Carrageenan is an additive made from seaweed.
It is used as a thickener in products such as ice cream, jelly, chocolate milk, infant formula, cottage cheese.
It is a vegetarian and vegan alternative to gelatin.
It has been used for hundreds of years in Ireland and China, but only made headway into modern food processing in the last 50 years. The processing steps after harvesting the seaweed include drying, grounding, filtration, treatment with potassium hydroxide, removal of cellulose by centrifuge, concentration by evaporation, drying, and grounding. Interestingly, the Philippines account for the vast majority of the world supply of carrageenan.
In some animal studies, carrageenan was shown to cause intestinal lacerations and tumors. A 2001 meta-study of 45 peer-reviewed studies concluded that carrageenan consumption may result in gastrointestinal malignancy and inflammatory bowel.
The FDA has approved carrageenan as safe, basing its decision on industry funded studies. European agencies and the World Health Organization have also deemed carrageenan safe, with the exception of infant formula. The fear is the a baby's gut may be unable to handle the large carrageenan molecules.
In some individuals carrageenan may cause intestinal discomfort or worse.
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Yang B, Bhattacharyya S, Linhardt R, Tobacman J. Exposure to common food additive carrageenan leads to reduced sulfatase activity and increase in sulfated glycosaminoglycans in human epithelial cells. Biochimie. 2012 Jun;94(6):1309-16.
Bhattacharyya S, O-Sullivan I, Katyal S, Unterman T, Tobacman JK. Exposure to the common food additive carrageenan leads to glucose intolerance, insulin resistance and inhibition of insulin signalling in HepG2 cells and C57BL/6J mice. Diabetologia. 2012 Jan;55(1):194-203.
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