Carrageenan (E407)

What is carrageenan and what is it used for?

Carrageenan is a polysaccharide, that is, a long-chain carbohydrate, extracted from certain species of red seaweed. It is not digested in the body and provides no energy. There are different types, called kappa, iota and lambda; some form firm gels, some soft gels, and some only add thickness.

Its most important role in food is to stabilise mixtures by interacting with milk proteins: it stops cocoa settling at the bottom of chocolate milk, prevents plant milks from separating and stops ice crystals forming in ice cream.

Which products contain it?

• Chocolate milk, puddings, crème caramel and ready-made milk desserts
• Ice cream and cream
• Plant-based drinks such as almond, oat and soya
• Cream cheese and some processed cheeses
• Processed meat products such as salami, sausages and ham; some vegan jellies

On the label it may appear as “thickener (carrageenan)”, “gelling agent (E407)” or “stabiliser (E407)”. E407a is processed Eucheuma seaweed and is assessed in a similar way.

Is it harmful? The scientific assessment

Much of the debate comes from confusing two different substances. Degraded carrageenan (poligeenan), broken down by acid and high heat into a low molecular weight form, has caused intestinal damage in animals and is classified by IARC as Group 2B (possibly carcinogenic to humans). But poligeenan is not permitted as a food additive. The carrageenan used in food has a high molecular weight and does not fall under this classification.

Even so, some animal and cell culture studies have suggested that food-grade carrageenan may also increase inflammatory responses in the gut. In its 2018 re-evaluation, EFSA found no clear safety problem with permitted use based on the available data, but because of data gaps it set a temporary daily intake value and called for further studies. It also recommended tighter limits on the additive's poligeenan content.

Studies in humans are limited; there are small studies looking at the benefit of reducing carrageenan, especially in people with inflammatory bowel disease, but they have not been conclusive.

Who should be careful?

• People with inflammatory bowel disease (Crohn's disease, ulcerative colitis): They can discuss the effect of reducing carrageenan on their symptoms with their doctor or dietitian.
• People with a sensitive digestive system: If you notice bloating or discomfort after certain products, comparing labels can help.
• Babies: The use of additives in infant formula is subject to separate and much stricter rules.

What to do when you see it on a label

For a healthy adult, an occasional dessert containing carrageenan is not a serious cause for concern. If you want to cut down on carrageenan, plain yoghurt, plain milk and homemade desserts are good options. Among plant-based drinks there are also products that use xanthan gum, guar gum or gellan gum instead of carrageenan.