ENN: Carrageenan food additive concerns
Carrageenan may cause stomach lesions, cancer
As Taken From the OEM Listserv - 10/18/01
Containers of pudding, ice cream, yogurt, or cottage cheese may
include the ingredient carrageenan, a thickener derived from red
seaweed. For decades, it has been presumed to be safe to eat, but new
research from a medical doctor on the faculty of the University of
Iowa shows that presumption may be wrong.
Carrageenan is a water-soluble polymer, also known as a gum, that is
used as a fat substitute in processed meats and can be found in
condensed milk and some soy milk products.
"Evidence from animal models has demonstrated that degraded
carrageenan causes ulcerations and malignancies in the
gastrointestinal tract," said Joanne Tobacman, M.D., University of
Iowa assistant professor of clinical internal medicine.
After conducting epidemiologic and laboratory research on carrageenan,
Dr. Tobacman published an extensive review of 45 investigations on
harmful gastrointestinal effects of carrageenan in animal experiments.
The article was published in the October issue of Environmental Health
Perspectives, the journal of the National Institute for Environmental
Findings over the years in Europe and the United States suggest that
assumptions about the safety of carrageenan need to be reconsidered
and that carrageenan may need to be better regulated by the Food and
Drug Administration (FDA), said Dr. Tobacman. "There seems to be
enough evidence associating carrageenan with significant
gastrointestinal lesions, including malignancies, to avoid ingesting
it," she said.
"I think the first consideration is to inform people about the risks
that have been associated with carrageenan," she added. "There was
evidence back in the 1970s that carrageenan has harmful effects, and I
think we've waited too long to act on that information."
In 1972 the FDA determined there was sufficient evidence from animal
experiments to propose limiting the type of carrageenan that could be
used in food products. "Many authoritative sources thought that the
proposal actually became a regulation. However, it didn't," Tobacman
In 1982, the International Agency for Research on Cancer found enough
evidence in animal models linking degraded carrageenan with
gastrointestinal cancers to state that it posed a carcinogenic risk to
humans. Other research groups also have listed it as a known
carcinogen based on animal studies.
Degraded carrageenan has a molecular weight of 30,000 or lower,
whereas undegraded carrageenan has a molecular weight of 100,000 or
higher. There is evidence that degraded carrageenan causes intestinal
ulcerations and cancers.
In addition, Tobacman explained, undegraded carrageenan, which has the
higher molecular weight and is thought not to be absorbed in the
intestine, may also be associated with the promotion of malignancy and
inflammation in the gastrointestinal tract.
Tobacman said other gums with similar thickening properties can be
used instead of carrageenan. These gums include locust bean, guar, and
[Please visit the original website to view the whole article. - Mod.]
Copyright 2001, Environmental News Network All Rights Reserved
Wednesday, October 17, 2001 By Environmental News Network
Environmental Health Perspectives Volume 109, Number 10, October 2001
Review of Harmful Gastrointestinal Effects of Carrageenan in Animal
Joanne K. Tobacman
College of Medicine, University of Iowa, Iowa City, Iowa, USA
In this article I review the association between exposure to
carrageenan and the occurrence of colonic ulcerations and
gastrointestinal neoplasms in animal models. Although the
International Agency for Research on Cancer in 1982 identified
sufficient evidence for the carcinogenicity of degraded carrageenan in
animals to regard it as posing a carcinogenic risk to humans,
carrageenan is still used widely as a thickener, stabilizer, and
texturizer in a variety of processed foods prevalent in the Western
diet. I reviewed experimental data pertaining to carrageenan's effects
with particular attention to the occurrence of ulcerations and
neoplasms in association with exposure to carrageenan. In addition, I
reviewed from established sources mechanisms for production of
degraded carrageenan from undegraded or native carrageenan and data
with regard to carrageenan intake. Review of these data demonstrated
that exposure to undegraded as well as to degraded carrageenan was
associated with the occurrence of intestinal ulcerations and
neoplasms. This association may be attributed to contamination of
undegraded carrageenan by components of low molecular weight,
spontaneous metabolism of undegraded carrageenan by acid hydrolysis
under conditions of normal digestion, or the interactions with
intestinal bacteria. Although in 1972, the U.S. Food and Drug
Administration considered restricting dietary carrageenan to an
average molecular weight > 100,000, this resolution did not prevail,
and no subsequent regulation has restricted use. Because of the
acknowledged carcinogenic properties of degraded carrageenan in animal
models and the cancer-promoting effects of undegraded carrageenan in
experimental models, the widespread use of carrageenan in the Western
diet should be reconsidered.
Key words: carcinogenesis, carrageenan, carrageenase, diet,
furcelleran (furcellaran), hydrolysis, inflammatory bowel disease,
nutrition, poligeenan, promoter, sulfated polysaccharide.
Environ Health Perspect 109:983-994 (2001).
Gary N. Greenberg, MD MPH Sysop / Moderator Occ-Env-Med-L MailList
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