Have you heard of carrageenan? Carrageenan, extracted from seaweed, is used extensively in the processed food industry as a thickener and emulsifier. It is found in almond milk, soy milk, coconut milk, cottage cheese, whipped cream, eggnog, and other related products. But not for long. It’s become impossible to ignore the large amount of  evidence showing that it is highly irritating to the stomach lining.

So this past week, in welcome news, WhiteWave Foods, manufacturers of a number of product lines, including those marketed under the brands Silk and Horizon, announced that they plan to phase out the use of carrageenan completely by 2016.

Through the years, I have seen a lot of patients previously diagnosed with “irritable bowel syndrome.” The word “syndrome” — a constellation of symptoms — can be helpful at times, both framing a problem as well as pointing both patient and physician in a more constructive direction. But not always. I wonder about diagnoses like “irritable bowel syndrome,” which is not a diagnosis at all, but rather a conclusion to which doctors frequently turn when we cannot figure out the cause of, for example, gastrointestinal distress. Giving symptoms a name satisfies the need to 1) reassure patients with a diagnosis and 2) bill the insurance company. These are important, but they don’t begin to get at the root of the patient’s belly pain.

What is irritable bowel “syndrome” anyway? It’s the diagnosis we assign to patients after we’ve tested for everything we can think of, and yet the entire negative workup has yielded no answers. With no test to prove its existence. it becomes a diagnosis of elimination as doctors rule out all the other possibilities.

When I meet a patient who carries a diagnosis of “irritable bowel syndrome,” the very first question I ask myself is “what could be causing this patient’s discomfort?” Could it be a medicine the patient is taking for an otherwise unrelated condition? undiagnosed gall stones? leaky gut? atypical migraines? porphyria? Crohn’s? ulcerative colitis? urinary tract infection? depression? anxiety? esophageal reflux? post nasal drip? appendicitis? endometriosis?

Or is it a food sensitivity, like a milk allergy, celiac disease, gluten sensitivity, soybean-sensitivity, or maybe a sensitivity to “processed American cheese food”? Some of these are, admittedly, much more common than others. For example, I myself have diagnosed porphyria only once, which is probably once more than your average internist. But yes it’s still a possibility, even though it’s a long shot.

Or could it be a normal reaction to carrageenan? Could it be that it’s actually the carrageenan, or some other additive, that is making yourself sick? Perhaps your irritable bowel symptoms are a normal reaction to an abnormal situation.

Remember this: carrageenan is not food, and it’s not the only thing that belongs in that category.  #notfood


5 thoughts on “Carrageenan

  1. When I see IBS-like symptoms in my nutrition practice, one of the firs things I do is advise the avoidance of all artificial sweeteners, colors, flavors, preservatives, etc. Often the problem resolves itself with that change alone. I like your assessment of a “normal reaction to an abnormal situation.” That is exactly what it is!

  2. Is carrageenan extracted from seaweed (nori) that people eat? If so, does the problem come from separating it from its source, like separating fructose from the fiber (as explained in Sugar: The Bitter Truth)?

  3. The Science of Carrageenan: A Safe Food Additive


    Numerous studies have been published on the overall toxicology of carrageenan and, in
    particular, around its interaction with gastrointestinal activity. Some of these studies have been performed in compliance with regulatory guidelines, using oral administration (consistent with the route of human ingestion), large groups of animals and several dose groups. Many others have been research studies, often using smaller numbers of animals, fewer or single dose groups, and including non-oral routes of administration of carrageenan. There are considerable discrepancies in outcomes among these studies, both with respect to the nature of the effects observed and, where reported, the levels at which they occur.

    Discussions in the media around scientific findings have also (mis)attributed the effects of poligeenan, a small molecular weight polysaccharide, to carrageenan under the theory that “degredation may occur” during ingestions changing carrageenan into poligeenan. But oral feeding studies have consistently confirmed that carrageenan, a natural high-molecular weight compound, passes through the body unaltered. (Poligeenan is a synthetic compound that is intentionally created using strong acids and high temperatures over an extended period of time; it is not produced naturally. Poligeenan is not allowed for use in food and has not been found in food that contains carrageenan.)

    In looking at specific studies to assess health risk factors for usage as a food additive the following should be considered:
    • The route of administration
    • The dosage administered
    • The actual material used (“carrageenan” or “poligeenan”) and whether it was in combination with another active ingredient

    Many studies will inform the overall knowledge about carrageenan, but not all will be relevant to the safety of carrageenan as a food additive. It is important to remember that carrageenan when used as a food additive is ingested through an oral administration. Carrageenan when ingested is known to not have a systemic effect specifically because it has been reported that < 6% of the excreted carrageenan is below 100,000 Da. and <1% is below 50,000 Da. Because of its large molecular weight carrageenan remains within the lumen of the digestive tract and is not absorbed (Weiner, 1988; 1991). Thus, there are no systemic effects of carrageenan following ingestion by rats, mice, or monkeys.

    Many of the experiments or “studies” currently being discussed in media are in vitro (outside the living body/artificial environment) some involving human colonic cells to elicit an immune response. Due to the lack of a systemic effect as noted above with carrageenan, the in vivo or studies involving direct oral administration are more pertinent. Chronic administration of carrageenan in the diet of numerous species did not result in adverse effects, other than soft stools or diarrhea. These effects are commonly seen when bulking agents or dietary fibers are fed at high doses. No evidence of tumor promotion or colon cancer has been found due to carrageenan in animal dietary feeding studies in vivo (Cohen and Ito, 2002).

    The issue of gastrointestinal inflammation is often thought to be still under debate with some studies verifying that carrageenan is associated with induction or promotion of gastrointestinal tract inflammation, ulcerations and neoplasms in animal models (e.g. Bernard et al, 2010) and human tissues (e.g. Borthakur et al, 2007; Bernard et al, 2010) while other studies have contradicted this finding (e.g. in vivo: Weiner et al, 2007; and in vitro: Tobacman and Walters, 2001). However, a more careful evaluation of the test materials in animal studies shows that the intestinal lesions stated (ulcerated, neoplasms) were reported only in studies where poligeenan (small molecular weight polysaccharide) was the test substance. Such effects were not found when food-grade carrageenan was the test substance in animal dietary feeding studies.

    Key Findings

    The weight of scientific evidence confirms the safety of carrageenan as a food additive.
    Many of the smaller research studies are in conflict with established findings that have not shown any induction or promotion of gastrointestinal tract inflammation, ulceration and/or neoplasms in animal models. Highlights of the more established studies focusing on the gastrointestinal tract as well as an epidemiological study focusing on immunosuppression listed as a snapshot below support the conclusion of carrageenan as a safe food ingredient.

    • Studies of male and female infant baboons raised from birth to 112 days of age on infant formulas containing concentrations of carrageenan varying from zero to 5 times the commercially-available formulas for human infants had no effects on infant development. No effect was seen through microscopic or macroscopic examination of the GI tract. (McGill, et al. 1977).
    • Long-term multigenerational studies, conducted by the FDA, feeding rats with a diet containing carrageenan at 5.0% found no effects on reproduction, fertility, average litter size, average number of live born animals, viability or survival of offspring, weight gain or any specific external, skeletal or soft tissue anomalies. (Collins, Black, Prew, 1977)
    • Rats and hamsters were fed 0, 0.5%, 2.5% or 5.0% carrageenan for their lifetime in a study by Rustia et al., 1980. Survival was not affected in either species. No statistically significant pathological effects were seen in either species at any of the dietary levels used in the study.
    • Retrospective study reported by Sherry et al (1993, 1999) between two populations of full term human infants in the first six months of life – those exclusively fed infant formula containing 0.03% carrageenan and those exclusively fed powdered formula containing 0% carrageenan showed no difference in frequency of upper respiratory infections between the two populations.
    Regulatory Opinion to Date

    Consistent with the scientific evidence, carrageenan has consistently been recognized as a safe food additive, including for use in organic foods:

    • United States FDA approval as a safe direct food additive (1961) and Generally
    Recognized as Safe (GRAS) listing assigned in 1973
    • Listing as a permitted additive in the Codex Alimentarius Commission of the Joint
    FAO/WHO (1999)
    • International Federation of Organic Agriculture Movements lists as a permissible food additive (1999)
    • The Pacific Organic Standards list carrageenan as an additive allowed in organic food processing (2006)
    • The East African Organic Product Standards lists carrageenan as an additive allowed in organic food processing (2007)
    • The European Economic Community (EEC) Council Regulation permits the use of carrageenan as a food additive in preparation of plant-origin organic food products of animal-origin, dairy-based organic food products (Commission of the European Communities, 2008)
    • Carrageenan is permitted for use in Canadian Organic handling and processing (2011); and
    • The U.S. National Organic Standards Board relists carrageenan as a permissible
    additive for organic foods (2012).


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  4. Dr.
    I worry about statements like “carrageenan is bad”. Maybe there is not enough information in this article, but it seems like some people might have a sensitivity to it. Should we phase out every ingredient that anyone can have a problem with? As far as I know carrageenan has been used as an ingredient to gel dairy for centuries. Lookup carrageenan pudding for example. Maybe what you are talking about is a matter of overuse causing the issue?

    • I appreciate your interest. Yes, overuse may be a big part of the problem. Another issue is that making carrageenan pudding is very different than eating significant amounts without being aware of it. So many people suffer with irritable bowel symptoms, and many have no idea where to start their journey to health. My goal here was to show one among many possible irritants.

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