Lactotripeptides do not lower ambulatory blood pressure in untreated whites: results from 2 controlled multicenter crossover studies.

BACKGROUND Dietary factors directly influence blood pressure (BP). The lactotripeptides (LTPs) IPP (isoleucine-proline-proline) and VPP (valine-proline-proline), formed by hydrolyzing dairy proteins, and potassium, a mineral mainly found in fruit, vegetables, and dairy products, are extensively studied for their BP-lowering effect. The efficacy of LTPs seems modest in whites compared with that in Asians. OBJECTIVE The objective was to study the effects of enzymatically produced LTPs alone or in combination with potassium on ambulatory BP in whites. DESIGN Two multicenter, placebo-controlled, randomized, crossover studies were conducted; each consisted of two 4-wk intervention periods separated by a 4-wk washout period. In study 1, 69 subjects received 200 g/d of a dairy drink with 5.8 mg IPP and 4.4 mg VPP or placebo. In study 2, 93 subjects received 100 g/d of a dairy drink with 2.7 mg IPP, 1.9 mg VPP, and 350 mg added K or placebo. The subjects were randomly assigned according to their daytime ambulatory BP. RESULTS Mean 24-h systolic and diastolic BP (baseline values-study 1: 137.1/81.6 mm Hg; study 2: 139.2/80.9 mm Hg) remained similar with no significant differences between treatments in either study (P > 0.10). Office BP decreased over the course of both studies (systolic BP > 5 mm Hg), but differences between interventions were not significant (P > 0.10). In both studies, nighttime BP dipped during all treatments (> or =15%) but was statistically more significant with placebo (P < 0.05). Sodium excretion increased significantly after consumption of LTPs and potassium compared with after placebo intervention (P = 0.01), but not after consumption of LTPs alone. CONCLUSION The data do not support a BP-lowering effect of LTPs in whites.