Who Needs Dentists? Early Humans Ate This Weed

The purple nut sedge, or nut grass, is generally considered a nasty, fast-spreading, and hard-to-kill nuisance weed today. But for our ancestors, it not only served as a nutritious meal, it cleaned their teeth, according to a new study on PLoS ONE. An analysis of hardened bits of plaque from the teeth of ancient skeletons in Sudan reveals that those who ate the plant had surprisingly few cavities, Nature World News reports. Why? It turns out that purple nut sedge naturally fights off the growth of bacteria that causes tooth decay, reports National Geographic.

One anthropologist calls it a "very exciting" find because it's the first reported example of a specific plant fending off tooth decay in ancient populations. The remains reveal that people in Sudan were eating nut sedge as far back as 7,000 years ago, before the dawn of agriculture, and the study's lead author finds it significant that they kept eating it even after learning how to cultivate crops, the Washington Post reports. They seemed to recognize its medicinal qualities. "These small biographical details add to the growing evidence that prehistoric people had a detailed understanding of plants long before the development of agriculture." (Click to see which stealth carbs actually rotted ancients' teeth.)