After trying and failing for two years to replicate research out of the University of Illinois at Chicago and the University of Chicago that suggested carrageenan in food causes intestinal inflammation, James McKim, the president of IONTOX, a consultancy and R&D firm that focuses on toxicology issues, concludes in a study in the peer-reviewed journal Food and Chemical Toxicology that carrageenan consumed in food does not cause intestinal inflammation, does not cross the intestinal epithelium and is not toxic to cells.
As such, he told FoodNavigator-USA, the red seaweed-based ingredient, cannot interact with other organs and is safe to consume.
“Over the past 10 years, there have been several studies from a single research group at the University of Chicago [and the University of Illinois at Chicago] which have reported that carrageenan in food causes intestinal inflammation. This work cited findings that carrageenan causes oxidative stress and binds to a receptor called Toll-Like-Receptor 4 (TLR4), which causes inflammation in the intestine when activated. These studies are in direct conflict with many peer reviewed studies that examined the effects of carrageenan when consumed by animals and demonstrated that carrageenan in food has no effect on the intestine,” said McKim, who also is a recognized carrageenan expert.
He explained that an important part of the Chicago group’s research was the use of human intestinal and liver cell lines to confirm the effects of carrageenan, but given the conflicting findings between the Chicago group and the rest of the peer-reviewed literature, he said it was necessary that an independent researcher test whether the findings could be substantiated in similar cell models.
“My study was designed to investigate each event that was reported by the Chicago group using cell lines. We did this by closely matching the experimental setup reported by the Chicago group and adding important positive and negative controls. We also increased the concentrations of carrageenan and exposure times in my experiments. These conditions went well beyond what would be expected in the body when carrageenan is consumed in food,” he said, adding, “My work clearly demonstrates that the Chicago group’s findings could not be replicated and that carrageenan does not cause the induction of inflammatory proteins.”
McKim’s findings align with the remaining bulk of published research that shows carrageenan is safe and is not broken down in the gut by low pH or microbes, isn’t absorbed in the intestines and, therefore, does not enter the body.
It is also important, he said, because “when science cannot be replicated, we must be very suspect of the findings and question what may have gone wrong.”
He hypothesized in the Chicago group’s case, the findings could be due to impurities or contamination introduced by the laboratory into the carrageenan used in the studies.
Study could influence NOSB decision on carrageenan
The study comes just as the US National Organic Standards Board is weighing whether to reapprove the use of carrageenan in organic food sold in the US.
Members of the board indicated at the Spring NOSB meeting in Washington, DC, that they were torn about whether the ingredient – which is nearing a mandated sunset – should remain on the list of non-organic products.
However, the board also made several comments at the meeting indicating the importance of McKim’s research in their decision-making process, noted Robert Rankin, executive director of the International Food Additives Council (IFAC). IFAC and the FMC Corporation helped fund McKim's research.
“We feel confident that the study will reassure them as to the safety of carrageenan as well as raise major questions about the validity of the scientific research cited by carrageenan detractors as evidence the substance should be not be permitted in organic foods,” Rankin added.
Convincing shoppers could be a challenge
Convincing NOSB to continue to allow the ingredient is only one challenge for the ingredient – supporters of its safety also must convince end-users that it will not cause harm.
Consumers increasingly are interested in what they consume and concerns about carrageenan’s safety have prompted some to avoid the ingredient. This in turn has placed pressure on some manufacturers to reformulate without the ingredient or discontinue products that use it.
“It is worth noting that while a few companies have pledged to remove carrageenan from their products as a result of pressure organized by several activist organizations, and not due to any concerns about safety, hundreds of companies continue to use carrageenan in many of their products. These companies use carrageenan because its safety continues to be supported by every regulatory body around the world,” Rankin said.
He added IFAC is trying to better communicate with consumers about what is in their food – as such, he said, “IFAC recently initiated a proactive communication program to better inform the public about the positive contributions ingredients make to a healthy, diverse and sustainable food supply … in language that is accessible to consumers from all walks of life.”
For carrageenan specifically, Rankin said, “a key partner in this effort will be carrageenan users who need to explain to their customers why carrageenan is used in their products and what would happen if it were removed.”
He added IFAC has provided research resources to these companies to “help them feel confidence about the safety of carrageenan when making formulation decisions responding to customer questions.”