Can tart cherry juice improve insomnia confirmed by polysomnography in older adults, and is tryptophan availability a potential mechanism?
Tart Cherry Sleep Extract, a crossover trial (Am J Ther 2018, PMID 28901958) — the completers showed an increase in sleep time by 84 minutes on polysomnography (P = 0.0182) and an increase in sleep efficiency on the Pittsburgh Sleep Quality Index (P = 0.03) when consuming cherry juice. Other questionnaires did not show significant differences.
Source: Am J Ther 2018, PMID 28901958 ↗ · Research map · How Magellan grades evidence · evidence confidence: high
Am J Ther · 2018 · PMID 28901958 · DOI 10.1097/MJT.0000000000000584
Tart cherry juice may help older adults with insomnia sleep longer and more efficiently, possibly by affecting tryptophan metabolism and inflammation.
The question
Can tart cherry juice improve insomnia confirmed by polysomnography in older adults, and is tryptophan availability a potential mechanism?
What they tested
Montmorency tart cherry juice will improve insomnia as measured by polysomnography, and this improvement may be linked to increased tryptophan availability through the inhibition of indoleamine 2,3-dioxygenase (IDO).
How they did it
A placebo-controlled, balanced crossover study was conducted with subjects over 50 years old experiencing insomnia. Participants were randomized to receive either placebo or tart cherry juice (240 mL twice daily) for 2 weeks, separated by a 2-week washout period. Sleep was assessed using polysomnography and 5 validated questionnaires. Serum levels of indoleamine 2,3-dioxygenase (IDO), the kynurenine-to-tryptophan ratio, and prostaglandin E2 were measured. In vitro experiments stimulated Caco-2 cells with interferon-gamma to measure the ability of cherry juice procyanidin to inhibit IDO. The content of procyanidin B-2 and other major anthocyanins in the cherry juice was also determined.
What they found
Out of 11 randomized subjects, 8 completed the study after 3 were excluded due to sleep apnea. The completers showed an increase in sleep time by 84 minutes on polysomnography (P = 0.0182) and an increase in sleep efficiency on the Pittsburgh Sleep Quality Index (P = 0.03) when consuming cherry juice. Other questionnaires did not show significant differences. Serum kynurenine-to-tryptophan ratio and prostaglandin E2 levels both decreased (both P < 0.05). In vitro, cherry juice procyanidin B-2 dose-dependently inhibited IDO.
What it means
Tart cherry juice increased sleep time and sleep efficiency in older adults with insomnia. The procyanidin B-2 in cherry juice inhibited IDO, which may increase tryptophan availability and reduce inflammation, potentially contributing to the observed improvements in insomnia.
Limitations
The study had a small sample size of 8 completers, which may limit the generalizability of the findings. Three subjects were excluded due to sleep apnea, indicating that the results may not apply to individuals with this condition.
The paper at a glance
| Title | Pilot Study of Tart Cherry Juice for the Treatment of Insomnia and Investigation of Mechanisms |
|---|---|
| Journal | Am J Ther |
| Year | 2018 |
| PMID | 28901958 ↗ |
| DOI | 10.1097/MJT.0000000000000584 ↗ |
| Topic | Sleep, circadian rhythm & stress |
Read the source: PubMed record (authors, abstract, full citation) ↗ · Publisher via doi.org ↗
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Tart Cherry Sleep Extract
In small randomized and crossover trials, tart cherry juice or concentrate has modestly increased total sleep time (by more than an hour of objectively measured sleep in one pilot), sleep efficiency and self-reported sleep quality, including in older adults with insomnia, and narrative and network-meta-analytic…
Tart cherry (Prunus cerasus), most commonly the Montmorency variety, is a fruit consumed as juice…
Research describes the compound or intervention studied. It is not a claim about any specific product.
Molecules & mechanisms in this paper
Each of these is named in the paper’s own words above. Open the monograph for the full mechanism and its other citations.
Cite this page
These citations point at this summary. To cite the original paper with its full author list, use the PubMed record or doi.org.
Magellan Longevity. (2026). Can tart cherry juice improve insomnia confirmed by polysomnography in older adults, and is tryptophan availability a potential mechanism? [Plain-English summary of Am J Ther 2018, PMID 28901958, DOI 10.1097/MJT.0000000000000584]. Magellan Longevity. https://magellanlongevity.com/study/d28901958.html@misc{magellan_d28901958,
title = {Can tart cherry juice improve insomnia confirmed by polysomnography in older adults, and is tryptophan availability a potential mechanism?},
author = {{Magellan Longevity}},
year = {2026},
howpublished = {\url{https://magellanlongevity.com/study/d28901958.html}},
note = {Plain-English summary of PubMed PMID 28901958; DOI 10.1097/MJT.0000000000000584; Am J Ther 2018. Reviewed by Gabriel Radu, DO},
urldate = {2026-08-11}
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