Chen HY, et al. - Authors evaluated the amount and duration of tea consumption concomitantly in relation to the risk of renal stone disease. They established the diagnosis of renal stone disease based on the results of abdominal sonography. They defined the average tea consumption per day as the amount of tea consumption per day multiplied by the frequency per week divided by seven. Results demonstrated a correlation of daily tea consumption ≥ 240 mL (two cups) with a lower risk of renal stone disease. A decreased associated risk of renal stone disease was seen with tea consumption ≥ 20 cup-year also.