Reading Herbal Tea Leaves: Benefits and Lore

Those who enjoy the caffeinated lift that comes from drinking traditional coffees and teas may tend to overlook the benefits of drinking herbal infusions. Now, as explained in this month's issue of Agricultural Research magazine, the idea that herbal teas may provide a variety of health benefits is no longer just folklore.

U.S. Department of Agriculture (USDA)-funded scientists in Boston, Mass., have looked into the science-based evidence of health benefits from drinking three of the most popular herbals in America. Diane McKay and Jeffrey Blumberg are at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston. Both work in the center's Antioxidants Research Laboratory, which Blumberg directs.

The Agricultural Research Service (ARS)-USDA's chief intramural scientific research agency-supports the HNRCA through an agreement. The work also was funded by Boulder, Colo.-based Celestial Seasonings, a brand of The Hain Celestial Group, Inc.

Chamomile tea has long been considered a brew that soothes. But when Blumberg and McKay reviewed scientific literature on the bioactivity of chamomile, they found no human clinical trials that examined this calming effect. They did, however, publish a review article on findings far beyond sedation, describing test-tube evidence that chamomile tea has moderate antimicrobial activity and significant antiplatelet-clumping activity.

The researchers also describe evidence of bioactivity of peppermint tea. In test tubes, peppermint has been found to have significant antimicrobial and antiviral activities, strong antioxidant and antitumor actions, and some antiallergenic potential. Based on a human clinical trial, the team also has reported that drinking hibiscus tea lowered blood pressure in a group of pre-hypertensive and mildly hypertensive adults.

McKay and Blumberg have concluded that the available research on herbal teas in general is compelling enough to suggest further clinical studies.

Read more about this research in the March 2011 issue of Agricultural Research magazine.