['Angiotensin-converting enzyme (ACE; EC 3.4.15.1) plays a dual role in the regulation of hypertension: it catalyzes the production of the vasoconstrictor angiotensin II and it inactivates the vasodilator bradykinin. By inhibiting these processes, ACE inhibitors have antihypertensive effects. Peptides derived from milk proteins can have ACE-inhibiting properties and may thus be used as antihypertensive components.', 'We evaluated the long-term blood pressure-lowering effect of milk fermented by Lactobacillus helveticus LBK-16H in hypertensive subjects.', 'In a randomized placebo-controlled study, 39 hypertensive patients received 150 mL/d of either L. helveticus LBK-16H fermented milk or a control product for 21 wk after a 2-wk run-in period. During the run-in period, the average baseline diastolic and systolic blood pressure values were 155 and 97 mm Hg, respectively, in the test product group and 152 and 96 mm Hg, respectively, in the control group. After the run-in period, blood pressure was measured at home on the same day every week with the use of an automatic blood pressure recorder.', 'There was a mean difference of 6.7 +/- 3.0 mm Hg in systolic blood pressure (P = 0.030) and of 3.6 +/- 1.9 mm Hg (P = 0.059) in diastolic blood pressure between the test product and control groups. Demographic factors had no significant effect on the responses.'] Does a fermented milk high in bioactive peptides have a blood pressure-lowering effect in hypertensive subjects?