Effect of peptides derived from food proteins on blood pressure: a meta-analysis of randomized controlled trials.
BACKGROUND
In clinical trials, peptides derived from food proteins have shown an effect on blood pressure. This biological mechanism is mainly due to inhibition of angiotensin-I-converting enzyme (ACE), thereby regulating blood pressure through the renin-angiotensin system. A meta-analysis of these trials is needed to better quantify their effect, sources of variation, and possible publication bias.


OBJECTIVE
To perform a meta-analysis of placebo-controlled clinical trials on peptides derived from food proteins and their effect on blood pressure.


METHODS
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.


RESULTS
Pooled effect of peptides was -5.13 mmHg (95% CI: -7.12, -3.14) for systolic blood pressure, and -2.42 mmHg (95% CI: -3.82, -1.03) for diastolic blood pressure. There were indications of publication bias for diastolic blood pressure data.


CONCLUSIONS
Peptides derived from food proteins may lead to significantly reduced blood pressure and could therefore be a supplement or alternative to pharmaceutical treatment for mild hypertension. Their effect seems more pronounced, or at least comparable, to that of other food components studied by randomized controlled trials. A high proportion of the reported trials was carried out using the well-known ACE inhibiting tripeptides - Valine-Proline-Proline (VPP) and Isoleucine-Proline-Proline (IPP).
Pripp
Are Hugo
AH
Research Services Department, Rikshospitalet, Oslo, Norway.