On the ground, Kudzu is a pesky weed that has ravaged nearly 10 million acres in the southeastern U.S. But in the laboratory, Kudzu has been found to contain a beneficial substance in the fight against metabolic syndrome.

Roughly 47 million people have metabolic syndrome, which is characterized by obesity, high blood pressure, high cholesterol and issues with insulin, putting them at increased risk for cardiovascular events such as heart attacks and strokes.

A prominent feature of metabolic syndrome is impaired glucose regulation. In metabolic syndrome, insulin/glucose impairment, hypertension, obesity and hypercholesterolemia synergize to accelerate the development of cardiovascular disease, stroke and type 2 diabetes.

Kudzu root is rich in isoflavone glucosides, the most abundant of which are puerarin (daidzein 8-C-glucoside), daidzein and daidzin (daidzein 7-Oglucoside). Essentially, puerarin acts as a traffic cop, regulating glucose by directing toward muscles and away from fat cells and blood vessels.

J. Michael Wyss, PhD, professor of Cell Biology and Medicine at The University of Alabama at Birmingham, said he and his colleagues have been studying the effects of polyphenols on cardiovascular health for 10 years but kudzu presented a new opportunity. “Kudzu is unique in that its major polyphenol (puerarin) is bound to glucose by a C-C bond (most polyphenols have a weaker O-O bond), which makes it very stable and therefore, unlike almost all other polyphenols, its glucose moiety is not cleaved off prior to entering the blood,” he explained. “It can therefore circulate through the body as an intact molecule that is not further degraded/metabolized, and it enters various organs intact. This is a great advantage for understanding its mode of action, since we can track where the molecule goes by various techniques. This gives us a clue to where it is acting.”

In their study, Dr. Wyss and his colleagues administered liquid Kudzu root extract to female hypertensive rats (a rat strain frequently used as a model for human metabolic syndrome) for two months and found the rats had lower cholesterol, blood pressure, blood sugar and insulin levels than the control group. Thus the team concluded that Kudzu root “may provide a dietary supplement that significantly decreases the risk and severity of stroke and cardiovascular disease in at-risk individuals.”

The group’s research will be published in the Journal of Agriculture and Food Chemistry (“Chronic Dietary Kudzu Isoflavones Improve Components of Metabolic Syndrome in Stroke-Prone Spontaneously Hypertensive Rats,” vol. 57, Nov. 16, 2009).

Dr. Wyss said that examining Kudzu in this light built upon the plant’s longstanding use in Chinese medicine. “It has been used for cardiovascular indications and as a form of anti-abuse for alcoholism,” he said. “It contains in addition to puerarin the polyphenols that are in soy, one of the most used botanicals. Our early studies suggested that Kudzu extract improved blood pressure. Later studies indicated that it also improved lipids and glucose regulation.

“I would note that our safety studies show that it has few if any adverse side effects, even at high doses,” he added.

Further research is planned to identify Kudzu’s mechanisms of action, however, Dr. Wyss did not foresee the creation of a stand-alone puerarin pill for metabolic syndrome. “We do not believe that this will ever serve as a stand-alone formulation for metabolic disease or its components, but as a complementary agent it may increase the actions of drugs given for metabolic disease components, and thereby delay desensitization to the beneficial effects of the drugs; an effect that occurs with most drugs over time (the longer you take them the higher dose you need, leading to adverse effects or insensitivity to the treatment). It may also serve as a useful stand-alone agent to reduce/delay the development of contributors to metabolic disease (hypertension, hyperlipidemia/obesity and diabetes), thus delaying the time at which medication is needed to treat an individual,” he concluded.