Carrageenan in the degraded form exposes an unstable sulfur compound that is known to cause inflammation in animals and humans. Degraded carrageenan is commonly used in the scientific world in order to induce inflammation in lab animals. Carrageenan was stable and safe while in the food product itself, but would too easily break down in the digestive process and cause health problems. Research linked carrageenan consumption to the development of diabetes and digestive problems.
Carrageenan could contribute to the development of ulcers and cancerous tissue growth. The International Agency for Research on Cancer reported in 1982 that there was enough evidence to claim that carrageenan is a likely carcinogen in humans.