Antihypertensive effect of sweetie fruit in patients with stage I hypertension

Background: Interventional studies have shown that increased intake of fruit and vegetables reduces blood pressure (BP). However, the contribution of specific dietary components has not been evaluated. The aim of the present study was to determine, in patients with stage I hypertension, the antihypertensive effect of juice of the so-called sweetie fruit (a hybrid between grapefruit and pummelo) with and without high flavonoid content. Methods: A double-blind, cross-over study was conducted in 12 patients. Each patient received alternately high-flavonoid (HF) sweetie juice and low-flavonoid (LF) sweetie juice, each for a 5-week period. The LF sweetie juice had 25% of naringin and 30% of narirutin content compared with the original HF sweetie juice. Results: The HF sweetie juice was more effective than LF sweetie juice in reducing diastolic blood pressure (P = .04). Systolic blood pressure declined in both groups; however there was no significant difference between subjects given HF sweetie versus those given LF sweetie juice. Conclusions: In this study HF sweetie juice was shown to have a significant beneficial effect in reducing diastolic blood pressure, compared with the effect observed with LF sweetie juice, in patients with stage I hypertension. These data suggest that the active ingredients associated with the antihypertensive effect of sweetie juice are the flavonoids naringin and narirutin.