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From the 29 May 1995 issue of Smart Drug News [v4n2]. Copyright (c) 1995, 2009. All rights reserved.

Research Update (Part 2):


by Mark D. Gold, Steven Wm. Fowkes and Ward Dean, M.D.

In Part 1 of this article we discussed how aspartame is metabolized into aspartate, phenylalanine, methanol and diketopiperazine (DKP) and the possible toxicities of those metabolites. We begin Part 2 with a discussion of the specific conditions for which aspartame might pose unusual risks.

Brain Tumors and Other Cancers

In 1981, Satya Dubey, an FDA statistician, stated that the brain-tumor data on aspartame was so “worrisome” that he could not recommend approval of aspartame.[14] In a two-year study conducted by the manufacturer of aspartame, twelve of the 320 rats fed a normal diet and aspartame developed brain tumors while none of the control rats did. Five of the 12 tumors were in rats given a low dose of aspartame.[3,15]

The approval of aspartame was a violation of the Delaney Amendment which was supposed to prevent cancer-causing substances such as methanol (through formaldehyde production) and DKP from entering our food supply. The late Dr. Adrian Gross, an FDA toxicologist, testified before the US Congress that aspartame was capable of producing brain tumors. This made it illegal for the FDA to set an allowable daily intake at any level. He stated in his testimony that Searle’s studies were “to a large extent unreliable” and that “at least one of those studies has established beyond any reasonable doubt that aspartame is capable of inducing brain tumors in experimental animals...” [emphasis added]. He concluded his testimony by asking, “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?.... And if the FDA itself elects to violate the law, who is left to protect the health of the public?”[16]

In the mid-1970s, the manufacturer of aspartame was discovered to have falsified studies in several ways. They surgically removed tumors from test animals and they listed dead animals as having survived the study. Thus, the data on brain tumors were likely worse than discussed above. In addition, a former employee of the manufacturer of aspartame, Raymond Schroeder, told the FDA on July 13, 1977 that the particles of DKP were so large that the rats could discriminate between the DKP-diet and their normal diet.[12,17]

It is interesting to note that the incidence of brain tumors in persons over 65 years of age has increased 67% between the years 1973 and 1990. Brain tumors in all age groups has jumped 10%. The greatest increase has come during the years 1985-1987,[18] four years after aspartame was approved for dry goods and two years after aspartame was approved for soft drinks. In his book, Dr. H. J. Roberts gives evidence that aspartame can cause a particularly dangerous form of cancer — primary lymphoma of the brain.[19]

Aspartame and Birth Defects

Dr. Diana Dow Edwards was funded by Monsanto to study possible birth defects caused by the ingestion of aspartame. After preliminary data showed damaging information about aspartame, funding for the study was cut off. A genetic pediatrician at Emory University has testified that aspartame may be causing birth defects.[20]

In the book, While Waiting: A Prenatal Guidebook by George R. Verrilli, M.D., and Anne Marie Mueser, it is stated that aspartame is suspected of causing brain damage in sensitive individuals. “A fetus may be at risk for these effects...some researchers have suggested that high doses of aspartame may be associated with problems ranging from dizziness and subtle brain changes to mental retardation.”


According to research conducted by Dr. Roberts (who is a diabetes specialist), aspartame 1) leads to the precipitation of clinical diabetes; 2) impairs diabetic control in diabetics on insulin or oral drugs; 3) aggravates such diabetic complications as retinopathy, cataracts, neuropathy and gastroparesis; and 4) causes convulsions. Incongrously, the American Diabetes Association (ADA) actually recommends aspartame to persons with diabetes.

In a statement concerning the use of products containing aspartame by persons with diabetes and hypoglycemia, Dr. Roberts says:

“Unfortunately, many patients in my practice, and others seen in consultation, developed serious metabolic, neurologic and other complications that could be specifically attributed to using aspartame products. This was evidenced by: the loss of diabetic control, the intensification of hypoglycemia, the occurrence of presumed ‘insulin reactions’ (including convulsions) that proved to be aspartame reactions, and the precipitation, aggravation or stimulation of diabetic complications (especially impaired vision and neuropathy) while using these products.”

“Dramatic improvement of such features after avoiding aspartame, and the prompt predictable recurrence of these problems when the patient resumed aspartame products, knowingly or inadvertently.”

Dr. Roberts goes on to state:

“I regret the failure of other physicians and the American Diabetes Association (ADA) to sound appropriate warnings to patients and consumers based on these repeated findings which have been described in my corporate-neutral studies and publications.”

Dr. Russell L. Blaylock has also stated that excitotoxins such as found in aspartame can precipitate diabetes in persons who are genetically susceptible to the disease.[5]

Emotional Disorders

A double-blind study of the effects of aspartame on persons with mood disorders was recently conducted by Ralph G. Walton and associates.[21] Since the study wasn’t funded or controlled by the makers of aspartame, the NutraSweet Company refused to sell him the aspartame. Dr. Walton was forced to obtain and certify it from an outside source.

The study showed a large increase in serious symptoms for persons taking aspartame. Since some of the symptoms were so serious, the Institutional Review Board had to stop the study. Three of the participants said they had been “poisoned” by aspartame. Dr. Walton concluded that “individuals with mood disorders are particularly sensitive to this artificial sweetener; its use in this population should be discouraged.”[21] Aware that the experiment could not be repeated because of the danger to the test subjects, Dr. Walton was recently quoted as saying, “I know it causes seizures. I’m convinced also that it definitely causes behavioral changes. I’m very angry that this substance is on the market. I personally question the reliability and validity of any studies funded by the NutraSweet Company.”[22]

There are numerous reported cases of low brain serotonin levels, depression and other emotional disorders that have been linked to aspartame and often are relieved by stopping the intake of aspartame. Researchers have pointed out that increased phenylalanine levels in the brain, which can and does occur in persons without PKU, can lead to decreased serotonin levels, which can, in turn, lead to a variety of emotional disorders. Dr. William M. Partridge of UCLA testified before the US Senate that drinking four 16-ounce bottles of diet soda per day leads to an enormous increase in phenylalanine levels.

Epilepsy and Seizures

With the large and growing number of seizures caused by aspartame, it is sad to see that the Epilepsy Foundation is promoting the “safety” of aspartame. At Massachusetts Institute of Technology, 80 people who had suffered seizures after ingesting aspartame were surveyed. The Community Nutrition Institute concluded the following about the survey, “these 80 cases meet the FDA’s own definition of an imminent hazard to the public health, which requires the FDA to expeditiously remove a product from the market.”

Both the Air Force’s Flying Safety and the Navy’s Navy Physiology magazines published articles warning about the many dangers of aspartame including the cumulative deleterious effects of methanol and the greater likelihood of birth defects. The articles note that the ingestion of aspartame can make pilots more susceptible to seizures and vertigo.[23]

Recently, a hotline was set up for pilots suffering from acute reactions to aspartame ingestion. Over 600 pilots have reported symptoms including some who have reported suffering grand mal seizures in the cockpit due to aspartame.[24]

One of the original studies on aspartame was performed in 1969 by an independent scientist, Dr. Harry Waisman. He studied the effects of aspartame on infant primates. Out of the seven infant monkeys, one died after 300 days, and five others had grand mal seizures. These negative findings were not submitted to the FDA prior to aspartame’s approval.[25]

A 1992 double-blind study of epileptic children has confirmed that aspartame aggravates EEG abnormalities that are associated with their epilepsy.[26] Other double-blind studies have connected aspartame consumption to headaches[27,28] and seizures.[29]

Hear No Evil, See No Evil

The reason many people do not hear about serious reactions to aspartame is two-fold:

1) Lack of awareness by the general population. Aspartame-caused diseases are not reported in the newspapers like plane crashes. This is because these incidents occur one at a time in thousands of different locations across the US.

2) Most people do not associate their symptoms with the long-term use of aspartame.

The approval of aspartame is a lesson in how chemical and pharmaceutical companies can manipulate government agencies like the FDA, “bribe” professional organizations like the American Dietetic Association, and flood the scientific community with flawed and fraudulent studies funded by a vested interest. Erik Millstone, a researcher at the Science Policy Research Unit of Sussex University has compiled thousands of pages of evidence, some of which have been obtained using the Freedom of Information Act,[30] showing:

1. Laboratory tests were faked and dangers were concealed.

2. Tumors were removed from aspartame-treated animals, and animals that had died were “restored to life” in laboratory records.

3. False and misleading statements were made to the FDA.

4. The two US Attorneys tasked with bringing fraud charges against Searle, the aspartame manufacturer, allowed the statute of limitations to run out and then took jobs with Searle’s law firm.

5. The FDA Commissioner overruled objections of the FDA’s own scientific board of inquiry. Shortly after that decision, he took a position with Burson-Marsteller, Searle’s public relations firm.

In 1980, a 3-member Public Board of Inquiry voted unanimously against aspartame’s approval. Later that year, the FDA formed a 5-member scientific Board of Inquiry to review that decision. After that board voted three to two to uphold the previous decision (recommending against approval of aspartame), a sixth member was added to the board and a re-vote deadlocked at 3 for and 3 against. This allowed the FDA Commissioner to break the deadlock and approve aspartame for dry goods in 1981. Dr. Jacqueline Verrett, a toxicologist and senior member of the review team stated, “It was pretty obvious that somewhere along the line, the bureau officials were working up to a whitewash.”

In 1987, Dr. Verrett testified before the Senate that the experiments conducted by Searle were a “disaster.” She stated that as senior scientist of the FDA team that reviewed the Bressler Report of Searle’s abuses during pre-approval testing, her team was instructed not to comment on or be concerned with the overall validity of the studies. She stated that questions about birth defects have not been answered and that DKP has been shown to increase uterine polyps and change blood cholesterol levels.[13]

The FDA and the aspartame industry have had a revolving door of employment for many years. In addition to the FDA Commissioner and the two US Attorneys who left to take positions with companies connected with Searle, four other FDA officials connected with the approval of aspartame took positions connected with the NutraSweet® industry between 1979 and 1982. These included the Deputy FDA Commissioner, the Special Assistant to the FDA Commissioner, the Associate Director of the Bureau of Foods and Toxicology and the attorney involved with the Public Board of Inquiry.[31] It is important to realize that this type of revolving-door activity has been going on for decades. The Townsend Letter for Doctors [11/92] reported on a study revealing that 37 of 49 top FDA officials who left the FDA took positions with companies they had regulated. They also reported that over 150 FDA officials owned stock in drug companies they were assigned to manage.

Many organizations and universities receive large sums of money from companies connected to the NutraSweet Association, a group of companies promoting the use of aspartame. In January, 1993, the American Dietetic Association received a $75,000 grant from the NutraSweet Company. The American Dietetic Association has stated that the NutraSweet Company writes their “Facts” sheets.[32] Many other “independent” organizations and researchers receive large sums of money from aspartame manufacturers. The American Diabetes Association has received a large amount of money from the NutraSweet Company, including money to run a cooking school in Chicago (presumably to teach diabetics how to use NutraSweet® in their cooking).

A researcher in New England who has pointed out the dangers of aspartame in the past is now a Monsanto consultant. Another researcher in the Southeastern US had testified about the dangers of aspartame on fetuses. An investigative reporter has discovered that he was told to keep his mouth shut to avoid causing the loss of a large grant from a diet-cola manufacturer in the NutraSweet Association.

What is the FDA doing to protect the consumer from the dangers of aspartame? Less than nothing, as the following examples illustrate. In 1992, the FDA approved aspartame for use in malt beverages, breakfast cereals, and refrigerated puddings and fillings. In 1993 the FDA approved aspartame for use in hard and soft candies, non-alcoholic flavored beverages, tea beverages, fruit juices and concentrates, baked goods and baking mixes, and frostings, and fillings for baked goods.

In 1991, the FDA banned the importation of Stevia, a powdered leaf that has been used for hundreds of years as an alternative sweetener. It is used widely in Japan with no adverse effects. Scientists involved in reviewing Stevia have declared it to be safe for human consumption — something which has been well known for decades in many parts of the world. It is a common belief within the health food market that Stevia was banned to keep the product from taking hold in the US and cutting into sales of aspartame.[33]


Despite corporate-sponsored studies that suggest that aspartame is safe, there are other independent studies and clinical evidence that would suggest otherwise. Given the scientific fabrication and regulatory improprieties that have taken place during aspartame’s approval in the US, the safety of aspartame is in serious doubt. Until such time as pivotal studies can be replicated by independent investigators, we recommend that aspartame be avoided. Aspartame-containing products are now in distribution in over 70 countries worldwide.

References and Footnotes

References 1-13 are listed with Part 1 of this article. Go to Part 1.

14. Internal FDA memorandum.

15. Analysis prepared by Dr. John Olney as a statement before the Aspartame Board of Inquiry of the FDA.

16. Congressional Record SID835: 131; 1 August 1985.

17. After Raymmond 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 Searle company employee had signed in immediately before them. During the interview, Mr. Schroeder retracted his statements about the DKP study. Fortunately, the FDA investigative team had photographic evidence of the large chuncks of DKP that the animals could eat around.

18. National Cancer Institute SEER Program Data. [see also: National Cancer Institute, Cancer Statistics Review 1973-87, Bethesda, NIH Publication No. 89-2789; Black, P. McL, Brain Tumors, New Engl J Med 324: 1471-76, 1991; Eby NL, Grufferman S, Flannelly CM, et al. Increasing incidence of primary brain lymphoma in the US. Cancer 62: 22461-65, 1988; Hochberg FL and Miller DC, Primary central nervous system lymphoma. J Neurosurg 68: 835-53, 1988; Hardwidge C, Diengdoh JV, Husfaud D and Nash JRG, Review: Primary cerebral lympoma—a clinico-pathological study. Clin Neuropath 9: 217-23, 1990].

19. H. J. Roberts, M.D., Aspartame (NutraSweet®) — Is it Safe?, The Charles Press, Philadelphia, 1990.

20. US Senate Committee on Labor and Human Resources, November 3, 1987 regarding “NutraSweet Health and Safety Concerns.” Document #Y4.L11/5:S.HR6.100, pages 360-372.

21. Ralph G. Walton, Robert Hudak and Ruth Green-Waite, Adverse reactions to aspartame: Double-blind challenge in patients from a vulnerable population. Biological Psychiatry 34: 13-17, 1993.

22. Barbara Mullarkey, How Safe Is Your Artificial Sweetner, Informed Consent Magazine, Sept/Oct 1994.

23. US Air Force, Aspartame Alert. Flying Safety 48(5): 20-21, May 1992. Articles sounding warnings about ingesting aspartame while flying have also appeared in the National Business Aircraft Association Digest [1993], Aviation Medical Bulletin [1988], Aviation Consumer [1988], Canadian General Aviation News [1990], Pacific Flyer [1988], General Aviation News [1989], Aviation Safety Digest [1989], and Plane & Pilot [1990]. A paper warning about aspartame was presented at the 57th Annual Meeting of the Aerospace Medical Association [Gaffney, C. “Aspartame in Aviation,” Armed Forces Institute of Pathology, presented April 1986].

24. Reported by the Aspartame Consumer Safety Network, P.O. Box 780634, Dallas, Texas 75378 (phone 214-352-4268).

25. Barbara Alexander Mullarkey, Bittersweet Aspartame: A Diet Delusion NutriVoice, PO Box 946, Oak Park, Illinois 60303 [also available from the Aspartame Consumer Safety Network (800-969-6050)].

26. Camfield PR et al. Aspartame exacerbates EEG spike-wave discharge in children with generalized absence epilepsy: a double-blind controlled study. Neurology 42: 1000-03, 1992.

27. Koehler SM and Glaros A, The effect of aspartame on migraine headache. Headache 28: 10-14, 1988.

28. Van Den Eeden SK et al. Aspartame ingestion and headaches. Neurology 44: 1787-93, 1994.

29. Kulczycki, Aspartame-induced hives. Journal of Allergy & Clinical Immunology 639-40, February 1995.

30. Eric Millstone, Sweet and Sour. The Ecologist 25: March/ April 1994.

31. Mary Nash Stoddard (ed), The Deadly Deception, source-book compiled by the Aspartame Consumer Safety Network, 1995.

32. ADA Courier, 32(1): January 1993.

33. Mark Blumenthal, FDA Rejects AHPA Stevia Petition, Whole Foods, April 1994.

Additional Reading

Roberts HJ, Reactions attributed to aspartame-containing products: 551 cases. Journal of Applied Nutrition 40: 85-94, 1988.

Matalon R et al., Aspartame consumption in normal individuals and carriers for phenylketonuria (PKU). In: Dietary Phenylalanine and Brain Function. Proceedings of the First International Meeting on Dietary Phenylalanine and Brain Function, Washington, DC, May 8-10, 1987. Center for Brain Sciences and Metabolism Charitable Trust, P.O. Box 64, Kendall Square, Cambridge, MA 02142.