Ancient Rome was the greatest empire in the world - until it collapsed. Did lead exposure doom the empire? Recent research uncovered high levels of lead in Imperial Rome's drinking water, but that wasn't the most dangerous source of lead in the ancient civilization. The Romans used an artificial sweetener called sapa, a grape syrup, to preserve wine and sweeten foods. And sapa, boiled in lead vessels, carried a highly toxic level of the heavy metal. The artificial sweetener contained lead levels 200 times higher than the EPA allows. One single teaspoon of sapa could cause chronic lead poisoning.