Blood pressure lowering effect of lactotripeptides assumed as functional foods: a meta-analysis of current available clinical trials

Abstract

The oral assumption of lactotripeptides Valine-ProlineProline (VPP) and Isoleucine-Proline-Proline (IPP) as nutraceuticals or functional foods is supposed to improve blood pressure (BP) control by angiotensinconverting enzyme-inhibition. However, data derived from clinical trials have reached conflicting conclusions. To perform a meta-analysis of placebo-controlled clinical trials evaluating the anti-hypertensive effect of lactotripeptides assumed as nutraceuticals or functional foods. Trials identified using a defined search strategy in PubMed were included in the meta-analysis, and their pooled effect was estimated with a random effects model, weighting for the inverse of the variance. Heterogeneity, publication bias, subgroup and metaregression analyses were performed. A total of 18 trials have been identified, the clinical data of which have been clearly reported.

Effects of 12 weeks of treatment with fermented milk on blood pressure, glucose metabolism and markers of cardiovascular risk in patients with type 2 diabetes: a randomised double-blind placebo-controlled study

“…Other studies have investigated at the effect of different types of milk peptides in patients with hypertension. Some meta-analyses have shown a significant effect on resting BP as measured at one standard time point during the day (18,19,20). A metaanalysis of the data from 15 studies showed a small effect on SBP, but no effect on DBP, as mentioned previously (4).…”

Can milk proteins be a useful tool in the management of cardiometabolic health? An updated review of human intervention trials

“…There was an imbalance in the literature as more RCT were conducted using mainly one type of casein-derived peptides, called lactotripeptides (LTP). We, therefore conducted an updated meta-analysis on the impact of LTP on BP (14) , which included all available and relevant RCT and detailed subgroup and regression analyses, which were somewhat limited in previous meta-analyses in this area (15)(16)(17)(18) . We found a small, but significant reduction in both SBP (−2·95 mmHg (95 % CI −4·17, −1·73; P < 0·001)) and DBP (−1·51 mmHg (95 % CI −2·21, −0·80; P < 0·001)) after 4 weeks of LTP supplementation in pre-and hypertensive populations.…”

Effects of long-term intake of lactotripeptides on cardiovascular risk factors in hypertensive subjects

“…12,14,23 In the present study, 24-h systolic and diastolic blood pressure decreased significantly only in the peptide group ( À 2.3 and À 1.8 mm Hg, respectively), but the difference between the groups was not statistically significant. As seen in the present and other trials (see meta-analyses [22][23][24] ), the effect of lactotripeptides varies individually from subject to subject, which may result in clinically significant mean reductions in blood pressure not reaching statistical significance in this number of study population.…”

“…23 Another meta-analysis by Pripp 22 included intervention studies on both lactotripeptides and other peptides derived from food, and found a significant effect on systolic blood pressure of À 5.1 mm Hg and diastolic blood pressure of À 2.4 mm Hg. A very recent metaanalysis by Cicero et al 24 on 18 placebo-controlled trials, with altogether almost 1700 subjects, showed as a pooled effect of peptide-containing products a reduction of À 3.7 mm Hg in systolic and À 2.0 mm Hg diastolic pressure. On the other hand, three recent intervention studies showed no significant decreases in blood pressure after ingestion of 4.6-14 mg per day of lactotripeptides for 4-8 weeks.…”

“…[19][20][21] Commercial products contain usually around 5 mg of peptides in recommended daily dose. Three recent meta-analyses [22][23][24] show mean reduction of systolic blood pressure 3.7-4.8 mm Hg and diastolic blood pressure 2.0-2.2 mm Hg.…”