Addendum to Weiner, M.L. (2016) Parameters and Pitfalls to Consider in the Conduct of Food Additive Research, Carrageenan as a Case Study. Food Chemical Toxicology 87, 31-44.

This paper is an addendum to a 2016 paper outlining pitfalls and parameters to consider in the conduct of food additive research with carrageenan (Fd. Chem. Tox. 87, 31-44 (2016)). The literature on the food additive, "carrageenan," contains many publications which either erroneously misuse the name, carrageenan, for a sample which is not carrageenan, but "degraded carrageenan" or "poligeenan" and also conduct studies without understanding the physical/chemical properties of carrageenan. Degraded carrageenan and poligeenan are not food additives and have a completely different physical/chemical and toxicological properties from carrageenan. Two recent publication examples, one in vivo and one in vitro, demonstrate the serious misunderstanding promulgated by incorrect sample identity/purity and poor study conduct. These new publication examples reiterate the problems in the literature summarized by the Weiner (2016). It is important to have thorough, rigorous peer review of all studies using carrageenan in vivo or in vitro.

A 90-day dietary study on kappa carrageenan with emphasis on the gastrointestinal tract.

Groups of Fischer 344 rats (20/sex/group) received control or treated diets at levels of 0, 25,000 or 50,000 ppm kappa carrageenan with a molecular weight range (Mw) of 196,000-257,000 Da for 90 days. The Low Molecular Weight Tail (LMT) ranged between 1.9% and 12.0%<50 kDa (mean 7%) based on the results of a program initiated to develop a validated analytical method to measure the LMT. This is the first GLP dietary study in which carrageenan is characterized by percentage LMT. Clinical examinations were performed daily. Individual food consumption/body weight measurements were made weekly. Ophthalmic exam was conducted prior to and at the end of treatment. Hematology/serum chemistry and urinalysis evaluations were done at necropsy, as were organ weight determinations for adrenals, brain, heart, kidneys, liver, ovaries, spleen, testes and thyroid with parathyroids. Full histopathological evaluation of organs was conducted on the control and 50,000 ppm groups, including hematoxylin-eosin-stained cross sections of paraffin-embedded rolled colon. Clinical signs were limited to soft feces in high dose rats and to a lesser extent in low dose rats. There were no treatment-related effects on body weights, urinalysis, hematology or clinical chemistry parameters, or on organ weights or ophthalmic, macroscopic or microscopic findings. The gastrointestinal tract appeared normal in detailed histopathological evaluation using the Swiss roll technique. The NOAEL is 50,000 ppm in the diet (mean calculated test material consumption of 3394+/-706 mg/kg/day in males, 3867+/-647 mg/kg/day in females). The results of the study provide evidence that it is not necessary to characterize carrageenan by a specification for LMT (less than 5% below 50 kDa) as has been done in Commission Directive 2004/45/EC of 16 April 2004 (Commission Directive, 2004/45/EC of 16 April 2004 amending Directive 96/77/EC laying down specific purity criteria on food additives other than colors and sweeteners. Official Journal of European Union 20 April, 2004, L113/19-L113/21).

Subchronic and developmental toxicity studies in rats with Ac-Di-Sol croscarmellose sodium.

Studies were conducted to evaluate the subchronic and developmental toxicity of Ac-Di-Sol (croscarmellose sodium). In the subchronic study, groups of Sprague-Dawley rats (20/sex/group) received 0 (control), 10000, or 50000 ppm Ac-Di-Sol in the diet for 90 consecutive days (equivalent to 757 and 893 mg/kg/day for males and females fed 10000 ppm, respectively, and to 3922 and 4721 mg/kg/day for males and females fed 50000 ppm, respectively). No mortality, clinical signs of toxicity, or adverse toxicological effects on hematology or serum chemistry parameters, feed consumption, or ophthalmologic examinations were noted in any treatment group. Body weight gain was depressed in high-dose males during the final 3 weeks. The only treatment-related histological lesion noted was moderate renal mineralization at the corticomedullary junction in one high-dose female. This lesion was not considered a specific effect of Ac-Di-Sol, but rather a secondary effect resulting from a potential increase in urinary pH and renal excretion of sodium due to the high intake of sodium associated with Ac-Di-Sol. In the developmental toxicity study, groups of pregnant Sprague-Dawley rats (25/group) received 0 (control), 10000, or 50000 ppm Ac-Di-Sol in the diet on gestational days 6 to 15. No evidence of maternal, fetal, or embryo toxicity was noted. The no-observed-adverse-effect level (NOAEL) for Ac-Di-Sol in both studies exceeds 50000 ppm in the diet, which represents doses of 3922 and 4712 mg/kg/day, for males and females, respectively. The results of these studies demonstrate the low subchronic oral toxicity and developmental toxicity of Ac-Di-Sol, and support the safe use of Ac-Di-Sol in oral applications such as pharmaceuticals, dietary supplements, and sweetener tablets.