Tea is one of the most popular drinks in the world, second only to water, and its effects on the human body have been examined ad infinitum. While researchers agree that tea affects blood pressure, new and ongoing studies debate the extent of that impact as well as how that impact varies based upon what type of tea is consumed. Tea’s impact on blood pressure also varies based on your health and any medications you are taking.
Caffeine
Tea naturally contains caffeine, a stimulant that affects your central nervous system and boosts your energy. As caffeine moves through your body, it causes a temporary spike in your blood pressure, though the reason for the increase is not yet clear. Doctors speculate that caffeine boosts blood pressure for one of two reasons: either the caffeine blocks a hormone that widens your arteries, or it tells your adrenal gland to produce and release more adrenaline.
Types of Tea
There are dozens of types and flavors of tea on the market, and the most common are black tea and green tea. Both black and green teas, because of their caffeine content, are associated with an increase in blood pressure. Caffeinated teas such as these are often used to help treat low blood pressure. Recent research from the American Heart Association and U.S. Department of Agriculture, however, shows that hibiscus tea can help lower blood pressure. A group of 65 participants was selected to drink 3 cups each day; half of the participants drank hibiscus tea, while the other half received a placebo beverage that contained hibiscus flavor and color. The group that consumed hibiscus tea saw, on average, a 7.2-point drop in their systolic blood pressure. The study has not yet been replicated, so further research is still in progress.
Moderation
Unless your blood pressure is chronically hypertensive, tea will not cause any long-term effects if consumed in moderation. Two or three cups of tea each day will not have a severe impact on your blood pressure, even if you are hypertensive, nor will it cause healthy blood pressure to suddenly become hypertensive. If you are concerned about how a moderate amount of tea will impact your body and your blood pressure, consult your doctor. Your doctor will be able to advise if tea is a good idea for you as well as how much, if any, you may be able to consume on a daily basis.
Monitoring
Because people react differently to caffeine, you may wish to test yourself to see how caffeine affects your body. Check your blood pressure prior to consuming a cup of tea, and then check your blood pressure half an hour after drinking tea. If you see an increase of 5 to 10 points, you may be extra-sensitive to caffeine’s effects. If you see minimal or no increase, your body may have a natural or a developed tolerance to the caffeine in tea.
Other Considerations
The caffeine in tea may cause adverse reactions to medications you may be taking. People who take propranolol or metroprolol, medications that treat high blood pressure and heart disease, may wish to consult a doctor regarding tea consumption as the caffeine can interfere with the medications’ intended effects. Additionally, people who take monoamine oxidase inhibitors — also known as MAOIs — to treat depression may see a severe increase in blood pressure, especially after consuming green tea.
