A team of German researchers specialized in diabetes and metabolic diseases (Wagner et al., 2024) studied the health effects of the consumption of carrageenan (E 407), a widely used additive in industrial foods. (1)
1) The study
The research was carried out at the Metabolic Research Center of the University Hospital of Tübingen, Germany, on 20 healthy men, average age 27,4 years, non-obese (BMI, body mass index 24,5 on average).
Volunteers were treated with oral intake of carrageenan (250 mg) or placebo, morning and evening, in two sessions of two weeks each with a rest interval of 21-35 days.
2) Carrageenan (E 407), a very common additive
The additive covered by the study is carrageenan (E 407) or carnegenan, an undesirable but vey common emulsifier in ultra-processed foods: chocolates and snacks, but also milk snacks so loved by children, ice creams, fresh pasta, spreadable cheeses, as found in our market research. (2)
‘The average daily intake of carrageenan has increased from 45 mg in the 1970s to over 250 mg at the beginning of the twenty-first century in some countries’, report the authors of the study in question.
3) Harmful effects already within the ADI
The acceptable daily dose (ADI) is set by EFSA (opinion 2018) at 75 mg per kg of body weight. (3) That is up to 5.250 mg for a 70 kg person or 750 mg per day for a 10 kg child.
The ADI expresses the maximum dose of exposure to the substance throughout life without any safety risk. However, the amount administered in the research in question (500 mg/day) – well below the ADI – shows harmful effects on health.
4) The results
Consumption of 500 mg of carrageenan showed effects on insulin sensitivity on a part of the participants and increased intestinal permeability.
‘In overweight participants, carrageenan exposure resulted in lower hepatic and total body insulin sensitivity, a trend toward increased brain inflammation, and elevated C-reactive protein (CRP) and IL-6 levels compared to placebo’, the researchers note.
4.1) Increased intestinal permeability
Carrageenan exposure also caused increased intestinal permeability.
‘Interestingly, this effect of carrageenan in inducing intestinal inflammation was not associated with any clinically relevant symptoms, indicating that these negative effects of increased exposure to carrageenan can go unnoticed for a considerable period of time’, underline the authors of the study.
5) Well-known harmful effects
Scientific research has been repeatedly shown that this additive can induce insulin resistance and intestinal inflammation in animal models and is suspected of causing adverse effects on human health.
‘Epidemiologically, an increase in carrageenan consumption has been associated with the incidence of breast cancer (+32%, ed.). (4)
An association between increased carrageenan consumption and a higher incidence of diabetes was found in a recent European population-based study.
In vivo studies in mice have shown that carrageenan added to drinking water induces glucose intolerance and exacerbates the adverse effects of a high-fat diet on blood sugar’, recall the authors of the study.
Marta Strinati
Footnotes
(1) Wagner, R., Buettner, J., Heni, M. et al. Carrageenan and insulin resistance in humans: a randomized double-blind cross-over trial. BMC Med 22, 558 (2024). https://doi.org/10.1186/s12916-024-03771-8
(2) See previous articles by Marta Strinati on GIFT (Great Italian Food Trade):
Tzatziki sauce, pay attention to the ingredients. 21.7.22
Additives at risk in Daygum Ferragni rubbers. 17.7.22
Fresh filled pasta, the taste of deceptive labels. 38 products in comparison. 10.2.22
Corn flakes and stuffed cereals, 24 in comparison. 22.1.22.
Frùttolo and other milk snacks, 10 products compared. 25.9.21
Fresh spreadable and flaked cheeses, 18 products in comparison. 30.7.21
Packaged ice cream, too many suspicious additives. Our market survey of 20 products. 6.7.21
(3) EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS). Re-evaluation of carrageenan (E 407) and processed Eucheuma seaweed (E 407a) as food additives. 14.3.18 EFSA Journal doi: 10.2903/j.efsa.2018.5238
(4) Marta Strinati. Emulsifiers increase cancer risk. Study. GIFT (Great Italian Food Trade).
Professional journalist since January 1995, he has worked for newspapers (Il Messaggero, Paese Sera, La Stampa) and periodicals (NumeroUno, Il Salvagente). She is the author of journalistic surveys on food, she has published the book "Reading labels to know what we eat".
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