The July issue of PLOS ONE included a research article entitled, “Dental Calculus Reveals Unique Insights into Food Items,
Cooking and Plant Processing in Prehistoric Central Sudan.” You can find the original article here. The researchers obtained dental calculus samples from several burial sites in Sudan, some dating back over 7000 years. In addition to discoveries regarding cooking and eating habits of pre agrarian humans the samples also indicated consumption of cyperus rotundus. The common name of this plant in English is purple nut sedge. Though it is often thought of as an invasive weed, it is also known for its nutritional and medicinal value.

In Chinese medicine cyperus rotundus is known as XiangFu (香附). This herb was first recorded during the Later Han Period, around the middle of the 10th century C.E. It is now still a commonly used herb in clinical Chinese medical practice. In both Taiwan and China XiangFu is one of the most commonly prescribed herbs for treatment of dysmenorrhea.

There are several ways in which XiangFu can be prepared; most commonly it is dry fried before being included in a prescription but it can also be soaked in vinegar or wine. The common form is used for its regulatory and pain relieving effects on menstruation. It can also be used as an analgesic in cases of stagnation type pain in other areas of the body, but most commonly around the flanks and intercostals. In cases of both menstrual pain or flank pain, XiangFu is used when the system of pattern diagnosis indicates a stagnation of qi or liver qi. Other symptoms of this type of pattern may include decreased appetite, irregular menstruation, indigestion and nausea, acid reflux, a deep rough pulse, and a short temper. For cases in which gastric symptoms are more apparent it is often added to formulas such as XiangFuSan(香附散) wherein it is combined with cooling herbs such as ZhiZi(梔子), ChuanLian(川連), ChenPi(陳皮), and BanXia(半夏). This compound formula can control stomach acid, relieve inflammation, suppress nausea, and alleviate epigastric and flank pain. For cases of menstrual pain XiangFu is often combined with formulas such as XiangFuXiongGuiTang(香附芎歸湯), XiaoYaoSan(逍遙散), DangGuiShaoYaoSan(當歸芍藥散), JiaWeiXiaoYaoSan(加味逍遙散), or SiWuTang(四物湯). These formulas help to regulate menstruation and relieve cramps, as well as alleviate psychological symptoms of mood swings, irritability, depression and nervousness. Research has shown that XiangFu can mitigate the intensity of uterine contractions (1). While part of the normal menstrual cycle, if contractions are overly intense the resulting hypoxia to surrounding tissues will result in cramping and pain. This is what is meant by qi stagnation.

In discussing their results, the researchers suggest that chewing the tubers of the purple nut sedge may have decreased the prevalence of cavities through an antibiotic effect. While this is true, it may in fact be an unintentional secondary effect. It is more likely that in addition to filling in for nutritional gaps in diet, that XiangFu was also used as a medicinal to alleviate gastrointestinal and menstrual discomfort.