The impact of milk proteins and peptides on blood pressure and vascular function: a review of evidence from human intervention studies

Abstract

CVD are the leading cause of death worldwide. Hypertension, a major controllable risk factor of CVD, is intimately associated with vascular dysfunction, a defect which is also now recognised to be a major, modifiable risk factor for the development of CVD. The purpose of the present review was to critically evaluate the evidence for the effects of milk proteins and their associated peptides on blood pressure (BP) and vascular dysfunction. After a detailed literature search, the number of human trials evaluating the antihypertensive effects of caseinderived peptides (excluding isoleucine-proline-proline and valine-proline-proline) was found to be limited; the studies were preliminary with substantial methodological limitations. Likewise, the data from human trials that examined the effects of whey protein and peptides were also scarce and inconsistent. To date, only one study has conducted a comparative investigation on the relative effects of the two main intact milk proteins on BP and vascular function. While both milk proteins were shown to reduce BP, only whey protein improved measures of arterial stiffness. In contrast, a growing number of human trials have produced evidence to support beneficial effects of both milk proteins and peptides on vascular health. However, comparison of the relative outcomes from these trials is difficult owing to variation in the forms of assessment and measures of vascular function. In conclusion, there is an accumulating body of evidence to support positive effects of milk proteins in improving and/or maintaining cardiovascular health. However, the variable quality of the studies that produced this evidence, and the lack of robust, randomised controlled intervention trials, undermines the formulation of firm conclusions on the potential benefits of milk proteins and peptides on vascular health.

Dairy Food Intake Is Inversely Associated with Risk of Hypertension: The Singapore Chinese Health Study

“…Another mechanism in which dairy products may reduce blood pressure is through milk proteins (4). Bioactive lactotripeptides are hypothesized to lower blood pressure by inhibition of angiotensin-converting enzyme and opioid-like activities (4,27). A reciprocal relation between dairy intake and healthier dietary pattern has been shown in our study as well as in other studies (6,7,10) and suggests that the association between dairy intake and risk of hypertension could be confounded by generally healthier lifestyle and eating habits.…”

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

“…Mariotti et al failed to report any significant effects of casein, whey or α-lactalbumin enriched whey protein on digital volume pulse (a measure of arterial stiffness) (57) (Table 2). Intriguingly, BP-lowering effects of milk proteins were not associated with changes in vascular function in the reviewed RCT (13) which is confirmed by emerging evidence on the relationship between BP and arterial stiffness. This suggests that the interaction between BP and arterial stiffness may be bi-directional (58,59) via complex interactions between different pathways such as inflammatory (60,61) , hormonal (e.g.…”

“…During our systematic literature search (13) we found that there were very few studies investigating the BP-lowering effects of other casein-derived peptides in human subjects (23)(24)(25)(26)(27) . Furthermore these studies were limited, used different types of peptides and were often uncontrolled with poor methodological and study design.…”

Whey protein lowers blood pressure and improves endothelial function and lipid biomarkers in adults with prehypertension and mild hypertension: results from the chronic Whey2Go randomized controlled trial

“…Milk is a complex food that contains several potential bioactive compounds; therefore, it remains to be confirmed which constituents may be responsible for the beneficial effect. Previous studies have linked milk-protein consumption with reduced BP (5); however, there has been an imbalance in the literature, because most attention has focused on the casein-derived lactotripeptides or other milk-protein hydrolysates (6) with a clear evidence gap on the effects of intact milk-protein isolates on BP (7). Milk proteins in liquid milk exist in intact forms, and evidence from robust randomized controlled trials (RCTs) would provide valuable information on the potential mechanism by which milk may affect BP.…”