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Methanol in the body - Aspartame

  1. Jul 5, 2011 #1
    According to the Pepsi website, a can of Diet Pepsi has 111mg of Aspartame per container.
    http://www.pepsiproductfacts.com/in..._fam_id=1051&brand_id=1000&product=Diet Pepsi

    In the body Aspartame metabolises primarily to Phenylalanine ~50%, secondarily to Aspartic Acid ~40%, and Methanol ~10%.

    I am unable to find out what happens to Aspartame in the acidic environment of our stomach. According to Wikipedia, "Under strongly acidic or alkaline conditions, aspartame may generate methanol by hydrolysis." which I have confirmed with several other research resources. I do not know how 'strongly acidic or alkaline' it must be. I would like to find this out. I am also unable to obtain pure aspartame to test its reactivity with different acids or chemicals.

    ~10% x 111mg = ~11.1mg of methanol after metabolization

    Wikipedia - If ingested, as little as 10 mL of pure methanol
    can cause permanent blindness by destruction of the optic nerve,
    and 30 ml is potentially fatal.

    http://en.wikipedia.org/wiki/Aspartame

    So for a quantity of Aspartame that would cause permanent damage and severe symptoms (if fully metabolized and absorbed) I shall calculate approximately how much you need to consume.

    Methanol's density is 0.791 g/mL

    Mass = density * volume
    Mass = 0.791*10.00 (for 10ml)
    Mass = 7.91

    Mass conversion: 7.91 g = 7,910mg

    7,910mg / 11.1mg = 712.612612-(just keeps going)

    713~ cans of Pepsi would produce a toxic methanol dose after metabolization (assuming nothing else would affect it)
    (also assuming you hadn't already suffered from some other effect from some other ingredient [like blood dilution from all that water? lol])

    [PLAIN]http://www.antizol.com/images/figure2.gif [Broken]

    Methanol is a potently toxic substance, the long term effects of small doses of the substance should be studied.... in any case the information I wish to find, but cannot is why I'm here.

    How long does it take for a dose of Methanol (and formaldehyde [and formic acid]) to metabolize in the body, and how long would it take for the body to get rid of it?

    I have read conflicting information about the rate at which humans metabolize or get rid of these substances, so I would appriciate some insight :)

    According to http://www.antizol.com/mpoisono.htm [Broken] :
    "Methanol is readily absorbed from the gut, skin, and lungs. Peak serum concentration usually occurs in 30-60 minutes following oral ingestions. Methanol distributes widely in body water with a volume distribution of 0.6 L/kg. Methanol is slowly and erratically metabolized in the liver and follows zero order kinetics. Approximately 3% of a methanol dose is excreted through the lungs or excreted unchanged in the urine. The half-life of methanol is prolonged to 30-50 hours during antidotal therapy (Palatnick 1995)."

    Oh, and I should probably mention that the size of the drink I looked at was 7.5fl oz, the smallest on the Pepsi website. The largest is 20 fl oz. The large size contains 295mg of Aspartame per container.
     
    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Jul 5, 2011 #2

    DaveC426913

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    Gold Member

    Well, I drink about a litre of the stuff a day, so if you find any symptoms, let me know.
     
  4. Jul 5, 2011 #3
    Well, I found a metric ton of hyped up info regarding Aspartame, so it's hard to sort facts out of that. However, I think an FDA complaints list can be trusted enough as a statistical base with which to start looking for side effects.

    The 4 most common side effects complained about for Aspartame are:
    Headaches
    Dizziness
    Mood change
    Vomiting/Nausea (I've actually had nausea from some 2 YEAR OLD diet soda)

    http://www.321recipes.com/symptoms.html [Broken]

    Methanol has some more concrete symptoms of poisoning, including:
    intoxication (like alcohol)
    drowsiness
    confusion
    ataxia
    weakness
    headache
    nausea
    vomiting
    abdominal pain
    blurred or misty vision - double vision - changes in color perception
    permanent blindness
    coma
    seizures
    death

    The list goes on quite a bit...

    http://www.antizol.com/mpoisono.htm [Broken]
     
    Last edited by a moderator: May 5, 2017
  5. Jul 5, 2011 #4

    DaveC426913

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    Gold Member

    The list goes on after that????


    Worse? How could it be worse?? Jehovah! Jehovah!
     
  6. Jul 5, 2011 #5
    Lol I just listed the worst and most easily recognizable symptoms, I simply meant that there were other symptoms that I hadn't listed.
     
  7. Jul 5, 2011 #6

    DaveC426913

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    Gold Member

    Headaches Nope.
    DizzinessNope.
    Mood change OK, well sure.
    Vomiting/Nausea Nope.

    Methanol has some more concrete symptoms of poisoning, including:
    intoxication (like alcohol) Nope.
    drowsiness Maybe.
    confusion Maybe.
    ataxia Nope.
    weakness Nope.
    headache Nope.
    nausea Nope.
    vomiting Nope.
    abdominal pain Nope.
    blurred or misty vision - double vision - changes in color perception Nope.
    permanent blindness Nope.
    coma Nope.
    seizures Nope.
    death Nope.
     
  8. Jul 5, 2011 #7
    What? Are you saying that sufficient doses of methanol don't have those effects?
     
  9. Jul 5, 2011 #8
    I think it's obvious that he's relating those symptoms to what he feels after drinking diet soda aroc91 :P
     
  10. Jul 5, 2011 #9

    SpectraCat

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    Science Advisor

    aspartame is a dipeptide .. basically a tiny protein fragment. It gets broken down into it's constituent amino acids (and methanol) in your stomach (the peptide bond gets hydrolyzed). The only medically recognized side-effects of which I am aware are those associated with phenolketoneuria (i.e. the ones you are warned about on the label). That is a very specific disease that prevents one from metabolizing one of the amino acids (phenylalanine) that aspartame breaks down into.

    Regarding methanol, the key passage from your post is "it is readily absorbed from the gut" ... it then goes to your liver where it is broken down. It is certainly not a bioaccumulative toxin like mercury or PCB's (which collect in fat and linger for long periods of time). I don't know what the half-life is, but it is short .. on the same order as ethanol, so a few hours at most. So, unless you are mainlining diet soda at a pace heretofore unknown to man, I think you are safe from the adverse effects of methanol from aspartame metabolism.
     
    Last edited: Jul 5, 2011
  11. Jul 5, 2011 #10
    I considered that, but I think it's obvious that you're not going to be poisoned by the amount you'd get from a can of pop.
     
  12. Jul 5, 2011 #11

    DaveC426913

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    A can of pop per how often?


    If there were no doubt about the risk of deleterious effects from aspartame intake, this thread would not exist.
     
  13. Jul 6, 2011 #12
    Ahh yes, I read some of that in my little research quest earlier. What I'd most like to know is how quickly it does this for certain quantities, and how quickly it would pass out of the system - in other words, allowing the determination for what kinds of effects it would have on the body before it is no longer an issue. Of course in microscopic doses we aren't going to learn much, so I'll have to continue research to find out if there are any long term effects, despite Aspartame and its metabolites (that's right right word right?) not being bioaccumulative.

    While others might easily hand out the safe stamp of approval for Aspartame, I would like to explore into further detail its effects. Until I am totally convinced that it has absolutely no bad effects on my body (within reason), I'll simply avoid it :)

    To address aroc91 again, DaveC426913 is indeed correct. There is so much nonsense, rumor, and propaganda surrounding aspartame, I can't be certain of most readily available information on it.
     
  14. Jul 6, 2011 #13

    DaveC426913

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    To be clear, I am not making any claim about the research. I would simply be interested to know if I am poisoning myself. So far, it would appear not, based on the lack of my symptoms. But I don't for a second suggest that my experience sheds any light of the validity of the claim, for or against.
     
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