carrageenan on a food label

Carrageenan: A Food Additive That’s Not as Safe As You Think

If you look towards the back of the ingredients list on many processed foods you’ll frequently see an ingredient called carrageenan. Like lots of other confusing sounding food-stuffs, most people blithely consume it daily without a scintilla of awareness about what it actually is or whether or not it’s good for you.

Overall carrageenan is (mostly) harmless, but it has a variety of troublesome side effects that shouldn’t go unnoticed, most notably high correlations to colon cancer, inflammation, and a depressed immune system.


What Is Carrageenan?

Carrageenan is a polysaccharide that’s derived from red seaweed. On a molecular level it’s actually very similar to plastic and is popular for that reason. It bends easily but snaps back into place, which makes it a useful additive to foods, gels, and foams.

It’s long been used to improve the texture of food, and the earliest reported uses of red seaweed to improve a food’s characteristics dates back to 600 BC in China. It began to be used commercially in the west starting in the 1930’s, and about 80% of the world’s red seaweed is harvested in the philippines.


Carrageenan is cheap, fairly docile, and easy to crank out. So it’s used in a lot things. You’ll often see it in milk products to improve viscosity, especially plant milks since they don’t have any cream. Its others uses include but are not limited to:

  • toothpaste
  • gummy products
  • dairy products/plant milks
  • beer
  • shoe polish
  • shaving cream

And the list goes on. You’ll often see carrageenan used in conjunction with agar, guar gum, or xantham gum.

commercially grown carrageenan
Carrageenan is grown commercially in southeast Asia

So Is Carrageenan Bad For You?

Carrageenan has always gotten a free pass from the health community. It’s frequently used as a vegan alternative to gelatin and recently herbivores have come to its defense because dairy companies have been framing it as a “weird additive” in its milk commercials.

Andy Bellatti recently wrote an article defending carrageenan as an additive, and most health/eco-oriented pundits seem to condone it since it’s often used in products they otherwise deem worthy…..most notably plant milks.

However, I think most of these people are suffering from the fallacy of mood affiliation.  Carrageenan helps make foods they like more palatable, and therefore they defend carrageenan as well.

I believe this sense of affiliation is incorrect.

Why, you ask?

Because carrageenan has a long and notable history of significant correlations to different types of cancer and acute-inflammatory responses which are not good for you, to say the least.


Whenever I write a summary article like this one of my first tasks is to type in the subject line into google scholar to see what studies come up.

When I did this for carrageenan I was surprised to see that the most relevant, cited papers had little to do with carrageenan as a food additive, but instead focused on its ability to induce acute inflammation in rats. Here’s the page I saw:

carrageenan and inflammation

After digging a little deeper into the literature I was surprised to find that by far the most notable aspect of carrageenan in medical research is its clockwork like ability to induce oedema and other inflammatory responses in rats. They’ve been doing it in labs for more than 40 years.

Carrageenan ingested in large amounts promotes inflation in two ways: it depresses the activity of macrophages (big immune cells that act like garbage collectors) and induces the creation of histamine,  Cox-2 and prostaglandins, all inflammation inducing compounds.


Regular ingestion of carrageenan also has a high correlation to different sorts of gastrointestinal cancers in rats. Most of the research done on the carrageenan/cancer relationship has been done in southeast Asia, and thus is not as well publicized as other harmful food additives like MSG.

However, the trail of research on this issue is long, and pretty consistent. Carrageenan (particularly the “degraded” kind) regularly induces carcinogenesis, neoplasia, and intestinal lesions. Ouch!

By far the most impressive research in this issue was carried out by a professor named Kazuo Wakabayashi, who’s centered in Japan (I believe).

I won’t bore you and write The Unabbreviated Scholarly Review on Carrageenan and Carcinogenesis, but let me point out two relevant studies for you to chew on:

  • A clinical study conducted by Wakabayashi found that rodents were fed daily with a 5% carrageenan aqueous solution had a 100% incidence rate of colon metaplasis after 15 months.
  • As far as I know there have been no clinical studies conducted on humans, but they have been performed on mice, rabbits, guinea pigs, and mice and they all show a connection between carrageenan and colon cancer. 
Food for thought.

So Is Carrageenan Safe?

Throughout most of the world carrageenan has been deemed “generally safe.” And in modest quantities it is, just like most other additives you consume in processed food.

However, I’m a bit miffed at the lack of attention its received for its potentially harmful side effects. The health community typically likes to throw stones at any and all preservatives added by the industrial process, and are quick to point out any harmful correlations that have been brought up in medical research. For example, the correlation between MSG and obesity has received a lot of scrutiny.

So I’m not sure why carrageenan gets a free pass.  It shouldn’t.

Research and References on Carrageenan

Vinegar, R, et. al “Quantitative Studies of the Pathway to Acute Carrageenan Inflammation” Federation Proceedings.  1976,  pgs. 2447-2456.


Di Rosa, M, et. al. “Studies of the Mediators of Acute Inflammatory Response Induced in Rats in Different Sites by Carrageenan and Turpentine” Journal of Pathology. May, 1971. Pgs 15-29.


Wakabayashi, Kazuo, et. al. “Induction by Degraded Carrageenan of Colorectal Tumors in Rats”  Cancer Letters. January 1978, pgs. 171-176.


Watanabe, Kenshi, et. al. “Effect of Dietary Undegraded Carrageenan on Colon Carcinogenesis in F344 Rats Treated With Azoxymethane or Methylnitrosurea”  Cancer Research. December 1978, pgs. 4427-4430.


Tobacman, Joanne. “Review of Harmful Gastrointestinal Effects of Carrageenan in Animal Experiments”  Environmental Health Perspectives. October 2001, pgs. 983-994.


Guay, Jocelyne, et. al. “Carrageenan-Induced Paw Edema in Rat Elicits a Predominant Prostaglandin E2 Response in the Central Nervous System Associated with the Induction of Microsoma PGE2 Synthase-1”  Journal of Biological Chemistry. June 2004, pgs 24866-24872.


Salvemini, Daniela, et. al. “Nitric Oxide: A Key Mediator in the Early and Late Phase of Carrageenan-Induced Rat Paw Inflammation”  British Journal of Pharmacology. Pgs 829-838.


190 thoughts on “Carrageenan: A Food Additive That’s Not as Safe As You Think”

      1. Steve the fact that is natural doesn’t mean is good for you. There are a lot of plants in the world that are poison to humans. For me Carrageenan is poison I am allergic to it big time just like others are allergic to peanuts and other fruits and vegetables.


  1. Carrageenan gives me migraines every time I eat it, so I usually avoid it and another 30 ingredients that trigger my migraines, preservatives and additives in our American diet. I eat fresh organic foods now and I keep a tight food diary, but I didn’t double check the “organic” cottage cheese last night and carrageenan strikes again!!! 6 pills later, terrible sleep last night, and almost vomiting from the pain I am finally almost back to my old self. I HATE CARRAGEENAN!



    1. Andrea – be sure to contact the company and ask them to take it out of their product. The more they hear from people the greater the chance they will remove. Hood removed carrageenan recently from its buttermilk. Many of the dairy and non-dairy milk manufacturers have been listening to consumers and removing carrageenan from their products. For e.g. So Delicious Coconut milk products even now state on their labels – Now without carrageenan! For many of us with gluten issues – seaweed alone in for e.g. canned beans, processed into carrageenan (red seaweed) or processed as align/alginate/sodium and other alginate (brown seaweed) causes a multitude of issues – very similar if not identical to gluten. (I have tried to encourage the researcher, who identified that several other proteins in wheat not just those in gluten cause celiac folks to respond, to test the proteins in the major seaweed species used in food products . At one point the organic folks were big on seaweed – it’s natural, it’s safe. Right. It’s cheap and plentiful as an emulsifier. Don’t feel badly from time to time my husband and I miss it in ingredients. We now look at all labels in our kitchen before using anything as a double and triple check before we use anything.


      1. One more point – I maintain and unless I am proven wrong – and I tried to tell Dr. Tobacman (see early on her comment in this blog) back in 2011 that it is not simply carrageenan processed from red seaweed, but the seaweed itself, and brown (kelp) seaweed alone or processed into algin or an alginate salt – there is something innate in the seaweed likely a protein that is similar to one – a non-gluten (not a glutenin or gliadin) protein in wheat. I know a doctor whose kid is gluten sensitive and could not understand the reason her kid got desperately ill as if she ingested gluten after eating maki rolls with gluten-free soy sauce. She acknowledged I was right – it was the seaweed. Again, a women I know with celiac disease was unhealed for years (I have told this story many times before). She showed me a bag of candy that made her sick – bemoaning the ingredients must be missing gluten – then I saw the carrageenan. It would be nothing for the researcher who identified the several non-gluten proteins in wheat that folks with celiac react to, to analyze the three or four major seaweed species used in our food products to identify a protein match to one in wheat, then manufacturers would take this crap out. In high school I remember in Biology an adjunct reading book – I thought it was the Silent Spring but have never checked it – that seaweed was the “wheat of the sea.” How ironic.


  2. I am curious whether this is the cause of the digestive issues my kittens are having. The vet even thought they might have coccidiosis, because they were having bloody, mucousy stools. Tests for parasites were negative. I noticed that their canned food was going through a formulation change, at that time, and when we would get some of the “old label” stuff, that still had carageenan, their diarrhea and blood in the stool would show up. Symptoms went away when we got cans of the newer formula, that had a substitution for carageenan, or had them eat dry kitten food.


    1. When I had to go gluten free my GI and other systems issues cleared completely. My health turned completely around. Had a taste of choc cream pie with whipped cream both had carrageenan (made from red seaweed) in ingredient list, and symptoms returned taking 3-4 weeks to clear. Considered it was the dairy (and three years later did develop dairy and soy protein issues) except weeks after I had a can of organic beans with kombu a brown seaweed and became ill. In the subsequent years got sick from bagels and breads made with algins or sodium other alginates (brown seaweed based) and agar another seaweed-based product.

      Increasingly, product manufacturers are taking these seaweed-based gelatins and emulsifiers out of products esp. the dairy and dairy-free milk products and GF bread products.

      Person who sold me my makeup bemoaned that 20 years later her intestines still not healed via scope and said there must be gluten undisclosed in foods and in this candy she was eating. No, but there was carrageenan! GI docs several years ago and still today do not choose to warn their patients with bowel disorders to completely eliminate food products with these seaweeds in them but rather put them on expensive drugs with horrific side effects rather than first work w diet to eliminate foods with this additives known to inflame the bowel. It is still widely used in ice cream – my brother and his wife until they switched to carrageenan-free brand had GI and severe leg muscle cramps and spasms. Nestle had to take it out of their baby formula because of many reports of intolerance. The European version of the FDA banned it from baby formulas.

      There was a study done three years back at Columbia that separated out a dozen or so proteins in wheat. They tested known celiacs and demo’d that in addition to reacting to the proteins in gluten most responded to several others if not all. I have to contact the researcher – we’ve talked in the past – because my hypothesis is that seaweed while it may be gluten free contains other proteins found in wheat that folks react to even if not a person with celiac disease.

      My former doctor’s kid had gluten issues – not sure if celiac but askedme reason her kid was getting sick on maki rolls w GF soy sauce. I said likely the seaweed. Now I’d also say consider the soy.

      Wheat/gluten-dairy-soy three big ones to try to eliminate for GI system issues with assist of doctor and reg dietitian. When lactose-free milk made me sick then even butter on toast I knew it was the proteins in the dairy I was reacting to at that point. Kind bars even a bite made me ill with the soy lecithin. My son brought home a fried tofu dish – a few pieces of that sealed the deal. Was fine for a year then gradually got quite sick – doctors doing all sorts of testing – turned out one vitamin D and oil-based magnesium I was taking had soy in it. Once I switched these out my health and symptoms started to improve. One caution w dairy – I foolishly missed this. I used to take just 600 mg of calcium a day bc I had 2-3 dairy servings daily. I should have increased to 1200 calcium a day once I stopped the dairy. So I started to have some minor bone loss and I was actually building bone post menopause because my intestine healed, and I was properly absorbing before I eliminated dairy. Now many of the non-dairy mills have added calcium and Vitamin D.

      At any rate, I wouldn’t give man nor beast anything with seaweed or seaweed derivatives under multiple extract names listed above. And chances are if that helps, eliminating gluten and possibly dairy and soy will also help.


      1. Caraganeen and all forms of seaweed extracts makes my tinnitus scream. MSG is made from seaweed too, I’m sure you know. Caraganeen is in ice cream and all
        kinds of foods, I’m not gluten or dairy intolerant but seaweed extracts blow my head noise up.


  3. Carrageenan and all other excitotoxins (msg and all such) cause tinnitus spikes. I never see this mentioned in the list of health issues exacerbated by these additives.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s