M. L. Weiner, Nuber D., Blakemore W., Harriman J., and Cohen S. A Ninety-Day Dietary Study on Kappa Carrageenan with Emphasis on the Gastrointestinal Tract. Food and Chem. Toxicol. 45: 98-106 (2007)
In this study scientists review the effects of carrageenan on the gastrointestinal tract and dispel erroneous conclusions that had suggested carrageenan could cause cell proliferation or tumor formation. The study was submitted and reviewed by the Joint FAO/WHO Expert Committee on Food Additives.
This study was specifically designed to evaluate carrageenan on the gastrointestinal tract. The sample of carrageenan used in this study was characterized for the low molecular weight fraction. After ingesting this carrageenan in feed for ninety days, no adverse toxicological effects on the gastrointestinal tract of the rat or any other organ system or tissue were observed.