Response from bpacnz editorial team:
It is claimed that cherries and cherry extracts, particularly tart cherry, are associated with several health benefits,
such as improving sleep, reducing muscle recovery time after exercise and decreasing inflammation.1 Cherries
are generally divided into sweet or tart varieties. There are two main types of tart cherries – morello and amarelle.
Montmorency tart cherries, which are a variety of amarelle, are the most common constituent of “medicinal” cherry products.
Tart cherries contain various phytochemicals, including anthocyanins, which are reported to have cellular oxidative stress
protection properties.1 They also contain anti-inflammatory cytokines and melatonin, which if absorbed, may
have sleep regulation properties.1
To date, there has been limited clinical research investigating the effect of cherry extracts on sleep. Notable small
- A randomised, double-blind, placebo-controlled, crossover study investigated twenty healthy adults who consumed tart
cherry concentrate or placebo within 30 minutes of waking and 30 minutes before their evening meal, for seven days. Based
on sleep diary data, participants had a significant increase in total sleep time when taking tart cherry extract, and
non-significant reductions in time taken to fall asleep (sleep latency - approximately five minutes) and wake after sleep
onset (approximately one minute).2
- Another randomised, double-blind, placebo-controlled, crossover study investigated the effect of tart cherry extract
in 15 older adults with chronic insomnia. Participants took treatment or placebo for two weeks, with a two week intervening
washout period. Assessment was based on sleep diary data and an insomnia severity index. Tart cherry was associated with
a significant reduction in insomnia severity (minutes awake after sleep onset), but no significant improvements in sleep
latency, total sleep time or sleep efficiency compared to placebo. The authors noted that the effects of tart cherry were
equal to or exceeded those found with valerian and equal to some but not all studies of melatonin. The effects were, however,
considerably less than for evidence-based treatments for insomnia such as cognitive behavioural therapy.3
- In a randomised, double-blind, placebo-controlled, crossover study investigating Jerte Valley (Spain) sweet cherry extract,
30 adults took the extract or placebo over seven 72 hour periods. When the cherry extract was taken, participants had
improved nocturnal rest measured by sleep efficiency, number of awakenings, total nocturnal activity, sleep latency, assumed
sleep, actual sleep and immobility. Older adults had greater improvements in sleep.4
In each of the studies, participants taking the cherry extracts were found to have detectable levels of melatonin in
their urine; melatonin was not detected after taking placebo. In the tart cherry studies, however, the amount of melatonin
taken was estimated to be 0.08 mg – less than the lowest doses of exogenous melatonin found to have an impact on sleep
(0.3 mg).1 The short half-life of melatonin (less than one hour) suggests that the improvements seen in wake
after sleep onset may also be due to other mechanisms or factors.1
None of the studies included discussion of adverse effects associated with the cherry extracts. In addition, there have
been no studies involving children, therefore the efficacy and safety of cherry extract in this group is unknown.
A pragmatic approach if a patient or parent wishes to trial the use of a tart cherry product (available in New Zealand
as juice, capsules, lozenges and sachets), is to suggest that the supplement is taken daily for one to two weeks while
monitoring sleep quality. The supplement should be ceased if sleep parameters do not improve within this time, or if the
patient believes they are experiencing adverse effects.
- Yurcheshen M, Seehuus M, Pigeon W. Updates on nutraceutical sleep therapeutics and investigational research. Evid Based Complement Alternat Med 2015;105256.
- Howatson G, Bell P, Tallent J, et al. Effect of tart cherry juice (Prunus cerasus) on melatonin levels and enhanced sleep quality. Eur J Nutr 2012;51(8):909–16.
- Pigeon W, Carr M, Gorman C, Perlis M. Effects of a tart cherry juice beverage on the sleep of older adults with insomnia: a pilot study. J Med Food 2010;13(3):579–83.
- Garrido M, Gonzalez-Gomez D, Lozano M, et al. A Jerte Valley cherry product provides beneficial effects on sleep quality. Influence on
aging. J Nutr Health Aging 2013;17(6):553-60.