标题：Evaluation of the Blood Pressure Lowering-Effect of the Lactotripeptides Valine-Proline-Proline and Isoleucine-Proline-Proline in Non-Hypertensive Japanese Subjects through a Meta-Analysis of Randomized-Controlled Studies
摘要：Several studies have reported the ability of the lactotripeptides valine-proline-proline (VPP) and isoleucine-proline-proline (IPP) to lower systolic blood pressure (SBP), including in Japanese populations. But the magnitude of the reported changes differs across trials. Conclusions from a previous meta-analysis in Japanese subjects suggest that this may be due at least partly to differences in subjects’ blood pressure (BP) status. Therefore, we decided to resume this analysis, focusing only on non-hypertensive subjects and including newly-published eligible studies, in order to further evaluate the SBP-lowering effect of VPP/IPP and study the influence of the ingested dose, type of ingredient (enzymatic or fermented) and food product (drink or supplement). The systematic search of four databases (including two in Japanese) allowed to identify 11 relevant randomized-controlled trials (581 subjects), which were included in the meta-analysis. Results reported a significant decrease in SBP following VPP/IPP intake in non-hypertensive Japanese individuals, with an estimated effect-size of -3.44 mm Hg (95% CI, -4.53 to -2.34, P < 0.0001) as compared to placebo. There was no indication of heterogeneity or publication bias. Furthermore, the type of food product and ingredient did not influence the SBP-lowering effect, which was significant and of same order of magnitude with either type of product and ingredient. Besides, the SBP-lowering effect remained significant when limiting to studies testing usual daily amounts of VPP/IPP (≤5 mg/d). This updated meta-analysis therefore confirms that VPP/IPP are effective in reducing SBP in non-hypertensive Japanese individuals, for amounts that may be ingested on a daily basis, and independently of the types of ingredient/food consumed. VPP/IPP-containing foods could therefore contribute to a better control of high-normal BP and/or to the maintenance of normal BP, and by such, may play a role in preventing high BP in individuals with normal or high-normal BP.
