Glutamate versus Gluten

Gluten and glutamate are two different beasts. We are lucky that we don’t seem to have reactions to gluten, just to glutamate, but it is possible to have sensitivities to either, or both. I’m focusing on glutamate here, as that’s my “hammer” right now.

Part One: What’s the difference between gluten and glutamate?

First, proteins consist of one or more polypeptides, or  linear chains of amino acids. Amino acids are simply the building blocks of proteins.  The way the chains are put together determine the differences between different proteins.

Gluten is a protein found in wheat, barley, rye.  People that react to gluten are reacting to the specific protein that these grains contain.  There are different ways people can react to gluten. In people with celiac disease, gluten in wheat, spelt, barley and rye triggers an autoimmune response that damages the small intestine.   Corn, rice, amaranth, millet, quinoa, sorghum, and teff are considered gluten-free grains as they have different forms of protein — different formations of their polypeptide chains.

Glutamate, technnically glutamic acid, is an amino acid found in proteins. Glutamic acid is present in every food that contains protein, but it can only be tasted when it is present in an unbound form, or “free”.  A “glutamate sensitivity” is when a person reacts to the unbound amino acid, free glutamic acid, or FGA.

So there is the difference in a nutshell: gluten is a specific protein in some grains (full of all kinds of amino acids bound up in chains :)). FGA is an amino acid, in all proteins, that has been broken out of it’s protein and resides separately in the food (or in your digestive system).

Note: Breaking down a protein is different than refinement of a grain. Refined grains have been processed to remove bran and germ, to improve texture and shelf life. This processing removes fiber, iron, and vitamins, and refined grains have less fiber and are less nutritious than whole grains. However, for the purposes of  avoiding glutamate, whole grain isn’t what matters, because from what I can find, refining grains  doesn’t seem to change the proteins significantly.*

Part Two: But Doesn’t Gluten have a lot of Glutamate in it?

Some sources claim that because the two proteins gluten and casein contain significant quantities of the amino acid glutamic acid, that these should also be avoided by those avoiding FGA. Personally, I’m not convinced.  To be more clear, I believe there are many people that are sensitive to dairy and gluten, but I am not convinced it has anything to do with FGA, for a few reasons.

First, other grains and meats also have significant quantities of glutamic acid. Why single out these two?

Table 1.  Percent Glutamic Acid in Common Food Proteins
Wheat Protein
31%
Cow Milk
22%
Corn Protein
18%
Beef Meat
16%
Rye Protein
24%
Poultry Meat
17%
Rice Protein
15%
Fish Protein Conc.
17%
Soy**
17%
Mammalian gelatin
11%
*From Food Chemistry 2nd Edition (1999) H.D Berliz & W. Grosch, Springer-Verlag, Berlin (copied from: http://www.greatlakesgelatin.com/consumer/noMSG.php)
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Second, the glutamates in these foods are bound into polypeptide chains, not free, and I personally haven’t heard of an issue with bound glutamate even with people that are extremely sensitive.

Lastly, I think it is hard to separate a reaction to a grain from the reaction to other hidden ingredients that contain FGA. In other words, most foods with gluten also contain glutamate. Most flours contain malted barley flour these days, since it makes the dough easier to work with, and most baked goods have FGA ingredients, e.g. dough conditioners, citric acid, enzymes, etc.

But, I’m not a chemist and I’m largely going on observations of my own family. Though I’ve seen reactions to malted barley flour, aluminum baking powder, L-cysteine and other dough conditioners***, my son can finish off most of a loaf of bread from our bread machine over the course of a single day, and feel perfectly fine. And in the end, that’s what it’s all about.

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Footnotes

*There is one exception to this idea that refining flours doesn’t break down the protein, which is sprouting/germinating/malting the grain. I did find a fascinating article that seems to show that storage decreases the FGA, but didn’t have time to analyze it fully. I found no indications that sprouting the grain increases the FGA content; in fact, the opposite, that through proteolytic activity, the liberated amino acids such as glutamic and proline are converted to limiting amino acids such as lysine (Wikipedia).

However, malting is a an entirely different process, particularly when making malt extracts. I was curious about why malted barley is an FGA trigger for us (although we can tolerate small amounts), and I found these statements:

“In addition to supplying amylases, malted barley flour was also once relied upon for proteolytic enzymes, but these have been replaced by proteases from plant and fungal sources. Addition of proteases enables high speed bread production by decreasing the mixing time needed to achieve pliable dough.” (http://www.classofoods.com/page1_7.html)

“Scientists aim to discover what goes on inside barley grains as they become malted…scientists are interested in specialized enzymes called proteases[17] that .. also break down stored proteins into their amino acid derivatives.” (http://en.wikipedia.org/wiki/Malting)

** More on the protein content of whole soy can be found at: http://www.jbc.org/content/177/1/29.full.pdf

*** Though I haven’t seen my son react to wheat flour, I did try adding “vital wheat gluten” (the powder that is sold to help bread be more elastic) to homemade bread once, and he seemed to react to it; one instance is not enough to form a conclusion, but it would make sense that the extraction process for gluten would create FGA, just like it does when soy protein is extracted, and I don’t plan to use it again.

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