Carrageenan farms consist of rows of seaweed plants growing on nylon strings floating in the water. The plants are harvested about every three months. After harvesting the plants, they are dried and baled. The plants, ready for manufacturing, are ground, sorted, and washed. The cellulose (plant cell walls) is removed from the carrageenan by centrifuge, filtration, and evaporation. Three different types of industrial processing can be used in the processing of carrageenan, semi-refined, refined, and mixed processing.
Similar to gelatin and cornstarch, the main industrial uses of carrageenan is as a thickening agent, emulsifier, and a stabilizer. Processed foods such as cheese, chocolate milk, and jellies may all contain carrageenan. Processed meats such as sausages and hams can also contain carrageenan. Foods such as jellies, marshmallow fluff, and syrups use carrageenan as a thickener. An emulsifying agent allows liquids to stay mixed together. In this sense, carrageenan is used to allow chocolate milk, yogurts and other dairies to stay mixed together. Also, carrageenan can be used in ice creams to prevent sugar and ice from crystallizing. Carrageenan is only needed in foods which may need to travel or sit on a shelf and still appear appealing. If food is to be eaten immediately, there is no need for carrageenan or any other “gum” agent. Because carrageenan is made from seaweed, it is considered to be “natural” and able to be used in USDA certified organic foods.
Other than the food industry, carrageenan is used for medical purposes; however this is not as common. It is said that carrageenan can be used to help with coughs, bronchitis, and intestinal discomfort. It may also aid peptic ulcers and used as a laxative or a topical ointment.
Undegraded carrageenan is food quality, however degraded carrageenan is not. Carrageenan becomes degraded when acid is used to separate the cellulose from the gelatin substance. It is said that degraded carrageenan is a known carcinogen and tumor promoter in many lab animals. Also, it is believed to cause gastrointestinal malignancy and inflammatory bowel disease. Studies funded by the carrageenan industry finds no proof of these claims; however, many claims do not believe carrageenan should be consumed at any levels or levels higher than 5%.
Whether tumors and discomfort are a side effect of carrageenan or not, for every product on the shelf which contains it, there is a readily available alternative most likely sitting on the shelf next to it.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1242073/
http://www.webmd.com/vitamins-supplements/ingredientmono-710-carrageenan.aspx?activeingredientid=710&activeingredientname=carrageenan
http://www.cornucopia.org/carrageenan-2013/
