Flavonoid Rich Black Tea Shows Blood Pressure Benefits
Black tea is packed with flavonoids, a naturally occurring antioxidant. A recent study has shown for the first time that drinking three cups of black tea daily may lower blood pressure variability by approximately 10% at night.
Nocturnal blood pressure variation has been linked to cardiovascular disease.
The study included 111 participants with baseline systolic blood pressure between 115 and 150 mmHg. Over the course of six months, half of the group drank three cups of black tea a day while the other half drank a placebo beverage with the same amount of caffeine but no flavonoids.
Results were observed from the first day of the study, with both systolic and diastolic blood pressure dropping by around 10% at night. Those effects were observed over the entire course of the study.
The researchers theorized that the flavonoids found in black tea may improve arterial stiffness or could possibly improve sleep quality.
Researchers at the University of Western Australia, Finders University in Australia, Unilever Research and Development in the Netherlands, the Russian Cardiology Research Center, and BakerIDI Heart and Diabetes Institute in Australia conducted the study. It was published in the May 2013 issue of The American Journal of Clinical Nutrition.
Previous studies have shown that the flavonoids in black tea may decrease inflammation, protect our DNA from damage, and improve heart and brain health by increasing blood flow.
Foods high in flavonoids include citrus fruits, grapes, strawberries, tea, cooked greens and dark chocolate, all of which are can be easily incorporated into your daily diet.