Purple Nutsedge: Ancient Cavity Fighter


2000 Years ago the Sudanese had the world's best smiles!


Purple nutsedge (Cyperus rotundus) is a colony-forming perennial weed that seriously impacts agriculture across the southernmost United States. Native to Africa and tropical Eurasia, purple nutsedge has become a major weed of vegetable, row, and plantation crops in tropical and warm temperate climates around the world, is very difficult to manage with either organic or conventional weed control strategies (William, 1976), and has been called the world's worst weed (Holm et al., 1991). Purple nutsedge is one of the most extensively researched non-cultivated plant species on the planet, yet the complexities of its life cycle, and its multiple adaptations to environmental extremes and weed control tactics are as yet incompletely understood. Now scientists who once fought to destroy this weed are viewing it as a remarkable aid to dental care.


Purple nutsedge is a grass-like weed in the sedge family (Cyperaceae) with top growth 4–30 inches tall (Fig. 1), an extensive underground network of basal bulbs, fibrous roots, thin wiry rhizomes (Fig. 2), and tubers borne in chains of 2–6 or more on rhizomes, with tubers spaced 2-10 inches apart. The leaves are mostly basal, dark green, 0.1–0.25 inches wide with a prominent midrib, and abruptly tapered at the tips. The purplish to red-brown inflorescence is triangular in cross section and usually taller than the foliage. . The leaflike bracts are usually shorter than the longest spikes .A new analysis of skeletons reveals that people who lived in Sudan 2,000 years ago were eating the purple nutsedge. Those people had surprisingly sound teeth—and the antibacterial properties of the weed may deserve the credit,


Purple nut sedge is an antioxidant. It might reduce blood sugar and prevent the growth of certain bacteria, including the type that causes dental cavities. The people were eating a tuber known as purple nutsedge – the so-called world's worst weeds – and not giving it a second thought. Less than one percent of that local population's teeth had cavities, abscesses, or other signs of tooth decay, even though those people were probably farmers (early farmers teeth typically had more tooth decay than hunter gatherers because the high grain content in their diet created a hospitable environment for bacteria that flourish in the human mouth, excreting acids that eat away at the teeth). Fourteen skeletons dating to approximately 6,700 B.C. were examined at Al Khiday – an archeological site near the Nile River. Each skeleton was found to have hardened starch granules on its teeth. These granules shared a chemical composition with nutsedge. Purple nutsedge, in high concentrations, can inhibit one type of bacteria that promotes tooth decay.



Karen Hardy, lead researcher for the study and professor of archeology at Universitat Autònoma de Barcelona, claimed this may explain why fewer cavities were found in Al Khiday compared to an archeological site to the north. Today, however, nutsedge is no longer considered little more than a nuisance. “It’s a veggie, weedy thing,” says Hardy. “It’s very prolific. That’s why it’s such a problem for farmers today.” Several companies have started purchasing the weeds for tooth decay remineralization purposes.

This weed also known as Cyperus rotundus Ethno-pharmacological relevance: Cyperus rotundus L. (Cyperaceae) is a medicinal herb traditionally used to treat various clinical conditions at home such as diarrhea, diabetes, pyresis, inflammation, malaria, and stomach and bowel disorders could be the next million dollar health aid!