Carrageenan
The short version
A seaweed-derived gelling agent — central to plant milks, ice cream, and processed meats; under scrutiny for gut microbiome effects.
A seaweed-derived thickener. It's approved and widely used, but some studies suggest a broken-down form can irritate the gut, and that debate isn't fully settled. That uncertainty is why we flag it.
Where it comes from
Extracted from edible red seaweeds (primarily Chondrus crispus — Irish moss — and Kappaphycus alvarezii). Used as a traditional thickener in Irish and Asian cuisines for centuries before commercial extraction in the 1930s.
How it's used
Used in ice cream, dairy desserts, plant milks, processed meats (for water retention), low-fat spreads, and toothpaste. Excellent at gelling at low concentrations (0.1–1%). Critical to the texture of many plant-based dairy substitutes.
Safety profile
ADI not specified by JECFA but use is restricted in infant formula in the EU and several other jurisdictions. The degraded form (poligeenan, not approved for food) is an established gastrointestinal inflammatory agent in animal models. Whether food-grade carrageenan has similar effects in humans is debated; recent in-vitro and animal studies have raised concerns about gut microbiome and intestinal inflammation.
Physical & chemical properties
Off-white to tan powder, soluble in hot water, forms gels on cooling. Different grades (kappa, iota, lambda) give brittle gels through soft creamy textures. Reactive with milk proteins, which underlies its use in dairy products.
Regulation worldwide
Permitted globally for food use. Banned in infant formula in the EU. The US National Organic Standards Board recommended removal from the organic list in 2016 but USDA reinstated it after public consultation.
Educational information only. Not medical or dietary advice.