Thursday Nov 28, 2013 (foodconsumer.org) -- A study led by N.A Baky from Faculty of Pharmacy, King Saud University, Riyadh, KSA suggests exposure to zinc oxide nanoparticles can damage the heart.  Zinc oxide is a supplement that is commonly used in food, dietary supplements and cosmetic products like zinc oxide cream and zinc oxide ointment.  While commonly used, the material has not been thoroughly tested for its safety.

The study published in Drug Research shows zinc oxide nanoparticles induce damage to the heart and supplementation of α-lipoic acid and vitamin E can ammoniate the adverse effect of zinc oxide nanoparticles on cardiac health.

In this study, rats were exposed to 600 mg/kg or 1 g/kg body weight of zinc oxide for five consecutive days.  A dose of 200 mg of lipoic acid per kg body weight of alpha-lipoic acid or 100 mg of vitamin E per kg body weight was given along with zinc nanoparticles or daily after rats were intoxicated with zinc oxide nanoparticles for 3 weeks.

Alpha-lipoic acid and vitamin E supplementation significantly ameliorated the toxicity of zinc oxide nanoparticles on the heart.  Also these two antioxidants reduced the inflammatory biomarkers increased by zinc oxide including "tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and C-reactive protein (CRP)."

Evidence also shows alpha-lipoic acid and vitamin E can reduce the increase in cardiac calcium concentration and oxidative DNA damage and cardiac caspase-3 activity induced by zinc oxide nanoparticles.

The study concluded "early treatment with either α-lipoic acid or vitamin E may offer protection against cardiac tissue injury induced by the deleterious toxic impacts of ZnO-NPs (zinc oxide nanoparticles)."

In another study, the same team of researchers found titanium dioxid nanoparticles can cause damage to the kidneys and quercetin and idebenone can help reduce the toxicity of titanium dioxide nanoparticles.

Titanium dioxide is also commonly used in dietary supplements, cosmetic products like sunscreens and food.  Fish exposed to high doses of nanoparticles in water die quickly, early studies show.

Another type of nanomaterial commonly used in food is silicon dioxide.

Studies have shown that nanoparticles can enter cells and disrupt DNA potentially causing mutations. 

Dietary supplements quercetin, idebenone, α-lipoic acid and vitamin E are available on the Internet and local health stores.   Other antioxidants like vitamin C may also help. (David Liu, PHD)