Impact of spirulina-enriched yogurt-like dessert on blood pressure in overweight individuals with high cardiometabolic risk: results from in vitro studies and a randomized, placebo-controlled clinical trial

Background and aim: Spirulina (Arthrospira platensis) contains peptides with angiotensin-I converting enzyme (ACE) inhibitory activity, suggesting possible antihypertensive effects. However, food-matrix interactions may alter peptide release or bioactivity. This study evaluated (i) the in-vitro ACE-inhibitory activity of <3 kDa peptide fractions after simulated gastrointestinal digestion of spirulina biomass (SB) and a spirulina-enriched yogurt-like dessert (YSB), and (ii) the effects of daily YSB consumption on blood pressure (BP) and vascular function in overweight/obese adults with elevated cardiometabolic risk. Methods and results: SB, YSB, and control yogurt (YC) underwent simulated gastrointestinal digestion and <3 kDa fractions were assessed for ACE-inhibition. In a randomized, placebo-controlled, parallel, clinical trial, adults (n = 64 completers; 32 per group) consumed YSB (4 g/day spirulina) or isoenergetic YC for 8 weeks, followed by 4 weeks of observation. Peripheral BP, central BP, pulse wave velocity (PWV), and augmentation index (AIx) were measured at baseline, week 8, and week 12. In-vitro, SB and YC exhibited ACE-inhibitory activity, while YSB did not. Clinically, no significant group∗time interactions were observed for BP, PWV, or AIx. Results were unchanged in sensitivity analyses excluding antihypertensive-treated participants and in subgroups with elevated baseline BP. Conclusions: SB exhibited ACE-inhibitory activity in vitro; however, incorporation into a yogurt-like matrix abolished this effect. Daily YSB consumption did not lower BP or improve vascular markers. Findings highlight the critical role of food-matrix interactions in functional food development. ClinicalTrials.gov: NCT06114563.