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  1. John E. Garst, Ph.D. (Medicinal Chemistry, Pharmacology, Toxicology, and Nutrition)

    Perhaps if you better understood toxicology you would realize there is no scientific issue at all regarding aspartame. Aspartame is perfectly safe used as directed in healthy people and judged so by ALL the world’s relevant regulatory agencies. Truth is that the critics all fail to understand or accept that any perceived issue with aspartame reflects the user’s own questionable health, specifically their own folate and related vitamin status.

    And here are the facts you don’t know. Only methanol amongst aspartame degradation products presents any risk to people—phenylalanine and aspartate are found in greater concentrations in normal foods, like milk and meat. But risk is dose dependent and the risk from the amount of methanol produced from aspartame degradation is also non-existent. Moreover, just like the methanol found in fruit juice, that released from aspartame is a vital nutrient. Why? Methanol is oxidized to formaldehyde and formate–both are chemically directly converted by the (tetrahydro)folate vitamin system into very valuable methyl groups. These methyl groups detoxify the true excitotoxic homocysteine, protect DNA from strand breakage (by converting break fostering uracil into methyluracil (thymine)), and when systematically methylated, methylated DNA acts to prevent errant DNA duplication. For more on its cycle see the figure p 3000 here,

    Formate and formaldehyde are [quoting another] “produced in the body during the endogenous demethylation of many compounds, including many foods and drugs. For example, the demethylation of the caffeine found in one cup of coffee produces 30 mg of formaldehyde (Imbus, 1988). Formaldehyde is essential in one-carbon pool intermediary metabolism. The metabolite of formaldehyde, formic acid, is a substrate for purine nucleotide synthesis (Sheehan and Tully, 1983). It can be calculated that more than 50,000 mg [that's 50 g] of formaldehyde is produced and metabolized in an adult human body daily and that an adult human liver will metabolize 22 mg of formaldehyde per minute (Clary and Sullivan, 1999). Consequently, it is quite clear that the formaldehyde from aspartame provides a trivial contribution to total formaldehyde exposure and metabolism in the body” (p 18 in and refs from

    That metabolism requires folate/B12 vitamins. Many people are simply deficient in them. And forty percent of some populations have folate enzyme issues that require even more folate, see

    So all adverse side effects ever claimed from aspartame are really due to personal issues revolving around the vitamins folate and B12, not to this sweetener. And that probably includes migraines (see In fact in 1998 folate was mandated to be added to grain products (flours) to reduce birth defects (spina bifida) in offspring of deficient mothers. Folate’s widespread deficiency in people and in early rat chow explains the very existence of this conspiracy theory.

    Critics claim ’92 symptoms for aspartame’. And you provide a list but all these issues are far more linked to folate deficiency and related issues than to this sweetener. And virtually all their “92 symptoms” are related instead to folate-B12 issues instead of this sweetener.

    Let’s explore the latest aspartame ‘disease of the month’ that you strangely don’t even mention–autism, but has appeared at various antiaspartame websites. In this regard consider; clearly folate issues are associated with autism, yet PubMed contains no documented association of aspartame with autism. Moreover folate polymorphism issues are also related to autism (see and especially
    Why is this? Folate problems diminish transfer of methyl groups to homocysteine ( to form methionine (methylhomocysteine, see the figure top of p 3000 here,

    Ultimate answers may also come from the autism and homocysteine linkage,, or from the autism and B12 linkage, Note that ‘the figure p 3000′ shows how these issues are interrelated and suggest troubles with biological methylation in autism, be it general or very specific (

    As to arguments about sweeteners increasing weight, affecting insulin, etc., consider recent criticism by Collison et al, I ask where was their folate evaluation control? It is missing in all studies of aspartame, but the evidence is overwhelming that folate adequacy is critical to any such study. Simply put none of these papers are done correctly. In that regard see for yourself; consider these points countering Collison’s arguments; learning and folate provides 235 references,; the effects of folate on the metabolic syndrome provide 162 references,; and even insulin tolerance test and folate provide 32 references, Her papers and those like them fail adequate controls and thus relevance to aspartame risk assessment and must be excluded.

    The same can be said of all the “Aspartame may trigger, mimic, or cause the following illnesses:” you quote. The problem is not aspartame, but in virtually all your cited cases, underlying personal issues involving folate, B12, and homocysteine better explain the concern.

    Overall, in people with personal sensitivity to aspartame, these adverse risks exist whether one uses aspartame or not. Widespread overindulgence in ethanol (acetaldehyde is an inhibitor of the folate reactions) only exacerbates these risks, just as it exacerbates breast and other cancers and facilitates fetal alcohol syndrome.

    And no, I have never received a penny from any of my comments. I am telling you the truth and why it will not be banned, but I really don’t care whether you use this sweetener or not. I do and have used it for forty years, but also take multiple vitamins daily; they lengthen your telomeres and let you live longer.

    John E. Garst, Ph.D. (Medicinal Chemistry, Pharmacology, Toxicology, and Nutrition)

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