Nanoparticles In Food Packaging Could Be Reducing Our Ability To Absorb Nutrients

Potentially providing more proof that fresh food is best, a revealing study from researchers at Binghamton University has found that zinc oxide nanoparticles, present in the lining of food packaging, could reduce the ability of our intestinal cells to absorb nutrients.

Zinc oxide nanoparticles are used in food packaging for their antimicrobial properties. Generally lining the inside of certain canned goods, these inorganic nanoparticles are traditionally considered to be relatively harmless, but a small body of evidence is beginning to suggest that they may have unforeseen health implications.

Using mass spectrometry, this new study first examined several samples of canned food – corn, tuna, asparagus and chicken – to understand how many zinc oxide nanoparticles were being transferred to the food. In some instances, the study found these foods contained up to one hundred times the recommended daily dietary allowance of zinc.

The study then constructed an in vitro model of the small intestine to observe what effect such volumes of nanoparticles were having on intestinal cells. Unlike prior work in the area, this study wasn't examining high levels of toxicity, but rather the more subtle effects of nanoparticle doses that are closer to actual human exposure levels.

Gretchen Mahler, a corresponding author on the study, suggests the results show that the zinc oxide nanoparticles change the way intestine cells absorb nutrients and express proteins.

It's important to note that these effects have only been demonstrated in cell models and not replicated in human beings at this stage. It is generally believed that zinc oxide nanoparticles, when ingested by humans, are dissolved by stomach acids into the form of ionic zinc. The researchers are currently looking at animal models to see if similar effects from ingesting nanoparticles can be observed.

This isn't the first study to raise questions about the human health effects of zinc oxide nanoparticles. Although much research has been done to establish the safety of the nanoparticles in sunscreens, there are still concerns about the effects of nanoparticles when ingested. A 2011 study from scientists in Singapore suggested that zinc nanoparticles could trigger mechanisms in cells that potentially lead to the development of cancer