In a 6-month, randomized, double-blind, placebo-controlled trial, Hodgson et al1 reported that the intake of black tea was associated with a 2–to 3–mm Hg lower systolic and diastolic blood pressure relative to controls at both the 3- and 6-month follow-up examinations.
All subjects in this study were regular tea drinkers and all also drank leaf tea during the run-in period. Subjects randomized to black tea continued to drink tea for the next 6 months; in other words, nothing changed for them (except, perhaps, they drank black tea, without milk, instead of in the way in which they were accustomed). In contrast, subjects randomized to placebo were abruptly withdrawn from tea.