High blood pressure is a stepping stone to life-threatening emergencies such as strokes and heart attacks. While teas are widely celebrated for their health benefits, two popular options could cause a stark increase in high blood pressure instead.
The research included two trials. The first one looked at the two hot drinks, plus water matched to the teas for caffeine, and plain water, while the second trial only considered black and green tea.
The first trial included 20 men without high blood pressure and the second trial involved hypertensive men and women.
Furthermore, the participants had to drink five cups of green and black tea during a seven-day period.
While these two options are rich in flavonoids that offer beneficial health effects, they also pack caffeine.
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The latter ingredient was exactly what brought about the acute response to the hot drinks.
The research team found that the hot drink led to an increase in hypertension after 30 minutes of intake.
However, the 60-minute mark, during which blood pressure was measured again, didn’t show any “significant” effects.
The research team concluded: “Contrary to our initial hypothesis, tea ingestion caused larger acute increases in blood pressure than caffeine alone.
“However, any acute effects of tea on blood pressure did not translate into significant alterations in ambulatory blood pressure during regular tea consumption.”
Despite the stark increase in blood pressure during this research, other studies highlighted the positive effects of drinking tea.
According to a review, published in the journal PLOS ONE, black tea was actually able to lower blood pressure.
Looking at 11 studies that had around 378 subjects together, the research suggests that regular consumption of tea could be beneficial for hypertension.
“Although the effect is small, such effects could be important for cardiovascular health at population level,” concluded the study.
Furthermore, green tea was also associated with a lower blood pressure reading in another research.
According to a study, published in the journal Scientific Reports, the green drink “significantly” lowered blood pressure.
Based on these conflicting results, it’s difficult to draw a firm conclusion.