02) in ADG, G:F, metacarpal and radius bone strength, and fat-free dry weight, and in the absorption and retention (g/d and % of intake) of P and Ca with increasing dietary concentration of aP from the near-isogenic cultivars NB, M422, M635, or M955 without added iP. There were linear decreases in the grams (P ≤ 0.02) and percentages (P < 0.001) of P and Ca excreted per day with increasing dietary concentration of aP without added iP. There were no responses for N or energy balance. Growth performance and bone response criteria did not differ for barrows fed the diet containing M955 or the near-isogenic diets containing NB, M422, or M635 with added iP. However, barrows fed the diet containing M955 had greater (P ≤ 0.02) percentages of P, N, and energy absorption and retention, Ca absorption, and DM digestibility and had less (P ≤ 0.02, g/d and %) excretion of P, N, energy, and Ca (g) per day than barrows fed the diets containing the near-isogenic NB or LPB cultivars with added iP. When dietary aP was equalized with iP, the excretion of P in feces plus urine (g/d) was reduced by 20.2, 27.9, and 44.6%, respectively, in barrows fed the diets containing M422 + iP, M635 + iP, or M955 compared with barrows fed the diet containing NB + iP. Energy utilization did not differ for barrows fed the diets containing hulled or hull-less LPB when ME/kg was equalized with lard. In conclusion, the apparent utilization of P and Ca, the bone strength and fat-free dry weight, and growth performance increased with increasing dietary concentration of aP provided by LPB, in association with linear decreases in P and Ca excretion. Barrows fed the diet containing M955 also had greater utilization and less excretion of P, Ca, N, energy, and DM than barrows fed the diets containing the near-isogenic NB or LPB cultivars with added iP to equalize aP at 0.30%.

Key Words: barley • nutrient absorption • nutrient excretion • phytate • pig • swine

((This abstract was available free from the journal.))

Interpretations? Honestly, I see this as more reason to love barley, which I already justified based on its low glycemic index. Barley in general tends to be lower phytate than, say, wheat.
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AnnaArcturus

[guestmama9910]

Influence of germination and fermentation on bioaccessibility of zinc and iron from food grains.

Influence of germination and fermentation on bioaccessibility of zinc and iron from food grains.

Eur J Clin Nutr. 2007 Mar;61(3):342-8. Epub 2006 Sep 13.

Hemalatha S, Platel K, Srinivasan K.

Department of Biochemistry and Nutrition, Central Food Technological Research Institute, Mysore, India.

Since this is so beautiful a read:

OBJECTIVE AND DESIGN: Food grains such as green gram, chickpea and finger millet are often subjected to traditional processing involving germination and fermentation. This study was designed to assess the effect of germination of these grains on the bioaccessibility of zinc and iron. The effect of fermentation of a cereal-pulse combination as encountered in the preparation of breakfast dishes - idli, dosa and dhokla - on the same was also evaluated. Bioaccessibility measurement was made employing an in vitro simulated digestion method. RESULT: Zinc bioaccessibility was significantly decreased by germination (48 h) of finger millet (38%) and green gram (44%), while iron bioaccessibility was increased by 62% (green gram), 39% (chickpea) and 20% (finger millet), concomitant with a reduction in tannin content. A fermented batter of rice+black gram - 2:1 (idli) and 3:1 (dosa) - had higher bioaccessibility values for zinc (71 and 50%, respectively), while iron bioaccessibility values were increased in these cases of fermentation to an even greater extent, namely 277 and 127%, respectively. Zinc and iron bioaccessibility was not improved by fermentation of the combination of chickpea, green gram, black gram and rice (1:1:0.5:0.5; dhokla). A fermentation of cereal-legume combinations of idli and dosa batter significantly reduced both phytate and tannin, while in the case of dhokla batter there was a continued significant presence of phytate associated with additional legumes - chickpea and green gram. CONCLUSION: Germination of food grains improved the bioaccessibility of iron but not that of zinc. Fermentation of a batter of cereal-pulse combination in the preparation of idli and dosa enhanced the bioaccessibility of both zinc and iron, but not that of the combination used for the preparation of dhokla.

I think that says it all.
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AnnaArcturus

[guestmama9910]

Effect of traditional fermentation and malting on phytic acid and mineral availability from sorghum (Sorghum bicolor) and finger millet (Eleusine...

Effect of traditional fermentation and malting on phytic acid and mineral availability from sorghum (Sorghum bicolor) and finger millet (Eleusine coracana) grain varieties grown in Kenya.

Food Nutr Bull. 2002 Sep;23(3 Suppl):241-5.

Makokha AO, Oniang'o RK, Njoroge SM, Kamar OK.

Jomo Kenyatta University of Agriculture and Technology, Department of Food Science and Post-Harvest Technology, Nairobi, Kenya.

For those who aren't familiar with the term, malting is a process that essentially makes a pre-de-phytitized flour. You sprout the grain, dry it, and then grind it up to use in your food. It's another traditional treatment of grains.

Fermentation resulted in a mean decrease of phytic acid in of 64.8% after 96 hours and 39.0% after 72 hours in sorghum grain. In finger millet, there was a mean decrease of 72.3% and 54.3% after 96 and 72 hours, respectively. Malting also resulted in a mean decrease of 23.9 and 45.3% after 72 and 96 hours, respectively. The extent of decrease of phytic acid differed among the grain varieties.

The study concluded that, in addition to reducing the phytate content of these foods, these processes increased the bioavailability of a wide range of minerals and nutrients. Fermentation was found, again, to be more effective a treatment than malting. But this is the money quote for TF fans:

Simple traditional food processing methods can therefore be used to increase mineral availability.

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AnnaArcturus

[guestmama9910]

Reduction of polyphenol and phytic acid content of pearl millet grains by malting and blanching.

Reduction of polyphenol and phytic acid content of pearl millet grains by malting and blanching.

Plant Foods Hum Nutr. 1999;53(2):93-8.
Archana, Sehgal S, Kawatra A.
Department of Foods and Nutrition, CCS Haryana Agricultural University, Hisar, India.

This work was undertaken to evaluate the changes in polyphenol and phytic acid content in malted and blanched pearl millet grains. For malting, grains were steeped for 16 hours, germinated for 48 or 72 hours and then kilned at 50 degrees C for 24 hours. Blanching was done for 30 seconds in boiling water at 98 degrees C. Results indicated that blanching resulted in significant reduction in polyphenol (28%) and phytic acids (38%). Destruction of polyphenols (38 to 48%) and phytic acid (46 to 50%) was significantly higher in grains subjected to malting than blanching: The overall results suggested that malting with 72 hours of germination was most effective in reducing the antinutrient levels of pearl millet grains.

I'm beginning to think that some of us ought to get together and start a malt production operation on the lines of Bob's Red Mill or King Arthur Flour, essentially creating a TF ready-to-use flour. The downside? Malt is higher in natural sugars.
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AnnaArcturus

[guestmama9910]

Effect of domestic processing and cooking methods on phytic acid and polyphenol contents of pea cultivars (Pisum sativum).

Effect of domestic processing and cooking methods on phytic acid and polyphenol contents of pea cultivars (Pisum sativum).

Plant Foods Hum Nutr. 1994 Jun;45(4):381-8.
Bishnoi S, Khetarpaul N, Yadav RK.
Department of Foods and Nutrition, Haryana Agricultural University, Hisar, India.

Summary: The conclusion was that the domestic methods of soaking, fermenting, and so on, had an effect on the phytate content, but the most effective method for reducing the phytate content was sprouting/germinating the peas for 48 hours.
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AnnaArcturus

[salt_phoenix]

AnnaArcturus

Thanks for all your work!

I know I grew up with TF (southern/cherokee) and my grandmother & ggm ALWAYS soaked beans/rice/grains and cooked them with animal fat/bones meat & salt. They actually said it was so you could digest it better.
These were VERY poor and uneducated people...
Funny what they knew without actually KNOWING.

[AJP]

Originally Posted by AnnaArcturus

I'm beginning to think that some of us ought to get together and start a malt production operation on the lines of Bob's Red Mill or King Arthur Flour, essentially creating a TF ready-to-use flour. The downside? Malt is higher in natural sugars.
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AnnaArcturus

There is a business called Summer's Sprouted Flour in New Mexico, they ship freshly-ground, sprouted (malted) wheat, spelt, kamut and rye. http://www.creatingheaven.net/eeproducts/eesfc/ Ordering from them requires some patience, I think they're mostly set up to do wholesale and their communication occasionally leaves something to be desired, but the product is lovely. I order 50 lbs. at a time usually, which lasts a good 6 months. (We set up an account a few years ago and just send in our order on the website, not expecting a confirmation or any other feedback, and the flour usually arrives within a couple of weeks. ETA: I did receive a confirmation and shipment info for my current order, and have always received the product in the past even if I didn't get an email.) I like the spelt best, use it for all kinds of things (cookies, muffins and other quickbreads, yeasted breads, etc.). I've made malted wheat flour at home, but never had any luck getting spelt to sprout consistently, and since I like spelt better and feel like I'm at capacity with kitchen projects, I love being able to get it from someone else.

Thanks for digging up these studies, interesting stuff.

[guestmama9910]

salt_phoenix, Thanks, it's always nice to be appreciated.

AJP, Thanks so much for the link! Could you elaborate on how you use the malted flour? Is it any different from working with ordinary flour and do you still soak it for that marginal reduction in phytate?
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AnnaArcturus

[AJP]

Anna, I use it just like any other flour. I usually bake with a standard recipe, and sub conventional ingredients with sprouted wholegrain flour, Rapadura or other unrefined sweetener, butter or coconut oil. Occasionally when I use spelt, either sprouted or not, the dough or batter will seem a bit too wet, and I'll sometimes add a little extra flour in that case (one would have to know the recipe well enough to know what consistency it's supposed to be), but most of the time I don't have to do that. Spelt tends to absorb less liquid than wheat, IME, but wholegrain flour, sprouted or not, absorbs more than white flour, so if I'm using a recipe calling for white flour it tends to be an equal substitution with sprouted spelt, especially if it's a recipe using flour weight rather than volume. Mostly I use volume measurements, though. On the rare occasion when something doesn't come out right because of my tinkering, it's still edible, and I learn something. The only special recipe I've come up with for sprouted spelt flour is for chocolate chip cookies, and I think that has less to do with the sprouted-ness of the flour and more with the specific texture of cookie I wanted that I wasn't getting from other recipes (soft, but not cake-like and not greasy).

The company says that their sprouted flours are drier than conventional flour, so you might need to use less flour to keep the product from being too dry, but I haven't found that to be the case. They have recipes on the website, but I have only tried a few, and the only one I really liked was for a stored-heat batter bread. I have a collection of baking recipes I use a lot that are amenable to tinkering, they're mostly conventional recipes that I just use as a template, subbing the ingredients I want like mentioned above. When I try one that works with my standard substitutions, I keep it in the rotation.

I rarely soak the malted flour intentionally. It does work for sourdough, and some slow-rise yeast bread recipes end up essentially getting soaked as well. Things like cookies and quickbreads just don't come out the way I like when soaked (like some of the terrible recipes in NT), and I think the malting is good enough in terms of enabling nutrient absorption, since my family's diet is nutrient-dense.

[Metasequoia]

Originally Posted by quietserena

Gale Force has a phytic acid email course on her site that will give you some practical info too.

Amanda's course is AWESOME!

[TopazBlueMama]

One of the quotes above kind of talked about it, but don't forget about complementary soaking! I have a bucket of grain mix that includes several different grains plus varieties of lentils for the legumes. I just add a scoop to whatever I'm making so that the grains can help completment each other where one is lacking it phytase, the other can make up. In nutrients and amino acids, too. I just believe in the synergy of it.

[hummingmom]

There's an ongoing discussion in the PPD forum about the use of very high dose inositol (12 g/day) to treat depression. I haven't read the whole thread (it's a bazillion pages long), but it seems as if many members have seen positive results.

According to a couple of nutrition sites I've seen, inositol = phytic acid = phytate. But maybe there are different forms, and there's a "good kind?"

Curiouser and curiouser...

[honeysesame]

wow, impressive research!!
couple things:
ajp, i'm getting tempted to look into sprouted flour again (as my discipline to try soaking and blender batter and sourdough -- or buy a grinder! etc. has proven faulty...)-- question: since it's already been sprouted does that mean you no longer have to worry that it wasn't just ground two days ago and can conveniently add it to recipes at your leisure? yes?

secondly, re the phytic acid subject, just wanted to pitch the reminder that folks of different ancestries have perhaps evolved differently in terms of how bodies and food co-exist, so what works for some may not for others (as i'm sure we all know anyhow)-- well, just felt compelled to add that annoying and not so productive comment. still interesting to see all the traditional ways tho!

oh, and for folks that do soak rice and beans, how long generally? i thought nt says beans for 12 hours but mine hadn't sprouted yet at that point. oh, and topazbluemama, what's in your grains and legumes mix?

thanks y'all!