Carrageenan
E407 · Irish moss extract · "natural thickener"
A gum extracted from red seaweed and used as a thickener and emulsifier — particularly in dairy and dairy-free products. Technically natural, but the evidence on gut effects is enough that many "clean label" brands have already removed it.
Why we flag it
The carrageenan debate hinges on a distinction most labels don't explain. "Degraded carrageenan" (also called poligeenan) is a clearly problematic version produced under acidic, high-heat conditions — it's classified as a possible human carcinogen and isn't legal for food use. "Undegraded" food-grade carrageenan is what's actually in your yogurt; regulators worldwide consider it safe at typical intake.
The complication: in the human stomach's acidic environment, animal studies have shown that food-grade carrageenan can partially break down toward the degraded form. Several lab studies have linked it to gut inflammation, ulcerative colitis flares, and impaired glucose tolerance. The evidence is suggestive but not conclusive — which is why we flag it as medium rather than high. If you have inflammatory bowel disease or chronic gut issues, avoiding it is a reasonable precaution.
Where you'll find it
It's used wherever a product needs to be creamy, thick, or shelf-stable without separating:
- Plant-based milks — almond, oat, coconut, soy (varies widely by brand)
- Yogurts and Greek yogurts, especially low-fat or flavored varieties
- Ice cream, gelato, and frozen desserts
- Cottage cheese, sour cream, cream cheese
- Deli meats, cold cuts, and processed meats (binds water and improves slice texture)
- Heavy cream substitutes, infant formula, nutritional shakes
- Some chocolate milks and creamy salad dressings
What to look for instead
Plenty of brands have switched to carrageenan-free formulas — you just have to read the label:
- Gum-free plant milks — some oat and almond brands now use only oats/nuts and water
- Locust bean gum, gellan gum, or guar gum — common substitutes with less concerning evidence
- Whole-milk full-fat yogurt — fat handles thickness, no stabilizer needed
- Homemade plant milks — blender + nuts/oats + water + strainer
- Look for "carrageenan-free" on the front of dairy alternatives — many brands now advertise it explicitly
USDA Organic certification doesn't ban carrageenan outright (a 2018 review let it stay), but many organic brands voluntarily exclude it.