Bovine dairy products and flow mediated dilation (FMD): a systematic review of the published evidence.

Purpose: Evidence suggests bovine dairy products may have neutral or beneficial effects on cardiometabolic health, despite being a source of saturated fat. The dairy matrix, the structure and combination of protein, fat, and other nutrients, and how they interact with each other, is purported to be responsible for these beneficial health effects. Whether this relationship extends to endothelial function, as assessed by flow mediated dilation (FMD), remains to be elucidated.

Methods: Three electronic databases (PubMed, Embase and Cochrane Central) were searched from inception until 5th September 2024. This review included randomised controlled trials (RCT) investigating any bovine dairy intervention which considered endothelial function using FMD in humans with a non-dairy or alternative dairy control.

Results: Of 4,220 records identified, 18 reports from 11 RCT including 508 (53.3% male) participants, examined endothelial function by FMD and were eligible for evidence synthesis. Eight papers reported an improvement, nine reported no effect and one reported a decrease in FMD. The greatest effects were found in those with impaired health at baseline, with whey protein and high dairy intakes observed to be most beneficial.

Conclusion: Bovine dairy intake has neutral or beneficial effects on cardiometabolic health. This review demonstrates that this relationship extends to endothelial function as assessed by FMD. Whey protein and high dairy intakes may be most effective, although further high quality RCT in this area are warranted.