Food additive found in candy, gum could alter digestive cell structure and function

February 16, 2017
Researchers exposed a small intestinal cell culture model to the physiological equivalent of a meal's worth of titanium oxide nanoparticles -- 30 nanometers across -- over four hours (acute exposure), or three meal's worth over five days (chronic exposure). Credit: Gretchen Mahler

The ability of small intestine cells to absorb nutrients and act as a barrier to pathogens is "significantly decreased" after chronic exposure to nanoparticles of titanium dioxide, a common food additive found in everything from chewing gum to bread, according to research from Binghamton University, State University of New York.

Researchers exposed a small intestinal cell culture model to the physiological equivalent of a meal's worth of titanium oxide nanoparticles—30 nanometers across—over four hours (acute exposure), or three meal's worth over five days (chronic exposure).

Acute exposures did not have much effect, but chronic exposure diminished the absorptive projections on the surface of intestinal cells called microvilli. With fewer microvilli, the intestinal barrier was weakened, metabolism slowed and some nutrients—iron, zinc, and fatty acids, specifically—were more difficult to absorb. Enzyme functions were negatively affected, while inflammation signals increased.

"Titanium oxide is a common food additive and people have been eating a lot of it for a long time—don't worry, it won't kill you!—but we were interested in some of the subtle effects, and we think people should know about them," said Biomedical Engineering Assistant Professor Gretchen Mahler, one of the authors of the paper.

"There has been previous work on how titanium oxide nanoparticles affects microvilli, but we are looking at much lower concentrations," Mahler said. "We also extended to show that these nanoparticles alter intestinal function."

Titanium dioxide is generally recognized as safe by the U.S. Food and Drug Administration, and ingestion is nearly unavoidable. The compound is an inert and insoluble material that is commonly used for white pigmentation in paints, paper and plastics. It is also an active ingredient in mineral-based sunscreens for pigmentation to block ultraviolet light.

However, it can enter the digestive system through toothpastes, as is used to create abrasion needed for cleaning. The oxide is also used in some chocolate to give it a smooth texture; in donuts to provide color; and in skimmed milks for a brighter, more opaque appearance which makes the milk more palatable.

A 2012 Arizona State University study tested 89 common food products including gum, Twinkies, and mayonnaise and found that they all contained titanium dioxide. About five percent of products in that study contained titanium dioxide as nanoparticles. Dunkin Donuts stopped using powdered sugar with titanium dioxide nanoparticles in 2015 in response to pressure from the advocacy group As You Sow.

"To avoid foods rich in nanoparticles you should avoid processed foods, and especially candy. That is where you see a lot of nanoparticles," Mahler said.

The paper, "Titanium dioxide nanoparticle ingestion alters nutrient absorption in an in vitro model of the small intestine," was published in NanoImpact.

Explore further: Children may have highest exposure to titanium dioxide nanoparticles

More information: Zhongyuan Guo et al, Titanium dioxide nanoparticle ingestion alters nutrient absorption in an in vitro model of the small intestine, NanoImpact (2017). DOI: 10.1016/j.impact.2017.01.002

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Whydening Gyre
1 / 5 (2) Feb 16, 2017
I now wonder what titanium dental implants might affect...
Jeffhans1
5 / 5 (3) Feb 16, 2017
I now wonder what titanium dental implants might affect...


If you are chewing your implants into micro-particles, you might have something to worry about. Otherwise, you should be fine.
Whydening Gyre
1 / 5 (1) Feb 16, 2017
I now wonder what titanium dental implants might affect...


If you are chewing your implants into micro-particles, you might have something to worry about. Otherwise, you should be fine.

Mine is essentially a denture that mounts on implants. It is removable (for cleaning). It does not seat as "fixed" as a perm-mounted. It might allow for some friction chafing of TiO2...
I've had a funky skin rash since I got it, that seems to alleviate when I go a few hours without the denture in...
nilbud
Feb 17, 2017
This comment has been removed by a moderator.
Tagbert
not rated yet Feb 19, 2017
The titanium implant is the socket screwed into your jaw. The denture that attaches is not titanium but is plastic and ceramic.

Intact titanium metal is not the same as these nano particles of titanium dioxide. The effect would be very different. Many material have an impact on cells when they come in as nano particles but not when they are in larger chunks.
Whydening Gyre
not rated yet Feb 19, 2017
The titanium implant is the socket screwed into your jaw. The denture that attaches is not titanium but is plastic and ceramic.

Intact titanium metal is not the same as these nano particles of titanium dioxide. The effect would be very different. Many material have an impact on cells when they come in as nano particles but not when they are in larger chunks.

Titanium exposed to oxygen builds a TiO2 layer. Constant unmount and remount would result in scraping of that oxide layer by the denture mounts. As I was unsure of how big of chunks were being removed, along with subsequent processing by stomach acids, etc., I cast it out to see if someone better versed in the material science of it might have a reasonable answer...
Was just a simple question...

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