A common ingredient which is found in chewing gum, mayonnaise and toothpaste could be a factor in triggering bowel cancer, experts have warned.
Titanium dioxide - listed as E171 on labels - is used as a whitening agent in hundreds of products and could have a harmful effect on the natural bacteria in the gut.
A trigger for cancer?
The ingredient crops up in more than 900 food products and a number of cosmetics items, such as suncream, eye shadow, blusher and pressed powder. Experts have warned about a number of health concerns related to it.
Researchers at the University of Sydney carried out a study on mice and found that eating food which contained the additive could impair some functions of the gut.
Their findings, published in the journal Frontiers in Nutrition, suggested that consuming E171 could trigger inflammatory bowel diseases and even lead to cancer.
Despite insufficient evidence about its safety, use of the additive in foods, medicines and clothing has increased considerably in the last decade.
While its use in foods has sparked concerns it could trigger bowel diseases, exposure to titanium dioxide nanoparticles has also been linked to a number of other health problems, including dementia, auto-immune disease, eczema and asthma.
It has also been associated with increasing the spread of cancer.
Plans for a ban?
Just last month, France announced titanium dioxide would be banned from products as of next year, following a 2017 review into the additive.
However, despite warnings over its safety, government officials in Britain have said that E171 is "not of concern" and there is currently no ban planned on its usage in the UK.
Co-lead author Associate Professor Wojciech Chrzanowski, from the University of Sydney, said, "It is well established that dietary composition has an impact on physiology and health, yet the role of food additives is poorly understood.
"There is increasing evidence that continuous exposure to nanoparticles has an impact on gut microbiota composition, and since gut microbiota is a gatekeeper of our health, any changes to its function have an influence on overall health.
"This study presents pivotal evidence that consumption of food containing food additive E171 (titanium dioxide) affects gut microbiota as well as inflammation in the gut, which could lead to diseases such as inflammatory bowel diseases and colorectal (bowel) cancer."
Fellow lead author Associate Professor Laurence Macia added, "Out research showed that titanium dioxide interacts with bacteria in the gut and impairs some of their functions which may result in the development of diseases."
Dr Macia recommended that consumption of the additive should be better regulated by food authorities.