Certain prior conditions, such as dairy consumption, influenced which supplement worked best. “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,” wrote scientists from Ezaki Glico Co., Ltd., (Japan) and Stanford University (USA).
According to the study, worldwide 20% of people experience insomnia. This condition can lead to health problems such as depression and hypertension. The US sleep category has experienced impressive growth over the past few years. According to SPINS, sales of sleep supplements increased 40% and 22% in 2020 and 2021, respectively, to hit $737 million. A slight decline in dollar sales of 4.2% was recorded in 2022 for the Natural and Mass channels, but the market is still a significantly bigger category than in 2019 when it was valued at $432 million.
The category is dominated by melatonin, which was responsible for 91.5% of all sleep supplement sales, according to SPINS. While the sleep benefits of melatonin have been extensively studied, the authors of this study tested four lesser-known supplements: l-theanine, GABA, AVLE, l-serine.
Dosage and Methodology
A total of 106 participants’ data was analyzed for the open, randomized cross-over intervention trial. Placebo pills and meditation were analyzed in addition to a control group. The efficacy of each supplement as well as the relationships among supplements, prior conditions (PCs) and sleep problems were analyzed. PCs included frequency of dairy consumption, vegetable consumption and frequency of interrupted sleep.
The dosages for each supplement were as follows: 200 mg per day of l-theanine, 111.1 mg per day of GABA (in the form of gamma-aminobutyric acid), 50 mg per day of AVLE (Apocynum venetum leaf extract) and 300 mg per day of l-serine. Each of these and the placebo were consumed within 30 to 60 minutes of bedtime. Mindfulness was performed within 10 minutes of bedtime.
Participants completed life-habit surveys, Athens Insomnia scale and the Oguri-Shirakawa-Azumi (OSA) sleep questionnaire throughout the study. The OSA factors included: sleepiness on rising, initiation and maintenance of sleep, frequent dreaming, refreshing, and sleep length.
Efficacy of Sleep Supplements
Each of the supplements as well as the placebo and meditation resulted in better OSA scores for participants, especially sleepiness on rising and refreshing. The initiation and maintenance of sleep was significantly improved with l-theanine, GABA, mindfulness, and the placebo. Sleep length was significantly improved with l-theanine.
The authors also found links between prior conditions and efficacy of the supplements. They write, “we found ... the dietary supplement with the greatest efficacy was dependent on a user’s PCs and sleep problems.”
These interactions varied for different OSA factors and supplements, with PCs ranging from consuming dairy products frequently to screen time habits. For participants whose OSA Factor 3 was improved with GABA supplementation, they admitted to consuming many vegetables. The authors suggest then that GABA might work better for people who frequently consume vegetables. They also suggest the possibility that life-habit recommendations could improve the efficacy of supplements for sleep problems.
2023, 15(10), 2377; https://doi.org/10.3390/nu15102377
“Analysis of the Effects of Known Sleep-Support Supplements in Relation to Life Habits, Sleep Conditions, and Sleep Problems”
Authors: F. Imafuku, et al.