Effects of Leu-Asp-Gln-Trp-enriched whey protein hydrolysate on mood and fatigue in healthy adults: A randomized, double-blind, placebo-controlled trial

Abstract

Background: Mental health concerns and fatigue are increasingly prevalent among healthy adults. This study evaluated the effects of whey protein hydrolysate (WPH) enriched with the functional tetrapeptide Leu-Asp-Gln-Trp (LDQW) on mood state and fatigue.

Methods: A randomized, double-blind, placebo-controlled, parallel-group comparative study was conducted on 112 healthy adults aged 18 to 64 years. Participants were randomly assigned to receive either an active food containing 1.0 g of MWPH (WPH with 0.1% of LDQW) or a placebo food daily for 12 weeks. The primary outcome was mood state using the Profile of Mood States-Short Form 2nd Edition (POMS2-SF), and the secondary outcome was fatigue, evaluated using the Visual Analog Scale (VAS).

Results: The active group showed significant improvements in several POMS2-SF scores (Total Mood Disturbance, Depression-Dejection, Fatigue-Inertia, and Friendliness) compared with the placebo group at 12 weeks. Notably, the active group showed significant improvements in the Vigor-Activity score of POMS2-SF compared to the placebo group, at as early as 4 weeks, which persisted throughout the study. The VAS score for shoulder discomfort also significantly improved in the active group compared with the placebo group at 4 weeks and beyond. No adverse events related to the test foods were observed.

Conclusions: Daily intake of the WPH enriched with LDQW improved mood state, reduced fatigue, and relieved shoulder discomfort, providing benefits for both mental and physical health.

Trial registration: The study protocol was registered with UMIN-CTR (ID: UMIN000054349).

Keywords: whey protein hydrolysate; mood; fatigue; shoulder discomfort; LDQW; functional peptides