NEW YORK — Billions of engineered nanoparticles in foods and pharmaceuticals are ingested by humans daily and new Cornell research warns they may be more harmful to health than previously thought.

A research collaboration led by Michael Shuler, the Samuel B. Eckert Professor of Chemical Engineering and the James and Marsha McCormick Chair of Biomedical Engineering, studied how large doses of polystyrene nanoparticles - a common, FDA-approved material found in substances from food additives to vitamins - affected how well chickens absorbed iron, an essential nutrient, into their cells. The results were reported online Feb. 12 in the journal Nature Nanotechnology.

According to the study, high-intensity, short-term exposure to the particles initially blocked iron absorption, whereas longer-term exposure caused intestinal cell structures to change, allowing for a compensating uptick in iron absorption.

The researchers tested both acute and chronic nanoparticle exposure using human gut cells in petri dishes as well as live chickens and reported matching results. They chose chickens because these animals absorb iron into their bodies similarly to humans, and they are also similarly sensitive to micronutrient deficiencies, explained Gretchen Mahler, Ph.D. ’08, the paper’s first author and former Cornell graduate student and postdoctoral associate.

The researchers used […]