Sour date seed has been used as a sleep aid in China and other Asian countries for over 2,000 years. The seed of a small tree called Ziziphus jujuba Mill var. spinosa, sour date is used alone or in combination with other herbal medicines to relieve insomnia and anxiety.
Despite its widespread use in Asia, no randomized controlled trials on sour date seed (also called sour jujuba seed) have been conducted on humans to determine its safety and efficacy. But preclinical tests on animals suggest that sour date seed (or one or more of its chemical constituents) acts on neurotransmitter systems that impact sleep and mood, and one observational study suggests that it may improve sleep in women with menopause-related insomnia. If you’re open to alternative treatments for insomnia, this one may interest you.
The GABA Connection
Exactly how sour date seed achieves its soporific effects is unknown. But laboratory tests have shown that it acts on the GABA system. In the brain, neurons that produce the neurotransmitter GABA are important for sleep. When the GABA neurons start firing, the lights in the brain go out.
Many sleeping pills prescribed today—zolpidem (Ambien), eszopiclone (Lunesta), zaleplon (Sonata), and temazepam (Restoril)—enhance the ability of GABA to do its job. They bind to GABAA receptor complexes on the receiving ends of nerve cells and increase the flow of chloride ions moving into the cells. The cells are then inhibited from firing, which tranquilizes the brain. Anti-anxiety medications such as alprazolam (Xanax), clonazepam (Klonopin), and diazepam (Valium) also bind to GABAA receptors, inducing relaxation.
Research on lab animals has shown that sour date seed also binds to GABAA receptors and has sedating effects. In one such study, investigators administered jujubosides—active components in sour date seed—to rats during the day and at night. The jujubosides significantly increased the rats’ total sleep time both day and night.
Other Calming Activity
In another study, scientists used rats to observe the effects of jujuboside A on the hippocampus, an area of the brain associated with emotion, memory, and the autonomic nervous system. The main finding was that jujuboside A inhibited arousal in key pathways in the hippocampus.
Still other animal studies have been done using suan zao ren tang (SZRT), a traditional Chinese herbal medicine whose main ingredient is sour date seed. It was found to modulate the activity of several neurotransmitter systems associated with sleep and mood alteration.
An Observational Study
SZRT is commonly used to treat insomnia connected with menopause in Taiwan, but its use there is traditional and not the result of scientific evidence attesting to its efficacy and safety. So a group of Taiwanese researchers set out to measure its effects on 67 midlife women with insomnia.
The form of SZRT used was a powdered extract made into a granulated compound prepared by the Kaiser Pharmaceutical Co. in Taiwan. The women took 4 grams 3 times a day.
By the end of week 1, the women reported no changes in their sleep. But after 4 weeks, the women experienced these significant changes:
- About 74 percent of the participants with mild to moderate menopausal symptoms reported improved sleep quality, and about 82 percent of those with moderate to severe symptoms reported improved sleep quality
- The women fell asleep about 23 minutes faster, on average
- The average total sleep time went from 4.7 hours to 5.5 hours a night
Three women withdrew from the study due to stomach ache, diarrhea, or dizziness—symptoms that disappeared once the SZRT was stopped.
Take These Results with a Grain of Salt
The main caveat here is that the study was neither randomized nor controlled. Without a control group taking a placebo, it’s impossible to know to what extent the results reflect the effects of SZRT and how much they reflect a placebo effect.
Also, as the authors of the study point out, the fact that by the end of the first week of the study the participants’ sleep remained unchanged suggests that SZRT—if it does improve sleep—works slowly. This is true of many herbal medicines, which must be taken for days or weeks before having an effect.
But the findings do suggest that sour date seed merits more study as a potential sleep aid. And as alternative treatments for insomnia go, this one—because of its history of use and current popularity in Asian countries—is likely fairly safe.