Aspartame: Methanol/Formaldehyde Toxicity
Methanol from aspartame is released in the small intestine when the methyl group of aspartame encounters the enzyme chymotrypsin (Stegink 1984, page 143). A relatively small amount of aspartame (e.g., one can of soda ingested by a child) can significantly increase plasma methanol levels (Davoli 1986a).
Clinically, chronic, low-level exposure to methanol has been seen to cause headaches, dizziness, nausea, ear buzzing, GI disturbances, weakness, vertigo, chills, memory lapses, numbness & shooting pains, behavioral disturbances, neuritis, misty vision, vision tunneling, blurring of vision, conjunctivitis, insomnia, vision loss, depression, heart problems (including disease of the heart muscle), and pancreatic inflammation (Kavet 1990, Monte 1984, Posner 1975).
The methanol from aspartame is converted to formaldehyde and then formic acid (DHHS 1993, Liesivuori 1991), although some of the formaldehyde appears to accumulate in the body as discussed above. Chronic formaldehyde exposure at very low doses has been shown to cause immune system and nervous system changes and damage as well as headaches, general poor health, irreversible genetic damage, and a number of other serious health problems (Fujimaki 1992, He 1998, John 1994, Liu 1993, Main 1983, Molhave 1986, National Research Council 1981, Shaham 1996, Srivastava 1992, Vojdani 1992, Wantke 1996). One experiment (Wantke 1996) showed that chronic exposure to formaldehyde caused systemic health problems (i.e., poor health) in children at an air concentration of only 0.043 - 0.070 parts per million!
Obviously, chronic exposure to an extremely small amount of formaldehyde is to be avoided. Even if formaldehyde adducts did not build up in the body from aspartame use, the regular exposure to excess levels of formaldehyde would still be a major concern to independent scientists and physicians familiar with the aspartame toxicity issue.
In addition to chronic formaldehyde poisoning, the excitotoxic amino acid derived from aspartame will almost certainly worsen the damage caused by the formladehyde. Synergistic effects from aspartame metabolites are rarely, if ever, mentioned by the manufacturer. Aspartame breaks down into a free-form (unbound to protein) excitotoxic amino acid which is quickly-absorbed (as long as it is not given in slow-dissolving capsules) and can raise the blood plasma levels of this excitotoxin (Stegink 1987). It is well known that free-form excitotoxins can cause irreversible damage to brain cells (in areas such as the retina, hypothalamus, etc.) in rodents and primates (Olney 1972, Olney 1980, Blaylock 1994, Lipton 1994). In order to remove excess, cell-destroying excitotoxic amino acids from extracellular space, glial cells surround the neuron and supply them with energy (Blaylock 1994, page 39, Lipton 1994). This takes large amounts of ATP. However, formate, a formaldehyde metabolite, is an ATP inhibitor (Liesivuori 1991). Eells (1996b) points out that excitatory amino acid toxicity may be the "mediators of retinal damage secondary to formate induced energy depletion in methanol-intoxication." The synergistic effects from the combination of a chronic formaldehyde exposure from aspartame along with a free-form excitotoxic amino acid is extremely worrisome.
It appears that methanol is converted to formate in the eye (Eells 1996a, Garner 1995, Kini 1961). Eells (1996a) showed that chronic, low-level methanol exposure in rats led to formate accumulation in the retina of the eye.
More details about chronic Methanol / Formaldehyde poisoning from aspartame can be found on the Internet at http://www.holisticmed.com/aspartame/aspfaq.html.
