Sunday Sep 14, 2014 (foodconsumer.org) -- In a study, scientists at Islamic Azad University in Urmia, Iran demonstrated that silicon dioxide, the dispersing agent or anti-caking agent that is commonly used in foods, dietary supplements, and cosmetics, can damage cells/tissues in the liver, kidney, lung and testis.

This is not the first study to show the toxicity of nanoparticles.  Early studies have revealed nanotoxicity of nanoparticles like titanium dioxide, zinc oxide and silicon dioxide, all of which are commonly used in foods, dietary supplements and personal care products. 

The current study examined the toxic effect of ingested silicon dioxide on 19 biochemical parameters and found silicon dioxide with diameters between 10 and 15 nanometers caused "significant changes in albumin, cholesterol, triglyceride, total protein, urea, high density lipoprotein cholesterol (HDL), and low density lipoprotein cholesterol (LDL as well as in alkaline phosphatase and aspartate aminotransferase activity".

The damage induced by ingested silicon dioxide was histopathologically evident in various tissues including liver, kidney, lung and testis.

The nanotoxicity of titanium dioxide has been recognized by some organizations.  Some dietary supplements manufacturers have stopped using titanium dioxide in their products.  But silicon dioxide and zinc oxide are still very commonly used in dietary supplements, processed foods, and personal care products and cosmetics. (David Liu PHD)

Hassankhani R, Esmaeillou M, Tehrani AA, Nasirzadeh K, Khadir F, Maadi H., In vivo toxicity of orally administrated silicon dioxide nanoparticles in healthy adult mice.  Environ Sci Pollut Res Int. 2014 Aug 13.