The Collison Newsletter July 2007


                            ASPARTAME - SAFE or TOXIC? *  


Aspartame – What is it? 

Aspartame is an artificial, non-carbohydrate sweetener. It is aspartyl-phenylalanine-1-methyl ester, that is, the methyl ester of the dipeptide of the amino acid aspartic acid and the essential amino acid phenylalanine. The chemical formula is C14H18N2O5.


Trade names are NutraSweet, Equal, Canderel and Spoonful.


As a food additive, it is listed as ‘Artificial Sweetener’ and its code number is 951 or E951.




Aspartame was discovered in 1965 by James M.Schlatter, a chemist working for the company G.D. Searle. He synthesized aspartame, and discovered its sweet taste serendipitously when he licked his finger, which had accidentally become contaminated with aspartame.


The U.S. Food and Drug Administration (FDA) did not approve of its use as a food additive (in the USA) for many years, because tests had suggested it may cause cancer in rats and it was possibly linked to brain cancer. In 1981, it was approved by the FDA for use in dry goods, and in 1983 approved for use in carbonated beverages. In 1993, the FDA extended its approval to use in other beverages, baked goods and confections, and finally, in 1996, all restrictions were removed.


In 1985, G.D.Searle was purchased by Monsanto and in this acquisition, Searle’s aspartame business became a separate Monsanto subsidiary, the NutraSweet Company. This company was subsequently sold to J.W.Childs Equity Partners in 2000. The U.S. Patent on aspartame expired in 1992.


Properties and Use


Aspartame is some 180 times sweeter than sugar in typical concentrations, without the high energy value of sugar.


It has a caloric value of 4 kilocalories (kcal) or 17 kilojoules (kj) per gram, but the quantity needed to produce a sweet taste is so small that its caloric contribution is negligible. This makes it a popular sweetener for those trying to avoid calories from sugar. A litre of carbonated soft drink with 12% sugar yields 480 kcal (2040 kj). A recent study from the U.S.A. indicates that up to one third of daily energy intake is obtained from soft drinks!


Like many other peptides, aspartame may hydrolyze (breakdown) into its constituent amino acids under conditions of elevated temperature or high pH. Thus it is undesirable as a baking sweetener and it is prone to degradation when used in products with a high pH, as required for a long shelf-life. Aspartame’s stability under heating can be improved to some extent by encasing it in fats or maltodextrin. The stability of aspartame when dissolved depends markedly on the pH of the solution. At room temperature, it is most stable at pH 4.3, where its shelf-life is some 300 days. At pH 7 (neutral) its half-life is only a few days. This means that every few days, half the aspartame has degraded. Most soft drinks have a pH of between 3 and 5, where aspartame is reasonably stable.




After ingestion, aspartame breaks down into several residual chemicals, including aspartic acid, phenylalanine and methanol. Further breakdown products include formaldehyde and formic acid.


The naturally occurring essential amino acid phenylalanine is a health hazard to those born with phenylketonuria, a rare inherited disease that prevents phenylalanine from being properly metabolised.


The Aspartame Controversy. How safe is it?


Aspartame has been the subject of a vigorous public controversy regarding its safety.


It took the FDA many years to clear aspartame for use as a food additive. Initial restricted approval was given in 1981, but it was not until 1996 that all restrictions were lifted. This strongly suggests that there had to have been very real grounds for the long delay in final unrestricted approval, and one has to wonder what ‘behind the scenes’ lobbying went on to achieve this.


In 1994, more than a year before all restrictions were lifted, FDA Epidemiology Branch Chief, Thomas Wilcox, reported that aspartame complaints represented 75 percent of all reports of adverse reactions to substances in the food supply from 1981 to 1994.


Concerns about aspartame are generally focused on symptoms and health conditions that were allegedly caused by the sweetener. A total of 92 different symptoms and health conditions were reported by physicians and consumers. It should be noted that physician-reported or self-reported health effects are not necessarily a basis for drawing scientific conclusions, however ‘where there is smoke, there is often fire’.


Independent of these reported case histories, questions have been raised about brain tumours, brain lesions, lymphoma and genotoxic effects.


Sources for reported symptoms and health conditions that have raised the above questions include:

  • reports and analysis of case histories published in scientific journals and given at medical conferences
  • symptoms reported to FDA and governmental agencies
  • symptoms reported to non-governmental organizations, researchers and physicians
  • reports of symptoms and health conditions in the media
  • self-reported cases on the internet.

The debate over the possible adverse health effects of aspartame is ongoing. It is true that some human and animal studies have found adverse effects and some have found no adverse effects.


Questions have been raised about the results of the research and also the design of the research. To give but one example: in human research, the aspartame was usually provided in slow-dissolving capsules. But the biochemical changes from ingesting aspartame in slow-dissolving capsules are many times smaller than those from ingesting aspartame dissolved in liquids such as carbonated beverages.


There have been more that 600 studies on aspartame and thousands of studies on aspartame breakdown products and metabolites.


Special focus in these studies has been made on four chemical components of aspartame:

  • Methanol and Formaldehyde.

Aspartame metabolism releases methanol, which is then rapidly broken down to formaldehyde and formic acid. Methanol, also known as wood alcohol, is a deadly poison. Methanol causes some 'skid row' alcoholics to end up blind or dead.

The absorption of methanol into the body is sped up condsiderably when free methanol is ingested. Free methanol is created from aspartame when it is heated to above 86oF or 30oC. This would occur when aspartame-containing products are improperly stored or when they are heated.

How is it that the FDA would approve, in 1993, aspartame as an ingredient in mumerous food items that would always be heated to above 86oF or 30oC, and in 1996 remove all restrictions allowing aspartame to be used in everything including all heated and baked goods?

The toxic effects of formaldehyde and formic acid have been addressed in my newsletter 'Formaldehyde', May 2007.

  • Phenylalanine.

This is unsafe for those born with phenylketonuria. About 50% of aspartame (by weight) is broken down into phenylalanine.

  • Aspartic Acid.

Some 40% of aspartame (by weight) is broken down into aspartic acid. This acid is in a class of chemicals known as excitatory amino acids, which also includes glutamate, found in monosodium glutamate (MSG). At high levels, excitatory amino acids can be toxic and might be considered excitotoxins.

  • Aspartylphenylalanine diketopiperazine.

This type of diketopiperazine (DKP) is created in products as aspartame breaks down over time. For example, 6 months after aspartame was put in carbonated beverages, 25% of aspartame had been converted to DKP. Concern has been raised that this form of DKP would undergo a nitrosation process in the stomach, producing a type of chemical that could cause brain tumours.


For a more detailed discussion of these 4 chemical components of aspartame, a suggested web reference is

Is Aspartame Safe? 

The end result is that the recognized medical and food safety bodies claim aspartame to be safe for human consumption.


Until a link between an ingredient, such as a food additive, and a symptom(s) is made, and people so informed, the possibility that the food additive is responsible for symptoms is not considered or even looked for.


It is more than likely that most victims, that is, those suffering health complaints and symptoms, do not have a clue that aspartame may be the cause of their many problems. After all, the trusting and gullible public, the consumer, accepts that, if a substance is added to a food or beverage, and available on the open market, then it must be safe.


I have already mentioned the high percentage of reactions to aspartame that were reported to the FDA. The FDA admits that fewer than 1% of those who have a problem with something they consume ever report it to the FDA!


Adverse Effects and Aspartame


What, then,  are the adverse effects that have been reported (both by physicians and by consumers)?


In  February 1994, the U.S. Department of Health and Human Services released the  list of adverse reactions reported to the FDA. As already indicated, aspartame accounted for more than 75% of all the adverse reactions reported to the FDA’s Adverse Reaction Monitoring System.


A selection of adverse reactions, as reported to the FDA linked to the ingestion of aspartame, includes the following. (These have been extracted from web references such as and

Adverse effects from short-term and/or long-term use:

·        seizures and convulsions

·        dizziness

·        tremors

·        migraines and sever headaches

·        memory loss

·        slurring of speech

·        confusion

·        numbness or tingling of extremities

·        chronic fatigue

·        depression

·        insomnia

·        irritability

·        panic attacks

·        marked personality changes

·        phobias

·        rapid heart beat, tachycardia (palpitations)

·        asthma

·        chest pains

·        hypertension (high blood pressure)

·        nausea or vomiting

·        diarrhoea

·        abdominal pain

·        pain on swallowing

·        itching and rashes

·        hives/urticaria

·        other allergic reactions

·        blood sugar control problems (eg hypoglycaemia or hyperglycaemia)

·        menstrual cramps and other menstrual problems or changes

·        impotency and sexual problems

·        food cravings

·        weight gain

·        hair loss/baldness or thinning of hair

·        burning urination and other urination problems

·        excessive thirst or excessive hunger

·        bloating, edema (fluid retention)

·        infection susceptibility

·        joint pain and arthritis

·        death

·        anxiety reactions

·        chronic cough

·        fatigue

·        brain ‘fog’

·        vision loss


It is also believed that aspartame mimics the following diseases, or worsens the symptoms of the following diseases

·        fibromyalgia

·        arthritis

·        multiple sclerosis (MS)

·        Parkinson’s disease

·        systemic lupus erythematosus (SLE)

·        multiple chemical sensitivity (MCS)

·        diabetes and diabetic complications

·        epilepsy

·        Alzheimer’s disease

·        birth defects

·        chronic fatigue syndrome (CFS)

·        lymphoma

·        Lyme disease

·        attention deficit disorder (ADD and ADHD)

·        panic disorder

·        depression and other psychological disorders.


‘The Chemical Maze’, 2nd edition (guide to food additives), by Bill Statham, lists the following under ‘Potential Health Effects’ for Aspartame, 951,E951: “Cancer; asthma; MS-like symptoms; headache; hyperactivity; fatigue; anxiety; dizziness; migraine; memory loss; depression; insomnia; irritability; impotence; epilepsy; blindness; diabetes; neuralgia; seizures; plus at least 80 others”.   


In my experience, three particular symptoms are especially common, namely headache/ migraine, diarrhoea and anxiety. It is routine in my history taking to enquire about diet drinks and/or intake of artificial sweeteners.


If a symptom is suspected to be linked to aspartame ingestion, then a specific exclusion diet is indicated, that is, eat or drink nothing containing aspartame. It should be noted that it may take up to two months before a significant improvement or resolution of the symptoms occurs.




If you are a user of any products with aspartame, and you have physical (especially headaches/migraine, diarrhoea, anxiety), visual, other mental problems, or any of the listed symptoms when no cause for them can be identified, take the 60-day no aspartame test. If, after two months with no aspartame, your symptoms are either gone, or much less severe … you have the diagnosis.


It is obvious, from the above, that everyone should avoid aspartame ingestion in any form, especially diet carbonated soft drinks.

 Aspartame is a poison. 


** Copyright 2007: The Huntly Centre.


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