For More Information GO TO Aspartame (NutraSweet) Toxicity Home Page: http://www.holisticmed.com/aspartame/ 6. Aspartylphenylalanine Diketopiperazine (DKP) The fact that Dr. Liebovitz did not even mention DKP, a chemical which can sometimes be more prevalent than aspartame itself, is rather distressing. At least one of the references he cites, AMA (1985) discusses DKP at length, so he must be aware of this breakdown product. Before aspartame was foisted upon the public, the amount of this particular DKP in the diet was essentially zero (Federal Register 1984). Therefore, no claim can automatically be made that DKP ingestion is safe. Several quality studies would have to be performed in order to conclude that DKP probably does not have a detrimental affect on humans. No such quality studies have ever been done. Most of the controversy surrounding DKP has involved the issue of brain tumors and uterine polyps. While I will limit my discussion in this section to cancer, there are two very important preliminary points that need to be made: a. Cancer is a very serious disease. However, there are countless other serious diseases and therefore no reason to limit the concern regarding DKP to cancer. The FDA and EPA have approved numerous drugs and chemicals that have unexpectedly caused or contributed to a wide range of serious adverse reactions other than cancer. There is no reason to believe that the possible detrimental effects of DKP are limited to cancer. Dioxin is an example of a chemical which was linked to cancer. Now it turns out that the biggest issue is that dioxin has an extremely deleterious effect on the immune system. b. When looking at the aspartame and cancer issue, DKP becomes a likely candidate for a possible cause. However, it is only one of several possibilities. Ingesting methanol or significant quantities of racemized amino acids could be another cause or contribuatory factor. Brain chemistry changes making one slightly more susceptible to brain tumors caused by long- term ingestion of aspartic acid and/or phenyalalnine might be another possibility as to how aspartame could contribute to brain cancer. We will discuss the studies that show aspartame caused cancer in laboratory animals later in this section. However, it should be understood that the pre-approval studies were so poorly designed and conducted that it would be impossible to conclude that aspartame is safe. Some of the flaws which show that the FDA could not possibly have concluded that aspartame does not cause cancer are as follows: Lack of Statistical Power (simplified discussion of statistics) --------------------------------------------------------------- Aspartame is being regularly consumed by over 70 million people in the U.S as discussed earlier. If aspartame was to cause cancerous tumors in 1% of the people who ingest it for several decades (as is what happens with cigarettes), 700,000 people would develop such aspartame-caused tumors in that time. A 5% tumor rate would lead to 3.5 million people developing tumors. etc. Let's say, for arguments sake that aspartame causes cancerous tumors in 2% of the people in their lifetime. That's 2% of 70 million people (in the U.S.) or 1.4 million people. If I wanted to see if this was really the case by testing aspartame in animals, I would feed aspartame to 70 million (test) animals. To another 70 million animals, I would give a normal diet. If the aspartame-ingesting animals had 1.4 million cancerous tumors more than the non-aspartame- ingesting (control) animals, the cancer rate of aspartame would be 2%. Of course, it would be impossible to conduct an experiment on this many animals. So, instead of 70 million test animals and 70 million control animals, I could use 1000 test animals and 1000 control animals. If the cancer rate was 2%, there would be, in theory, 20 more cancerous tumors in the test animals than in the control animals. If there was a 2% cancer rate for aspartame, the reality is that each time I conducted the experiment, an average of 20 more cancers in the test animals would appear than in the control animals. If I ran the experiment ten times I may get something like this: Number of Excess Tumors in Test Animals As Compared to Control Animals Run #1 24 Run #2 14 Run #3 18 Run #4 22 Run #5 28 Run #6 19 Run #7 13 Run #8 20 Run #9 22 Run #10 20 As you can see, the numbers would vary, but the more times I conducted the experiment, the closer the average of all of the runs would be to 20. Instead of running the experiment on 1000 test animals and 1000 control animals, a researcher may choose to use only 100 test animals and 100 control animals. If there was a 2% cancer rate for aspartame, there would be an average of 2 more cancerous tumors for the test group as opposed to the control group. However, since there are variations for each experimental run, the results might look something like this for 10 runs (on 100 test animals and 100 control animals): Test Group Control Group Run #1 2 0 Run #2 4 1 Run #3 0 0 Run #4 3 0 Run #5 4 1 Run #6 0 2 Run #7 5 1 Run #8 3 1 Run #9 5 0 Run #10 0 0 The average over 10 runs is a 2% more cancer rate in the test group, but there is a wide variations for each individual run. As you can see, the smaller the group of animals used, the wider the percentage variation for each run. Instead of 10 runs on 100 test animals and 100 control animals, had I simply done a single run, the results would likely be meaningless because there is such a wide variation for a particular run with this few amount of animals. For example, Run #9 shows 5 cancerous tumors in test animals and 0 in control animals. Whereas Run #6 shows 0 cancerous tumors in test animals and 2 cancerous tumors in control animals. Therefore, in order to more accurately investigate whether aspartame causes a 2% cancer rate (1.4 million in 70 million users), I would have to use many times more than 100 animals or make numerous test runs with 100 animals each. As you can see, if I was to use a small amount of animals, I could not accurately determine whether there was a 2% cancer rate of aspartame. I may be able to conclude that there is not a 20% cancer rate for aspartame use (or 14 million cancers). If I can say that aspartame does not cause 14 million cancers, that does not help me very much. It begs the question as to whether it causes a 5% cancer rate, a 2% cancer rate (1.4 million people) or a 0.2% cancer rate (140,000 people). G.D. Searle used such a small number of animals in their experiments relating to cancer that it would have been impossible to conclude that aspartame was safe even had the experiments been conducted properly and had there been no significant number of tumors found. FDA Chief of Statistical Evaluations Branch, Satya D. Dubey stated the following in a memo to the FDA Commissioner's office (Farber 1989, page 101): "From the design viewpoint, the probability of observing a statistically significant result at 5% significance level with 60 animals in the control group and 40 animals in the treatment group when the true difference in incidence rates of brain tumors is not more than 5% would be less than 27.9% . . . Even 27.9% of statistical power will generally be considered to be very low power. The studies, E33/34 and E70, which I have statistically reviewed, thus possess very low power to detect true significant effect of the kind stated above. . . . Therefore, their results should not be considered confirmatory for decision purposes." What Dr. Dubey is saying is that there is only a 27.9% liklihood that a cancer rate of less than 5% would be found for the experiments discussed above. A 4.9% cancer rate still amounts to 3,430,000 cancers in 70 million aspartame users! E33/34 and E70 are two studies which showed that aspartame caused cancer in laboratory animals and will be discussed later. This is one of the tricks that is sometimes used in animals experiments. If the researcher uses a small amount of animals, the study may not find an increase in cancer rates for the test animal as opposed to the control animal, but the lack of statistical power caused by the use of a small number of animals made such a finding very unlikely. When a researcher does use a small number of animals, the condition of every single animal is very important. If even one animal's cancer is missed, the results of the experiment can be changed dramatically. Had the studies E33/34 and E70 been run perfectly, there would have been a 27.9% chance that the researchers would have found a 5% or more tumor rate. Since the experiments were so incredibly sloppy and the condition of the animals was really a guess, it is likely that a 10% cancer rate would have been missed. G.D. Searle employees attempted to increase the statistical power of the cancer studies by combining the results from different studies such as E33/34 and E70 (Cornell 1984). E70 studies the effects of aspartame on Charles River albino rat offspring by giving adding it to the mother's feed through the period of lactation and then the offspring's feed until death. The offspring were supposed to be examined at 104 weeks (or at death). E33/34 was a chronic dosing study of aspartame given in four different doses to rats for 104 weeks. However, FDA Senior Statistician, Dr. Satya Dubey stated in1981 in a memo to the FDA Commissioner's science advisory team on aspartame (Farber 1989, page 102): "Since the protocol of E70 study is different, its design is deficient, its data exhibit certain peculiar patterns, and the statistical conclusions derived from such data are much different from that of the E33/34 study (compare the statistical results of E33/34 and E70 studies), it does not appear proper to me to combine the results of these two studies." In his treatise on aspartame, Farber (1989, page 102) states in regards to combining E33/34 and E70: "I asked Myrto Lefkopoulou of the Harvard School of Public Health, Biostatistics Department for her comments on the statistical aggregation of E70 and E33/34. She considered the aggregation of these studies inappropriate because the effect of an in utero study [E70] is different than a chronic feeding study [E33/34]. ...she stated that the in utero study is looking for a teratogenic effect, whereas the chronic feeding study was concerned with carcinogenicity -- did aspartame promote brain tumors?" Farber points out that even if the results of these studies are (improperly) combined, there is only a 67% chance that a 5% tumor rate could be discovered (Farber 1989, page 103). Live / Dead Status ------------------ Below are listed a selection of animals from G.D. Searle's studies where the researchers couldn't even determine whether the animal was alive or dead. This information comes from the original data observation sheets as audited by the first FDA Task Force in 1975/1976. While not all of this information applies to aspartame studies, it should serve to give you a sense of the confusion that was rampant throughout the animal observations (Schmidt 1976a, page 21 of US Senate 1976a). J24HM Found dead 3/21/71 Alive 5/19/71 Dead 5/16/71 Alive 7/14/71 Dead 8/11/71 K18LF Alive 4/22/71 vanished (dead ?) 5/20/71 Alive 6/17/71 vanished (dead ?) 7/15/71 M25CF Found dead 3/6/71 Alive 6/18/71 Dead 7/16/71 Alive 9/10/71 Alive 10/8/71 Dead 11/5/71 H28MF Alive 7/13/71 vanished (dead ?) 8/10/71 H15CF Alive 7/13/71 vanished (dead ?) 8/10/71 G 2HM Found dead 3/10/71 Alive 8/9/71 A15MM Found dead 3/13/71 Alive 5/3/71 Dead 6/1/71 Alive 8/23/71 Dead 9/20/71 G16HM Found dead 3/9/71 Alive 8/9/71 Dead 9/7/71 A 6HM Found dead 2/25/71 Alive 5/3/71 Dead 6/1/71 Alive 8/23/71 Dead 9/20/71 G23HM Found dead 3/7/71 Alive 8/9/71 Dead 9/7/71 E15MM Found dead 1/21/72 Alive 2/25/72 G 8MM Found dead 9/3/71 Alive 11/29/71 Dead 12/27/71 B19HF Alive 6/29/71 vanished (dead ?) 7/27/71 Alive 8/24/71 vinished (dead ?) 9/21/71 Alive 10/19/71 vanished (dead ?) 11/16/71 Alive (?) 2/22/72 B21HF Found dead 2/25/71 Alive 8/24/71 Dead 9/21/71 Alive 10/19/71 Dead 11/16/71 Alive 2/22/72 B14MF Killed 7/30/71 Alive 10/19/71 Dead 11/16/71 Alive (?) 2/22/72 B12HF Found dead 9/2/71 Alive 10/19/71 Dead 11/16/71 Alive (?) 2/22/72 B 4CF Found dead 9/12/71 Alive 10/19/71 Dead 11/16/71 Alive (?) 2/22/72 D30LF Found dead 1/22/72 Alive 2/22/72 B15HF Found dead 1/25/72 Alive 2/22/72 C29LM Found dead 3/29/71 Alive 6/2/71 Dead 6/30/71 C12HM Found dead 8/10/71 Alive 10/20/71 Dead 11/17/71 There may have been numerous animals which were listed incorrectly as alive and then dead. There would have been no way for the Task Force to discover errors such as that. An animal's alive or dead status is only one of the variables which goes into the statistical analysis of an experiment testing for cancer. Whether an animal has a tumor is another important piece of information. Tumor Status ------------ There were many instances in which the FDA Task Forces discovered that G.D. Searle had confused animals to such an extent, the tumor status was not known. To give you a sample of the confusion that reigned during this period of time in the G.D. Searle laboratories, here a sample from just one cancer study of one of G.D. Searles drugs. The testimony is that of FDA Toxicologist Dr. Addrienne Gross (Gross 1976b, page 44-49): What may be added here is that the live/dead status of the experimental animals is not the only "careless" type of error present in the Observation for Drug Effects. The following are merely a few samples of the way entries are kept on externally visible tissue masses in these animals; most of such tissue masses turn out to be benign or malignant mammary tumors. 1. Animal M21 (a control female), is said to have developed a tissue mass in the left cervical area; the mass is said to have been initially detected on 6/18/71; at the next observation period on 7/17/61 this animal is checked off as having no tissue masses; however, the next animal on the list (M22 - an exposed female) is now listed as having its tissue mass "larger" (presumably than at the previous observation period); but this particular animal had not been listed as having exhibited any such masses at any time in the past; at the next observation period on 8/13/71, the tissue mass in the control animal is said to be "larger" while the exposed animal is said to have no tissue mass whatsoever. 2. Animal J16 is said on 2/23/72 under "Tissue Masses - Lesions" to have an abscess in the left inguinal region which is "larger"; no mention of any such abscess is evident for any prior observation. 3. Animal B26 is said on 12/14/71 under "Tissue Masses - Lesions" that its mass is larger. But no tissue mass in this animal is previously reported. Four weeks later on 1/12/72 a tissue mass is said to have been initially detected on that day. 4. Animal B27 is said on 9/21/71 to have developed a tissue mass initially detected on that day; at the next observation period on 10/19/71 the mass is said to be unchanged; at the next observation period on 11/16/71 the mass is said to have regressed; at the next two observation periods on 12/14/71 and 1/12/72 this animal is said to be free of tissue masses; on 2/8/72, the next observation period, the mass for this animal is said to be the "same"(!) 5. Both animals A2 and A3 are said on 9/20/71 to have developed tissue masses initially detected on that day; at the next observation period, on 10/8/71 both of these animals are indicated to be free of any tissue masses; at the next observation period on 11/5/71 it is indicated that both of these masses regressed. 6. Animal E3 is said on 7/1/71 to have developed a tissue mass initially detected on that day; the following are the results of the six subsequent examinations: 7/29/71 - animal is free of any masses 8/26/71 - mass is the same (as what?) 9/23/71 - mass is the same 10/21/71 - animal is free of any masses 11/08/71 - mass is the same 12/06/71 - mass regressed 7. Animal E9 is said on 9/23/71 to have developed a tissue mass initially detected on that day; the following are the results of the four subsequent examinations: 10/21/71 - mass regressed 11/18/71 - animal is free of any masses 12/16/71 - mass regressed 1/13/72 - animal is free of any masses 8. Animal D29 is said on 7/1/71 to have developed a tissue mass initially detected on that day; the following are the results of the seven subsequent examinations: 7/29/71 - animal is free of any masses 8/26/71 - animal is free of any masses 9/23/71 - mass is the same 10/21/71 - animal is free of any masses 11/18/71 - mass regressed 12/16/71 - mass is the same 1/13/72 - animal is free of any masses 9. Animals H26, D12, K25, D5, K17, and D19 each are indicated to have developed more than on tissue mass; in each case, however, observations made subsequently fail to distinguish to which tissue mass they apply. 10. Animal H19 is said on 11/2/71 to have developed a tissue mass initially detected on that date; the subsequent observation dated 11/30/71 indicates this animal to be free of any tissue masses; at the next observation made on 12/28/71 the mass in this animal is said to be the "same." This list of 10 examples involving some 16 animals could be extended further but it is sufficient to make the point that records maintained at Searle on the appearance, persistence or "regression" of tissue masses do not give one much assurance on their reliability. One may ask -- can this sort of thing be shrugged off as merely "careless" observations made by those who were supposed to make such observations? Or was this a situation that could be expected to have occurred, given the policy and practice in force in the Department of Pathology and Toxicology at Searle? A review of the names of the "observers" entered on these sheets referring to "Observations for Drug Effects" reveals different names for subsequent observations. Question: If whoever observed the animals on a given day and who recorded such observation in his or her notebook, is someone else than the one having observed them at the previous observation period, who made similar observations in some other notebook, how can it be said that a certain tissue mass is the "same" or "larger" or "unchanged"? After a certain period in the experiment no names of any observers appear on these records. Searle maintains in their last communication (line 10, page 15) "In the truest sense, the errors identified by the FDA (in these records) were completely irrelevant to the scientific conclusions of the study..." We note this evaluation of "irrelevant" by Searle but we cannot agree with it, and the reason for this is very clear: The title printed on these "Observation for Drug Effects" is "Statistical Work Sheet"; this says that it is reasonable to expect that these "careless" entries must have formed the basis for input for statistical operation which are crucial to the "scientific conclusions of the study." The methodology used in these statistical operations at Searle (the Horton and Sachs Life-Table procedures) depend completely on the time a certain tissue mass (tumor) is observed and on the time the animals with the mass (and all other animals in that group) died. Now, if the live/dead status of each animals was "carelessly" entered on these "Statistical Work Sheets" as conceded by Searle and if its status as a tumor-bearer at any time was largely in doubt (as demonstrated here) of what value are any of the statistical computations based on this kind of raw input data and would this not affect the "scientific conclusions of the study"? Searle complains (line 2, page 14) that these records "became a subject of considerable levity at the hearing." I believe, however, that the members of the Subcommittee are sufficiently knowledgeable in the ways of the world to realize that animals seldom die more than once. However, I would tend to agree with Searle here, that the state of their records on observations collected during the course of this study is indeed no laughing matter. Given the lack of statistical power of NutraSweet's animals experiments and their inability to be certain whether their test animals are alive or dead and whether they did or did not have tumors, how could any unbiased individual rely on this information to make health policy determinations that would effect an entire country? The items discussed above combine to render the G.D. Searle experiments that tested for cancer totally worthless as far as using them to prove safety. However, these abuses were just the beginning of what was discovered. Other Problems -------------- The following testimony by Dr. Jacqueline Verrett, a former toxicologist of the FDA, who was the Senior Scientist of the FDA Bureau of Foods Task Force describing a few of the other problems with G.D. Searle's cancer studies (Verrett 1987): 1. There was no protocol written until the study was well underway. 2. Animals were not permanently tagged to avoid mixups over the course of the study. 3. Changes were introduced in some laboratory methods during the study with inadequate documentation. 4. There was either sporadic or inadequate reporting and monitoring of both feed consumption and animal weights. 5. In some cases, tumors were removed, and the animals then returned to the study. 6. Animals were recorded as dead and then subsequent records, after varying periods of time, indicated the same animal was still alive--almost a certain evidence of mixup. 7. Many animal tissues, a significant number, were autolyzed, that is, decomposed, before any post mortem examinations were performed. 8. And finally, of extreme importance is that in the DKP study there was evidence, including pictures found in notebooks at Searle, that the diets were not homogeneous, and that the animals could discriminate between feed and the included particles of DKP. In other words, they may or may not have been eating what it was assumed they were eating. Almost any single one of these aberrations would suffice to negate a study designed to assess the safety of a food additive, and most certainly, a combination of many such improper practices would, since the results are bound to be compromised. Raymond Schoeder, a former G.D. Searle employee told the FDA that the particles of DKP (in experiments to test DKP for cancer) were so large that the rats could discriminate between the DKP and their normal diet (Graves 1984, page S5500 of Congressional Record 1985a). After Raymond Schroeder had made his original statements regarding the DKP study, FDA Investigators went to interview him. He was then employed at a different company. When the investigators got there, they noticed that a G.D. Searle company employee had signed in immediately before them. During the interview, Mr. Schroeder retracted his statements about the DKP study (Olney 1987, page 8). The evidence is very strong showing that the amount of DKP ingested was much less than originally intended. This evidence includes the statement by Mr. Schoeder as well as a picture of the large DKP particles. This is a crucial issue as it shows that the uterine tumors and other problems found in NutraSweet-fed rats in the DKP studies may have occurred at a relatively low dose of DKP. Dr. Adriene Gross describes problems with a 115-week study testing DKP in rats (Gross 1987a, page 7): 1. Substitutions of some of the animals in that study. 2. The presence of intercurrent disease amongst the test animals and the administration of drugs to combat this, neither of which were completely reported to the FDA. 3. Incomplete examination of tissues from the experimental animals. 4. Excision of tissue masses likely to be tumors from live animals during the study. 5. Absence of batch records for the mixing of the test substance into the diet of the test animals. 6. Incomplete stability studies for the agent on test. 7. Absence of homogeneity studies for the agent on test. 8. Deficiencies in the methods of chemical assay for the actual DKP that was mixed into the diet of the experimental rats. 9. Problems with the dosage of the DKP that was given to those rats. 10. Problems with the fixation-in-toto and autolysis (decomposition of tissue). 11. Failure to report to the FDA all tissue masses (likely to be tumors) which were found in the experimental rats. 12. Failure to report to the FDA all internal tumors present in the experimental rats, eg., polyps in the uterus (Animal K9MF), ovary neoplasms (Animals H10CF, H19CF, and H7HF) as well as other lesions (Animal D29CF). 13. Inconsistencies between different parts of the report on this study submitted by GD Searle & Co. to the FDA on the precise nature of the lesions manifested by the test rats. 14. Numerous transcription errors in that report. Brain Tumors ------------ The pre-approval studies submitted to the FDA by G.D. Searle were so bad that it would be impossible to determine safety of aspartame from them. However, statistically significant increases in cancer rates in several of the pre-approval experiments are an indication that aspartame may cause cancer. Two pre-approval studies showed an unusually large number of brain tumors in the test animals. Those studies where called, E33/34 and E70. Before discussing these studies in detail, it is useful to see how Dr. Andrian Gross prefaced his discussion of brain tumors in G.D. Searle's pre-approval studies (Gross 1987b, page 1-2): "However, having said all of this, let us assume that in fact those studies were of an acceptable quality; let us pretend that the test animals were actually exposed qualitatively and quantitatively to what G.D. Searle & Co. would have us believe that they were exposed; that there was no post- mortem autolysis [decay] of their carcasses rendering vast numbers of their tissues to a state unsuitable for pathology examination; that the technicians involved in the conduct of those studies were fully trained, competent, and adequately supervised to make observations on those animals prior to their death; that the same was true with respect to the observations made after their death; that in fact those technicians actually made proper such observations; that the proper samples of tissues with grossly observed lesions were in fact collected for additional microscopic examination; that the identity of such tissue specimens corresponded (as they should) to the identity of each animal that was their source, etc. In short, let us make believe in a spirit of Halloween that nothing which was uncovered for the aspartame studies by the FDA investigations of 1975 and 1977 was actually true, i.e., that in fact we are dealing here with studies of an absolutely perfect quality or reliability. Of course, such assumptions belong to the domain of Fantasyland, but nevertheless, let us play this little game for a while." "Under such highly speculative hypothetical conditions, let us now ask again whether aspartame can be viewed as being safe with "reasonable certainty." E33/34 ------ E33/34 was a 104-week study of Charles River CD rats. There were four experimental groups each consisting of 80 rats. Each experiment group was given a different dose of aspartame. The Control group had 119 rats. Twelve brain tumors were found in the experimental rats and zero in the control rats (Gross 1987b, page 2-3): Group Sex Animal # Type of tumor 1 M 83-651 Astrocytoma 1 M 83-745 Astrocytoma 1 F 83-769 Astrocytoma 1 F 83-766 Astrocytoma 2 M 83-837 Astrocytoma 3 M 83-919 Astrocytoma 3 M 83-888 Oligodendroglioma 3 M 83-892 Astrocytoma 3 M 83-895 Astrocytoma 3 F 83-934 Astrocytoma 4 F 84-010 Medulloblastoma 4 F 84-019 Astrocytoma The UAREP pathologists found only 11 brain tumors in the experimental rats and 1 brain tumor in the control rat. Dr. John Olney had this to say about that discrepancy (Olney 1987, page 6-7): "There were other problematic aspects of the brain tumor data. In the pre-1975 records that I reviewed, it was clear that several competent pathologists had carefully examined the original microscopic slides from the first study and agreed that there were 12 brain tumors in the NutraSweet- fed rats and zero brain tumors in the controls. When the FDA conducted a task force investigation of these laboratories in 1975, they singled out these studies for further investigation and ordered that all laboratory records, including microscopic slides etc. be impounded under FDA seal. Several years later when a group of pathologists (UAREP) was sent to authenticate these studies, they could not find the microscopic slides. The UAREP pathologists were finally taken to a laboratory where the slides were not supposed to be and there they found some but not all of the original slides. Clearly they had not been kept under FDA seal and by mysterious coincidence the slides that were finally presented to the UAREP pathologists contained evidence for 11 brain tumors in Nutrasweet-fed rats and 1 tumor in contols. It is important to recognize that if there are zero tumors in the controls, it is very difficult to argue that the tumor incidence in the control and Nutrasweet-fed rats is the same. But if there is 1 tumor in the control group, it is possible with statistical acrobatics to reach the conclusion that the incidence is the same. And, indeed, this is exactly the argument that the manufacturer and the FDA Bureau of Foods pressed at the Public Board of Inquiry. They accepted the finding of 1 brain tumor among the controls even though the authentic record showed zero brain tumors in the controls, then they proceeded to break down the animals into smaller and smaller sub groups according to sex, dose level etc. and finally the 1 brain tumor in one sub group of control animals appeared to be not significantly different from 2 or 3 tumors in each of the experimental sub groups. I seriously doubt whether this method of data analysis would stand the scrutiny of competent disinterested statisticians. Even more seriously I wonder why FDA allows microscopic slides to disappear (while supposedly impounded) and why they do not question the de novo emergence of a brain tumor among the controls when the slides reappear." In addition, the tumors that were found were large, leading one to believe that they were not normal "spontaneous" tumors. As Dr. John Olney stated (Olney 1987, page 7): "Being a neuropathologist, I know that spontaneous brain tumors in laboratory rats are extremely rare. The archival literature documents an incidence not exceeding 0.6%. Since the above incidence in Nutrasweet-red rats is 3.75%, this suggests that Nutrasweet may cause brain tumors and certainly suggests the need for additional in depth research to rule out that possibility. .... "The PBOI panel member who was primarily responsible for reviewing the brain tumor issue was Peter Lampert, M.D., Neuropathologist and chairman of the pathology department at Univ. of Calif. San Diego. Dr. Lampert personally examined the microscopic slides pertaining to the brain tumor studies and told me a year or so after the PBOI report was completed that he had been surprised at the large size of the brain tumors in the Nutrasweet-fed rats. This reinforced his impression that they had been caused by some tumorigenic agent since spontaneous brain tumors are not only rare in laboratory rats but when they do occur they are usually not so large. Dr. Lampert is now deceased; he died in 1986 of cancer. At the time he participated in the PBOI, he was the President of the American Association of Neuropathologists." It is also important to note that there may have been more brain tumors in the E33/34 than reported. As Dr. Adrian Gross discovered (Gross 1987b, page 4-5): "Furthermore, Appendix IV-20 on page 391 of that same UAREP report reveals in the first row of the table on that specific page that GD Searle & Co. or their agents had provided to the subcontracting EPL pathologists, i.e., to those whose report that firm had originally submitted to the FDA:- a) only 8 (or only 10%) of the brain sections for the 80 animals in Group [1]. b) only 7 (or only less than 9%) of the brain sections for the 80 animals in Group [2]. c) only 5 (or only less than 7%) of the brain sections for the 80 animals in Group [3]; and the UAREP were provided with the brain sections of 2 fewer animals than were provided to the EPL. ... This, quite by itself, is sufficiently eloquent on just how G.D. Searle & Co. saw fit to discharge their responsibilities in reporting fully and completely their results of the Two Year Rat Study with aspartame to the FDA;" 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.