Study identifies importance of personalisation with sleep supplements
The studied supplements, as well as the placebo and mindfulness interventions, were found to all significantly improve sleep problems across the participants studied. Yet, the PCs were found to be more helpful to predict supplement efficacy than for the placebo and mindfulness groups.
In addition, the supplement with the greatest efficacy was found to be dependent on the user’s specific sleep issues and PCs, such as dairy and vegetable intakes; an observation hypothesised to result from the functional compounds contained within such foods.
“This study suggests the possibility of personalizing sleep-support supplementation based on personal life habits, sleep conditions, and sleep problems, in addition to the known efficacy of dietary supplements,” the researchers conclude.
Sleep and health
Sleep disorders are vastly prevalent in the modern day, with 20% of the global population estimated to suffer with insomnia. The condition has been linked to increase the risk of developing diseases such as hypertension and type 2 diabetes.
Whilst pharmacotherapy solutions have demonstrated a good efficacy in improving the condition in some, the treatment has been found to cause an array of adverse side-effects including dependency and memory loss.
Therefore, in the face of increased stressors and heightened levels of anxiety and depression, the demand for natural sleep-support solutions is high. Certain substances have demonstrated effectiveness in decreasing such sleep problems with studies observing the potential benefits of l-theanine, γ-aminobutyric acid (GABA), Apocynum venetum leaf extract (AVLE) and l-serine.
Yet, it has been noted that the effectiveness of each supplement varies amongst individuals, due to differing sleep problems and lifestyles. Thus, there is a need to understand the effects of such supplements across different people, to enable for the tailoring of specific supplements to improve their effectiveness.
As a result, the present study sought to investigate the influence of preconditions (PCs), including lifestyle habits and sleeping behaviours, before supplementation with l-theanine, GABA, AVLE, l-serine, and placebo, to identify new criteria for predicting their effects.
The study consisted of a randomised cross-over intervention trial, recruiting 160 healthy subjects suffering with sleep problems, as determined using the Pittsburgh Sleep Quality Index (PSQI).
The supplements used included 200 mg/day l-theanine, 111.1 mg of barley lactic acid fermentation extract/day for GABA, 50 mg/day for AVLE, 300 mg/day for l-serine, and 3300 mg of maltodextrin/day as placebo. Subjects were split into in six intervention periods and administered the supplement, placebo, or conducted mindfulness over seven days, with five washout periods of at least seven days.
Prior to supplementation, the life habits and sleep conditions were obtained to determine the PC of each participant. For supplement and sleep problem combination, these PCs were compared between subjects who had an improvement in their sleep problems and those whose sleep problems were not improved with supplementation.
All the supplements administered were noted to significantly improve the sleep problems. Furthermore, the PCs were found to be different in the subjects who showed improvements.
For example, it was found that in each of the supplements consumed, dairy intake was a observed to be a factor associated with an improvement in sleep problems. The researchers theorise that this may result from the functional compounds contained within certain dairy products, with previous studies noting that α-lactalbumin reduced sleepiness by increasing plasma tryptophan.
“This study confirms the efficacy of dietary sleep-support supplements and further extends prior research by clarifying the significant PCs that impact personalized supplementation. As a result, the possibility of implementing personalized supplementation based on significant PCs was suggested,” the report emphasises.
The researchers draw attention to one observed example within the study, whereby a high frequency of eating vegetables was a PC only observed in those who responded positively to GABA with regards to their specific sleep issue.
With regards to the potential mechanism of action explaining this, the scientists hypothesise: “Some functional ingredients contained in some vegetables may affect the GABA-specific ADME and enhance the sleep-improving effect of GABA.” Yet, they stress there is a lack of research in this area.
“Analysis of the Effects of Known Sleep-Support Supplements in Relation to Life Habits, Sleep Conditions, and Sleep Problems”
by Fuminori Imafuku, Kazuya Yamamoto, Eiji Tanaka, Ryo Aoki and Seiji Nishino