Carrageenan is a natural material that comes from the red seaweed plant found in the Atlantic Ocean. When carrageenan is extracted from red seaweed by boiling it or treating it with hot alkali, it forms a gel-like material that gives it firmness and makes it an effective thickener for food products. Not surprisingly, carrageenan has been embraced as a food additive by the food industry where it’s commonly used to thicken and add texture and stability to foods and beverages that would otherwise be too thin and lack the proper “mouth feel.”
All it takes is a glance at a few food labels to see how common carrageenan is as a food additive. Some common products that may contain carrageenan are salad dressings, cottage cheese, ice cream, non-dairy milk, syrups, sauces, breakfast cereals, processed cheese, jams, jelly, yogurt, pudding, wet dog food and other processed foods that need a more substantial texture and feel.
Carrageenan is also used as a binder for meat products like sausage and hamburger and is used to bind and stabilize some vegetarian-meat alternative marketed to vegetarians and vegans. In some of these products, carrageenan serves as an emulsifier, a compound that keeps oil and water-soluble ingredients from separating. Without emulsifiers, the ingredients in products would be more unstable and separate in much the same way oil separates from vinegar. That’s why it’s a common ingredient in salad dressings that contain both oil and water-soluble components.
Carrageenan is also commonly added to personal care and cosmetic products. Here, it’s used to give products additional texture, thickness and added stability. Without a thickening and emulsifying agent like carrageenan, ingredients would separate from each other and the product would feel less substantial.
Some cosmetic and personal care products that may contain carrageenan include shampoos, toothpaste, air freshener gels, lubricants, moisturizers and facial scrubs. It’s a common ingredient in hair conditioning products, due to its ability to bind water and coat the hair shaft. Carrageenan helps to stabilize the ingredients in these products and gives them a more substantial texture, thickness and a better "feel."
Despite its widespread use in processed foods and packaged food products, there’s some controversy about its health effects, at least in animals. Research has linked degraded carrageenan, carrageenan that’s been broken down, with colon cancer in animals. Fortunately, the FDA only allows carrageenan that hasn’t been degraded in food products, but there’s some concern that degradation could occur after ingestion by bacteria in the intestines. There’s also concern that carrageenan could cause intestinal inflammation and may increase the risk of inflammatory bowel diseases like Crohn’s disease and ulcerative colitis. Some people report experiencing intestinal symptoms like nausea and bloating after consuming a product that contains it. So far this hasn’t been resolved, but the FDA classifies carrageenan as GRAS or "generally recognized as safe." It’s possible that some people are sensitive to carrageenan in food products, while others can consume it without any problems.
Fortunately, the controversy surrounding carrageenan in food products is of less concern with regards to cosmetic and personal care products since carrageenan is too large to be absorbed through the skin. Instead it serves the useful purpose of giving products added thickness and a smoother texture while stabilizing the ingredients so they don’t separate out and destroy the benefits of the product.
With such widespread use of carrageenan, it's easy to see that both food manufacturers and manufacturers of cosmetic and personal care products find it to be a useful addition to their products. Interestingly, some research suggests that applying carrageenan topically to the skin blocks the growth of viruses like human papillomavirus that cause genital warts and cervical cancer. So, carrageenan may have benefits that go beyond thickening and adding texture to products even if isn’t healthy for the intestines.
From a cosmetic perspective, carrageenan appears to be safe at the levels found in these products, although there are some questions about its health effects as a food additive. The Environmental Working Group classifies carrageenan as a low-hazard ingredient in the amounts in cosmetic and personal care products.