3 ms·

Really? Please observe the differences between https://en.wikipedia.org/wiki/File:L-Glutamate_Structural_Formulae.png https://en.wikipedia.org/wiki/File:L-Gluta

Really? Please observe the differences between https://en.wikipedia.org/wiki/File:L-Glutamate_Structural_Formulae.png https://en.wikipedia.org/wiki/File:L-Glutamate_Structural_Fo... and https://upload.wikimedia.org/wikipedia/commons/f/ff/Glutamins%C3%A4ure_-_Glutamic_acid.svg https://upload.wikimedia.org/wikipedia/commons/f/ff/Glutamin... . The only difference is the relocation of hydrogen ions, which is a normal and expected occurrence of all molecules in the presence of other molecules. The equilibrium of these different forms of the same molecule is mediated by pH, among other things. They are in fact the same molecule. The word "acid" only means that it likes to give up a hydrogen ion when given the opportunity.

ars 13y ago
You understood me in reverse. In the body the glutamate (acid or not) is bound up with other things, i.e. not free. I said acid because my understanding was the MSG disassociates from the sodium once ingested.
- tptacek 13y ago
  I read some glutamate metabolism papers last night and I don't think this is likely to be true at all. I think it's a manifestation of the naturalist fallacy: you believe the "free glutamic acid" released by the dissolution of MSG to be artificial and are trying to rationalize a distinction for the glutamates that the body produces that doesn't exist. In reality, glutamic acid isn't simply an amino acid that happens to be present in the human body. It is fundamental to the way our bodies work; it's required for nitrogen metabolism! Glutamate toxicity seems very unlikely.
  - ars 13y ago
    > ... naturalist fallacy: you believe ... distinction ...that doesn't exist. I believe no such thing. I don't know what you read, but in the body glutamic acid doesn't just float around randomly, it's carefully stored near the nerves that need it. Excess glutamic acid where it doesn't belong causes nerve problems. It's like the difference between sucrose and starch. Chemically they are the same, but the effects are very different because one needs more digestion than the other.
    - tptacek 13y ago
      Your body can't metabolize nitrogen without glutamic acid. It's part of how you, and I think maybe all the rest of your siblings in phylum chordata, build proteins. I don't see a lot of reason to believe that it causes "nerve problems" in the human body, but would welcome a citation to the literature that shows that. It gets worse for your argument. Here's a paper that demonstrates that very large oral doses of MSG in both mice and humans don't even significantly raise the plasma concentration of glutamates. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3136011/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3136011/ This should probably be unsurprising. Your body is designed to deal with consumption of glutamates; in fact, even though it's so vital to your system that you produce it yourself, humans get most of their glutamic acid from dietary sources. Hypersensitivity to dietary glutamate would be maladaptive. The idea that your body has carefully delineated locations where it's safe to have glutamic acid (probably not coincidentally in the nervous system, the most complex part of the body), and that ingesting "artificial" sources of glutamic acid throws that out of whack, is again I think a manifestation of the naturalistic fallacy.

ars 13y ago

You understood me in reverse. In the body the glutamate (acid or not) is bound up with other things, i.e. not free. I said acid because my understanding was the MSG disassociates from the sodium once ingested.

tptacek 13y ago
I read some glutamate metabolism papers last night and I don't think this is likely to be true at all. I think it's a manifestation of the naturalist fallacy: you believe the "free glutamic acid" released by the dissolution of MSG to be artificial and are trying to rationalize a distinction for the glutamates that the body produces that doesn't exist. In reality, glutamic acid isn't simply an amino acid that happens to be present in the human body. It is fundamental to the way our bodies work; it's required for nitrogen metabolism! Glutamate toxicity seems very unlikely.
- ars 13y ago
  > ... naturalist fallacy: you believe ... distinction ...that doesn't exist. I believe no such thing. I don't know what you read, but in the body glutamic acid doesn't just float around randomly, it's carefully stored near the nerves that need it. Excess glutamic acid where it doesn't belong causes nerve problems. It's like the difference between sucrose and starch. Chemically they are the same, but the effects are very different because one needs more digestion than the other.
  - tptacek 13y ago
    Your body can't metabolize nitrogen without glutamic acid. It's part of how you, and I think maybe all the rest of your siblings in phylum chordata, build proteins. I don't see a lot of reason to believe that it causes "nerve problems" in the human body, but would welcome a citation to the literature that shows that. It gets worse for your argument. Here's a paper that demonstrates that very large oral doses of MSG in both mice and humans don't even significantly raise the plasma concentration of glutamates. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3136011/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3136011/ This should probably be unsurprising. Your body is designed to deal with consumption of glutamates; in fact, even though it's so vital to your system that you produce it yourself, humans get most of their glutamic acid from dietary sources. Hypersensitivity to dietary glutamate would be maladaptive. The idea that your body has carefully delineated locations where it's safe to have glutamic acid (probably not coincidentally in the nervous system, the most complex part of the body), and that ingesting "artificial" sources of glutamic acid throws that out of whack, is again I think a manifestation of the naturalistic fallacy.