Carrageenan exposure and enzyme activity in human cells
What it found
In lab tests on human cells, carrageenan lowered the activity of several enzymes and raised levels of certain sugar molecules.
The effects were strongest with lambda-carrageenan.
What they found
Animal and lab studies
Enzyme activity dropped
In human gut and breast cells grown in dishes, all three types of carrageenan lowered the activity of several enzymes that remove sulfate groups. Lambda-carrageenan caused the biggest drop, while iota-carrageenan caused the smallest.
Cell sugars increased
After 4 days of carrageenan exposure, the total amount of natural cell sugars rose sharply in human gut cells. Cells not exposed to carrageenan had about 10 times less of these sugars than the treated cells.
New sugar forms appeared
Treated human gut cells contained double-sulfated sugar building blocks that were completely absent in untreated cells. New forms of heparin-related sugars also appeared only after carrageenan exposure.
Enzyme amounts unchanged
Although enzyme activity fell, the actual amount of enzyme protein in the human cells stayed the same after 48 hours of lambda-carrageenan exposure. Gene activity for these enzymes also did not change significantly.
Other findings
Uses in food products
Carrageenan is added to items like ice cream, yogurt, soymilk, infant formula, and deli meats to improve texture and solubility. A joint UN and WHO committee recommended keeping it out of infant formula and reviewing current intake levels.
What the authors conclude
- They conclude that carrageenan exposure significantly reduced the activity of multiple enzymes in human gut and breast cells grown in the lab.
- They note that these enzyme changes came with a sharp rise in natural cell sugars and new sugar forms not seen in untreated cells.
- The authors suggest these shifts may affect vital cell processes.
How it was done
People eat an estimated 250 mg of carrageenan a day on average, and possibly several grams if they eat many foods containing it. The authors wanted to see how this additive affects enzymes that remove sulfate groups from natural cell sugars, since carrageenan carries many sulfate groups itself.
The researchers grew human gut and breast cells in dishes and exposed them to three types of carrageenan at 1 µg/ml for 4 to 6 days. They measured the activity of several enzymes and the amount and makeup of natural cell sugars. They compared treated cells to untreated cells grown under the same conditions.
What it can’t tell you
- These experiments used cells grown in dishes, so they cannot show what happens when people eat carrageenan.
- The cells were exposed to 1 µg/ml of carrageenan, and scientists do not yet know if eating typical amounts leads to the same concentration reaching human cells in the body.
Who paid
- Funding
- Funded by NIGMS NIH HHS (from the PubMed record).
- Authors work at
- Rensselaer Polytechnic Institute, USA
The paper
- Title
- Exposure to common food additive carrageenan leads to reduced sulfatase activity and increase in sulfated glycosaminoglycans in human epithelial cells
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Full text
- Cite
- Yang B, Bhattacharyya S, Linhardt R, Tobacman J (2012). Exposure to common food additive carrageenan leads to reduced sulfatase activity and increase in sulfated glycosaminoglycans in human epithelial cells. Biochimie. doi:10.1016/j.biochi.2012.02.031Free full textPubMed 22410212DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error