Possible Side Effects of NutraSweet

There is a seemingly endless list of side effects from aspartame ingestion. Since it was discovered, scientist have found adverse effects through experimentation including brain tumors, headaches, vision loss, and many other neurological problems. They have also reached conclusions about the causes of these adverse affects. In 1994, a report was released that listed 92 symptoms associated with aspartame ingestion and said that aspartame accounted for 75 percent of all adverse reactions reported to the Adverse Reaction Monitoring System.

Some of the 92 long-term and immediate adverse effects of aspartame ingestion are:

In addition, aspartame can mimic symptoms or worsen the following diseases:

  • Fibromyalgia
  • Arthritis
  • Multiple Sclerosis (MS)
  • Parkinson's Disease
  • Lupus
  • Multiple Chemical Sensitivities (MCS)
  • Diabetes and Diabetic Complications
  • Epilepsy
  • Alzheimer's Disease
  • Birth Defects
  • Chronic Fatigue Syndrome
  • Lymphoma
  • Lyme Disease
  • Attention Deficit Disorder (ADD)
  • Panic Disorder
  • Depression and other Psychological Disorders

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So what causes these problems? Scientist believe that when aspartame is ingested it breaks down into 3 potentially harmful products:

  1. Phenylalanine
  2. Aspartic Acid
  3. Methanol
There is also concern over aspartame forming diketopiperazine in liquids when stored for a long time.


Phenylalanine is normally found in the brain but excessive levels of it can be dangerous. This is the problem that people with phenylketonuria have; they are unable to metabolize phenylalanine and as a result dangerously high levels of it can build up in their brain. Excessive amounts of phenylalanine in the brain can lead to schizophrenia and depression. Too much phenylalanine in the brain also increases a person's chances of having a seizure. All of these problems caused by phenylalanine have also been associated with aspartame ingestion. Studies have shown that the amount of phenylalanine in the blood increases in people who use aspartame regularly. This increase in the amount of phenylalanine in the body leads to an increase in the amount of phenylalanine in the brain. As with many of the amino acids that we eat, phenylalanine enters the brain on transport molecules; phenylalanine shares its transport molecule with two other amino acids. Normally, when people eat food, they ingest many amino acids that then have to compete for space on the shared transport molecules thus limiting the amount of each amino acid that can enter the brain. With aspartame, however, phenylalanine is the only amino acid for that particular transport molecule that is ingested so, as a result, there is less competition and more phenylalanine enters the brain. This increase in phenylalanine in the brain explains some of the side effects that result from aspartame ingestion.

Aspartic Acid

When broken down, aspartame is 40 percent aspartic acid and this means that ingesting aspartame increases the amount of aspartic acid in the body. Like the glutamic acid found in monosodium glutamate, or MSG, aspartic acid is an excitatory amino acid that can have many adverse effects. Aspartic acid, also referred to as aspartate, can act as an excitotoxin in the human body. Normally, aspartate acts as a neurotransmitter in the brain. However, as with other excitotoxins, the presence of too much aspartate in the brain can cause the killing of certain brain cells by over-stimulating them. This slow damaging of neurons can lead to Parkinson's disease and memory loss as well as many other neurological problems. These are some of the long-term side effects that have been associated with aspartame ingestion. Because of its composition, aspartame acts very similar to MSG, a chemical which is generally known to have adverse effects. However, MSG use has been reduced whereas aspartame is being consumed in large amounts daily.


Methanol is ten percent of what is released from aspartame when it is broken down by the digestive system. Methanol is released by aspartame when the methyl group (CH3) of aspartame comes in contact with the enzyme chymotrypsin in the small intestine. Inside the body, methanol breaks into formic acid and formaldehyde. Both of these products are toxic and symptoms of poisoning include headaches and nausea. Methanol poisoning can also result in retinal damage leading to vision problems including blurring and blindness. In addition, formaldehyde is both a neurotoxin and a carcinogen. These severe effects of methanol poisoning were seen in a study of the effects of aspartame on humans. Methanol is also released from aspartame when it is heated above 86 oF. This could happen when storing foods or drinks in hot places or by cooking with aspartame. Some people have attributed the Desert Storm Syndrome, which has symptoms similar to those of formaldehyde poisoning, to the large consumption of methanol from aspartame-containing drinks that had been heated to over 86 oF in the desert sun. The ingestion of free methanol that has already been released from overheated aspartame greatly increases the body's absorption of methanol. Methanol takes a long time to be excreted from the body and as a result, ingesting large amounts can cause methanol to build up in the body. This is similar to a drugs with a long half-life. The recommended limit of consumption for methanol is 7.8 milligrams per day but a twelve ounce can of a diet cola with aspartame contains about 20 milligrams of methanol. Even though it is likely that not all of this 20 milligrams is released from the aspartame and absorbed by the body, consuming a lot of aspartame daily will cause the amount of methanol in the body to slowly build up. It should be noted that people ingest methanol from other sources such as fruit juices and alcoholic beverages. In these cases, however, the ingestion of methanol is accompanied by the ingestion of ethanol which counteracts the effects of methanol. In aspartame, there is only methanol present and no ethanol to counteract the methanol. This addition of methanol from aspartame into the body results in many of the side effects associated with aspartame ingestion.


The breaking down of aspartame into its components is not the only way that the artificial sweetener creates chemicals which have an adverse effect on humans. It is known that if a liquid containing aspartame is stored for a long time, diketopiperazine is formed in the liquid. Scientist have concluded that diketopiperazine causes brain tumors. According to Dr. John W. Olney, once digested, diketopiperazine produces a compound that is similar to a carcinogenic chemical called N-nitrosourea. Studies using rats that were conducted by NutraSweet have shown that aspartame causes brain tumors. One of these studies showed 12 out of 320 rats getting brain tumors, and this is even with NutraSweet falsifying the results. The production of diketopiperazine by aspartame explains how aspartame causes brain tumors.

If there are all of these side effects and aspartame is bad, why is it sold and why was it it approved? Find out.

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