The next time you opt1 for canned foods such as corn, tuna, asparagus or chicken, think twice. They may contain zinc2 oxide3 that can potentially damage your digestive system, warn researchers.
The findings showed that nanoparticles of zinc oxide present in the lining4
of certain canned goods, usually considered good for its antimicrobial properties and preventing staining of sulfur-producing foods, may negatively affect the way in which human digestive tract5
"We found that zinc oxide (ZnO) nanoparticles at doses that are relevant to what you might normally eat in a meal or a day can change the way that your intestine6
or your intestinal9
and protein expression," said Gretchen Mahler, Associate Professor at the Binghamton University in the New York.
Researchers found that canned food contained 100 times the daily dietary allowance of zinc.
"They tend to settle onto the cells representing the gastrointestinal tract and cause remodelling11
or loss of the microvilli, which are tiny projections12
on the surface of the intestinal absorptive cells that help to increase the surface area available for absorption," Mahler added.
This loss of surface area tends to result in a decrease in nutrient7
Some of the nanoparticles also cause pro-inflammatory signaling at high doses, and this can increase the permeability of the intestinal model, the researcher said.
In other words, it can even allow the passage of compounds that are not supposed to pass through into the bloodstream.
The study, published in the journal Food & Function, looked at how many particles might be transferred into the canned food.