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Sept. 13, 2012 Volume 34, No. 4

Tongue analysis in Chinese medicine may have backing of Western science


More studies needed to confirm research

Stick out your tongue, but don’t say “ah.” Instead, note the color of your tongue. Your overall health may depend on it.

For 5,000 years, the Chinese have used a system of medicine based on the flow and balance of positive and negative energies in the body. In this system, the tongue’s appearance is an important measure to classify the physical status of the body, or zheng

University of Missouri researchers have developed computer software that combines the ancient practices and modern medicine by providing an automated system for analyzing images of the tongue, according to an article published in the peer-reviewed journal Evidence Based Complementary and Alternative Medicine.

“Knowing your zheng classification can serve as a pre-screening tool and help with preventive medicine,” said Xu Dong, chair of MU’s computer science department in the College of Engineering and the study’s co-author. “Our software helps bridge Eastern and Western medicine, since an imbalance to zheng could serve as a warning to go see a doctor. 

“Within a year, our ultimate goal is to create an application for smart phones that will allow anyone to take a photo of their tongue and learn the status of their zheng,” he said.

The software analyzes images based on the tongue’s color coating to distinguish between tongues showing signs of “hot” or “cold” zheng. Shades of red and yellow are associated with hot zheng, whereas a white coating on the tongue is a sign of cold zheng.

Both suggest the body is not quite healthy.

“Hot and cold zheng doesn’t refer directly to body temperature,” Xu said. “Rather, it refers to a suite of symptoms associated with the state of the body as a whole.” For example, a person with cold zheng may feel chills and coolness in the limbs, have a pale face and a high-pitched voice. 

In Chinese traditional medicine, hot and cold zheng can be symptoms of gastritis, an inflammation of the stomach lining frequently caused by bacterial infection.

But is the diagnosis accurate? A study involving 263 gastritis patients and 48 healthy volunteers had their tongues examined. 

The gastritis patients were classified by whether they showed a bacterial infection and the intensity of their gastritis symptoms. 

In addition, most of the gastritis patients had been previously classified with either hot or cold zheng. This allowed the researchers to verify the accuracy of the software’s analysis.

Ye Duan, associate professor of computer science at MU and co-author of the study, said the software program was able to classify people based on their zheng, though more studies are needed.

“Eventually everyone will be able to use this tool at home using webcams or smart phone applications,” Duan said. 

“That will allow them to monitor their zheng and get an early warning about possible ailments.”