arsenic

Coca-Cola has never shied away from trying new variations of its classic beverage. The company also is known for adding flavorful twists like lime and lemon to its drinks. But last week, both Coke and archrival Pepsi revealed that a more disturbing addition had made its way into their drinks: fungicide.

Last week, TV host Dr. Mehmet Oz took on apple juice, declaring that the classic drink may be slowly poisoning America's children with arsenic. But the FDA and the juice companies have credibly refuted his claims. So was Dr. Oz's announcement meant to be a legitimate health warning, or just a cynical attempt to boost ratings?

NASA has discovered a bacteria that can use arsenic -- which is toxic to most forms of life -- as a building block of its DNA. Scientists say the discovery may broaden our definition of what constitutes life and may revolutionize how we search for life beyond Earth.