Next to water, tea is the most consumed beverage in the world, and in the U.S., the drink can be found in nearly 80% of households, according to the Tea Association of the USA.
Now, research has shown that consuming the beverage could have blood pressure-lowering benefits.
Since, high blood pressure, also called hypertension, puts people at risk for developing heart disease and stroke — two leading causes of death in the U.S. — the news of tea’s antihypertensive properties could lead to developing new blood pressure-lowering medications.
The study from the University of California, Irvine reveals that compounds in green and black tea relax blood vessels by activating protein channels in the blood vessel wall. The compounds are two antioxidants called catechins, a press release from the UCI School of Medicine said. Particularly, researchers discovered that KCNQ5, a specific type of protein channel, is activated by the two antioxidants.
“We found by using computer modeling and mutagenesis studies that specific catechins bind to the foot of the voltage sensor, which is the part of KCNQ5 that allows the channel to open in response to cellular excitation. This binding allows the channel to open much more easily and earlier in the cellular excitation process,” said Geoffrey Abbott, Ph.D., in a statement.
Abbot is a professor in the department of physiology and biophysics at the UCI School of Medicine. He made the discovery about the tea compounds’ ability to relax blood vessels.
Findings of the study were published in the journal Cellular Physiology & Biochemistry.
Last year, Americans consumed more than 84 billion servings of tea, which is equal to over 3.8 billion gallons, the Tea Association of the USA. said. Black tea made up the bulk of all tea consumed at around 84%. That was followed by green tea at 15% and oolong, white and dark tea made up the remaining 1%.
Americans and U.K. residents commonly mix milk with black tea before consuming it. In the UCI study, researchers observed that when adding milk to black tea that was directly applied to cells containing the KCNQ5 channel, it blocked tea’s beneficial KCNQ5-activating effects.
“We don’t believe this means one needs to avoid milk when drinking tea to take advantage of the beneficial properties of tea,” Abbot said. “We are confident that the environment in the human stomach will separate the catechins from the proteins and other molecules in milk that would otherwise block catechins’ beneficial effects.”
Another way tea is consumed in America is iced. According to the Tea Association of the USA, about 75%-80% of tea consumed in America is iced.
Using mass spectrometry, UCI researchers found that that warming green tea to 95 degrees Fahrenheit changed its chemical composition, which made it more effective at activating KCNQ5.
“Regardless of whether tea is consumed iced or hot, this temperature is achieved after tea is drunk, as human body temperature is about 37 degrees Celsius,” or 98.6 Fahrenheit, Abbott said. “Thus, simply by drinking tea we activate its beneficial, antihypertensive properties.”
