United States Food & Drug Administration
US Food and Drug Administration Statement on European Aspartame Study
CFSAN/Office of Food Additive Safety
April 20, 2007
The FDA has completed its review concerning the long-term carcinogenicity study of aspartame, conducted by the European Ramazzini Foundation (ERF), located in Bologna, Italy. FDA reviewed the study data made available to them by ERF and finds that it does not support ERF's conclusion that aspartame is a carcinogen. Additionally, these data do not provide evidence to alter FDA's conclusion that the use of aspartame is safe.
Aspartame was first approved in the United States in 1981 and is one of the most widely used artificial sweeteners. When metabolised by the body, aspartame is broken down into two common amino acids, aspartic acid and phenylalanine, and a third substance, methanol. These three substances are available in similar or greater amounts from eating common foods.
Considering results from the large number of studies on aspartame's safety, including five previously conducted negative chronic carcinogenicity studies, a recently reported large epidemiology study with negative associations between the use of aspartame and the occurrence of tumors, and negative findings from a series of three transgenic mouse assays, FDA finds no reason to alter its previous conclusion that aspartame is safe as a general purpose sweetener in food.
To read the full statement, click here.
Response to "Nancy Markle" Allegations
I have been requested by the FDA Center for Drug Evaluation and Research to respond to your request for an evaluation of the article written by Nancy Markle received via an e-mail message on the alleged toxicities of the artificial sweetener, aspartame.
My name is David Hattan and I am currently Acting Director of the Division of
Health Effects Evaluation in the United States Food & Drug Administration
(USFDA) Center for Food Safety and Applied Nutrition. I have worked on questions
relating to the safety of aspartame repeatedly since 1978 and am familiar with
the safety studies that have been conducted to support the safety of this food
additive. There were well over 100 separate toxicological and clinical studies
conducted to establish the safety of aspartame before it was approved for
regulatory acceptance. Since its approval in 1981 by the USFDA, there have been
many additional studies performed to follow up on some of the more creditable
reports of aspartame- mediated adverse effects. Below I have tried to succinctly
respond to certain of the allegations of toxicity proposed by Nancy Markle.
First, reports of the ingestion of aspartame in patients who later have
suffered multiple sclerosis or systemic lupus is obviously not scientifically
sustainable evidence that aspartame is responsible for the occurrence of either
disease. Both of these disorders are subject to spontaneous remissions and
exacerbations so it is entirely possible that when patients stopped using
aspartame they might have also coincidentally have had remission of their
symptoms. There is no credible evidence that I am aware of that suggests that
aspartame elicits multiple sclerosis or systemic lupus.
Second, the claim that aspartame ingestion results in the production of
methanol, formaldehyde and formate: These claims are factual. In the
gastrointestinal tract aspartame is hydrolyzed to one of its component
materials, methanol, as well as the two amino acids, phenylalanine and aspartic
acid. This methanol is taken up by the cells of the body and metabolized first
to formaldehyde and then to formate. The key information that is missing in the
description by Ms. Markle is that the levels of ingestion are very modest. In
fact, there are other foodstuffs that we ingest that supply as much and
sometimes even more methanol; e.g., citrus fruits and juices, and tomatoes or
tomato juice. There are even higher quantities of methanol ingested when ethanol
is consumed. Thus, in the final analysis this methanol is the same as from other
sources and in the quantities consumed from aspartame, it is readily and
naturally metabolized via the one-carbon biochemical cycle to entirely innocuous
and natural body components.
Third, the claim that the two amino acids, phenylalanine and aspartic acid
have neurotoxic effects. This is true in certain individuals and in high enough
doses. The only subpopulation of individuals potentially susceptible to adverse
effects from phenylalanine is homozygous phenylketonurics and in this case, food
itself with much higher levels of phenylalanine from the protein in the diets
contributes much higher toxicity for these unfortunate individuals. For those
individual phenylketonurics that want to carefully control their intake levels
of phenylalanine, they can do that by simply taking into consideration the
amount of phenylalanine supplied by the aspartame product or, even more likely,
simply refraining from use of these products. The USFDA requires that the
aspartame product be labeled specially for phenylketonurics patients so that
they will be aware of its presence in these products. As for the other amino
acid in aspartame, the levels of aspartic acid ingested with aspartame use are
many fold less than those levels responsible for causing adverse effects on the
brain of animals and/or man. In fact, it is not clear that the experimentally
derived data from animals is relevant to man. In any case, the levels of
aspartic acid intake from aspartame are many fold below those needed to mediate
Fourth, there have been numerous animal and human studies done to evaluate
the possibility that aspartame causes seizures or enhances the susceptibility to
seizures. In clinical studies done in adults and children with pre-existing
seizures, there was no evidence of contributing to the frequency of occurrence
or severity of seizures in seizure-prone individuals. There were additional
studies done on seizure-prone experimental animal models to assess the possible
influence of aspartame on their seizuring activity. Again, the result was the
same and no influence was demonstrated on the frequency or severity of seizures.
Fifth, aspartame was comprehensively evaluated for its potential to mediate
reproductive effects and birth defects. In all cases of animal testing, there
was no evidence of aspartame-mediated effects on the experimental animals at
doses many times higher than those to which the human population is exposed.
Sixth, more recent allegations about aspartame mediating an increase in the
incidence of brain tumors in the human population has been thoroughly refuted by
both government and academic scientists.
The internet provides a convenient means of communicating information of all
kinds in a potentially widespread manner. Unfortunately, the recipient of that
information has no way of assessing the strength and reality of that
information. There are a number of internet web sites that regularly distribute
information adverse reactions supposedly mediated by aspartame that is based on
anecdotal reports that cannot be confirmed. The legitimate attempts that have
been made to confirm and replicate these allegations of adverse reactions from
aspartame ingestion have not been successful and the USFDA continues to consider
this to a be among the most thoroughly tested of food additives and that this
information continues to confirm the safety of aspartame.
David G. Hattan, Ph.D.
Acting Director, Division of Health Effects Evaluation
13 January 1999
Click here to see what the US Food & Drug Administration thought in 1986.