Research has shown that carrageenan induces the body to produce a cytokine (messenger molecule) called tumor necrosis factor alpha (TNF-⍺). This molecule stimulates inflammation and promotes apoptosis (cell death). These counterbalancing functions help maintain the equilibrium of the immune system, and play an important role in defending an organism's system from invading pathogenic organisms such as bacteria.
However, TNF-⍺ is thought to be a causal factor in many chronic inflammatory diseases, such as asthma and inflammatory bowel disease (IBD), autoimmune diseases, and — despite its hopeful-sounding name — cancer.
All types of carrageenan stimulate the production of TNF-⍺.