Are all prolamins detrimental (aka is rice really gluten free)?

adam7117

Jedi Council Member
FOTCM Member
There's been some recent discussion on the forum regarding the gluten-free status of rice (e.g., here or here). Peter Osbourne's research is quoted which talks about prolamins - or gluten. All grains have prolamins - even rice (i.e., Orzenin) - and this is a bit of a worry. However, the usual protein of interest is Gliadin which is contained by wheat grains - as well as other similar molecules in stuffs like barley and rye.

This is a bit confusing. Buckwheat has prolamins as well, though at lower levels. Some people on the forum are reporting sensitivity to it, and I just might be one of those people. Eating lotsa pancakes gives me bad bloating and a sore tummy (though it could just be the high fat and/or fibre content).

On the other hand, I also feel wrong after eating lots of brown rice - and this feeling I attributed to its high lectin content. Having switched to white rice varieties, that ceased to be a problem... Of course, this is just a single personal account and everybody is different but there has to be an underlying rule here, something that we all share. Perhaps, it is a diet consisting of meat and vegetables only - but is it?

Maybe this is just a bit of wishful thinking on my behalf - maybe all prolamins are bad and should be removed from the diet completely. If you find some spare energy at the next session, please ask - it would be interesting to hear C's comments on this quandary.
 

Deckard

The Living Force
FOTCM Member
adam7117 said:
Eating lotsa pancakes gives me bad bloating and a sore tummy (though it could just be the high fat and/or fibre content).
another thing to consider in case you were using it, is xylitol. I use to use a lot with my pancakes and had exactly the same symptoms which I blamed on buckwheat.
 

Finduilas495

Jedi Council Member
FOTCM Member
Loren Cordain, the author of "The Paleo Diet", has published a scientific article on the topic titled "Cereal Grains: Humanity's Double-Edged Sword" back in 1994, which can be found here: _http://www.thepaleodiet.com/articles/Cereal%20article.pdf.

The article mentions rice amongst the cereal grains that might cause health problems.
 

adam7117

Jedi Council Member
FOTCM Member
Corto said:
another thing to consider in case you were using it, is xylitol. I use to use a lot with my pancakes and had exactly the same symptoms which I blamed on buckwheat.

Thanks, Corto. No, I don't use Xylitol at all. It's possible to source it on the net (yet to find it in an Oz store) but I'm not sure I fully trust a chemical compound like this. I also don't use sugar in my cooking and prefer natural sweetness of fruit - but if a sweetened snack happens (e.g., in takeaway), I'm not too devastated about it.

There has to be something else. Not sure why I get so bloated - maybe it's because I eat too much of it in a single go, come to think of it. The pancakes are really nice and I tend to finish the whole lot by the time I'm out of the kitchion. :lol: This could be a major clue - overeating and the subsequent expansion of the flour in my stomach.

I'll start to progressively remove rice from my diet (though it is a major staple) and see what happens. It's gonna be tricky but what the hay.

I would still like to know what the deal is here, though. So I've started searching for more information about prolamins in various grains. It ain't easy and I ain't a doctor - but let's get some of this information together and see if anyone notices anything interesting.

Prolamins in buckwheat and rice...
 

adam7117

Jedi Council Member
FOTCM Member
Buckwheat Prolamin and Its Antioxidative Activity (2001)
Takanori KUSANO, Hiroko CHIUE and Kimikazu IWAMI

Department of Nutrition, Kobe-Gakuin University
Ikawadani-cho Arise, Nishi-ku, Kobe 651-2180, Japan
Department of Biological Resource Chemistry, Kyoto Prefectural University
Shimogamo Nakaragi-cho, Sakyo-ku, Kyoto 606-8522, Japan

Source: http://lnmcp.mf.uni-lj.si/Fago/SYMPO/2001sympoEach/2001s-629.pdf

ABSTRACT
Buckwheat prolamins were most effectively extracted from buckwheat (Fagopyrum
esculentum Moench) flour by 55% n-propanol and were 3.37 to 4.95% of total protein under
the most efficient conditions for extraction (at 60°C). Amino acid analysis data showed that
buckwheat prolamin didn't exhibit one of characteristics of cereal prolamins, the high
glutamate/glutamine and proline content.
The antioxidative activity of buckwheat prolamin
was investigated. The peroxide value under powder model systems and radical scavenging
effect were evaluated. Buckwheat prolamin was effective inhibitor of the oxidation of linoleic
acid.


INTRODUCTION
Oxidative deterioration of unsaturated lipid-rich foods doesn't only lessen their tasty or
nutritive value but also brings about toxicity in an extreme case. Food manufactures make use
of antioxidants and often package their goods under anaerobic conditions for prevention of
possible troubles. The use of synthetic antioxidants such as butylhydroxyanisole and
butylhydroxytoluene tends to be recently avoided because of a doubt upon their safety for
health (Grice 1988, Witschi, 1986).

Instead, much interest has been directed toward the
development of natural and more safe antioxidants, e.g. amino acids (Gopala et al., 1994,
Kawashima et al., 1979), peptides (Yamaguchi et al., 1979), proteins (Laakso 1984) and so on
(Nakatani 1990, Namiki 1990). Among such promising foodstuffs are cereal prolamins
represented by wheat gliadin (Iwami 1987), maize zein (Wang 1991) and barley hordein
(Chiue 1996).

In previous paper (Iwami et al. 1987, 1988) we have offered a plausible
explanation for the mechanism from a physical rather than chemical point of views. Although
all of prolamins are soluble in aq. alcohols, they vary considerable in their other properties,
notable MW and pI values and amino acid compositions.


While cereal prolamin has been
intensively studied in relation to the quality of the grain for baking (wheat), malting (barley),
and feeding to domestic animals, we know relatively little about dicotyledonous prolamins.
Our object is to investigate the properties of buckwheat prolamin and to check its
antioxidative activity.


MATERIALS AND METHODS
Commercially available common buckwheat (Fagopyrum esculentum) was used. The husks
of the seed were removed and ground.
Flour was extracted with 0.5M NaCl before alcohol extractions. The range of concentration
of the three alcholols tested, I-propanol (n-propyl alcohol), 2-propanol (iso-propyl alcohol)
and ethyl alcohol, was 30-80% (w/w) at room temperature and 60°C.

Nitrogen contents and
Protein content of the extracts were determined by the Kjeldahl method and the Lowry method
using bovine serum albumin as a standard. The protein fraction was thoroughly dialyzed
against the aqueous alcohol and distilled water, lyophilized and. pulverized. Wheat gliadin was
prepared in a similar manner from their respective flours for reference. Other chemicals were
of analytical grade and commercially available, and used as such without further purification.

SDS-PAGE. Extracted proteins of buckwheat were electrophoresed using the discontinuous
buffer system of Laemmle (Laemmle 1970)on a slab gel containing 12.5% acrylamide.

Amino acid analysis
Protein samples were hydrolyzed in evacuated sealed tubes in 6N HCI at 110°C for 22hrs
and then analyzed with an amino acid analyzer. Tryptophan and cystine content were not
determined.

Powder model system for autoxidation
Buckwheat prolamin was suspended in an equivoluminal mixture of chloroform and
methanol containing linoleic-palmitic(2: 1) acid at 10wt% of protein. These samples were then
put in a 60°C or 100°C incubator without moisture control after completely removing the
organic solvent. Definite amounts of the respective samples were taken out after specific
periods and assayed for both accumulated hydroperoxides and residual fatty acids. PV at each
sampling time during the storage period is, for convenience, expressed as the absorbance at
500nm under the routine assay conditions. Unimpaired linoleic ans palmitic aicd, which were
almost quantitatively extracted with chloroform-methanol (1: 1), were esterified with PNBDI
and determined by HPLC. a-Corn starch was used as a reference control not having
antioxidative activity throughout this experiment.

Radical-scavengging effect
In the 1.0 x 10-4 M ethanol solution of DPPH, tested compounds were added. The solution
was shaken vigorously and kept in the dark for 30 min. The absorbance of the samples was
measured on a spectrophotometer at 517nm against a blank of ethanol without DPPH.

RESULTS AND DISCUSSION
There has been little work on buckwheat prolamin except for the standpoint of gluten sensitive
enteropathy
(Skerritt 1986, Friis 1988). There are probably several reasons for this,
including the low content and the problems in purifying single homogenous proteins.
Prolamins were extracted from mature common buckwheat flour with aqueous alcohols. Most
effective solvent was 55% n-propanol and more prolamin was extracted at 60°C, which was
used in preparation of prolamin unless otherwise stated. The amount of prolamin was from
3.37 to 4.95 % of total protein.


Cereal prolamin is generally rich in glutamate/glutamine and
proline
(Shewry et aI., 1994), but as in buckwheat the combined proportions of these two
amino acids vary from 11.1 to 20.4 % well below average in other cereals. Buckwheat
prolamin was composed of many kinds of subunits polyperptides.
Their molecular weight
from SDS-PAGE data was smaller than that of most cereal prolamins which were about 30,000
to 90,000 (Shewry et aI., 1994).

Although it had been reported that cereal prolamin exhibited antioxidative activity against
linoleic acid, the acceptable hypothesis had not been offered so far. Buckwheat prolamin was
found to exhibit antioxidative effect in powder model systems and radical scavenging activity
.

At the same time non-protein antioxidant compounds from buckwheat have been reported
(Oomah et al. 1996, Watanabe et aI., 1997). A possibility that tocopherols may function as a
primary antioxidant can be excluded by the finding that the washing treatment of buckwheat
prolamine with several kinds of organic solvents scarcely lowered its antioxidative activity. In
addition, it seems unlikely that flavonoids are kept back in buckwheat prolamin, because the
protein in preparing it has not only been extracted with 55% n-propanol but also adequately
dialyzed against the same solvent.

To understand the relationship between the antioxidative activity and physical and chemical
properties of buckwheat prolamin, the evaluation of antioxidative activity of buckwheat
prolamin should be performed at the subunit level.

In any case, further investigation is required to elucidate the mechanism of antioxidation and
its practical application to food storage.

REFERENCES
Chiue, H., Kusano, T. and Iwami, K. 1997. Antioxidative activity of barley hordein and its loss
by deamidation..J.Nutr. Sci. Vitaminol. 43: 145-154.

Friis, S. U. 1988. Enzyme-linked immunosorbent assay for quantitation of cereal proteins toxic
in coeliac disease. Clinica Chimica Acta, 178:261-270.

Grice, H. C. 1988. Safety evalution of butylated hydroxyanisole from the perspective of effects
on forestomach and oesophageal quamousepithelium. Food Chern. Toxicol., 26:717-723.

Gopala, A. G. and Prabhakar, J. V. 1994. Antioxidant efficacy of amino acids in
methyllinoleate different relative humidities. J. Am. Oil Chern., 71:654-647.

Iwami, K., Hattori. M. and Ibuki, F. 1987. Prominent antioxidant effect of wheat gliadin on
linoleate peroxidation in powder model system at high water activity.. J. Agric. Food Chern.,
35 : 628-631.

Kawashima, K., Hoh, H., Miyoshi, M., and Chibata, I. 1979. Antioxidant properties of
branched-chain amino acid derivatives. Chern. Pharm. Bull., 227,: 1912-1916.

Laakso, S. 1984. Inhibition of lipid peroxidation by casein; evidence: evidence of molecular
encapsulation of 1,4-pentadiene fatty acids. biochim. Biophys. Acta, 792: 11-15

Laemmli, U. K. 1970. Cleavage of structural proteins during the assembly of the head of
bacteriophage T4. Nature 227 : 680-685.

Nakatani, N. 1990. Recent advances in the study in natural antioxidants. Nippon Shokuhin
Kogyo Gakkaishi , 37 : 569-576.

Namiki, M. 1990. Antioxidants/antimutagens in food. Crit. Rev. Food Sci. Nutr., 29 : 273-300.

Oomah. B. D. and Maza G. 1996. Flavonoids and antioxidative activities in buckwheat.
J.Agric. Food Chern., 44: 1746-1750.

Shewry, P. R., Miles, M. 1. and Tatham, A. S. 1994. The prolamin storage proteins of wheat
and related cereals. Prog. Biophys. Mol. Biol., 61 : 37-59.

Skerritt, 1. H. 1986. Molecular Composition of alcohol-solble wheat and buckwheat proteins.
Cereal Chern., 63 : 365-369

Yamaguchi, N., Yokoo, Y and Fujimaki, M. 1979. Antioxidative activities of protein
hydrolyzates. Nippon Shokuhin Kogyo Gakkaishi, 26 : 65-70.

Wang, J. Y, Miyazawa, T. and Fujimoto, K. 1991. Inhibition of methyllinoleate peroxidation
by maize zein in powder model systemat high water activity. Agric. BioI. Chern., 55 : 1531-1536.

Watanabe M., Ohshita Y. and Tsushida T. 1997. Antioxiant compounds from buckwheat hulls.
J. Agric. Food Chern. 45 : 1039-1044.

Witschi, H. P. 1986. Enhanced tumor development by butylated hydroxytoluene (BHT) in the
liver, lung and gastrointestinal tract. Food Chern. Toxicol., 24 : 1127-1130.

Maybe not the most relevant of papers but at least it is available online. Certainly some clues there...
 

adam7117

Jedi Council Member
FOTCM Member
There is an interesting-looking research paper here (well, actually it is a book chapter). Does anyone have access to it? It sounds great and could provide interesting pieces of information.

Characterization of Gluten Proteins in Grain Flours by Liquid Chromatography-Tandem Mass Spectrometry Using a Quadrupole Time-of-Flight Mass Spectrometer

Dorcas Weber, , Benjamin P.-Y. Lau, and Samuel Benrejeb Godefroy

Bureau of Chemical Safety, Food Directorate, Sir Frederick Banting Research Centre,
Health Canada, Ottawa, Ontario K1A 0K9, Canada

Food Contaminants
Chapter 32, pp 482–500
Chapter DOI: 10.1021/bk-2008-1001.ch032
ACS Symposium Series, Vol. 1001
ISBN13: 9780841269545eISBN: 9780841221444
Publication Date (Print): October 20, 2008
Copyright © 2008 American Chemical Society

ABSTRACT
Grain flours from a local bulk food store were analysed using liquid chromatography Quadrupole-Time of Flight tandem mass spectrometry for the proteins in the ethanol soluble gluten fraction after extraction and enzymatic digestion. Glutens from wheat, rye, barley, and oat were readily identified using a database search of the MS/MS data. Prolamins were also detected in "gluten-free" flours such as rice and corn. Extracts of multi-grain mixtures were analysed and the major glutens present were easily identified.
 

adam7117

Jedi Council Member
FOTCM Member
OK, here's more research papers on prolamines in buckwheat. I'm hoping that somebody will have access to these and share the gist of it with the rest of us...

I'm looking for information on buckwheat first, then rice - the objective is to compare the prolamin composition between rice and buckwheat and to look for differences in terms of chemistry. There have to be differences, right? And the hypothesis could be: not all prolamins are bad for human consumption. It would be good to know which ones those are - or if levels of concentration make a difference - or if other nutritional compounds mitigate the bad effects of prolamins.

Any comments would be greatly appreciated. Finduilas495 - thanks for your link. It's very interesting though it's missing information on the prolamin content of various grains and cereals.

Studies on the amino acid and mineral content of buckwheat protein fractions

Yi-min Wei, Xin-zhong Hu, Guo-quan Zhang, Shao-hui Ouyang

Article first published online: 27 MAR 2003
DOI: 10.1002/food.200390020

ABSTRACT
Protein fractions were extracted by successive extraction and analysis method in four buckwheat varieties including Japanese spring buckwheat, Japanese summer buckwheat, Yuqiao No. 1 and Yuqiao 6-21. The amino acid and the mineral content of each protein fraction were also analyzed in this paper. The basis for the data on the experiment was the relationship between protein fractions and amino acids, and the mineral contents of protein fractions. The distribution and proportion of amino acids and the minerals in each protein fraction in the buckwheat kernel as well as the nutritional value of buckwheat kernel were discussed. The results showed that there is a high amount of soluble protein and very low amount of prolamin in the buckwheat kernel. Leucine is the first limited amino acid in buckwheat, and buckwheat protein is only a seminutritional protein. The buckwheat kernel is rich in K, Zn in the albumin, Ca, Mg and Mn in the globulin, Na in the prolamin and glutelin.

_http://onlinelibrary.wiley.com/doi/10.1002/food.200390020/abstract

Immunochemical analysis of buckwheat proteins, prolamins and their allergenic character

P. Á. Biacs, E. Aubrecht

Journal: Acta Alimentaria
Publisher: Akadémiai Kiadó
ISSN: 0139-3006 (Print) 1588-2535 (Online)
Issue: Volume 28, Number 3 / August 1999
DOI: 10.1556/AAlim.28.1999.3.5
Pages: 261-268
Subject Group: Biomedical and Life Sciences
Online Date: Friday, July 22, 2005

ABSTRACT
Prolamin content of buckwheat flour and processed foods was 24.2–42.1 mg/kg dry material measured by ELISA. According to in vitro results buckwheat is suitable for use in coeliac diet, although it contains some antinutritive materials, protease inhibitors and tannin. The allergenic properties of buckwheat are poorly understood. In our investigation intensity of the 24 kD protein band of buckwheat, of which allergenic activity is known has decreased, and 30–35 kD protein associations have been formed after heat treatment. Immunochemical reaction of buckwheat proteins were studied with blood specimens of coeliac and healthy persons.

_http://www.akademiai.com/content/u423345x7082w317/
 

zlyja

Jedi Master
FOTCM Member
Hi adam7117,

Thanks for your research! The papers look very interesting. I don't have university access, and thus can't get them for free, but if you know someone who goes to a university, perhaps they could request the full article for you? If you don't then maybe you could try finding the contact info of the authors and explain what you want to know.

You can get the info of one of the papers you mentioned here: _http://onlinelibrary.wiley.com/doi/10.1002/food.200390020/pdf. I haven't read it yet, though. If I find anything noteworthy, I'll let you know. :)

Edit: For reference, here's data from that PDF:

3.1 Protein fractions of buckwheat kernel

The mean protein content in buckwheat is 14.96% (Table 2).
The average albumin content is 20.99%, highest content of
albumin being 30.30%. The decreasing order of fraction content
from high to low is glutelin, globulin and prolamin, the
average content of prolamin is 4.35%. The protein fraction is
different in different varieties. The coefficients of variation
from high to low are globulin, prolamin, albumin, and glutelin.
The water-soluble protein fraction is high and the prolamine
fraction is low, which caused the different nutritional and processing
quality from other cereal grains such as wheat.

3.2 Amino acid contents of buckwheat protein
fractions

On the basis of the buckwheat protein content, glutamic
acid content, which is 3.41 g/100 g of total protein, is the highest.
Arginine, aspartic acid, glycine, and lysine contents were
higher than phenylamine, threonine, and tyrosine contents.
The cysteine content at 0.18 g/100 g was the lowest (Table 3).
By studying the distribution of the seventeen amino acids in
the protein fractions, we can draw some conclusions. The
sequence of amino acid content from high to low in albumin
was glutamic acid, aspartic acid, lysine, arginine, glycine, and
valine. The leucine content was close to the average content
(0.43%). The sequence of amino acid content from high to low
in globulin was glutamic acid, arginine, aspartic acid, glycine,
and histidine. The contents of all amino acids in globulin were
significantly lower than in albumin. The glutamic acid content
was the highest in prolamin, but the content of all amino acids
descended greatly. The methionine, histidine and cysteine contents
were the lowest in prolamin. The sequence of amino acid
contents from high to low in glutelin was similar to albumin,
except that the isoleucine content was high. From the results,
the methionine and cysteine contents were always the lowest of
the four protein fractions. The tyrosine, serine and leucine contents
were stable. The glutamic acid content was the highest of
the four protein fractions. The aspartic acid content was the
second highest in the albumin, the prolamin and the glutenin.
The arginine content was the second highest in globulin. The
lysine content decreased from albumin > glutelin > globulin >
prolamin, the threonine content from prolamin >glutelin >
albumin > globulin. Glutamic acid, aspartic acid, arginine, and
lysine were abundant in the buckwheat kernel, and the lysine
content was higher than in other cereal grains. The first limited
amino acid was leucine and the others were threonine, methionine,
cysteine, phenylamine, and tyrosine. Furthermore, the
proportions of methionine, cysteine, threonine, and tyrosine
were low. As for the nutritional value, buckwheat is not a good
source to be used as a staple food, but it can be used with other
cereal grains.

3.3 Mineral conent of the buckwheat protein
fractions

K exists in albumin, globulin, and prolamin, and is abundant
in albumin and globulin, but is not found in glutelin (Table 4).
There is a small amount of Na in prolamin, the regularity of its
content in albumin and glutelin is irregular, and it is not found
in globulin. Globulin is rich in Ca (64.13%). A small content of
Ca in albumin and globulin and even less in prolamin is found.
Mg is also abundant in globulin. The amount of Mg in globulin
is about 49.98% of the total, but there is only a small amount of
Mg in albumin, prolamine, and glutelin. Zn is highest in albumin,
whose Zn content is 60.02% of the total, and 0.84 lg/g in
globulin, but it is very little in prolamin and glutelin. The Mn
content is 17.63%, 40.71%, 3.18%, 7.99% in albmin, globulin,
prolamin, and glutelin, respectively. The reason why there is no
Fe in protein fractions is unknown. The amount of Se, Ge, Pb,
Li, Co and Cu is less than 10 lg/g in protein fractions.
The content of K and Na is high, while Zn and Mn are low
in buckwheat kernel (Table 4). There are different mineral contents
in protein fractions. The buckwheat kernel is rich in K
and Zn in albumin, Ca, Mg and Mn in globulin, and Na in prolamin
and glutelin. The physiological and biochemical reasons
for these phenomena need continuing research.

In conclusion, the buckwheat kernel has a high amount of
soluble protein and a very low amount of prolamin. Leucine is
the first limited amino acid in buckwheat, and buckwheat protein
is only a seminutritional protein. The buckwheat kernel is
rich in K and Zn in albumin, Ca, Mg and Mn in globulin, and
Na in prolamin and glutelin.

The tables didn't copy so well, so I left them out. I'm not knowledgeable enough to give you a good interpretation, though. FWIW.
 

Laura

Administrator
Administrator
Moderator
FOTCM Member
We have noticed that cutting out rice actually does have a profoundly beneficial effect. So far, eaten in moderation with other foods, we have almost no bad reactions to buckwheat though there are a couple people in the house here still testing that. for themselves.
 

Galaxia2002

Dagobah Resident
FOTCM Member
I have heard that sometimes the packing machine used on rice may also have been used to pack wheat and that contaminates it. It can trigger reactions to wheat in celiac persons that eat rice. Maybe rinse the rice with water before cook it could help.

I have started to read a book of Jean seignalet called "food the third medicine" which is very agree to paleodiet. He explains that "bad proteins" have always existed, but that primitive man was adapted through the evolution because they always eat the same kind of the same plant. In the last thousand years man had manipulated and recombined plants varieties and in this way altering gene combination, so proteins, making new peptide combination which man in slow to adapt. We need new enzimes that we don't have and there would be persons that would have a little more evolved pool of enzimes to adapt to this "new" foods. This could explain differences in reactions to the same food by diferent people. This is already known, but this autor add that the temperature of the cooking is also very important because when you heat it you change the terciary structure and maybe the structure of food's proteins to deeper level making it unrecognizable to the molecular structure of enzymes that are highly specific. You could be making trash the food to heat it a lot. He recommended not to exceed 110 celsius degrees and lower the better.
 

Nathan

Dagobah Resident
FOTCM Member
adam7117 said:
Thanks, Corto. No, I don't use Xylitol at all. It's possible to source it on the net (yet to find it in an Oz store) but I'm not sure I fully trust a chemical compound like this.

I've been able to find it in every health food store I've walked into in Melbourne (except one, who was out of stock). Perhaps it's more scarce where you are? If so, there's no shortage of it online. I did a quick google search and found these:

_http://www.xlear.com.au/p/3012/naturally-sweet-xylitol-500g-pack.html
_http://www.inspiredwellbeing.com/store/naturally-sweet-xylitol-2.5kg.html
_http://www.organicsaustraliaonline.com.au/prod1944.htm
_http://www.organicsaustraliaonline.com.au/prod2921.htm
_http://www.naturallysweet.com.au/c/784/1/naturally-sweet-xylitol.html
 

adam7117

Jedi Council Member
FOTCM Member
zlyja said:
Thanks for your research! The papers look very interesting. I don't have university access, and thus can't get them for free, but if you know someone who goes to a university, perhaps they could request the full article for you? If you don't then maybe you could try finding the contact info of the authors and explain what you want to know.

No worries. I don't really know that much about this topic and maybe somebody will find the data useful. As far as the article access goes, I'm actually a uni graduate and it turns out that I can still get access to online journals. So went to the campus today and renewed the account - got the papers now, plus some more. Thank you for your suggestions!

To keep it all in one place, I started an online spreadsheet with results and notes. There isn't much in there at the moment but I'll spend the rest of the day reading and adding stuff in. Food Chemistry is a good resource on buckwheat - but rice is a little tricky. I wonder why that is - maybe there is a better journal... Definitely looking forward to the next issue of the Dot Connector where this issue will be discussed in greater detail. Additional references will be interesting.

In the meantime, I'm gonna spend this Friday evening reading up on food chemistry. :P

To be honest, it's not looking very good for grains in general although buckwheat is probably more beneficial and has more nutritious content as opposed to rice. But there are also reports here on the forum where people with IBS-related illness tolerate white rice very well. That makes me curious and I hope that there is some sort of explanation. Since my diet is mostly Ultra Simple, with the exception of rice and a few other odds and ends, I'll re-introduce buckwheat again and see what happens. I'm wrong all the time.

Speaking of being wrong, thanks for the links Nathan. I went to the Healthy Life store today and asked again. Success, this time I was led to a shelf full of Xylitol. I prob just pronounced it wrong last time or the attendant was in a hurry or something. Thanks for the links, mate - might give it a go at some stage. Once I read up a bit more on it.
 

zlyja

Jedi Master
FOTCM Member
That's great! :D The spreadsheet looks very promising. If you find other interesting facts in the papers that don't quite fit with the data on the spreadsheet, maybe you could mention them here. Haven't really had the time for research, but if I find anything, I will let you know.

Just wondering: the percentages are exactly as they appear in their respective references, right? If you have the time, maybe you could make notes of percentages from other papers, keeping experimental error in mind. You might be able to compute an average, but, then again, it's probably not necessary.

Good luck!
 

zlyja

Jedi Master
FOTCM Member
I found some interesting data from this PDF (_http://onlinelibrary.wiley.com/doi/10.1111/j.1398-9995.1996.tb02108.x/pdf). Not sure what to make of the entire thing, but I think that the correlation between buckwheat and rice allergies is of note. The prolamins might not be the cause of sensitivities in some people.

Allergenic properties and other features
and problems in buckwheat food hypersensitivity
and allergic asthma

The immunologic properties of buckwheat have
been identified by new techniques using the
immunoblotting method, radioallergosorbent test
(RAST), and RAST-inhibition assay (17,18). A 24-
kDa buckwheat protein (BW24KD) was the most
frequently recognized allergenic component, binding
to IgE antibodies from 100% of the patients’
sera. Of subjects (n = 41) with positive IgE RAST
to buckwheat antigens, 85.4% were positive to
BW24KD. All patients with positive prick tests for
buckwheat antigens were positive for BW24KD.
The RAST-inhibition assay using patients’ sera
showed positive IgE antibodies to both whole buckwheat
extract and BW24KD. There was effective
inhibition in a dose-dependent manner between
BW24KD and buckwheat extract. These findings
indicate that the major allergenic properties in
buckwheat were to be found in the BW24KD
protein.
Buckwheat is used instead of gliadin-containing
cereals such as wheat by gluten-allergic patients
(celiac disease) (19). The enzyme-linked immunosorbent
assay (ELISA) for quantification of cereal
proteins toxic in celiac disease is of value to plan
an elimination diet. An inhibition ELISA has been
developed, with a purified, polyclonal prolamin
antibody reacting with gliadin-like polypeptides in
the food. The buckwheat flour was thus analyzed
for antigen content.
An amount of 39.5 mcg gliadin like
polypeptides per gram flour was measured,
corresponding to 0.06% of the gliadin content in
wheat flour. The antibody did not react with maize,
millet, rice, or soybean prolamines. The detection
limit of the assay was 1 ng antigen, ensuring a high
degree of sensitivity.

Recently, it has been found that cross allergenicity
between rice and buckwheat occurs
especially (20). This resulted in an inhibited immediate
hypersensitivity reaction (IHR) in 28 out of
48 subjects with positive RAST values for both
buckwheat and rice.
RAST values for buckwheat
and rice were significantly correlated with each
other in the IHR-negative group, but not in the
IHR-positive group. An effective dose-dependent
inhibition was obtained in a RAST-inhibition assay
between homologous combinations of inhibitor
and disk antigens such as rice and rice or buckwheat
and buckwheat. The IHR-positive group
showed no significant RAST inhibition between
heterogeneous combinations of rice and buckwheat
antigens, whereas the IHR-negative group showed
a significant decrease in IgE binding even in the
RAST inhibition between heterogeneous combinations
of rice and buckwheat antigens. The conclusion
was that IgE antibodies from IHR-negative
subjects might recognize the epitopes on buckwheat
antigens which cross-react with rice antigens.
In 1991, a similar study concluded that subjects
without IHR to buckwheat showed higher IgE
RAST values for rice than those with IHR, whereas
there were no differences in IgE-RAST for Dermatophagoides
pteronyssinus, egg white, and cow’s
milk between groups with and without IHR (21).

The difficulties in identifying food hypersensitivity
with IgE antibodies that cross-react with diverse
products such as vegetable foods, pollen, and
Hymenoptera venom have been shown by
Aalberse et al. (22). IgE identified in some human
sera reacted with an antigen in various unrelated
foods such as potato, spinach, wheat, buckwheat,
peanut, and honey. The antigen could also be found
in pollen, and in vitro it reacted also with bee and
vespid venom and was sometimes induced by
Hymenoptera stings.
Problems with accurate and safe diagnosis of
food hypersensitivity including buckwheat allergy
were demonstrated by Matsumoto & Murakami in
1991 (23). In 41 children with suspected IgEmediated
food allergy, oral exposure to hen’s egg,
cow’s milk, chicken, buckwheat, red bean, salmon,
and common dolphin was effectuated. Seven
showed an anaphylactic skin reaction (systemic
urticaria and/or angiodema) to the foods. The
authors recommend diagnosis with the oral
Prausnitz-Kustner (P-K) test in combination with
RAST instead. The sera that had RAST scores of
3 or greater were negative in the oral P-K reaction
in 26 out of 36 tests, and the sera that showed
positive oral P-K reaction to buckwheat or chicken
were zero in the RAST scores. It was suggested
that a soluble, e.g., histamine-releasing, factor in
addition to the IgE antibody might be involved in
the oral P-K reaction, and that the RAST technique
does not always recognize the food antigens
digested during the absorption process in viva
Allergic asthma to buckwheat in children is a
serious problem in some Asian countries such as
Japan. A study on total serum IgE and specific IgE
antibodies in children with asthma found that in a
total of 342 asthmatic children, the median and
range of serum IgE were 1.050 IU/ml and 20-10000
IU/ml, respectively (24). Positive rates were highest
for mites and house dust (87-91%) and lowest for
milk, dog, buckwheat, and egg (2-8%). In general,
patients with higher RAST scores had higher
serum IgE levels (18).
Treatment with ketotifen has been tried experimentally
but is not generally accepted. In 64
patients with bronchial asthma, it was shown effective
in 50% and very effective in 6% (25). In allergy
to house dust and buckwheat, it seemed effective
in 516 patients and in all three with buckwheat
allergy, respectively. Ketotifen was considered to
inhibit type I allergic reactions caused by specific
allergens and clearly IgE-mediated reactions.

Here's the abstract for the referenced study in regards to buckwheat and rice allergies:

_http://www.ncbi.nlm.nih.gov/pubmed/7621062

Abstract

BACKGROUND: Immediate hypersensitive reactions induced by buckwheat ingestion are considered to be IgE-mediated. Some subjects, however, develop no immediate adverse reactions after buckwheat ingestion despite high levels of buckwheat-specific antigens IgE. The mechanism is unknown.

OBJECTIVE: To investigate the mechanisms.

METHODS: RAST for buckwheat and rice and RAST inhibition between these antigens were performed using sera from 23 buckwheat-sensitive subjects and 30 buckwheat-tolerant subjects who had IgE antibodies for both buckwheat and rice.

RESULTS: RAST values for buckwheat and rice were significantly correlated with each other (P < .01) in the buckwheat-tolerant group, but not in the buckwheat-sensitive group. This suggests the IgE antibodies from the subjects without any overt symptoms after buckwheat ingestion recognize the cross-reactive epitope between buckwheat and rice, whereas the IgE antibodies from those with immediate reactions to buckwheat ingestion do not. RAST inhibition assays were performed to evaluate this. RAST inhibition of heterogeneous combination of inhibitor and disc antigen such as rice and buckwheat was significantly smaller than that of homologous combination of rice and rice or buckwheat and buckwheat in the group with immediate symptoms after buckwheat ingestion. There was no significant difference in RAST inhibition between homologous and heterogeneous combinations in the group without the symptoms.

CONCLUSIONS: There was cross-reactivity with IgE antibodies between buckwheat and rice and IgE antibodies from the buckwheat-tolerant subjects with high levels of IgE antibodies from the buckwheat might recognize the epitopes on buckwheat antigens which cross-react with rice antigens, whereas IgE antibodies from the buckwheat-sensitive subjects might bind to buckwheat-specific epitopes.

Unless I misread something, it doesn't seem like the researchers took cross-contamination with wheat into account. Hope it helps. :)
 

Laura

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Puhleeeeeeeeze don't tell me I can't have buckwheat!!!
 
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