IBS and Carrageenan

11. February 2022
Eline Randulff Hillestad
Eline Randulff Hillestad
Clinical nutritionist

In recent years, a debate has arisen about the use of the additive carrageenan in food products. In this article, we want to shed light on the topic and look a little at the research behind it.

What is carrageenan?

Carrageenan (E407) is an additive formed from red algae and is made up of two simple sugars. Carrageenan contains minimal energy and has the ability to form a jelly-like consistency. This means that the compound is used as a thickener in foods and as a substitute for fat by binding water and making products juicier without the addition of fat (1). For an additive to be approved by the Norwegian Food Safety Authority, it must first be approved by the EU (EFSA; European Food Safety Authority), and the use of the ingredient must, among other things, not pose a health risk (2). Carrageenan is approved by both the EU and the Norwegian Food Safety Authority.

Image: Carrageenan is formed from algae

The debate surrounding the use of carrageenan

In recent years, new research studies have initiated a debate around the use of carrageenan in food. Various mouse studies indicate that consumption of carrageenan can cause a recurrence of inflammation in the colon (in humans, the most common chronic inflammatory diseases of the intestine are Crohn's disease and ulcerative colitis, with the joint condition "IBD" (inflammatory bowel disease in English, inflammatory bowel disease in Norwegian), changes in the immune system and an increased risk of type 2 diabetes (3, 4). The researchers behind several of the studies believe this occurs through a change in the composition of intestinal bacteria. Consumers have been engaged, which has led to several food manufacturers now considering stopping the use of the additive (5) .

Image: Various products with carrageenan, which is low FODMAP. Having to cut these items can be challenging on an already restricted diet.

The studies that have been done are mainly mouse studies. There are several challenges associated with animal studies. Several of the studies have been done on a small number of mice that have often received high doses of carrageenan per kilogram of body weight compared to what humans get through food. In addition, the mice often received the additive in pure form or in the drinking water, and not as part of a food product as humans do. Furthermore, one cannot draw direct conclusions from animal studies to humans.

Admittedly, animal studies are the basis when an acceptable daily intake (ADI) of additives is determined. In contrast, the ADI is determined from the dose that shows no serious effects for the most sensitive serious effect, and this dose is multiplied by a safety factor (often 1/100) to add an additional safety margin. In this way, the level of the additive that is safe to use in foodstuffs is considerably reduced so that one can be sure of consuming a quantity that is not harmful (6). This means that the assessment to approve an additive and the decision to remove an additive are made based on two different ways.

There are few studies on the effects of carrageenan that have been done on humans. In a study from 2017 (3), 12 people who had improved their inflammatory bowel disease (remission) were divided into two groups; one group of seven people (three dropped out, four completed) received capsules without carrageenan while the other group of five people received capsules with carrageenan. In the last group, three out of five had a recurrence of their inflammation in the intestine.

Inflammatory bowel disease is a chronic disease, and improvement in the disease is often present for periods and is transient. It is therefore difficult to say whether the relapse for the group that received capsules with carrageenan is coincidental or not. The study had very few participants and low power (statistical power tells something about the probability of finding an effect, and low power can mean that you find an effect that in reality is not there (7, 8)). In addition, the study was stopped when the difference between the groups was statistically significant (statistical significance is achieved when you test using statistics that the result is 95% certain, and that it is only 5% certain that the result you have obtained is random), which can interfere with a real result if the study had continued.

The results in the study are based on so-called p-values which are barely statistically significant (more info on p-values: https://forskning.no/matematikk-om-forskning-samfunn/hva-er-p-verdi-og-hva-betyr-statistisk-signifikant/1321080). This way of measuring a difference between two groups is very uncertain when the study only contains 12 participants (a p-value gives a more certain result the more participants are in the study). In addition, it is not particularly valuable to only use p-values alone to say that there is a real difference between the groups (9)

Carrageenan and IBS, and what to do while waiting for more knowledge?

To date, there is little or no research on how carrageenan affects IBS. In IBS, one does not have inflammation in the intestine, and it is unlikely that carrageenan will cause inflammation. EFSA is in the process of a new safety assessment of the additive (10). It is difficult to give advice on what to do while waiting for more studies and more knowledge. Until now, there are too few studies with too wide a range of results (on conditions other than IBS) for these to provide guidance for conclusions and recommendations.

It must be up to each individual to choose whether to be "precautionary" or not, but consistently opting out of products with carrageenan for people who already have a restricted diet, such as with IBS or IBD, could potentially lead to nutritional problems and deficiency states. In addition, it is important not to attribute properties to foods that we do not know for sure that they have. This can create unnecessary food anxiety and fear of eating certain foods. For food manufacturers, it is important to be sure that substances that may replace carrageenan are a better alternative (5).

We recommend listening to professionals and their handlers (doctor and clinical nutritionist) when it comes to advice on health, diet and nutrition.


1. Store norske leksikon. Karragenan (E407) 2019 [Available from: https://snl.no/karragenan_-_E407.

2. Mattilsynet. Godkjenning av tilsettingsstoffer 2013 [Available from: https://www.mattilsynet.no/mat_og_vann/tilsatte_stoffer/tilsetningsstoffer/godkjenning_av_tilsettingsstoffer.11241

3. Bhattacharyya S, Feferman L, Tobacman JK. Distinct Effects of Carrageenan and High-Fat Consumption on the Mechanisms of Insulin Resistance in Nonobese and Obese Models of Type 2 Diabetes. J Diabetes Res. 2019;2019:9582714.

4. Martino JV, Van Limbergen J, Cahill LE. The Role of Carrageenan and Carboxymethylcellulose in the Development of Intestinal Inflammation. Front Pediatr. 2017;5:96.

5. NRK. Flere matprodusenter vurderer stans i bruk av populært e-stoff 2021 [Available from: https://www.nrk.no/vestfoldogtelemark/flere-matprodusenter-vurderer-stans-i-bruk-av-populaert-e-stoff-1.15617224.

6. US Food and Drug Administration - Center for Food Safety and Applied Nutrition. Chapter II, Agency Review of Toxicology Information in Petitions for Direct Food Additives and Color Additives Used in Food. URL: https://www.fda.gov/media/72232/download Toxicological Principles for Safety Assessment of Direct Food Additives and Color Additives Used in Food1993.

7. Låg T. Statistisk svakhet er en utfordring i forskning 2018 [Available from: https://psykologisk.no/2018/08/statistisk-svakhet-er-en-utfordring-i-forskning/

8. Melby-Lervåg M. Å vurdere kvalitet på forskning: Se opp for de trøblete tre 2016 [Available from: https://utdanningsforskning.no/artikler/2016/a-vurdere-kvalitet-pa-forskning-se-opp-for-de-troblete-tre/.

9. Lysne V, Olsen T. Veiledende eller villedende? En simulert studie 2018 [Available from: https://www.ntfe.no/journal/2016/4/c-8/Veiledende_eller_villedende?_En_simulert_studie.

10. Authority EFS. Call for technical and toxicological data on carrageenan (E 407) for uses in foods for all population groups including infants below 16 weeks of age 2018 [Available from: https://www.efsa.europa.eu/en/consultations/call/call-technical-and-toxicological-data-carrageenan-e-407-uses-foods