Effect of a nutraceutical combination on sleep quality among people with impaired sleep: a randomised, placebo-controlled trial

Abstract

In this randomised, placebo-controlled trial, adults with impaired sleep (Pittsburgh Sleep Quality Index ≥ 5) were randomly assigned using a minimization algorithm to receive a formulation containing L-theanine plus lemon balm, valerian, and saffron extracts, or placebo, during 6 weeks. Objective sleep quality parameters were measured using an actigraphy device. We enrolled and randomised 64 individuals, 31 from the active group and 27 from the placebo group completed the 6 week follow-up. Mean sleep efficiency remained unmodified in the active group, and increased by 3% in the placebo group, the between-group difference in the change was not statistically significant (p = 0.49). Total sleep time also improved more with placebo (13.0 vs. 1.33 min, p = 0.66). Time wake after sleep onset (WASO) decreased more in the active group (4.6% vs. 2.4%), but the difference was not significant (p = 0.33). Mean PSQI decreased by 3.11 points (32.3%) in the active group, and by 3.86 points (39.5%) in the placebo group (p = 0.41). SF-36 increased more with placebo (+ 18.3 in active, + 32.1 in placebo, p = 0.68). Salivary cortisol remained unchanged in both groups. No serious adverse events were reported. Among adults with impaired sleep, a nutraceutical combination did not improve objective or subjective sleep parameters more than a placebo infusion.

Figure 1

Study timeline.

Figure 2

Study scheme.

Figure 3

Change in primary and secondary outcomes, by intervention group. (A) Sleep efficiency. (B) PSQI score. (C) Wake-after sleep onset. (D) Total sleep time. (E) SF-36 subdomain 8: “General Health”. (F) Salivary cortisol. The p value represents the statistical significance of the between-groups difference in the final-basal change in each variable. PSQI Pittsburgh sleep quality index, SF-36 36-item health survey questionnaire.