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Are Foods Containing Nanoparticles Safe To Eat?

 Did you know that some foods have nanoparticles added to them? Which foods? Nanoparticles in foods are ingredients so small that they are measured in nanometers or billionths of one meter. The most common nanoingredients are: titanium dioxide, silicon dioxide, and zinc oxide. What, if anything, do nanoingredients do to humans? That is, are there any effects from ingesting them? No one really knows. However, several articles in the past year raise a number of concerns, especially because so much is still unknown. Meanwhile the use of nanoingredients is unregulated in the U.S., and the number of foods with nanoingredients is growing rapidly.

Nanoparticles are typically used in foods as additives, flavorings, coloring, or even anti-bacterial coatings for packaging. It is thought that nanocoatings are being used on some fruits and vegetables. Even though ingredients such as titanium dioxide are considered to be "generally recognized as safe" (GRAS) before they're made into nanoparticles, the question is whether they’re safe in their nanoparticle form. This is because nanoparticles can exhibit new or altered properties at nanoscale dimensions. Some concerns about nanoparticles are that they are small enough to penetrate the skin, lungs, digestive system, and perhaps pass through the blood-brain barrier and placental-fetal barrier, and cause damage.

A 2016 report by Friends of The Earth reported finding nanoparticles in various brands of baby formulas. None listed nanoparticles as ingredients, but independent laboratory testing found the baby formulas to contain them. The Medscape article (below) reported on recent research  that suggested that nanoingredients can cause problems such as intestinal inflammation, especially for certain groups, such as those with intestinal bowel disease (IBD). According to the Science News article (below): "Tests show that on average more than one-third of the titanium dioxide in foods is in the form of nano-sized particles."

The Center For Food Safety states: "Bulk scale titanium dioxide is used as a food coloring agent, often to make foods look whiter or brighter, but the FDA has not set exposure limits yet for its use at the nano scale in the US. Moreover, the largest review of nano titanium dioxide studies show that many basic questions have not been answered. Candies like M&M’s, processed cheeses, and chewing gum have all been found to contain nano titanium dioxide.  Nano titanium dioxide is small enough to cross through the intestine and into organs where it can damage DNA and disrupt cell function." They have established a searchable data base of foods containing nanoparticles. The list is incomplete, but some popular foods containing nanoingredients (may not be on ingredient list, but lab tests found them) include: M&Ms, Lindt chocolate, Dannon Greek Plain Yogurt, Cadbury Milk Chocolate bars, Nabisco Chips Ahoy cookies, and Nabisco Oreos.

From Medscape [UPDATE: The Medscape link no longer works. Link to original study and to a discussion of the research in The Rheumatologist.]:  Titanium Dioxide Additives May Boost Intestinal Inflammation

Murine [mice] and other studies suggest that titanium dioxide (TiO2) nanoparticles, widely used as food additives and in drug formulations, may be involved in intestinal inflammation, according to Swiss researchers..... "It seems that titanium dioxide nanoparticles are not harmful for a healthy person with a normal intestinal barrier. But this may be different in an individual with impaired intestinal barrier function such as patients with inflammatory bowel disease (IBD).".... IBD is increasing in many nations undergoing westernization. Among possible causes are microparticles of agents such as Ti02, which are used to improve the appearance of products including food.

The researchers go on to point out that there is increasing evidence that exposure to TiO2 "can cause adverse effects, including the production of reactive oxygen species (ROS) inflammatory responses and tumor formation.".....Finally, wrote the investigators, "An increase of titanium burden in blood of patients with ulcerative colitis having active disease was found, evidencing an impaired barrier function and suggesting that TiO2 nanoparticles could pose a specific risk to patients with IBD."

Good eye-opening article. From Science News: Nanoparticles in foods raise safety questions

It seemed like a small thing when Paul Westerhoff’s 8-year-old son appeared, with his tongue and lips coated bright white. The boy had just polished off a giant Gobstopper, a confectionery made of sugary, melt-in-the-mouth layers. Curious about the white coating, Westerhoff, an environmental engineer, pored over the jawbreaker’s contents and discovered just how incredibly small the matter was. Among the Gobstopper’s ingredients were submicroscopic particles of titanium dioxide, a substance commonly added to plastics, paint, cosmetics and sunscreen. At the time, Westerhoff’s lab group at Arizona State University was actively tracking the fate of such particles in municipal wastewater systems across the nation.

Titanium dioxide is also a food additive approved by the U.S. Food and Drug Administration. Ground to teensy particles measuring just tens of billionths of a meter in size — much smaller than a cell or most viruses — titanium dioxide nanoparticles are frequently added to foods to whiten or brighten color. 

Weeks after his son’s candy-coated encounter, Westerhoff went to the supermarket, pulled more than 100 products off the shelves and analyzed their contents. His findings, published in 2012 in Environmental Science & Technology, show that many processed foods contain titanium dioxide, much of it in the form of nanoparticles. Candies, cookies, powdered doughnuts and icing were among the products with the highest levels. Titanium dioxide is also found in cheese, cereal and Greek yogurt.

Titanium dioxide isn’t the only nanoingredient added to food. Various other materials, reduced to the nanoscale, are sprinkled into food or packaging to enhance color, flavor and freshness. A dash of nano will smooth or thicken liquids or extend the shelf life of some products. Scientists have designed nano-sized capsules to slip beneficial nutrients, such as omega-3 fish oil, into juice or mayonnaise, without the fishy taste.  

But as scientists cook up ways to create heart-healthy mayo and fat-fighting ice cream, some are also considering the potential risks that might accompany the would-be benefits. Because of their small size, ingested nanoparticles may interact with cells or behave differently than their bulkier counter-parts. So far, less-than-perfect laboratory studies offer contradictory results.

Researchers, including those developing nanofoods, say more information is needed on the ingredients’ potential impacts. Current studies, limited to mice or lab dishes, often analyze megadoses of particles far beyond what any normal diet would include. Scientists need a better handle on what happens when people nosh on nanolaced foods daily, taking in small doses at a time, says Ohio State University pathologist James Waldman. He and others are devising tests to find out.

So far, only a few nanoingredients are added directly to foods or packaging: Titanium dioxide, silicon dioxide and zinc oxide are the most common. Larger versions of these ingredients have been used in food and medicines for decades and are considered “generally recognized as safe” by the FDA, which requires that any substance added to food be evaluated for safety.

Scientists have developed numerous ways to test the safety of substances that go into food, but most of the tests were designed decades ago, before ingredients began to go nano. Titanium dioxide, for example, was evaluated in the late 1960s, using particles larger than 100 nanometers. Human cells were exposed to the substance to test for toxic effects and to work out how much of it can be safely consumed. But those safety tests may not apply to some nano-substances. Size and surface features can improve or impair a nanoparticle’s ability to enter cells. Some nanoparticles — including those considered safe by the FDA — interact with cells in odd or unexpected ways, according to several recent studies.

Most studies of nanoparticles in food focus on the gastrointestinal tract — the mouth, esophagus, stomach and intestines. Waldman’s group at Ohio State is tracking the fate of nanoparticles once they’re swallowed to see if they travel beyond the gut. In February, the researchers showed that nanoparticles force-fed to mice can reach the liver, kidneys, lungs, brain and spleen. Details were published in the International Journal of Nanomedicine. “Particles are getting into the bloodstream, and once they’re there, they can go to any other organ,” Waldman says.

The FDA has not erected new hoops for food manufacturers that use nanoparticles. Requests to use a food ingredient at the nanometer scale are subject to the same safety requirements applied to other food additives, according to FDA press officer Megan McSeveney. Manufacturers must demonstrate that the substance is safe under the conditions of its intended use. In June 2014, the agency issued guidelines that go only as far as advising manufacturers to consult with the government before launching nanotechnology products.....Meanwhile, scientists agree that, based on studies to date, the nanofoods found on supermarket shelves are probably safe to eat — when consumed at “typical” quantities. 

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