Carrageenan is a common food additive extracted from red seaweed. Manufacturers often use it as a thickening agent. The United States Food and Drug Administration (FDA) have approved the additive for use, but concerns about its safety remain. Some scientists believe that what is carrageenan can cause inflammation, digestive problems, such as bloating and irritable bowel disease (IBD), and even colon cancer. However, the validity of these claims is hotly debated because the only supporting evidence comes from studies in cells and animals. In this article, we take a closer look at the risks and uses of carrageenan.

Is carrageenan bad for you?
Different forms of carrageenan have different uses and potential risks. Food-grade carrageenan is extracted from red seaweed and processed with alkaline substances. When carrageenan is processed with acid, it creates a substance called degraded carrageenan, or poligeenan, which carries significant health warnings. Poligeenan is an inflammatory substance. Researchers often use it to test new anti-inflammatory drugs in the laboratory. Poligeenan is not approved as a food additive.

What does the research say?
Degraded carrageenan, or poligeenan, is not safe to eat. Research in animals indicates that it causes gut tumors and ulcers, and may even trigger colon cancer. Because of the possible danger, fewer studies have investigated the potential effects in humans. Findings like these have led the International Agency for Research in Cancer to list poligeenan as a possible human carcinogen. This means that the agency has reviewed the evidence that poligeenan can cause cancer in animals and concluded that it may have the same effect in humans.
Some scientists are concerned that food-grade carrageenan is also dangerous. This is because various studies, dating back to the 1960s, show that the substance may degrade and become toxic when it mixes with stomach acid. The medical community is unsure to what extent carrageenan degrades in the digestive system. This means that we do not know if any amount is toxic. It is important to note that no related studies have involved human participants. Findings of a review from 2017Trusted Source indicated that even non-degraded carrageenan can cause inflammation and bowel disorders, suggesting that this substance may contribute to ulcers and IBD. However, authors of a 2018 reviewTrusted Source concluded that there is not enough evidence to draw conclusions about the exact health effects of what is carrageenan. Anecdotal evidence suggests that eliminating carrageenan from the diet can provide relief from digestive problems, such as bloating and IBD. However, these reports are not the result of scientific research.

What is carrageenan used?
Carrageenan has a variety of uses. Though it has no flavor or nutritional value, it is a useful thickening agent and stabilizer. Some manufacturers include it in products like chocolate milk, to stop the milk from separating. It can also substitute for fat in non- or low-fat foods and dairy replacement products aimed at the vegan market. Some manufacturers use carrageenan as a binder in processed deli meats. Others inject it into pre-cooked poultry to tenderize the meat and keep it juicy for longer. Companies often use carrageenan as a vegan alternative to gelatin, in desserts, for example. It is also a common ingredient in canned pet food. Non-food products, such as air freshener gels and toothpaste also frequently contain carrageenan.