The Truth About Aspartame Toxicity & Nancy Markle
Aspartame (NutraSweet) Toxicity Information Center
A "World Environmental Conference" email has been working its way around the
Internet. The World Environmental Conference did occur with an EPA
representative speaking and the discussion turning to aspartame toxicity.
However, the summary was not written by Nancy Markle. Because there are
a few scientific inaccuracies in the email, Monsanto/NutraSweet may attempt
to create the image that aspartame poisoning is a hoax and that the email is
a hoax. As independent researchers know, this is definately not the case.
A short summary of the aspartame toxicity issue will be presented below.
Please see the case histories, scientific FAQs, and other important details
Aspartame / NutraSweet Toxicity Information Center web page for more details.
In addition, please see the
Healthier Sweetener Resource Center web page for details on finding healthier
sweeteners for the general population, dieters, and diabetics, so as to avoid
switching from one toxic sweetener to another.
Aspartame is a dipeptide, but breaks down into the following chemicals:
methanol (wood alchol) -- whether aspartame is heated or not, aspartic
acid, phenylalanine, aspartylphenylalanine diketopiperazine (DKP),
beta-aspartame, and a few odds and ends.
The methanol is absorbed and converted to formaldehyde in the body.
Formaldehyde is known to cause damage to the immune system, nervous
system, and irreversible genetic damage at very low-level, long-term
exposure. The most recent evidence (this year) indicates that the
formaldehyde from aspartame ingestion accumulates in the body as
"These are indeed extremely high levels for adducts of
formaldehyde, a substance responsible for chronic deleterious
effects that has also been considered carcinogenic.
A few comments from independent research scientists regarding this
and other recent aspartame research:
"It is concluded that aspartame consumption may constitute a
hazard because of its contribution to the formation of
[Life Sci. (scientific journal), Vol. 63, No. 5, pp. 337+, 1998]
"It was a very interesting paper, that demonstrates that
formaldehyde formation from aspartame ingestion is very
common and does indeed accumulate within the cell,
reacting with cellular proteins (mostly enzymes) and
DNA (both mitochondrial and nuclear). The fact that it
accumulates with each dose, indicates grave consequences
among those who consume diet drinks and foodstuffs on a
The independent scientists and physicians who claim that aspartame
causes toxicity, base their claims on three areas:
Russell Blaylock, MD [Neurosurgeon & Neuroscientist]
"...following aspartame ingestion, methanol or formaldehyde
is distributed all over the place. Even more striking is
the fact that formaldehyde accumulates. That's scary."
- Significant toxicity of aspartame metabolites (e.g., formaldehyde)
seen in numerous scientific studies.
- Nearly 100% of the independent research has found problems with
aspartame. This includes animal studies and controlled human studies
(as well as double-blind studies).
- An enormous number of people have reported serious toxicity reactions
from extended use of aspartame including seizures, vision loss,
neuropathy symptoms, loss of blood sugar control, nausea, memory loss,
depression, and other signs of gradual damage to the body's
neurological and immunological systems.
More details on a. - c. follows:
- Toxic metabolites. Aspartame breaks down into methanol (wood
alcohol) -- whether it is heated or not, free-form aspartic acid,
aspartylphenylalanine diketopiperazine (DKP), phenylalanine,
beta-aspartame, and a few other chemicals. The methanol, free-form
aspartic acid and DKP appear to represent the most significant hazards:
- Methanol -- is absorbed and converted to formaldehyde. Formaldehyde
has been shown to cause gradual damage to the immune system, nervous
system, and irreversible genetic damage. The manufacturer,
played a number of games to convince scientists that the
methanol-->formaldehyde was not a problem. Addressing a few:
- "Methanol is found in alcoholic beverages and fruits at 10 times
higher levels than in aspartame"
A. Both alcoholic beverages and fruits have been shown to
contain protective factors which prevent methanol conversion
to formaldehyde and subsequent toxicity.
- "Methanol levels are too low to cause toxicity"
A. They are only too low to cause immediate death. They are
within the range necessary to cause chronic, low-level
poisoning. The same can be said of the formaldehyde.
- "Methanol levels do not rise after aspartame ingestion."
A. The aspartame manufacturers funded 13 years of studies
where a 1960's methanol testing procedure was used. The
method used was incapable of registering any increase
from normal aspartame ingestion. A properly-conducted test
in the mid-1980's showed a significant increase from the
equivalent of one can of soda in a 30 kg child.
4) "The body contains methanol and formaldehyde already"
A. Metabolism does create an extremely low level of methanol
and formaldehyde in the body. However, these levels are
very tightly controlled. Even as little as 0.75 mg of
formaldehyde exposure in children (daily for several months)
has been shown to cause chronic toxicity.
5) "Formaldehyde is found in some foods"
A. Formaldehyde is extremely toxic once it makes it into the
bloodstream and the rest of the body. The digestive system
can break down formaldehyde before it reaches the
bloodstream. With aspartame, however, it is absorbed as
methanol and breaks down into formaldehyde after it is
already in the bloodstream. (Actualy, methanol is break down
into formic acid in other areas such as the eye, for
6) "People ingesting aspartame do not have increases in formic acid
A. Formaldehyde breaks down into formic acid (aka formate) in
the body. However, it appears that with aspartame, the
formaldehyde accumulates in the body as "adducts." Even if
it didn't though, having excess levels of formaldehyde
passing through the body is a significant toxicity hazard.
The manufacturers used urine formic acid measurements. It
has recently been shown that such measurements are not
reliable for low-level, chronic formaldehyde poisoning. The
technique they used for plasma formic acid measurements was
flawed and has been called "notoriously inaccurate" by one
formic acid researcher.
- Aspartic acid.
It is well-known that excitotoxic amino acids such as aspartic acid
can be used in conjunction with formaldehyde to increase pain and
adverse effects on the nervous system. The aspartic acid is in
"free-form" (unbound to protein), so unike food, it is absorbed
suddently, bypassing the normal absorption and metabolism process.
Combining this with formaldehyde from aspartame is bound to
increase the gradual damage.
- Aspartylphenylalanine diketopiperazine (DKP)
The DKP is suspected to be converted in the gut into a potential
brain tumor agent. One of the most reknowned neuroscientists in
the world called this an "enormously complex subject" so this piece
won't go into too many details.
There were two pre-approval studies which showed (upon
*independent* review) to cause dose-related brain tumors in the
test animals. DKP appears to be able to cause mutations (although
I think the formaldehyde could be a candidate as well). A recent
review of the epidemiological data shows a rise in certain types of
brain tumors (the same in the animals) in the most susceptible
population group within several years after aspartame came on the
- "A recent study (Gurney) did not show a rise in brain tumors"
A. That study looked at children. Children would be
considered to be the least likely population group to
experience the aspartame-caused brain tumor. The study
by Olney focused on the middle aged and older population
- "Brain tumors rates have been increasing since before aspartame
A. A brain tumor in adults can take many years or decades to
become large and easily detectable. Aspartame couldn't
have been the original cause of these brain tumors because
it wasn't on the market long enough. However, it is known
that certain less deadly brain tumors can transform into
more deadly and larger forms in a shorter period of time.
If aspartame was a brain tumor agent, that is what we
would see first. Olney showed that in the most susceptible
population group, there has been an enormous increase in
these deadly types of brain tumors since within a few years
after aspartame appeared on the market. Of course, there
has been a corresponding decrease in the less deadly
types of brain tumors during that time. That is why the
*overall* brain tumor rate looks somewhat stable. So,
whenever some government official talks about *overall* brain
tumor rates, they clearly didn't read the Olney study.
- "Ishii study in Japan showed that aspartame didn't cause brain
A. The study was conducted by a close business partner of the
manufacturer. At the time, this company who was leading the
International Technical Glutamate Committee and sponsoring
research with aspartame hidden in the beverages given to the
control group during double-blind MSG "research." There is
a long history of what I think is clearly scientific fraud
on the part of this group who sponsored the research. Still,
even if the study is accepted, there are two pre-approval
studies with opposite results.
- "The animals were given high doses of aspartame"
A. The metabolites of aspartame are anywhere from 5 to 60 times
more toxic in humans than in rodents (dependent upon the
metabolite). So high doses are required to simulate human
- Independent studies find problems
Please see: Survey of the Scientific Literature by Researcher
The reason the manufacturers studies never find problems (at least
never report them in the abstract) is that they play games (not unlike
the tobacco industry). For example, nearly 100% of the subjects in
their aspartame and seizure studies were on anti-seizure medication.
Another study found that aspartame caused more problems than placebo,
so they split up the reactions into enough tiny categories so they
could claim in the abstract that there was no significant difference
within the categories (e.g., 1 reaction to aspartame in a tiny
category is not a significant difference (statistically) than 0
reactions to placebo in that category). (Note: this severely
flawed study is often passed around on the Net. It is:
"Safety of Long-Term Large Doses of Aspartame," Archives of
Internal Medicine, Volume 149, page 2318-2324)
Number of and types toxicity reactions.
Please see the following for an analysis:
Reported Aspartame Reactions
and the following page for samples of cases:
Samples of Reported Toxicity Reactions