Rat Study Links Aspartame to Cancer
Lymphoma, Leukemia in Rats Fed Sweetener; Industry Group Says Aspartame Is Safe
WebMD News Archive
July 28, 2005 -- A study of rats links low doses of aspartame -- the
sweetener in NutraSweet, Equal, and thousands of consumer products -- to
leukemia and lymphoma.
But food industry officials point out that many other studies have found no
link between aspartame and cancer.
The rats in the study were fed various doses of aspartame throughout their
lives. In female but not male rats, lymphoma and leukemia were significantly
associated with daily aspartame doses as low as 20 milligrams (mg) per kilogram
(kg) of body weight. And there was a trend toward these cancers at doses as low
as 4 mg/kg of body weight.
To reach a dose of 20 mg/kg, a 140-pound woman would need to drink three
cans of diet soda a day. A 180-pound man would need to drink four cans of diet
soda a day.
And diet soda isn't the only source of aspartame. The sweetener is in
thousands of products, ranging from yogurt to over-the-counter medicines.
The average person consumes about 2 or 3 mg/kg aspartame each day. However,
that figure goes way up for children and young women.
The study comes from an independent research team led by Morando Soffritti,
MD, scientific director of the European Ramazzini Foundation of Oncology and
Environmental Sciences in Bologna, Italy.
"What I am recommending is for healthy children and women -- if they do
not have diabetes -- to avoid consumer use of aspartame," Soffritti tells
WebMD. "We cannot continue to use aspartame in 6,000 types of products,
soft drinks, yogurt, and whatever."
Consumer Group Reacts
A consumer watchdog group, the Center for Science in the Public Interest,
has called for FDA action. At a minimum, the FDA should start its own studies
and warn consumers of the potential danger, says CSPI Executive Director
Michael F. Jacobson, PhD.
"The U.S. government really should analyze this study very carefully. If
it is accepted as top quality, it could lead to a ban on aspartame,"
Jacobson tells WebMD. "I think a lot of companies are going to see the
writing on the wall from this study and switch to newer artificial sweeteners.
Meanwhile, I think consumers should switch to Splenda, the sweetener known as
But Jacobson urges consumers not to panic.
"The risk to an individual is quite small," he says. "So people
shouldn't fear that if they have one diet soda a day they are going to develop
cancer. And I must say, the one qualm I have about the study is they found an
increased risk of cancer at such a low level of exposure. If aspartame were
that potent a carcinogen, I wonder if we wouldn't be seeing a real epidemic of
Soffritti has presented his findings to the European Food Safety Authority.
In its 2002 review of aspartame safety, the EFSA found no cause for alarm. It
promises that the new data will get a "high priority" evaluation.