Relationship of a Special Acidified Milk Protein Drink with Cognitive Performance: A Randomized, Double-Blind, Placebo-Controlled, Crossover Study in Healthy Young Adults

Abstract

A previous in vivo study with rats suggested that a special milk protein drink manufactured using an acidification procedure to suppress the aggregation of milk proteins was absorbed quickly after feeding. We performed a randomized, double-blind, placebo-controlled, repeated-measure crossover study to investigate the short-term effects on cognitive performance in 29 healthy young adult men after they consumed this drink in the morning. After an overnight fast, subjects were tested for performance in the Uchida–Kraepelin serial arithmetic test and the Stroop test as well as for subjective feeling, body temperature, and heart rate variability before and after consumption of either the acidified milk protein drink or an isoenergetic placebo drink. Subjects showed a significant improvement in performance in the Uchida–Kraepelin test, the primary outcome measured, when they consumed the acidified milk protein drink compared with the placebo control condition. In addition, consumption of the acidified milk protein drink, compared with the placebo control, was associated with increases in vagally-mediated heart rate variability indices which, from recent theoretical perspectives, may reflect a higher ability to modulate cognitive and behavioral processes. There was no significant difference in subjective feelings and body temperature between the test drink conditions. These data suggest that consumption of the acidified milk protein drink may improve cognitive performance, with possible involvement of physiological systems that regulate cognition and behavior.

Effects of β-Lactolin on Regional Cerebral Blood Flow within the Dorsolateral Prefrontal Cortex during Working Memory Task in Healthy Adults: A Randomized Controlled Trial

“…Participants were given a 10-s resting period before each task periods. Kraepelin and 2-back are relatively easy cognitive tasks and used repeatedly in one day of the examination without leaning effects [ 23 ].…”

Orally Administered Plasmalogens Alleviate Negative Mood States and Enhance Mental Concentration: A Randomized, Double-Blind, Placebo-Controlled Trial

“…Increased performance in the plasmalogen group was more notable in the middle (5 and 6 min) and toward the end of the 10-min task ( Figure 3 ). To our knowledge, none of the previous intervention studies have addressed the effect on the minute-specific performance in the Uchida-Kraepelin test ( Ataka et al, 2008 ; Johnson et al, 2016 ; Takanari et al, 2016 ; Saito et al, 2018 ). It could be argued that plasmalogens may maintain the performance in the middle of work, elicit the so-called last spurt in work performance, and increase mental concentration.…”

Effects of Euglena gracilis Intake on Mood and Autonomic Activity under Mental Workload, and Subjective Sleep Quality: A Randomized, Double-Blind, Placebo-Controlled Trial

“…However, the sympathetic nervous system was in a dominant state in these individuals, with a high LF/HF ratio, which is an indicator of the autonomic nervous system balance, exceeding the normal value of 2.0. Previous studies have shown that Uchida-Kraepelin stress affects heart rate variability [31][32][33][34]. We selected subjects who felt that taking the Uchida-Kraepelin test was stressful had a substantial increase in their LF/HF ratios.…”