Carrageenan: food additive linked to diabetes

Posted on Mon, 3 Sep 18

Carrageenan is a common food additive, despite being linked to adverse health effects. A carrageenan-free diet significantly improved blood glucose metabolism in people with early stage diabetes. 

The food additive carrageenan is commonly used as a food additive in dairy products, dairy alternatives, processed and pre-prepared foods, nutritional shakes and dietary supplements.

Previous human clinical research has linked carrageenan to adverse effects, such as provoking inflammation and digestive disease. 

Because inflammation is known to play a role in the development of poor blood glucose regulation and type 2 diabetes, the effects of a carrageenan-free diet were examined in a group of people with prediabetes [1]. 

During the study, participants consumed either a  carrageenan containing, or carageenan-free diet. Inflammatory and blood glucose biomarkers were measured before and after the diets. 

After 12-weeks there was a significant improvement in blood glucose metabolism with the carrageenan-free diet.  Specifically, there was a significant decline in hemoglobin A1c and insulin resistance. Inflammation was also reduced, as indicated by significant declines in and leukocyte phospho-serine IRS-1 and NF-kappaB.

Additional research elucidated the mechanisms involved. In mice, even low exposure to carrageenan increased levels of the immunological mediator galectin-3, which inhibited hepatic insulin-induced glucose uptake and was highly correlated with a decline in insulin signalling (tyrosine phosphorylation of IRS-1). Further, it was found that expression of galectin-3 was reduced by 69% in people on the carrageenan-free diet [2]. 

Want to avoid carrageenan? Read ingredients lists on labels carefully, and contact manufactures if you are unsure as carrageenan is not always declared on labels. Here is a link to a consumer guide that provides a list of organic products with and without carrageenan with a simple Red and Green colour system. 

References: 

1. Tobacman JK. Impact of the No-Carrageenan Diet on Glucose Tolerance and Insulin Resistance in Adults with Prediabetes. Diabetes 2018 Jul; 67(Supplement 1). 

2. Tobacman JK., et al. Increase in Galectin-3 Contributes to Glucose Intolerance and Insulin Resistance following Exposure to the Common Food Additive Carrageenan. Diabetes 2018 Jul; 67(Supplement 1)