Like the antibiotic penicillin, aspartame (the sweetener marketed as Equal and NutraSweet) was discovered quite by accident, when a chemist was attempting to produce a drug to treat ulcers. Instead, he synthesized aspartame, and realized its sweet taste when he licked his contaminated finger (an unsafe practice for a chemist, even in 1965). It was not approved by the FDA as a food additive until 1981 due to concerns about potential cancer risks.
Once ingested, aspartame breaks down into several other chemicals including methanol (wood alcohol, a poison) and formaldehyde (preservative used in embalming). Approximately 50% of the aspartame becomes the amino acid phenylalanine. This is a naturally occurring essential amino acid. It is called essential because human beings need it but their bodies cannot synthesize it, so it must be consumed in food.
However, persons with a genetic condition called phenylketonuria (PKU) are unable to metabolize this amino acid, and must follow strict diets to avoid any trace of phenylalanine or brain damage will result. Therefore, products containing aspartame are required by U.S. and European government agencies to list the chemical among the ingredients and, in addition, provide a clear warning such as “Phenylketonurics: contains phenylalanine.”
There is no controversy about this particular danger of aspartame. However, controversy has arisen over other effects of aspartame as well as the circumstances of its approval, both in the U.S. and in Europe. A large-scale review of the literature on aspartame, published in the journal Critical Reviews in Toxicology, found “no credible evidence that aspartame is carcinogenic or neurotoxic or has any other adverse effects,” according to author Bernadene Magnuson.
The authors of this review declared no known conflicts of interest or potential biases, in spite of the fact that they received unlimited funding from a major Japanese aspartame manufacturer. The authors were kept from knowing the source of funding until after the review was complete, and the corporation did not know the names of the expert panelists who conducted the review. According to the American Academy of Neurology, this review can be considered definitive regardless of the funding source.
Perhaps aspartame does not have proven adverse effects when examined statistically. However, enough case studies have been compiled so that clinical information directed at practicing physicians presents a different story. For instance, dermatologists are told that contact dermatitis can result when the formaldehyde by-product of aspartame activates an allergy to the chemical which is also found in cosmetics, home cleaners, deodorants, and fabric treatments. Physicians who treat patients with fibromyalgia, interstitial cystitis (painful bladder syndrome), urinary incontinence, migraine headaches, and ADD/ADHD are told their patients should avoid aspartame (among other chemicals/foods). The aspartame in soft drinks seems to be especially problematic since it is often combined with caffeine, another substance associated with the above conditions.
In addition, given that some studies did show a clear, statistically based link between aspartame and dangerous conditions such as brain tumors, I would like to have those results explained. If they did not reflect an actual effect of aspartame, were they due to interfering factors, statistical errors, poor research design? In my opinion, the jury is still out on aspartame. I advise careful, limited use of this sweetener or complete avoidance.
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