Research reveals how tea may lower blood pressure

 Drinking tea is associated with a range of health benefits, including reductions in blood pressure.

• Researchers have discovered how compounds called catechins, found in green and black teas, relax the smooth muscle that lines blood vessels, which may lead to lower blood pressure.
• The discovery could lead to the development of better medications for high blood pressure, also called hypertension.
• The finding could also inspire new treatments for a debilitating condition called epileptic encephalopathy.

Humans first drank caffeinated tea more than 4,000 years ago in China. Since then, it has become one of the most popular drinks worldwide, second only to water.

Both green and black teas are brewed from the leaves of the same shrub, Camellia sinensis, but green tea, which is made from unfermented leaves, contains more antioxidants.

Oxidation during the fermentation process of black tea reduces its antioxidant levels.

Several studies have found that green tea inhibits the formation of cancers, lowers high blood pressure, and reduces the risk of heart disease.

However, the molecular mechanism responsible for the effect on blood pressure has been unclear until now.

Scientists at the University of California, Irvine (UCI) and the University of Copenhagen, in Denmark, have found that antioxidants in tea open ion channels and can relax the muscles that line blood vessels.

Preventable risk factor

The discovery could guide the design of more effective antihypertensive drugs, which could potentially improve the health of millions of people around the world.

According to the National Heart, Lung, and Blood Institute, controlling or lowering high blood pressure can help prevent chronic kidney disease, heart attacks, heart failure, and possibly dementia.

The Centers for Disease Control and Prevention (CDC) report that almost half of all adults in the United States have hypertension. It estimates that in 2018, the condition played a role in the deaths of nearly half a million people in the country.

The World Health Organization (WHO), meanwhile, estimate that more than 1 billion people worldwide have hypertension.

The new study first shows that two antioxidants in tea, known as catechins, open a protein channel in the membranes of the smooth muscle cells that line blood vessels. This allows positively charged potassium ions to leave the cells.

Channels in nerve and muscle cells maintain voltages across their membranes by allowing negative and positive ions to pass in and out in a controlled way. They are “voltage-gated,” which means that they respond to changes in this voltage by opening or closing.

The researchers found that the catechins in green tea activate a particular type of potassium ion channel, called KCNQ5.

Previous work by some of the same scientists suggests that this protein channel may underlie the antihypertensive effects of several plants used as folk medicines for millennia.

Source:Medical News Today