For More Information GO TO Aspartame (NutraSweet) Toxicity Home Page: http://www.holisticmed.com/aspartame/ 10. Cumulative and Synergistic Reactions Monsanto/NutraSweet is fond of addressing the safety of each individual breakdown product separately from the other breakdown products. While it is important to consider the breakdown products separately, it is equally important to consider combinations of breakdown products that could damage a person's health when ingested over a long period of time. Three types of cumulative or synergistic situations need to be looked at very carefully when addressing the "safety" of aspartame: a. Breakdown products which, when acting together, have a much more damaging effect than the sum of the two effects when these breakdown products are taken separately. The experiment by Ershoff (1976) discussed earlier showed just how damaging certain chemicals can be when given in combination. One combination which may prove to be one of the significant problems with aspartame is methanol and aspartic acid. Methanol breaks down into formaldehyde. Aspartic acid is an excitatory amino acid. In animal experiments, formaldehyde solutions are used to induce tissue injury causing neurons with N-methyl-D-aspartate (NMDA) receptors to fire for a prolonged period (Haley 1990, Coderre 1992). The neural responses were enhanced in the Coderre (1992) experiment by the pretreatment with L-glutamic acid and L-aspartic acid. Therefore, it is possible that damage caused by formaldehyde or formic acid may cause neurons with NMDA receptors to fire for a prolonged period of time. This negative effect is enhanced by the administration of an excitatory amino acid. Also, neurons damaged by formaldehyde or formic acid may be much more susceptible to excitotory amino acid damage. b. Certain breakdown products may have a cumulative effect such that slight or moderate damage or biochemical change caused by each breakdown product may add up to major damage over time. For example, methanol, aspartic acid, and phenylalanine have all been shown to cause vision damage in animals at some level. It is possible that methanol is not the only breakdown products from aspartame that is causing vision damage in some aspartame ingesters. It may be the cumulative damage caused by two or three of the breakdown products. c. Years of exposure to the damaging effects of aspartame breakdown products are very likely to cause one to become more susceptible to a variety of chronic illnesses. This is the cumulative negative effect from aspartame plus other non-aspartame causes. Years of very gradual damage to the unprotected areas of the brain by aspartic acid, very gradual changes in brain chemistry from phenylalanine, gradual damage to the immune system and the nervous system from methanol, and other possible damage from other breakdown products are bound to set a person up for a wide variety of chronic health problems five, 10, 20, or 50 years later. It would be almost impossible to trace these problems back to aspartame on an individual basis because a) the primary cause of the disease may not have been aspartame, and b) eliminating aspartame may not necessarily cure the illness because the internal damage is done and the aspartame was just the (or one of the) "set-ups" for the disease, but not the primary cause (at least for this example). Well- controlled, independent epidemiological studies of randomly-selected, long-term (5+ years) aspartame users (10 mg/kg/day or more) looking at all adverse reactions may be helpful.