What is Carrageenan?

Carrageenan – a gum derived from boiling red seaweed plants that are found in the Atlantic Ocean, near North America and Europe – is a widely used food additive.


Why is it used?

In the home, food is easily manipulated by mixing various ingredients together and serving immediately after preparation. However, milks and cheeses tend to separate and some other products may mix well initially but are often not stable over time. The role of carrageenan in industrial food processing is similar to that of gelatin and cornstarch in the home. However, the effects of carrageenan last longer and therefore products that are made for mass marketing need to have additives that extend the shelf life of the product in the desired form.

Processed foods contain a variety of gums in addition to or in place of carrageenan, such as cellulose gum, agar, locust bean gum, and xanthan gum. Manufacturers use these gums in their processed foods for four main reasons:

To thicken foods – foods like ice cream benefit from thickening especially when made from lower fat milk.

To emulsify foods – they help liquids stay mixed together instead of separating over time. Whipping cream would likely separate when being transported from the processing plant to the store if it did not contain a gum.

To change the texture – often a gum will change a product to make it chewier or thicker.

To stabilize crystals – a gum can reduce the crystallization of sugar or ice in products such as pancake syrup or ice cream.


In what foods is Carrageenan found?

Carrageenan is found in some of the following products: whipping cream, ice creams, condensed milk, pancake syrups, soymilks and other soy products, yogurts, and processed meats. Check the nutrition label on any of the above products to determine if your particular brand contains carrageenan. Be aware that if a product, for example, contains condensed milk, the additive carrageenan may not be listed separately on the label as it is contained within the condensed milk.


What have the studies found in reference to Carrageenan?

According to Dr. Tobacman (Environmental Health Perspectives 2001, 109:983-984), there is cause for concern in carrageenan consumption. She reviewed 45 published studies, which found the development of cancerous tumours in the gut, and intestinal ulcers in animals such as rabbits, rats, mice and guinea pigs, with carrageenan usage. Her report indicated that carrageenan is easily taken up by intestinal cells but does not get metabolized. When it accumulates, it may cause cells to breakdown, which eventually leads to ulcerations. These ulcerations appear to lead to the development of cancerous malignancies and intestinal inflammation in animals.



Although most of the studies completed have been on animals during the 1970s, Dr. Tobacman questions the safety of this food additive in humans. More research needs to be done to determine if there is indeed a danger in using this product. Carrageenan is likely to be found in many foods. If you choose to limit carrageenan in your diet, its presence in food can usually be found on the nutrition label of any of the above products you may be using, but be aware of the possibility that the ingredients of prepared products added to others may not be listed out in full.

Mary Flesher, Clinical Dietitian, Richmond Hospital
First published in the Inside Tract® newsletter issue 128 – November/December 2001