Black tea may help lower blood pressure A study finds that drinking three cups of black tea a day may be helpful in lowering blood pressure. Wendy Lamm / Los Angeles Times By Jeannine Stein, Los Angeles Times / For the Booster Shots blog January 24, 2012, 11:08 a.m. Drinking three cups of black tea daily over months may help lower blood pressure, a study suggests. In a research paper released this week in the Archives of Internal Medicine, black tea was tested against a placebo to see whether drinking the beverage over time had any effect on lowering blood pressure in male and female test subjects, ages 35 to 75. The 95 study participants had systolic blood pressure readings ranging from 115 to 150 and were randomly assigned to one of two groups. One group drank three cups a day of regular leaf tea that contained 1,493 milligrams of powdered black tea solids with 429 milligrams of polyphenols and 96 milligrams of caffeine. The other group drank a placebo that had the same flavor and caffeine content but had no tea solids. Polyphenols are antioxidants found in foods such as cherries, broccoli, cranberries, red wine and tea. Antioxidants may prevent cell damage and could help avert certain types of cancer as well as reduce the risk of cardiovascular disease. Those in the black tea solids group saw a drop of systolic and diastolic blood pressure over six months of between two and three points compared with the placebo group. The study authors said that when spread over the population this could mean a 10% drop in the prevalence of high blood pressure and a 7% to 10% decrease in the risk of cardiovascular disease.