The Carrageenan Controversy: Unfounded?

Published on August 08, 2016 by Dr. Traj Nibber

Widely used in the food industry as a gelling or thickening agent, the use of carrageenan as a food additive has been heavily discussed.  In this blog Dr. Nibber will summarize what carrageenan is and will review some of the controversial and unfounded negative health effects of this food additive.

What is Carrageenan?

Extracted from edible seaweed, carrageenans comprise a family of sulphated polysaccharides. Due to their structure, carrageenans are highly flexible, have large molecular weights, and strong binding capabilities, making them excellent gelling and stabilizing agents.  Despite having no nutritional value, carrageenans provide an excellent alternative to gelatin, as it is vegan.

First extracted on the industrial scale in the 1930's, carrageenan as a food additive has increased in popularity and current global sale estimates of carrageenan are between 600-750 million USD.  Carrageenan can be found in: cream, yogurt, sauces, beers, soya products, a variety of processed meats, baby formula, as well as in toothpastes and shampoos.

A wide variety of regulatory bodies including the FDA, Health Canada and the European Food Safety Authority (EFSA) have all allowed carrageenan to be added as a direct food additive, and this additive is considered to be safe.  It should be noted that the EFSA has not yet allowed carrageenan to be added in baby formula, unlike the FDA and Health Canada.

So, this begs the question: if it is virtually impossible to buy products at your local supermarket of which carrageenan is not an ingredient, and carrageenan is a regulatory-body approved food additive, why is there such controversy?

The Controversy and Animal Studies

As with many food additives (particularly those without nutritional value), carrageenan has been the subject of dietary health studies. Many of the opponents of carrageenan have cited that carrageenan may have long-term effects on proper functioning and overall health of the gastrointestinal (GI) tract. It is very important to note that many of these concerns have risen from the findings of animal studies.

Some animal studies in the 1980's suggested that carrageenan may have carcinogenic properties and promoted the development of tumors in the GI tract of rats.  The methodology used in many of these older studies have since been disregarded by numerous, recent large-scale industry funded studies.

A few studies have also shown histological (the study of the microscopic anatomy) differences in the GI-tract after administering undegraded carrageenan through drinking water to animals.  However, whether these histological effects are indeed the direct result of carrageenan, and whether these changes are indeed harmful remains to be clarified.

Not all animal studies have shown negative effects of carrageenan.  Indeed many animal studies have strengthened the argument that the use of carrageenans as a food additive is safe. Some studies have shown that oral feeding of carrageenan (amounts similar to those ingested in the human diet) to laboratory animals does not result in the accumulation of the additive in the body, further highlighting that it is unlikely that carrageenan causes changes to the GI tract and tumor promotion.  To study these effects further, some research groups have raised animals (baboons) on formulas containing higher concentrations of carrageenan than is in the human diet (up to five times the amount) and once again found no negative health effects.

So it seems that a few animal studies conducted in the 1980's, and with questionable methodology and incomplete analysis, have caused some controversy with regards to carrageenan as an additive. It should be reiterated that carrageenan has undergone continual review by expert committees from world-wide regulatory bodies, and remains an approved food additive.

The unfounded carrageenan controversy highlights a bigger problem; that is, whether or not animal models are representative models of the health effects of ingredients in humans (particularly studies including mice and rats). Many research groups and research funding bodies are moving away from animal studies as they can be very expensive and the findings are often scrutinized for their relevance to humans.

For more information on this topic, stay tuned for next week’s blog about animal studies and high science.

Blog Contributors

Dr. Anjan Nibber is a Scientific and Research Consultant for AOR.  Dr. Nibber holds a BSc (Hons) in Biological Sciences from the University of Calgary and a DPhil in Clinical Neurology from the University of Oxford.  Anjan has extensive research, business, and communications experience. Anjan has worked as a medical researcher in respiratory medicine and is a Co-founder and Editor-in-Chief of Career Insight, a magazine publication supported by Oxford Careers Service.