When I was a kid, my father was a big believer in cough syrup, just not natural cough syrup. He bought the other kind—the stuff that tastes like a mentholated cherry popsicle and dyes your tongue bright red. My dad didn’t know about potential side effects like hives and seizures, or the links between food dyes and hyperactivity in children. Whenever I had a cough, he dosed me with a teaspoon every few hours until I was so woozy I slept it off. But I’m a different kind of parent. There’s more access to information today, and I research everything that goes on my children’s bodies and into their mouths—often…