Last year the FDA rejected a 2008 citizen petition, which presented scientific studies linking carrageenan to gastrointestinal inflammation and disease, including cancer. The petition was filed by Dr. Joanne Tobacman, a physician-researcher at the University of Illinois -- Chicago College of Medicine, who has been studying food-grade carrageenan for more than a decade.
"The FDA's justification for denial was based on a sloppy and incomplete evaluation of available published research, and it was riddled with overt bias which appears to protect an industry's profits at the expense of public health," says Charlotte Vallaeys, Director of Farm and Food Policy at Cornucopia, a Wisconsin-based non-profit food policy research group. "We have asked them to reevaluate."
Scientists have raised concern about its safety for decades, based on research linking food-grade carrageenan in the diet of laboratory animals to gastrointestinal disease, including colon tumors.
"Carrageenan has a unique chemical structure, and research has shown that this chemical structure may trigger an innate immune response in the body," says Dr. Pradeep Dudeja, Professor of Physiology in Medicine at the University of Illinois -- Chicago, who has co-authored nine studies on carrageenan.
"The immune response leads to inflammation, which is a serious public health concern since chronic, low-grade inflammation is a well-known precursor to more serious diseases, including diabetes and cancer," he adds.
More than a dozen animal studies, conducted since the late 1960s, have raised concern about carrageenan's safety, but the FDA failed to consider the vast majority of these studies in its analysis. The FDA also asserted that these studies have been "disputed," a claim based on a paper by Duika Burges Watson, a geography professor from Durham University in the UK who appears to have no medical or scientific degree or background.
"It is unclear why the FDA would place higher value on the opinion of a social scientist from the UK than on the medical studies funded by the National Institutes of Health," observes Vallaeys.
"It is disappointing that the FDA continues to permit carrageenan to be used as a food additive despite clear evidence that it causes inflammation," says Dr. Tobacman.
Medical specialists in the US are taking these concerns seriously. Dr. Stephen Hanauer, MD, Chief of Gastroenterology, Hepatology and Nutrition at the University of Chicago School of Medicine, states: "The rising incidence and prevalence of ulcerative colitis across the globe is correlated with the increased consumption of processed foods, including products containing carrageenan."
Dr. Hanauer and Dr. Tobacman are currently conducting a study using human patients with ulcerative colitis, a serious gastrointestinal disease.
"Since carrageenan has been found to cause colitis in animal models of ulcerative colitis we felt it would be important to perform a well-controlled dietary study to determine whether carrageenan causes exacerbations (flare ups) of ulcerative colitis in patients in clinical remission," adds Dr. Hanauer, who is also the Joseph B. Kirsner Professor of Medicine and Clinical Pharmacology at the University of Chicago School of Medicine.
The Cornucopia Institute also just released a report , Carrageenan: How a "Natural" Food Additive Is Making Us Sick, which compiles scientific studies pointing to harm from consuming food-grade carrageenan. Cornucopia also produced an accompanying buyer's guide for avoiding the ingredient. Some well-known physicians, like Dr. Andrew Weil, have been warning consumers about carrageenan for years.