Research on carrageenan in animals has provided mixed results — often depending on who funded the study. One leading researcher, Joanne Tobacman, MD, has studied the effects of carrageenan on intestinal epithelium and the substance's role in inflammation and carcinogenesis for more than 20 years. While her research has been criticized by the carrageenan industry, she remains convinced that the harmful effects of carrageenan occur with both native (food-grade) carrageenan and degraded (poligeenan) forms. Both have been shown to increase free radicals, directly cause intestinal inflammation, and disrupt insulin metabolism (potentially leading to diabetes), and there is increasing evidence for carrageenan's role in cancer development.
Heat, digestive enzymes, acid, and bacteria can convert high-weight carrageenans to dangerous poligeenans in the human (and presumably animal) gut. The feline stomach environment is extremely acidic; could this make carrageenan especially dangerous for the animals? Could carrageenan be a factor in IBD, food intolerance, and the skyrocketing rates of cancer and diabetes in cats?