Sixty-seven individuals aged from 18 to 63 suffering from severe anxiety were enrolled in this randomised, double-blind study. To detect changes in psychological and physiological stress, State-Trait Anxiety Inventory, Profile of Mood States, salivary cortisol, inflammatory markers, blood pressure, heart rate variability (HRV) and actigraphy were monitored.
Results showed higher ratings of vigor and reduced feeling of inefficiency in the active group. HRV (baseline adjusted mean 49.1 ± 2.3 ms) and recovery index (106.6 ± 33.4) were significantly higher in the active group than in controls (42.5 ± 2.2 ms and 80.0 ± 29.3). Even if these results still need confirmation, they once again put the anti-stress effects of certain peptides in milk proteins into the spotlight.