I’m Shelley Schlender for How on Earth. Up next is an extended interview with University of California in San Diego scientist Ajit Varki about his team’s new mouse study that indicates that a “sugar” in red meat, called sialic acid, can trigger inflammation when fed to mice. This sugar is intriguing because it’s a molecule that two million years ago, our human bodies made on their own. It differs from the current sialic acid made in our bodies by just one atom of oxygen. Yet the mouse studies indicate that might be enough to cause an immune system reaction in the lab mice. More research and human studies will be needed, to determine whether or not a similar reaction occurs in susceptible humans. Now here’s Ajit Varki.