Effect of powdered fermented milk with Lactobacillus helveticus on subjects with high-normal blood pressure or mild hypertension

Objective: Two tripeptides (Val-Pro-Pro and Ile-Pro-Pro) that have inhibitory activities for angiotensin I-converting enzyme are produced in milk fermented with Lactobacillus helveticus. In this study we evaluated the effect and safety of powdered fermented milk with L. helveticus CM4 on subjects with high-normal blood pressure or mild hypertension. Methods: A randomized, placebo-controlled, double-blind study was conducted using 40 subjects with high-normal blood-pressure (HN group) and 40 subjects with mild hypertension (MH group). Each subject ingested 6 test tablets (12 g) containing powdered fermented milk with L. helveticus CM4 daily for 4 weeks (test group) or the same amount of placebo tablets for 4 weeks (placebo group). Results: During treatment, the decrease in systolic blood pressure (SBP) and diastolic blood pressure (DBP) in the test group tended to be greater than in the placebo group for both blood pressure groups. At the-end of treatment (week 4), a significant decrease in DBP in the HN group was observed (i.e. 5.0 mm Hg (0.1, 9.9; p = 0.04) compared with the placebo group). There was no significant change in SBP (3.2 mm Hg (95% CI -2:6; 8.9; p = 0.27). In the MH group; SBP decreased by 11.2 mm Hg (4.0, 18.4; p = 0.003) and there was a statistically non-significant decrease in DBP of 6.5 mm Hg (-0.1, 13.0; p = 0.055) compared with the placebo group. No marked changes were observed in other indexes, including pulse rate, body weight and blood serum variables, and no adverse effects attributed to the treatment was found in each group. Conclusions: Daily ingestion of the tablets containing powdered fermented milk with L. helveticus CM4 in subjects with high-normal blood pressure or mild hypertension reduces elevated blood pressure without any adverse effects.