What is Carrageenan?
Carrageenan is a common food additive (E407) derived from red seaweed (Irish moss). It is a polysaccharide used extensively in the food industry for its gelling, thickening, and stabilizing properties. Due to its plant-based origin, it is also a popular vegan alternative to animal-derived gelatin. You can find it in a wide array of products, including dairy-free milks, yoghurts, deli meats, vegan cheeses, ice cream, and certain processed ready meals.
The crucial distinction: Food-grade vs. Degraded Carrageenan
A significant source of confusion and concern arises from the difference between food-grade carrageenan and degraded carrageenan, also known as poligeenan.
| Feature | Food-Grade Carrageenan (E407/E407a) | Degraded Carrageenan (Poligeenan) |
|---|---|---|
| Processing | Extracted from seaweed using an alkaline process. | Created by processing with acid and high temperatures. |
| Molecular Weight | High molecular weight (over 100,000 daltons). | Low molecular weight (typically 10,000–20,000 daltons). |
| Function | Used as a thickener, gelling agent, and stabiliser in foods. | Has no technological use in food and is not a permitted additive. |
| Safety Status | Approved for food use by UK and EU regulators. Considered safe by JECFA. | Associated with causing ulcers and cancer in animal studies; not permitted in food. |
The scientific and regulatory perspective in the UK
In the UK, food safety is overseen by the Food Standards Agency (FSA), which relies on scientific assessments from bodies like the European Food Safety Authority (EFSA).
- EFSA’s Re-evaluation (2018): In 2018, EFSA's re-evaluation of carrageenan and processed eucheuma seaweed reaffirmed their safety for food use. However, the panel did identify some data gaps concerning potential degradation in the gut, especially in infants, and requested additional toxicological data. This prompted further data collection, which is ongoing.
- Food-Grade vs. Degradation Concerns: The primary regulatory concern has been to ensure food-grade carrageenan is not contaminated with significant levels of its degraded form. EU and now UK specifications limit the amount of low molecular weight components in food-grade carrageenan. The debate continues among some scientists about whether food-grade carrageenan can be broken down into harmful compounds within the human digestive tract, but large-scale human studies are lacking.
The case for concern: What the studies suggest
While regulatory bodies maintain that food-grade carrageenan is safe, some scientific studies have raised potential red flags. The majority of these are lab-based (in-vitro) or animal studies, which cannot be directly extrapolated to human health outcomes.
Evidence for potential negative effects includes:
- Gut Inflammation: Animal studies have consistently shown that carrageenan can trigger intestinal inflammation, with researchers using it to induce inflammatory conditions to test anti-inflammatory drugs.
- Intestinal Permeability ('Leaky Gut'): Research indicates carrageenan might affect the gut wall, increasing intestinal permeability and potentially allowing toxins to enter the bloodstream.
- IBD and Digestive Issues: A 2017 human study on ulcerative colitis patients suggested that carrageenan intake could potentially contribute to disease relapse. Many people with digestive issues, including IBD, report anecdotally that their symptoms improve after removing carrageenan from their diet.
- Glucose Intolerance and Insulin Resistance: Recent studies in mice and human cells suggest a link between carrageenan consumption and impaired glucose tolerance or increased insulin resistance, particularly in individuals with a higher BMI.
- Potential Link to Cancer: While food-grade carrageenan has not been shown to be carcinogenic on its own, some animal studies suggest it could act as a 'promoter' for colon tumours when combined with other known carcinogens, although this is heavily debated.
How to avoid carrageenan
For those in the UK who wish to reduce or eliminate their carrageenan intake, it is crucial to read ingredient labels. The additive will be listed as 'carrageenan' or by its E-number, E407. Alternatives used for thickening and stabilising can include:
- Guar gum (E412)
- Xanthan gum (E415)
- Locust bean gum (E410)
- Gellan gum (E418)
- Agar-agar
Choosing less processed foods is a straightforward way to reduce exposure, as carrageenan is predominantly found in ultra-processed products. For items like plant-based milks, many brands now offer carrageenan-free varieties, though they may require a good shake before use to prevent separation.
Conclusion
In the UK, food-grade carrageenan is a regulated and approved additive (E407), with official bodies concluding it is safe for consumption within specified levels, based on the distinction from its unsafe degraded form, poligeenan. However, a persistent and unresolved scientific debate, fuelled by animal studies and anecdotal reports, points towards potential links with gut inflammation, IBD symptoms, and glucose intolerance. Given this uncertainty and the lack of nutritional benefit, individuals with pre-existing gastrointestinal issues or those simply wishing to take a precautionary approach may choose to limit or avoid carrageenan-containing foods. The decision ultimately rests on weighing the regulatory assurances against the concerns raised by a body of scientific and anecdotal evidence. As with any dietary concern, consulting a healthcare professional is advisable for personalised guidance.
