Aiming to further the research on these pint-sized particles, scientists developed a new method for detecting silver nano particles in food during a study published in the Journal of Agricultural and Food Chemistry. The method—actually a combination of several established techniques—was able to identify and measure relatively small amounts of these nano particles in pears and will be used to study their potentially toxic effects in food, says Mengshi Lin, PhD, study author and associate professor of food science at the University of Missouri. In the process of developing this new procedure, researchers made some unsettling discoveries. Pears were immersed in a silver nano particle solution, similar to a pesticide application, and then washed and rinsed repeatedly. Four days after the treatment and rinsing, the silver nano particles were still attached to the skin and some even penetrated the skin to reach the pear pulp. Meaning: You may actually end up eating them. And you’re probably consuming these nano particles in other foods as well, says Jaydee Hanson, senior policy analyst for the Center for Food Safety, a non-profit organization petitioning government agencies for stricter regulations and further safety testing of nano particles in food. “Many of the world’s leading food companies have invested heavily in nanotechnology in their foods and food packaging, but they’re not required to label, and we don’t yet know whether or not they’re leaching into foods and beverages.” More from Prevention: The Sketchy Food Additive You Haven’t Heard Of So what’s the harm? Even the experts aren’t totally sure. “There are many unanswered questions,” says Marina Quadros, PhD, associate director of the Virginia Tech Center for Sustainable Nanotechnology. “What we know so far is that silver nano particles don’t seem to be acutely toxic—some people even use nanosilver suspensions as health supplements because of silver’s antibiotic properties—but researchers are still trying to understand the effects that repeated exposure to these materials over time can have on cell metabolism.” While research on humans is lacking, preliminary research on animals is a bit concerning. “Some studies show that, once ingested, a small amount of these particles can move from the intestines into the blood and reach other organs, such as the liver and brain of rats, and damage cells there,” says Hanson. Size may be a big factor. “Many industries classify nano particles as materials whose dimensions are less than 100 nm, but at 300 nm we know that these particles are able to penetrate individual cells and that they may interfere with the structure and function of DNA.” Disclosure about nano particles use by companies is not required, but there are a few that do make statements. Highlighting the unknown health risks of nano-technology and the need for more research, McDonald’s website (yes, McDonald’s!) contains the following disclaimer: “Given the current uncertainty related to potential impacts of nano-engineered materials, McDonald’s does not currently support the use by suppliers of nano-engineered materials in the production of any of our food, packaging and toys.” The home of the Happy Meal is in the minority when it comes to companies that disclose anything regarding their use of nano particles. So what’s a concerned consumer to do? Hanson has a few strategies on how you can reduce your exposure:
Eat more whole foods. Companies aren’t required to label their use of nano materials in food packaging, so the fewer foods you eat from a package, the less likely you are to consume them. Buy local. Some foods that are transported long distances are treated with nanosilver to keep them fresh—a shiny coating may be a sign of this. Go organic. Organic produce, while not officially exempt from the use of nanosilver pesticide application, is less likely to be treated this way than conventional produce. It’s also grown without the use of human sewage sludge fertilizer, a byproduct from wastewater treatment plants that may be tainted with nanoparticles.
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