May 23, 2018
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Is seaweed-sourced carrageenan inflaming you?

By Georgia Clark-Albert, Special to the BDN

Approximately 30,000 tons of carrageenan is produced per year. This amounts to an estimated annual benefit of $300 million to the U.S. and other nations. U.S. carrageenan producers get much of their seaweed from family farms in Indonesia the Philippines and East Africa. In many African village communities, the farming of seaweed allows women the opportunity to expand their role in helping to provide for their families. Seaweed farming provides the primary economic base for hundreds of coastal villages and family owned farms.

Carrageenan, an indigestible family of large molecules that come from seaweed, is a thickening, gelling and stabilizing agent that is used in the food manufacturing of ice cream, jelly, chocolate milk, infant formula and cottage cheese. It is also found in toothpaste, lotions and hair products. Often it is used in place of animal-based products such as gelatin, which is extracted from animal byproducts.

The term “carrageenan” is believed to have its roots in the Gaelic language, dating back as many as 600 years when it was used in Ireland and Scotland to make a milk pudding that is still made today.

Carrageenan has been used as a food ingredient for many hundreds of years. Small amounts found in food are considered safe. Large amounts have been found to harm the colons of test animals.

The carrageenan found in food is considered a “non-synthetic” food additive because it does not undergo any chemical changes during the processing or digestion. The carrageenan in food is the same carrageenan present in the seaweed from which it was processed.

Some people complain that carrageenan has caused inflammation in their digestive tract. However, research has not found this to be true. As recently as 2007, animals were fed carrageenan at levels equal to human consumption and there was no gastrointestinal inflammation seen or any other negative health effects. There has been some small research projects insists there is a connection between ingestion of carrageenan and gastrointestinal inflammation, but the research is not considered credible because the methodology was found to be flawed and there are no relevant comparisons.

When carrageenan is injected directly into the body, it does cause inflammation. There have been studies where it has been injected into the paws of rats or to their lungs to test anti-inflammatory drugs.

There is no correlation between what is seen when carrageenan is injected and when it is ingested in foods that are consumed.

Many of the studies that have taken place actually were conducted outside the living body, involving human colonic cells, in order to elicit an immune response. Since there was a lack of a systemic effect with carrageenan, the studies involving direct oral administration are more pertinent. Chronic administration of carrageenan in the diet of numerous species did not result in adverse effects. The only thing that was noted was that stools were soft or there was some diarrhea. These effects are considered common when bulking agents or dietary fibers are fed to test subjects at high doses. There has been no evidence of colon cancer or tumor promotion due to carrageenan in when it has been fed to animals.

Carrageenan at times has been confused with an unrelated substance poligeenan, a small molecular weight polysaccharide. Poligeenan requires a very aggressive chemical process utilizing strong acids and high temperatures to be produced. Poligeenan is not allowed as a food additive and carrageenan does not turn into poligeenan during digestion.

The issue of gastrointestinal inflammation is still under debate for some. Some studies supposedly have verified that carrageenan is associated with induction or promotion of gastrointestinal tract inflammation, ulcerations and neoplasms in animal models and human tissues while other studies have contradicted these findings. A more careful evaluation of the test materials in animal studies shows that the intestinal lesions stated were reported only in studies where poligeenan was the test substance.

Such effects were not found when food-grade carrageenan was the test substance in animal dietary feeding studies.

Another concern that comes up when carrageenan is mentioned is that it is believed to be harmful to the environment. Seaweed farming is thought to be one of the most environmentally friendly types of aquaculture. It doesn’t need fresh water or fertilizers and has a beneficial effect on climate change.

This process traps carbon and removes nitrogen and phosphorus nutrients from local water. Seaweed-based aquaculture provides a practical, sustainable farming practice.

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

Georgia Clark-Albert is a registered dietitian nutritionist and certified diabetes educator at Penobscot Community Health Care in Bangor. She provides nutrition consultant services through Mainely Nutrition in Athens. Read her columns and post questions at or email her at


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