Carrageenan, poligeenan and degraded carrageenan compared
What it found
The authors say carrageenan is not the same as poligeenan or degraded carrageenan, and that confusion between them has led to wrong claims about carrageenan in food.
The work is a review of chemistry, naming and animal and lab studies.
What they found
Animal and lab studies
Body cannot convert it
Carrageenan cannot be broken down into poligeenan inside the body.
Studies in people and animals
Cancer studies
Current studies support that carrageenan does not cause cancer or tumours in humans.
Other findings
Naming confusion
In early studies, poligeenan was called 'degraded carrageenan' and degraded carrageenan was called 'carrageenan'. This naming has been corrected, but confusion remains.
Different substances
Carrageenan, degraded carrageenan and poligeenan differ in their chemistry, how they are made, and how they react with proteins.
Molecular weight
A lack of understanding of the molecular weight distribution of carrageenan has made the confusion worse.
What the authors conclude
“As CGN cannot be hydrolyzed to PGN in vivo , concerns over the use of CGN as a food additive are unfounded, particularly since current studies support the lack of oncogenic and tumorigenic activity of CGN in humans.”
Also in their conclusions
- They say carrageenan has been proven safe for human consumption.
- They state that concerns over the use of carrageenan as a food additive are unfounded.
- They note that current studies support the lack of oncogenic and tumorigenic activity of carrageenan in humans.
How it was done
Early studies used confusing names, calling poligeenan 'degraded carrageenan' and calling degraded carrageenan simply 'carrageenan'. This mix-up has led to wrong information about carrageenan in food.
The authors reviewed the chemistry, how each substance is made, how they react with proteins, and animal and lab studies on carrageenan, degraded carrageenan and poligeenan taken by mouth.
What it can’t tell you
- We summarised it from the abstract only.
- This is a review of other studies, not a new experiment.
- It cannot prove cause and effect on its own.
- It relies on how the earlier studies were designed and named.
The paper
- Title
- Clarifying the confusion between poligeenan, degraded carrageenan, and carrageenan: A review of the chemistry, nomenclature, and in vivo toxicology by the oral route
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Abstract only
- Cite
- McKim JM, Willoughby JA, Blakemore WR, Weiner ML (2019). Clarifying the confusion between poligeenan, degraded carrageenan, and carrageenan: A review of the chemistry, nomenclature, and in vivo toxicology by the oral route. Critical reviews in food science and nutrition. doi:10.1080/10408398.2018.1481822PubMed 29902080DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error