Carrageenan: Nutrients, What Research Shows and Safety
Carrageenan (E407) from red seaweeds: food-grade versus degraded poligeenan, what EFSA, JECFA and FDA say, the Tobacman critiques, small human trials, and the 2016 organic board vote.
Content last updated . This page has not been medically reviewed.
Carrageenan is a thickener and gelling agent taken from red seaweeds such as Chondrus, Kappaphycus and Eucheuma. US rules describe it as the refined extract of red seaweeds in the families Gigartinaceae and Solieriaceae. [1] It is used in foods, mostly to hold dairy and plant drinks, desserts and meats together. In Europe it has the additive number E 407, and "processed Eucheuma seaweed" is E 407a. [2] This page is about the additive, not whole sea moss. The debate about it is real, so we say what each source found, who paid for it where we could tell, and what is still unsettled.
Read this first
- Two different things share a name. Food-grade carrageenan is a large molecule. Poligeenan (also called degraded carrageenan) is a much smaller molecule made on purpose with strong acid and heat. EFSA says poligeenan has never been authorised as a food additive and is not used in food. [2]
- Regulators: EFSA's 2018 re-evaluation found no concern about cancer or genetic damage for carrageenan and processed Eucheuma seaweed, but kept the acceptable daily intake (ADI) as temporary because of data gaps. [2] JECFA (FAO/WHO) lists the ADI as "not specified". [3]
- Infants: the sources disagree. JECFA in 2014 found carrageenan in infant formula up to 1,000 mg per liter "not of concern". [3] EFSA did not adopt that view and repeated the earlier EU committee advice that it is inadvisable in formula fed from birth. [2]
- Human evidence is small. One trial of 12 people with ulcerative colitis, one trial of 20 young men, and one survey study. They do not settle the question either way. [7] [8] [9]
- Whole food vs additive: this is a food additive. We found no evidence that eating whole sea moss and taking the additive have the same effects. See sea moss.
- If you have trouble breathing or swelling of the face or throat after eating anything, call 911 (or your local emergency number).
What is in it (USDA values)
No USDA entry for this food. Carrageenan is an extract used in small amounts and is not listed in USDA FoodData Central SR Legacy. What we read instead:
| Fact | What the source says |
|---|---|
| What it is | A sulfated polysaccharide (a sugar chain with sulfate groups) whose main units are galactose and anhydrogalactose, with 20 to 40% sulfate on a dry-weight basis. [1] |
| Absorption | Not absorbed intact (EFSA 2018). [2] |
| Rat studies | No harm at the highest doses tested: 3,400 to 3,900 mg per kg body weight per day in a subchronic study, and up to 7,500 mg per kg per day in chronic studies. [2] |
| Current ADI | EFSA: group ADI 75 mg per kg body weight per day, called temporary. JECFA: not specified. [2] [3] |
| Yield from seaweed | In dried Kappaphycus lots from four Indonesian sites, carrageenan yield ranged from 15.1 to 27.0%. [10] |
The ADI applies to carrageenan and processed Eucheuma seaweed together. [2] Amounts vary with seaweed species, site and processing.
What research says
| Question | What the sources found | Strength of evidence | What was studied |
|---|---|---|---|
| Is food-grade carrageenan safe at current use? | EFSA 2018: no concern for genotoxicity or cancer; temporary ADI; in a "brand-loyal" worst-case scenario the 95th percentile intake exceeded the ADI up to about 10-fold, which the Panel said may be overestimated but may be a safety concern. [2] JECFA: ADI not specified. [3] A 2002 review found long-term animal studies showed no colon tumor promotion and that many toxicity studies used doses far above human intake. [6] | Regulators judge it acceptable, with open questions | Animal studies, intake modeling |
| Degraded carrageenan (poligeenan) and the gut | In rats degraded carrageenan caused colitis then tumors; in monkeys colon lesions appeared. EFSA says the findings relate mainly to the degraded form, not food-grade carrageenan. [2] | Lab or animal only (degraded form) | Rats, monkeys |
| Tobacman critique | A 2001 review of animal studies linked both undegraded and degraded carrageenan to gut ulcers and tumors, and argued its use should be reconsidered. It suggested low-molecular-weight contamination or breakdown in digestion as explanations. [5] EFSA said results suggesting carrageenan might enhance human inflammatory bowel disease "need clarification". [2] | Lab or animal only; disputed | Animal studies review |
| Reply to the critique | A 2019 review argued that carrageenan cannot be converted to poligeenan in the body and that many harm claims mix up the two substances. [4] The authors' later addendum says many studies mislabel degraded carrageenan as carrageenan. [11] Both papers list FMC Corporation, a carrageenan maker, as funder. | Disputed; industry-funded | Chemistry and toxicology review |
| Ulcerative colitis relapse | In a 2017 double-blind trial, people in remission followed a no-carrageenan diet and took capsules with carrageenan or placebo. Three of the carrageenan group relapsed and none of the placebo group (p = 0.046). Only 12 completed the study. [7] | Promising but limited; very small | Capsules, below usual dietary intake, adults with UC |
| Insulin sensitivity | In a 2024 crossover trial of 20 young men, carrageenan 250 mg twice a day for 2 weeks did not change overall insulin sensitivity. In overweight participants, insulin sensitivity was lower and CRP, IL-6 and gut permeability were higher than with placebo. [8] | Mixed; small trial | Capsules, young men (mean age 27) |
| Inflammation marker (CRP) | A 2026 survey study of 922 US adults found carrageenan-containing protein drinks were not significantly linked with CRP overall, with a possible link in people in poorer health. The authors call it hypothesis-generating. [9] | Preliminary and mixed; observational | Protein drinks, NHANES survey |
Observational findings do not prove cause. The small trials used capsules, not foods, and should not be read as a ban or a green light.
Food vs supplement. The additive is eaten in foods. The trials above gave it as capsules. We found no source that says capsules and foods act the same way.
How much is a normal serving
There is no serving, because carrageenan is an ingredient, not a food. The only official figures we read are the EFSA temporary ADI (75 mg per kg of body weight a day, for carrageenan and processed Eucheuma seaweed together) and JECFA's "not specified". [2] [3] US rules allow it as an emulsifier, stabilizer or thickener in the amount needed, and require that the label say "carrageenan". [1] That is information, not a prescription.Safety, allergy and medicines
- Infants and young children: EFSA says the ADI does not apply to infants under 12 weeks, repeats that it is inadvisable in infant formula fed from birth, and has no objection to follow-on milks and weaning foods. [2] JECFA's 2014 view differs (up to 1,000 mg per liter "not of concern"), and noted infants on special formulas are normally under medical supervision. [3] Ask a pediatrician about formula.
- Inflammatory bowel disease: the only trial we read was very small. [7] Ask your own gastroenterologist; we do not tell anyone to avoid or eat carrageenan.
- Overweight and insulin resistance: a signal in one small trial only. [8]
- Medicines: Proper evidence not found in the sources we read for specific drug interactions.
- Allergy: Proper evidence not found in the sources we read. For emergency signs see food allergy basics. Call 911 for trouble breathing or swelling of the face or throat.
- Data gaps: EFSA asked for better chemistry, narrower molecular-weight limits so food-grade stays well apart from poligeenan, and more data within five years. [2]
Choosing, storing and food safety
- Reading labels: look for "carrageenan" in the ingredient list in the US. [1] In the EU look for E 407 or E 407a. [2]
- Organic rules, 2016 and 2018: in 2016 the US National Organic Standards Board recommended removing carrageenan from the list of non-organic ingredients allowed in organic foods. We read a trade-press report that its reason was that substitutes such as gellan, guar and xanthan gums were judged sufficient, not safety. The USDA Agricultural Marketing Service decided in April 2018 to keep it, saying substitutes did not adequately replicate its function, with a new sunset date of May 29, 2023. [12] We did not read the board's own documents, so we do not give the vote count.
- Storing: nothing specific to carrageenan from the sources we read.
Related pages
Health connections for Carrageenan
What research links to eating or drinking this food, and how strong the evidence is. Many studies are observational or use juice, powder, oil or extracts rather than the food as eaten; each card says which.
Carrageenan (E407) safety at current food use
Preliminary or mixedEFSA 2018 found no concern for genetic damage or cancer but kept the acceptable daily intake temporary because of data gaps; JECFA lists the ADI as not specified.
Supplements: Regulators judge food-grade carrageenan acceptable at current use; open questions remain.
Degraded carrageenan (poligeenan) versus food-grade carrageenan
Lab or animal research onlyPoligeenan is a much smaller molecule made with acid and heat; it has never been authorised as a food additive. Animal studies of gut damage and tumors mostly involve the degraded form.
Supplements: Lab and animal findings on the degraded form; one review arguing the two are often confused was funded by a carrageenan maker.
The Tobacman critique: carrageenan and gut ulcers or tumors in animals
Lab or animal research onlyA 2001 review linked both undegraded and degraded carrageenan to gut ulcers and tumors in animal studies and argued its use should be reconsidered. EFSA said suggestions of a role in human inflammatory bowel disease need clarification.
Supplements: Animal evidence; disputed by industry-funded reviews and by regulators.
Carrageenan and ulcerative colitis relapse
Preliminary or mixedIn a 2017 double-blind trial of 12 completers, 3 of those given carrageenan capsules relapsed and none given placebo did; the sample was very small.
Supplements: Capsules below usual dietary intake, not foods. Too small to settle the question.
Carrageenan and insulin sensitivity
Preliminary or mixedIn a 2024 crossover trial of 20 young men, carrageenan 250 mg twice a day for 2 weeks did not change overall insulin sensitivity but signals appeared in overweight participants (lower insulin sensitivity, higher CRP and IL-6, higher gut permeability).
Supplements: Small trial, capsules, short term.
Carrageenan and the inflammation marker CRP
Preliminary or mixedA 2026 NHANES analysis of 922 US adults found carrageenan-containing protein drinks were not significantly associated with CRP overall; a possible association in people in poorer health was called hypothesis-generating.
Supplements: Observational; does not prove cause.
Carrageenan and the US organic rules (NOSB 2016)
Not enough evidenceIn 2016 the National Organic Standards Board recommended removing carrageenan from the non-organic list, reportedly because substitutes were judged sufficient, not for safety; USDA kept it in April 2018 (trade press).
Supplements: Not evidence about health effects.
Connected topics
Open a group to see how each topic connects and how strong the evidence is.
Health goals (2)
- Blood Sugar BalancePreliminary or mixed
No overall change in insulin sensitivity in one small trial; a signal in overweight participants.
- Inflammation BalancePreliminary or mixed
One small trial saw higher CRP and IL-6 in overweight participants; a survey study saw no overall link with CRP.
Body systems (2)
- Digestive SystemPreliminary or mixed
Small human trials looked at relapse of colitis and gut permeability; results are mixed and the trials are tiny.
- Gut HealthPreliminary or mixed
Safety debate for gut inflammation; no large trial.
Body parts (2)
- GutPreliminary or mixed
Animal studies of the degraded form show gut damage; the human evidence is a 12-person colitis trial and other small studies, so it is unsettled.
- ColonLab or animal research only
Colon lesions and tumors were seen in rats and monkeys given degraded carrageenan; EFSA says this relates mainly to the degraded form.
Root causes (1)
- InflammationPreliminary or mixed
Animal and small human findings are mixed; regulators did not find a concern at food use.
Biomarkers (2)
Conditions & symptoms (2)
- Ulcerative ColitisPreliminary or mixed
One very small trial (12 completers) saw earlier relapse with carrageenan capsules; EFSA says suggestions of a role in human inflammatory bowel disease need clarification.
- Insulin ResistancePreliminary or mixed
A 2024 crossover trial of 20 young men saw no overall change but lower insulin sensitivity in overweight participants.
Documented risks and interactions (2)
- Carrageenan in infant formula and for young children. JECFA (2014) found up to 1,000 mg per liter in infant formula not of concern; EFSA did not adopt this and repeated that carrageenan is inadvisable in formula fed from birth; the ADI does not apply to infants under 12 weeks.
- Carrageenan intake compared with the EU ADI. In EFSA's worst-case brand-loyal scenario, intake at the 95th percentile exceeded the temporary ADI by up to about 10-fold, which the Panel said may be overestimated but may be a safety concern.
Frequently asked questions
Is carrageenan safe?
EFSA found no concern for cancer or genetic damage but kept its ADI temporary, and JECFA lists the ADI as not specified. [2] [3] Critics point to animal studies, which regulators say mostly involved the degraded form. [2] [5]
What is the difference between carrageenan and poligeenan?
Poligeenan is a much smaller molecule made with acid and heat, and has never been authorised for food. [2] Reviews say mixing the two names led to wrong claims, but one such review was funded by a carrageenan maker. [4]
Is carrageenan bad for the gut?
Animal studies of the degraded form show gut damage. [2] The human evidence is a 12-person colitis trial and other small studies, so it is unsettled. [7] [8] [9]
Is carrageenan allowed in baby formula?
Rules differ: JECFA said up to 1,000 mg per liter was not of concern, while EFSA repeated that it is inadvisable in formula fed from birth. [2] [3]
Why did the organic board vote on carrageenan?
In 2016 it recommended removal because it judged substitutes sufficient, according to trade press; USDA kept it in 2018. [12]
References
- U.S. Government. 21 CFR 172.620 Carrageenan. Read 2026-10-24.
- EFSA Panel on Food Additives and Nutrient Sources added to Food. Re-evaluation of carrageenan (E 407) and processed Eucheuma seaweed (E 407a) as food additives. EFSA Journal 2018;16(4):e05238 (first part of the full text read). Read 2026-10-24.
- WHO. JECFA database: Carrageenan (INS 407). Evaluations 2007 and 2014 (79th meeting). Read 2026-10-24.
- McKim JM, Willoughby JA, Blakemore WR, Weiner ML. Clarifying the confusion between poligeenan, degraded carrageenan, and carrageenan. Crit Rev Food Sci Nutr 2019;59(19):3054-3073 (abstract read via Europe PMC; grant from FMC Corporation listed). Read 2026-10-24.
- Tobacman JK. Review of harmful gastrointestinal effects of carrageenan in animal experiments. Environ Health Perspect 2001;109(10):983-994 (abstract read via Europe PMC). Read 2026-10-24.
- Cohen SM, Ito N. A critical review of the toxicological effects of carrageenan and processed eucheuma seaweed on the gastrointestinal tract. Crit Rev Toxicol 2002;32(5):413-444 (abstract read via Europe PMC). Read 2026-10-24.
- Bhattacharyya S, et al. A randomized trial of the effects of the no-carrageenan diet on ulcerative colitis disease activity. Nutr Healthy Aging 2017;4(2):181-192 (abstract read via Europe PMC). Read 2026-10-24.
- Wagner R, et al. Carrageenan and insulin resistance in humans: a randomised double-blind cross-over trial. BMC Med 2024;22:558 (abstract read via Europe PMC). Read 2026-10-24.
- Lam CS, et al. Evaluation of the association between carrageenan and systemic inflammation: results from NHANES. Mol Nutr Food Res 2026;70(9):e70484 (abstract read via Europe PMC). Read 2026-10-24.
- Ramadhan W, et al. Multi-trait dataset on dried tropical Kappaphycus seaweed from four cultivation locations in South Sulawesi, Indonesia. Data Brief 2026;68:113178, doi 10.1016/j.dib.2026.113178 (abstract read via Europe PMC, PMID 42676627). Read 2026-10-24.
- Weiner ML, McKim JM, Blakemore WR. Addendum to Weiner (2016) Parameters and pitfalls to consider in the conduct of food additive research. Food Chem Toxicol 2017;107(Pt A):208-214 (abstract read via Europe PMC; funding listed as FMC Corporation). Read 2026-10-24.
- FoodNavigator-USA. Carrageenan can continue to be used in organic products despite opposing NOSB vote, USDA says. 5 April 2018 (trade press, secondary report). Read 2026-10-24.