E70 --- E70 was a study of aspartame being fed to pregnant Charles River CD rats. Aspartame was given to the offspring for 104 weeks. Two groups of experimental animals were used, Group 1 was given a lower dose and had 78 rats, Group 2 was given a higher dose of aspartame and had 79 rats. The control group had 115 rats. The brain cancer which was found in E70 was as follows: Group Sex Control M Control M Control M Control F 1 M 1 M 1 F 2 M 2 F A total of nine brain tumors were reported, 4/115 rats in the control group (3.48% incidence rate) and 5/157 rats in the experimental groups (3.18%). Four of the nine brain tumors were reported as astrocytomas. This seemed like an unusually high number of brain tumors in both the experimental and control groups. As described by Dr. John Olney in his testomony (Olney 1987, page 6): "The manufacturer had done an additional study [E70] and submitted it to FDA at the same time as the former study [E33/34] was submitted. The second study also showed a very high incidence of brain tumors in Nutrasweet-fed rats but in this study the control rats also had a similarly high incidence. This did not make any sense, unless both the control and experimental rats were exposed to a tumor promoting agent. A subsequent FDA investigation of the laboratories where these studies were conducted revealed appearances that the control and experimental animals may very well have been fed one another's chow in a sloppily randomized manner so that, in essence, all animals on the study may have been fed Nutrasweet during portions of the study. The judges at the PBOI agreed with me that the exceedingly high incidence of brain tumors in the Nutrasweet-fed rats of the first study and a similarly high incidence in all rats of the second study was a "bizarre" collection of data that could not be considered evidence for the safety of Nutrasweet." FDA Toxicologist, Dr. Andriene Gross concluded, in part, the following in his testimony before the US Senate (Gross 1985, page S10835-S10840 of Congressional Record 1985b; Gross 1987b, page 453 of US Senate 1987): Even if, contrary to the FDA's view in 1976, the quality of the conduct of those studies could be relied upon by the same agency to even begin making such a determination, at least one of those studies had revealed a highly significantly dose- related increase in the incidence of brain tumors as a result of exposure to aspartame. The full incidence of those brain tumors was not disclosed by G.D. Searle & Co. to the FDA prior to the initial approval for the marketing of aspartame in 1974; moreover, the review of that study in the FDA was so flawed that the Agency apparently did not even realize at that time that only a portion of the observations on brain tumors had in fact been submitted by G.D. Searle & Co. in their petition for that approval. Quite aside from the remarkable significance of the increased incidence with dose of those brain tumors, the ADI [Acceptable Daily Intake] of 50 mgm/kgm body-weight recently set by the FDA for the human consumption of aspartame is alarmingly dangerous in that it involves an extremely high and, therefore, a totally unacceptable upper limit on the risk for those consuming aspartame: between 1/1,000 and 5/1,000 population to develop brain tumors as a result of such exposure. .... In view of all these indications that the cancer- causing potential of aspartame is a matter that had been established way beyond any reasonable doubt, one can ask: What is the reason for the apparent refusal by the FDA to invoke for this food additive the so-called Delaney Amendment to the Food, Drug, and Cosmetic Act? Is it not clear beyond any shadow of a doubt that aspartame had caused brain tumors or brain cancer in animals, and is this not sufficient to satisfy the provisions of that particular section of the law? Given that this is so (and I cannot see any kind of tenable argument opposing the view that aspartame causes cancer) how would the FDA justify its position that it views a certain amount of aspartame (50 mg/mg body-weight) as constituting an ADI (Allowable Daily Intake) or "safe" level of it? Is that position in effect not equivalent to setting a "tolerance" for this food additive and thus a violation of that law? And if the FDA itself elects to violate the law, who is left to protect the health of the public? In 1991, Dr. H.J. Roberts published an article in the Journal of Advancement in Medicine (Roberts 1991), which showed a possible correlation between the sudden, rising incidence of Primary Brain Cancer and Primary Brain Lymphoma and the years soon after aspartame went on the market. Dr. Roberts concludes with a recommendation for a closer look at the relationship between aspartame and brain cancer: The relationship between aspartame consumption and the development of primary brain cancers in humans requires careful analysis by corporate-neutral investigators. In the event that such a correlation is shown and brain cancer incidence rates continue to rise, the FDA should declare aspartame products an "imminent public health hazard." It should be noted that it may take a generation or two of ingesting aspartame before a significant increase in brain cancer incidence (due to aspartame ingestion) is noticed. Hopefully, aspartame will be banned long before that time. Industry Arguments ------------------ 1. Dosage At first glace, the dosage of aspartame given in the E33/34 and E70 experiments seems absurdly high and based on that, it would not be appropriate to extrapolate the results to human beings. However, upon more careful consideration, the dosage given to the rats was not so high after all. The dosage given in experiment E33/34 was: Control Group 0 mg/kg Group 1 1000 mg/kg Group 2 2000 mg/kg Group 3 4000 mg/kg Group 4 6000-8000 mg/kg In E70 the dosage was: Control Group 0 mg/kg Group 1 2000 mg/kg Group 2 4000 mg/kg However, Dr. Adrian Gross points out that a very important adjustment in the figures needs to take place in order to attempt to extrapolate results in small rodents to what might occur in larger humans (Gross 1985, page S10840 of Congressional Record 1985b): "The first item to be considered is that if one wishes to extend safety data from small laboratory rodents such as rats to much larger mammals such as humans, the exposure rates expressed in grams per body-weight must be modified or corrected by a certain adjustment. "The reason for this is that relatively small animals have, per unit body-weight or mass, a much larger body-surface. It is well known that most metabolic functions are better related to body- surface than they are to body-weight. For example, if one were to provide general anesthesia, say, for an elephant, and one were to select the same dose in mgm/kgm body-weight of a general anesthetic which is used in humans, chances are excellent that the animal will promptly die due to a drug-overdose, the reason for this is the same-- for a given unit of body-weight, the elephant has a much smaller total surface area than the human and, therefore, a much lower tolerance for any drug given on a basis of body-weight." On a body-weight basis, Dr. Gross points out that one average adult human is worth 143.37 average rats or: 60,000 grams / 418.5 grams = 143.37 rats. However, on a body surface basis, the average human is worth only 27.39 rats. Therefore, the dosages listed in E33/34 and E70 must be divided by: 143.37 / 27.39 = 5.23 Therefore, the body-surface adjusted dosages given in experiment E33/34 were: Control Group 0 mg/kg Group 1 191.2 mg/kg Group 2 382.4 mg/kg Group 3 764.8 mg/kg Group 4 1147.2-1529.6 mg/kg In E70 the the body-surface adjusted dosages were: Control Group 0 mg/kg Group 1 382.4 mg/kg Group 2 764.8 mg/kg Even these adjusted doses seem much higher than the 50 mg/kg ADI suggested for human beings. However, there are some well- known differences in the toxicity of aspartame breakdown products which would bring these adjusted dosages down considerably more. For example, - It has already been discussed that methanol is relatively non-toxic in rodents compared to humans. In fact it takes nearly 10 times more methanol to cause death in rodents than it does in humans (Roe 1982). In addition, the way relatively low doses of methanol affects rats is not harmful and is completely dissimilar to the dangerous ways low doses affect human beings. In rats, there is no formate buildup, no metabolic acidosis, and no optic nerve atrophy. It seems likely that slow damage from low-level exposure to methanol does not occur to any significant extent in rodents as it does in humans. - Wurtman (1988) used several published studies to show that approximately 60 times more phenylalanine needs to be given to rodents to cause the same effect as in humans. This will be discussed in more detail in a later section. For the phenylalanine part of aspartame, the original doses in E33/34 and E70 should be divided by 60. - In the Aspartic Acid section, we will see how the negative effects from spikes in the aspartic acid levels occur at five times lower doses in humans than in rodents. Therefore, for the aspartic acid part of aspartame, the original doses should be divided by five. - It is unknown as to whether DKP is more toxic in humans than in rodents. It should be noted that the fresh aspartame given to rodents in E33/34 and E70 contained a many times smaller percentage of DKP than is commonly found in real world aspartame-containing products ingested by humans. Therefore, those seemingly high doses do not seem nearly so high when one considers that several of the components of aspartame are many times more toxic in humans than in rodents. The argument that the dosage was too high has no basis in scientific reality. It might have been too high to simulate what happens in humans. On the other hand, it might have been too low. Finally, all of this assumes that the animals actually got the dosage claimed -- a shakey assumption at best. 2. Spontaneous Tumor Rate The FDA Commissioner, Arthur Hull Hayes, and G.D. Searle argued that the spontaneous brain tumor rate was really 2.2% in Charles River CD rats (not 0.7% as determined by the Public Board of Inquiry (PBOI) experts) and therefore it would not be unusual to see tumors rates of 3% to 4% in G.D. Searle's experiments on these rats (Federal Register 1981). In order to determine if the brain tumor rate in E33/34 of 3.75% in the experimental group and the rates of over 3% in the experimental and control group of E70 was unusually high for the Charles River CD rats used in those experiments, the Public Board of Inquiry (PBOI) needed to find out what the "spontaneous" brain tumor rate is in those type of rats. In order to do this, the PBOI looked at four different studies. Mawdesly-Thomas (1974) found a spontaneous brain tumor rate of 0.09% (38 brain tumors in 41,000 rats). The researchers used both the experimental groups and the control group and eliminated and tumors that were suspected of being caused by the experimental substance. All of the rats were the Sprague- Dawley strain used in G.D. Searle's aspartame and DKP studies, but not all of them came from the Charles River Laboratories. One of the advantages of this study was that it used a large number of rats so that the spontaneous rate could be determined more accurately. However, that fact that the some brain tumors were eliminated because of "suspicion" of being caused by the experimental substance and the fact that not all of the rats were from Charles River Laboratories, caused the PBOI to believe that the spontaneous rate of 0.09% found in this study was too low. MacKenzie (1973) found a brain tumor rate of 0.6% (3 brain tumors in 535 Charles River CD rats). This was a well- conducted study which was given some weight by the PBOI. The FDA Commissioner criticized this study for two reasons (Federal Register 1981, page 38297). First, both the experimental groups (rats who received irradiated feed) and the control groups were used. This is not a valid criticism because one would expect that the group receiving the irradiated feed would have more brain tumors, not less. Even if the irradiated feed somehow protected against brain tumors, one would expect that there would be a statistically significant difference between the tumors in the experimental and control groups (i.e., many fewer brain tumors in the experimental group), but this was not the case. In addition, the FDA Commissioner pointed out that "the authors state that 'many small tumors' found in other studies would not be called neoplasms." What the author actually states is: "Gillman et al. (7) reported an incidence of pheochromocytoma of 50% in females and 82% in males in 18-month-old rats. Many small tumors described in their study we would not have considered neoplasms." Pheochromocytomas are adrenal tumors and were not found in E33/34 or E70. Even if MacKenzie did discount small brain tumors, although he certainly did not state that he did so, the FDA Commissioner's argument would still not make sense. As pointed out earlier, the PBOI judge, Peter Lampert, M.D. who was the President of the American Association of Neuropathologists, told Dr. John Olney that he was "surprised by the large size of the brain tumors in Nutrasweet-fed rats." MacKenzie certainly did not discount large brain tumors. Fitzgerald (1974) found a brain tumor rate of 0.7% (5 brain tumors in 650 rats). The FDA Commissioner criticized this study as he did for MacKenzie (1974) stating that both the experimental and control groups were used. The same argument applies, however, that the experimental substance would not be expected to protect again brain tumors and that there was no statistically significant difference in the brain tumor rate between the experimental and control groups. The FDA also made some legitimate criticisms of the study, stating that the authors did not state at what intervals the animals were sacrificed. Therefore, if some of the animals had been sacrificed early, some of the brain tumors could have been missed. On the other hand, the authors cited nine earlier studies showing that: "This is especially true for albino rats, in which spontaneous brain tumors are considered extremely rare." One criticism of the Fitzgerald (1974) study by the FDA Commissioner was that the authors did not say how many brain sections were examined and did not go into enough detail about their methods. It is interesting to note that the FDA Commissioner later used a study that did not say anything at all about the methodology to claim that the spontaneous brain tumor rate in Charles River CD rats is 2.2%. The PBOI gave the Fitzgerald (1974) study some weight even though it had a few flaws. Thompson (1963) found a brain tumor rate of 3.2% (4 brain tumors in 125 rats). This study was used by G.D. Searle at the Public Board of Inquiry (PBOI) to claim that the spontaneous brain tumor rate of Charles River CD rats was closer to 3.2%. However, the PBOI rightly put little weight on this study because such a small number of rats were used. One might expect some fluctuation in the brain tumors when such a small number of animals are used. It is interesting to note that none of the brain tumors found were astrocytomas. In addition, three of the four brain tumors were found in the experimental group, although this may have been due to chance and not due to the irradiated feed of the experimental group causing the tumors. The experts on the Public Board of Inquiry made a comprimise between the two best studies it looked at, Fitzgerald (1974) and MacKenzie (1973) and determined that the spontaneous brain tumor rate in Charles River CD rats was approximately 0.7%. The PBOI did not put much weight on the two other studies with more serious flaws, Mawdesly-Thomas (1974) and Thompson (1963). The FDA Commissioner took exception to this decision and put forth another study, Gart (1979), which he claimed shows that the spontaneous brain tumor rate in Charles River rats is 2.2% and therefore the E33/34 study which showed much higher rates of brain tumors (3.75%) in the experimental group and the E70 study which showed rates of brain tumors of over 3% were not much more than 2.2% found by Gart (1979). Gart (1979) found a brain tumor rate of 2.2% (8 brain tumors in 368 Charles River CD rats). However, as Dr. John Olney points out, the study states absolutely no methodology. In addition, a smaller number of rats were used than in the Fitzgerald (1974) or MacKenzie (1973) studies. While this study deserves some weight, it is unlikely that expert neuropathologists (which the FDA Commissioner is not) would give it more weight than the two better quality studies considered by the PBOI. If the PBOI had reconvened to consider this study it is unlikely they would have raised their estimated spontaneous brain tumor rate to over 1.0%. The FDA Commissioner argued that the Gart (1979) study deserves more weight because it is a "concurrent" spontaneous brain tumor study as opposed to a "historic" spontaneous brain tumor study. A historic spontaneous brain tumor study is where a lab other than the lab conducting the experiment in question tried to determine the spontaneous brain tumor rate. Gart (1979) acted as a "concurrent" spontaneous brain tumor study because the experiment was conducted at the same laboratory as E33/34 and E70 (Hazelton Laboratories). The FDA Commissioner argues correctly that the thoroughness and methodology of discovering brain tumors are specific to a particular laboratory and therefore since the Gart (1979) study was conducted at the same laboratory, it would, upon initial consideration, seem to act as a better control for the spontaneous tumor rate in Charles River rats. There is one major flaw in this argument, however. E33/34 and E70 were conducted in the early 1970s at Hazelton Laboratory. Almost everyone agrees that at that time the technicians were not fully trained or competent. They were not adequately supervised. There was enormous confusion in the lab. Much of the tissue was allowed to decay. There were mixups in animals and animal feed, etc. In other words, the Hazelton Laboratory was in near total disarray in the early 1970s. When the Gart (1979) study was conducted, one would expect that after three US Senate hearings in 1975 and 1976, the adoption of the FDA Good Laboratory Practices, and assurances from the heads of the G.D. Searle and Hazelton Laboratories on improving the quality of their work, that the lab in which Gart (1979) was conducted in no way resembled what went on when E33/34 and E70 were conducted. The enormous change in laboratory practices would mean that the Gart (1979) cannot be thought of as a "concurrent" spontaneous brain tumor rate study. The best way to find a "concurrent" spontaneous brain tumor rate of Charles River CD rats is to look at the brain tumor rates in rats from E33/34, E70, and E77/78 (a 115-week study of DKP on rats) which were definately part of the control group. The FDA Commissioner attempted to do this by stating (Federal Register 1981, page 38297): "If the controls from all three Searle studies are combined, the resulting incidence rate is very comparable to the NCI data [Gart (1979)] for sample populations of nearly identical size: 2.0% (7 [brain tumors]/356 [rats]) for combined Searle control data and 2.2% (8/368) for NCI control data." There are two problems with this statement by the FDA Commissioner. First, the number of brain tumors found in the control groups of the three G.D. Searle studies is 6 not 7. The FDA Commissioner, inaccurately stated that one brain tumor was found in the control group of E33/34. This would bring the control brain tumor rate down to 6/357 or 1.68% (not 2.0%). In addition, it is completely inappropriate to use the control brain tumor rates from E70. This is because Dr. John Olney as well as the Public Board of Inquiry was questioning whether the experimental group and the control group received the same aspartame-containing feed (Olney 1987, page 6): "A subsequent FDA investigation of the laboratories where these studies were conducted revealed appearances that the control and experimental animals may very well have been fed one another's chow in a sloppily randomized manner so that, in essence, all animals on the study may have been fed Nutrasweet during portions of the study." Other evidence which seems to show a mixup in the diets of E70 rats was the biochemical measurements. In a memorandum from Richard Condon, one of the FDA scientists who reviewed the PBOI decision, he stated (Farber 1989, page 104): "In E70, liver PHE [phenylalanine] hydroxylase activity was measured and found to be greater in treated groups than in the control groups. The attached reference indicates that PHE hydroxylase is suppressed when excess PHE is added to the diet. If PHE is being released from aspartame in the gut and absorbed, what is the explanation for the above results?" It is ridiculous to include data that is being questioned in a calculation for the standard spontaneous brain tumor rate. Therefore, the actual spontaneous brain tumor rate should use the two brain tumors found in control group in the E77/78 experiment and the zero brain tumors found in control group in the E33/34 experiment, or 2/242 = 0.83%. This rate is very close to the 0.7% determined by the PBOI to be the spontaneous brain tumor rate in Charles River CD rats. The decision by the FDA Commissioner, Arthur Hull Hayes (who would soon thereafter consult for G.D. Searle's public relations firm at $1,000/hour) to not require additional studies, to play statistical games, and to use poorly conducted studies as a basis for spontaneous brain tumor rates appears to be reckless, at best. Dr. Olney testified the following about the FDA Commissioner's decision in regards to the spontaneous rate of brain tumors (Olney 1987, page 9): "In his written decision approving Nutrasweet, the Commissioner of the FDA argued quite incorrectly that the spontaneous incidence of brain tumors in Sprague Dawley rats is much higher than 0.6%. In spurious support of this conclusion he cited several irrelevant and/or unreliable studies which he considered more compelling than the appropriate scientific evidence cited by the PBOI judges." NutraSweet-supported scientists sometimes cite Dagel (1979) as an example of a study which shows that the types of spontaneous tumors which were found in aspartame pre- approval studies appear in similar proportions in this study (Koestner 1984). In other words, they claim that because the proportion of astrocytomas to other brain tumors found in aspartame studies is similar to what was found in Dagel (1979) that the tumors found in the aspartame studies were probably spontaneous brain tumors (i.e., unrelated to aspartame). What they do not highlight is the fact that Dagel (1979) found a spontaneous brain tumor incidence rate of only 1.2%, which is far below the 3.75% found in E33/34 and below the 3%+ rates found in E70. The Dagel (1979) study does not prove that the tumors in E33/34 and E70 were spontaneous. On the contrary, it is another example of a spontaneous tumor rate below what was claimed by G.D. Searle and the FDA Commissioner. The fact that the proportions of the types of tumors in each experiment had some similarity could be coincidence or could simply mean that aspartame changes brain chemistry in such a way that the likelihood of "spontaneous" brain tumors appearing increases significantly. 3. Dose-related tumors? G.D. Searle and the FDA Commissioner argued that there was not a dose-related incidence of brain tumors in the E33/34 study. These arguments are based on statistical games and more importantly, do not take into account certain major flaws in the conduct of the study. As stated earlier, the brain tumor incidence in E33/34 was: Control Group 0 0 mg/kg Group 1 4 1000 mg/kg Group 2 1 2000 mg/kg Group 3 5 4000 mg/kg Group 4 2 6000-8000 mg/kg At first glance this appears to be a random distribution of brain tumors among the experimental groups. However, Group 4 should be dropped from any determination of whether the incidence was dose-related. In a memorandum from Richard Condon, one of the FDA scientists who reviewed the PBOI decision, he stated (Farber 1989, page 104): "Additionally there are some questions about the conduct of E33/34. Why were the PHE [phenylalanine] blood levels significantly (P<.05) higher in control males than in high level treated males?" It appears from the phenylalanine level measurements that the males rats in Group 4 did not even get any (or hardly any) aspartame. In Group 3, there were 4 male rats with brain tumors and only one female rat with a brain tumor. Therefore, had the male rats in Group 4 been given aspartame, one might expect that there may be as many as 8 male rats with brain tumors in that group. Since it seems that Group 4 male rats did not receive aspartame and one cannot be certain how many cancers would have occurred had they received aspartame, it is best to discard the group altogether. As discussed in his statistical analysis of E33/34, Dr. Adrian Gross shows that the change in brain tumor incidence does show a statistically significant dose related response to aspartame for the animals of both sexes together (p=0.023) and for the male animals alone (p=0.021) even though Group 2 results do not fit perfectly with the rest of the results (Gross 1987b, page 5-6). The variation of brain tumor incidence in Group 2 could simply be due to chance or it could be a problem with decayed tissue or the animals not receiving the correct diet. It is also important to note that not all substances which contribute to the formation of cancer do so on a linear dose- response curve. It may very well be that above a certain dose level and in certain, susceptible individuals (or rats), brain cancer will occur. 4. Fetal susceptibility Koestner (1984) argued that fetuses are many times more sensitive to certain compounds (e.g., 50-100 times more sensitive to N-nitroso compounds) than adults. Therefore, he says, the study E70 (where the pregnant mothers were exposed to aspartame) should have had a higher tumor rate than E33/34. The incidence rate for aspartame-exposed groups was 3.75% (12/360 rats) in E33/34 and 3.18% (4/157 rats) in E70. There a couple of problems with Koestner's theory: 1. If the feed was regularly mixed up between the experimental group and the control group in E70 as evidence seems to show, the experimental group may have received much less aspartame than intended over the course of the study. Had such regular mixups not occurred, the aspartame-fed group may have had a much larger tumor rate. 2. This theory assumes that whatever would cause the brain tumors in aspartame-fed rats would a) cross the placental barrier in the mothers and b) affect the fetal brains the same way as the adult brain. Since we don't know what may be contributing to brain tumors in aspartame-fed rats, it's pure speculation that it would affect the fetuses to increase the tumor rate. Due to likely mixups in the feed and a lack of knowledge about the aspartame metabolite(s) that might contribute to brain cancer in rats, this theory remains wishful speculation on the part of NutraSweet. 5. Age of Tumor Appearance Koestner (1984) claims that since the majority of the tumors in E33/34 and E70 did not appear at a younger age, aspartame therefore does not meet the definition of a carcinogen. This is perhaps the most ridiculous of NutraSweet's arguments. First of all, there is no way to be certain when the tumors appeared. However, many of the tumors were not small as pointed out by Dr. Peter Lampert after the PBOI (Olney 1987, page 7). In addition, the UAREP pathologists also found that the tumors were much more remarkable than the original G.D. Searle consulting pathologists (ESL) claimed (Gross 1987b, page 3-4). Therefore, despite what Koestner (1984) says, many of those tumors may have appeared at a younger age. Secondly, it surprises me that Koester is not familiar with cigarettes and other substances that cause cancer after regular exposure over a lifetime. Finally, if aspartame sets up a condition in the brain of susceptible rats (or humans) where cancer is more likely to occur, it may take long-term exposure before the necessary brain chemistry changes take place. This argument by Koestner (1984) is ridiculous and should be discounted. Uterine Tumors -------------- As discussed earlier, there was evidence that the rats in the 115-week DKP study (E77/78) were able to avoid most of the DKP because the DKP chunks were so large they would simply eat around them. Florence Graves of Common Cause Magazine described the uterine tumor situation (Graves 1984, page S5500 of Congressional Record 1985a): "FDA officials and Searle defend the study, saying that although there may have been problems, the study was still valid. Both the FDA and Dr. Daniel Azarnoff, president of Searle's research and development division, say one of several indications that the rats ate the required amount of DKP is the fact that a statistically significant number of rats developed tumors in their wombs (called 'uterine polyps')." In testimony before the U.S. Congress, former FDA Toxicologist, Dr. Jacqueline Verrett stated (Verrett 1987, page 388-389 of US Senate 1987): "This (DKP) is the famous study with the uterine polyps, and it is also the study in which there were changes in serum cholesterol, significant changes over the dose range. "Now, we still are not sure exactly how much of DKP each group of animals or any individual animal got; they may not have gotten what would be calculated on the basis of daily consumption had the diet been homogeneous. "The fact is, in spite of that, there were significant increases--and I think everybody agrees with that--of uterine polyps and also changes in blood cholesterol. "When that was then taken into consideration, they said, oh, well, obviously, they must have gotten the diet, because we have these changes. But then they disregarded the changes as being significant- -you know, uterine polyps were not pre- carcinogenic. Well, I can rustle up 15 million women by this afternoon who will disagree with that." Even if the FDA is correct that the uterine polyps in the animal studies were not cancerous, it is still a concern for women. Research -------- I am not aware of any human research on the chronic ingestion of the aspartylphenyalanine diketopiperazine (DKP) from aspartame. a. Cho (1987) In this study conducted in the early 1980s and published in 1987 (Cho 1987), a single dose of aspartame with DKP was ingested by six subjects. The urine and plasma levels of DKP was measured at 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 4, 5, 6, 7, 8, and 24 hours. Approximately 5% of the DKP was excreted in the urine during the first 24 hours. No DKP was found in the blood. Flaws i. The dose of DKP used was only 2.2 mg/kg! This is an exceptionally low dose. As seen in the Tsang (1985) study, large amounts of DKP (e.g., 135 mg/liter) within only six months after bottling at *room temperature*. At higher temperatures the breakdown to DKP would occur much faster. Since the minimum testing dosage of aspartame should be double the FDA's ADI or 100 mg/kg, the minimum testing dosage of DKP should be ~25 mg/kg. A 20 kg child drinking a 2- liter orange soda in a day, stored in the garage for a number of months could easily get 500 mg of DKP (~2000 mg aspartame / 4 = 500 mg of DKP) or 25 mg/kg (500 mg / 20 kg). ii. The study was a single dose study. It is impossible to extrapolate the results of a single dose of a substance which never existed in the human diet to the chronic ingestion of such a substance over a lifetime. iii. The authors speculated on what may have happened to the other ~95% of the DKP that was consumed. It is sad to see that we are basing the future health of millions of people on the wishful thinking and speculation of researchers funded by the aspartame manufacturer. Blood tests for DKP are not necesarily relevant as Olney's original concern was that some DKP was chemically changed in the gut (e.g., nitrosated) and then absorbed (Blaylock 1994, page 212). iv. The authors try to convince readers of likely safety by pointing out that there are other DKPs which are natural. These are different chemicals and likely have a different pharmacological effect. v. The authors try to convince readers of likely safety by citing pre-clinical studies conducted by G.D. Searle and a study conducted by G.D. Searle's long- time partner, Ajinomoto Co. of Japan (MSG inventor) (Ishii 1981). As seen earlier, the preclinical DKP studies are laughable and show that aspartame may have caused uterine tumors. Here is the testimony of Dr. John Olney in regards to the Ajinomoto Co. study (Ishii 1981) (Olney 1987, page 9): "Although there is one study that has been reported since the PBOI which claims to have demonstrated that neither Nutrasweet nor DKP has tumorigenic activity, I am not very impressed with this study. It was conducted by the Ajinomoto Co. of Japan which is one of the world's largest manufacturers of Monosodium glutamate and hydrolyzed vegetable protein and a company which I believe has had a contractual relationship with GD Searle to manufacture Nutrasweet. This study, which was reported sketchily in a journal of poor quality, pertains to a different strain of rat than was used in the GD Searle studies (Wistar instead of Sprague Dawley) and therefore has not adequately addressed the questions raised by the GD Searle studies. The only way to address those questions is to conduct studies that use the same strain of rat and carefully control all experimental variables which were not carefully controlled in the GD Searle studies. One wants to know why Sprague Dawley rats exposed to Nutrasweet had a 3.75% incidence of brain tumors in the GD Searle study. Would another study of Sprague Dawley rats, if properly conducted, show the same thing or would it cleanse the record and show that there is a very low incidence of brain tumors in both the Nutrasweet- fed and control rats? The record has not been set straight by the Ajinomoto study on Wistar rats briefly reported in a journal which is not rigorously refereed (and whose editor is finanacially dependent on the food industry). The FDA Commissioner's office stated at the time he approved Nutrasweet that he was not relying on the newly reported Ajinomoto study but rather was satisfied with the original GD Searle data on Nutrasweet and did not believe any further studies are necessary. I am not satisfied with the original GD Searle studies. The record shows them to be of exceedingly poor quality and the only way to overcome such a record is to have the key studies repeated, preferably by an independent laboratory of the highest possible integrity." In addition to Dr. Olney's comments about this study conducted by Ajinomoto Co. of Japan, it is important to understand that studies by Ajinomoto Co. from that era are highly suspect. As we will discuss in the next section, Ajinomoto Co., through the Glutamate Association and the International Glutamate Technical Committee, funded studies during that era where key information, which would have invalidated those studies, was left out of the published reports and only discovered years later.