A study in mice has suggested that common food additives, called emulsifiers, cause inflammation in the gut that in turn triggers bowel cancer.
Researchers divided the mice into three groups: two received emulsifiers, either sodium carboxymethycellulose (CMC) or polysorbate 80 (P80), and the third group received water.
Scientists found more and bigger cancerous tumours in mice given the emulsifiers, in addition to some inflammatory changes.
However, although there has been a lot of media industry in this story, it remains too early to say whether this phenomenon will also apply to humans.
The study was carried out by researchers from Georgia State University in Atlanta and was funded by a National Institutes of Health (NIH) grant, and published in the peer-reviewed medical journal Cancer Research.
It was suggested the reason could be that emulsifiers altered the balance of gut bacteria, creating an environment more favourable to the development of cancer.
Study lead, Professor Sanders from Kings College London, noted that the mice were fed the E numbers at a level of 1%, described as “a very high intake of the food additives compared to what might be found in human diets”.
Sanders added, though, that “we can’t assume this study is applicable to humans, so it shouldn’t be cause for concern.”
Emulsifiers prevent foods from separating and give food body and texture, and are commonly found in products such as ice cream.
Following the 13 week trial period, the mice were given an injection of azoxymethane (AOM), a strong cancer-causing substance in rodents, to induce colon cancer.
Five days later a dose of dextran sulfate sodium (DSS) used to induce colitis (inflammation of the lining of the colon).
At the end of the experiment, the mice receiving CMC and P80 showed a small but significant increase in their body mass.
The researchers concluded thus:
“We found that emulsifier induced alterations in the microbiome were necessary and sufficient to drive alterations in major proliferation and apotosis [cell death] signalling pathways thought to govern tumour development. Overall, our findings support the concept that perturbations in host-microbiota interactions that cause low-grade gut inflammation can promote colon carcinogenesis [tumour formation].”
While the biological processes that underpin these results are yet to be fully understood, there will certainly be more research undertaken after this illuminating result.