Dr. Yvonne Wan surrounded by her tea collection

Tea is one of the most-consumed beverages. Yet it is among the least studied.

Yu-Jui “Yvonne” Wan, a researcher and professor at UC Davis Health, is working to change that. She recently published research findings on the health benefits of tea. She studied a compound in tea that affects the gut microbiome and its effects on obesity.

For her work, organizers of the 2019 World Tea Expo named her the Best Tea Health Advocate at the largest U.S. tea industry event in June in Las Vegas.

“There is a desperate need for really good medical and scientific research on the health benefits of tea,” said Katharine Burnett, founding director of the Global Tea Initiative at UC Davis. “There are many myths, while likely to be true, but require scientific proof.”

In a recent research article, Wan examined whether tea had the potential to treat obesity. Her research identified a compound in tea leaves, known as epigallocatechin-3-gallate (EGCG), that has potent anti-inflammatory, anti-obesity, anti-bacterial and anti-cancer effects. She also found that within the intestine, EGCG shifts the structure of the bacterial community and regulates the metabolism of fat and sugar to produce health benefits, including weight reduction.

“We provided very new knowledge on how food or nutrients can shift gut microbes that, in turn, reduce body weight,” Wan said. “My goal is to generate scientific proof to show that tea, which has been widely consumed for thousands of years, has health benefits.”

While more research is needed to understand other mechanisms, she stated that this type of research is critically important because metabolic disease and obesity have become a modern-day crisis.

Tea as a dietary supplement

“Tea is not just a drink, it can be used as a dietary supplement,” Wan said. “Different types of tea likely have different benefits, and that’s why research is critically needed.”

Wan’s research supports other studies that found the gut microbiome also contributes to the development of and response to cancer treatment. In a paper published in Nature Reviews Gastroenterology & Hepatology, she issued an urgent call to develop precision medicine and to personalize dietary supplements based on an individual’s gut microbiome.

The study of tea is not only a scientific question but also a personal interest for Wan. She has an extensive teapot collection, and fond memories of drinking tea with her father, who drank tea exclusively.

“My 96-year-old dad never drank water, only tea,” Wan said.

Learn more about teas from the National Center for Complementary and Integrative Health