Table 2 shows sleep values of seven different sleep
parameters (sleep efficiency, actual sleep time, number of
awakenings, total nocturnal activity, sleep latency, assumed
sleep, and immobility) obtained during the intake of either a
JVCP (Table 2a) or a placebo (Table 2B) in young, middle-
aged and elderly participants. actual sleep time and immobility
values were elevated (P < 0.05) in young (f = 2.82 and 1.53,
respectively), middle-aged (f = 1.73 and 1.73 respectively) and
elderly (f = 1.67 and 1.60, respectively) individuals after the
consumption of the JVCP with respect to their corresponding
basal values. However, values related to sleep efficiency and
assumed sleep only increased significantly (P < 0.05) in elderly
(f = 1.60 and 1.69, respectively) participants after the intake of
a JVCP with respect to their corresponding basal values. in
relation to the number of awakenings and total nocturnal
activity, a substantial diminution (P < 0.05) was ascertained
after the intake of the JVCP in young (f = 1.96 and 1.45,
respectively), middle-aged (f = 0.94 and 1.30, respectively) and
elderly (f = 0.80 and 0.92, respectively) individuals, with
respect to their corresponding basal values. Moreover, sleep
latency values largely decreased (P < 0.05) after the ingestion
of this JVCP in both middle-aged (f = 1.82) and elderly (f =
1.48) subjects. regarding post-assay values, it was observed
that, in some cases, the sleep-enhancing effects of the ingestion
of JVCP were maintained after the end of the trial in some of
the groups studied. Thus, actual sleep time post-assay values
remained substantially elevated (P < 0.05) in middle-aged (f =
1.73) volunteers, and sleep latency post-assay values remained
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A JERTE VALLEY CHERRY PRODUCT PROVIDES BENEFICIAL EFFECTS ON SLEEP QUALITY
significantly decreased (P < 0.05) in elderly (f = 1.48)
participants, with respect to their corresponding basal values.
The other parameters went back to values close to the basal
ones, with the exception of the number of awakenings in the
middle-aged participants, which increased (P < 0.05; f = 0.94)
with respect to its corresponding assay value. interestingly,
sleep parameters were not modified after the intake of the
placebo with respect to their basal values in young, middle-
aged and elderly participants (Table 2B).
a significant rise (P < 0.05) in aMT6-s levels was found
after the consumption of the JVCP in young (Figure 1a),
middle-aged (Figure 1B) and elderly participants (Figure 1C).
Moreover, aMT6-s levels were increasingly raised with the
advance of age, the rise being 1.52 ± 0.15-fold in young (f =
0.52), 2.40 ± 0.56-fold in middle-aged (f = 0.59), and 2.52 ±
0.78-fold in elderly (f = 0.61) participants, with respect to their
corresponding basal values. Concerning aMT6-s post-assay
values, they remained elevated in middle-aged (1.81 ± 0.65 fold
increase) and elderly (1.73 ± 0.77 fold increase) volunteers,
although these values were not significant with respect to their
corresponding basal values. remarkably, the consumption of
the placebo did not change aMT6-s levels found in the urine of
these participants.
as shown in Figure 2, the consumption of the JVCP
enhanced (P < 0.05) serum concentrations of il-1β, measured
at the acrophase of melatonin rhythm (1.00 am), in young
(0.004 ± 0.001 pg/ml; f = 1.27; Figure 2a), middle-aged
(0.003 ± 0.0006 pg/ml; f = 0.79; Figure 2B), and elderly
(0.003 ± 0.0005 pg/ml; f = 0.77; Figure 2C) volunteers, with
respect to their corresponding basal values. Such effect tended
to decline towards basal values one day following the trial
termination. importantly, the intake of the placebo did not
modify il-1β levels found in the serum of these participants.
levels of serum TnF-α assayed at 1.00 am were also
increased (P < 0.05) after the ingestion of the JVCP in young
(0.25 ± 0.07 pg/ml; f = 1.65; Figure 3a), middle-aged (0.40 ±
Table 2A
Sleep parameters obtained during a 5-day consumption of a Jerte Valley cherry product (assay), and during 5 days afterwards
(Post-assay), with respect to their basal values in young, middle-aged and elderly volunteers
Young Middle-aged Elderly
Basal Assay Post-assay Basal Assay Post-assay Basal Assay Post-assay
Sleep efficiency 80.90±5.10 83.32±3.23 80.09±1.61 82.50±5.01 84.97±4.12 83.32±2.47 71.21±3.27 79.04±3.40 a 77.61±2.69
(%)
actual sleep time 394.00±9.10 425.52±11.82 a 401.88±17.58 398.00±10.82 445.76±19.82 a 453.72±19.82 a 356.79±15.23 403.17±14.54 a 388.90±10.97
(min)
number of 10.57±1.73 7.39±1.26 a 8.35±2.53 12.43±2.06 10.06±0.87 a 12.80±0.99 b 12.25±1.75 10.90±0.36 a 11.39±0.36
awakenings
Total nocturnal 5327.51±210.23 4315.28±272.92 a 4901.3±479.47 5889.93±207.92 4299.64±312.29 a 4476.34±556.79 10631.68±225.81 8292.27±669.48 a 8717.97±669.48
activity
(activity pulses)
Sleep latency 18.00±2.44 13.68±5.76 14.22±4.32 19.54±2.88 13.67±2.14 a 18.56±2.73 42.46±5.89 31.84±2.54 a 27.59±8.49 a
(min)
assumed sleep 369.30±13.31 387.76±7.38 369.30±25.85 368.57±8.45 394.36±29.48 405.42±29.48 306.39±6.90 330.90±12.38 a 324.77±12.38
(min)
immobility 300.30±8.51 330.33±9.00 a 285.28±21.02 283.44±9.64 331.62±20.34 a 320.28±20.34 267.50±7.37 302.27±16.07 a 288.90±12.72
(min)
each value represents the mean ± SeM from ten participants. a. P < 0.05 with respect to their corresponding basal values; b. P < 0.05 with respect to their corresponding assay values.
Table 2B
Sleep parameters obtained during a 5-day consumption of a placebo (assay), and during 5 days afterwards (Post-assay), with
respect to their basal values in young, middle-aged and elderly volunteers.
Young Middle-aged Elderly
Basal Assay Post-assay Basal Assay Post-assay Basal Assay Post-assay
Sleep efficiency 80.90±5.10 84.94±6.47 79.28±5.66 82.50±5.01 78.37±2.82 82.50±3.47 71.21±3.27 69.78±2.13 69.07±4.27
(%)
actual sleep time 394.00±9.10 358.54±35.46 374.30±23.64 398.00±10.82 398.00±11.86 409.94±11.84 356.79±15.23 360.35±14.27 342.51±24.97
(min)
number of 10.57±1.73 9.62±0.95 9.72±0.63 12.43±2.06 12.43±0.99 12.18±0.12 12.25±1.75 12.00±0.98 12.12±0.61
awakenings
Total nocturnal 5327.51±210.23 5380.78±159.82 5380.78±159.82 5889.93±207.92 6243.32±330.09 6320.02±176.69 10631.68±225.81 10737.99±285.58 11056.94±337.90
activity
(activity pulses)
Sleep latency 18.00±2.44 17.64±1.62 19.26±1.80 19.54±2.88 19.54±0.78 19.14±1.17 42.46±5.89 40.33±2.54 44.58±2.12
(min)
assumed sleep 369.30±13.31 365.60±18.46 365.60±25.85 368.57±8.45 361.19±22.11 379.62±18.42 306.39±6.90 306.39±18.38 291.07±21.44
(min)
immobility 300.30±8.51 306.30±21.02 282.28±18.01 283.44±9.64 280.60±17.00 277.77±5.66 267.50±7.37 254.12±18.72 256.80±18.72
(min)
each value represents the mean ± SeM from ten participants.
CHerrY ProduCTPlaCeBo
0.19 pg/ml; f = 1.83; Figure 3B), and elderly (0.69 ± 0.26
pg/ml; f = 2.47; Figure 3C) subjects, with respect to their
corresponding basal values. likewise, our results showed that
the ingestion of the JVCP augmented nocturnal levels of serum
il-8 in young (5.11 ± 0.74 pg/ml; f = 0.61; Figure 4a),
middle-aged (6.39 ± 0.85 pg/ml; f = 1.31; Figure 4B), and
elderly (8.28 ± 1.07 pg/ml; f = 2.51; Figure 4C) volunteers,
compared to their basal values. it is also important to note that
both TnF-α and il-8 levels were increasingly high with
advancing age after the consumption of the JVCP. Moreover,
TnF-α and il-8 post-assay values remained slightly elevated
after the 5-day intake of the JVCP. Curiously, the consumption
of the placebo did not change TnF-α and il-8 levels found in
the serum of these participants.
Figure 1
effect of the Jerte Valley cherry product or the placebo intake
on urinary 6-sulfatoxymelatonin (aMT6-s) levels obtained in
first-void morning urines, in young (a), middle-aged (B) and
elderly (C) participants. Basal values are urine samples
obtained before the intake of the cherry product or the placebo,
assay values are urine samples taken on the last day of a 5-day
product intake or placebo intake, and post-assay values are
urine samples obtained after the termination of the assay. data
are expressed as fold increase over the basal levels. each value
represents the mean ± SeM from ten participants
*P < 0.05 with respect to their corresponding basal values.
Discussion
up to now, an impressive and growing number of bioactive
compounds have been identified in foodstuffs. Through the
consumption of fruits and vegetables, such components are
incorporated into the organism and contribute to exerting
positive effects on health. in this study, we found that the intake
of a JVCP strikingly improved sleep quality in young, middle-
aged and elderly participants, these findings being supported by
the fact that the intake of the JVCP elevated the levels of
aMT6-s and pro-somnogenic cytokines in all age groups, whilst
the ingestion of a placebo neither had effect on sleep quality
nor affected aMT6-s and/or cytokine levels. Taking into
account the sleep-promoting properties of melatonin, it is
feasible to assume that melatonin contained in the JVCP may
be responsible for enhancing the different sleep parameters
assessed. likewise, since tryptophan and serotonin are also
present in the JVCP (30) they may also contribute to improving
sleep quality in young, middle-aged and elderly participants
due to their beneficial effects on sleep disturbances, as reported
elsewhere (29).
Figure 2
effect of the Jerte Valley cherry product or the placebo intake
on interleukin-1β (il-1β) levels obtained at 1.00 am, in young
(a), middle-aged (B) and elderly (C) participants. Basal values
are serum samples obtained before the intake of the cherry
product or the placebo, assay values are serum samples taken
on the last day of a 5-day product intake or placebo intake, and
post-assay values are serum samples obtained after the
termination of the assay. data are expressed as pg/ml. each
value represents the mean ± SeM from ten participants
*P < 0.05 with respect to their corresponding basal values.
although volunteers enrolled in this study were healthy
subjects, i.e. individuals without major sleep disturbances, it is
remarkable to note that the consumption of the JVCP succeeded
in enhancing sleep quality in all age groups, as shown by the
improvement of several sleep parameters including actual sleep
time, number of awakenings, total nocturnal activity or
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The Journal of Nutrition, Health & Aging©
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557
immobility. in this regard, several studies have demonstrated
that the supplementation with tryptophan and/or melatonin
produces important sleep-promoting effects not only in subjects
with sleep disturbances, but also in subjects who manifested no
sleep complaint (33-36). Moreover, the ingestion of tryptophan
appears to be an effective daytime hypnotic for healthy adults,
by facilitating sleep onset at times outside the normal circadian
rhythm and modulating sleep stages during the day (37).
Figure 3
effect of the Jerte Valley cherry product or the placebo intake
on tumor necrosis factor α (TnF-α) levels obtained at 1.00 am,
in young (a), middle-aged (B) and elderly (C) participants.
Basal values are serum samples obtained before the intake of
the cherry product or the placebo, assay values are serum
samples taken on the last day of a 5-day product intake or
placebo intake, and post-assay values are serum samples
obtained after the termination of the assay. data are expressed
as pg/ml. each value represents the mean ± SeM from ten
participants
*P < 0.05 with respect to their corresponding basal values.
despite the fact that clinical studies of melatonin secretion
are usually based on measuring its serum concentration, the
evaluation of aMT6-s excretion has become accepted and
validated as a useful indirect index of the secretory activity of
all cells that produce melatonin (38). in fact, the levels of
urinary aMT6-s, the major urinary metabolite of melatonin,
have been reported to accurately reflect nocturnal serum
melatonin (11). Herein, our results showed that the intake of a
JVCP twice a day (as lunch and dinner dessert) elevated aMT6-
s levels in first-void morning urine, these results being
consistent with previous findings, which established an
association between fruits or vegetables consumption and
elevated aMT6-s levels (29, 39-41).
Figure 4
effect of the Jerte Valley cherry product or the placebo intake
on interleukin-8 (il-8) levels obtained at 1.00 am, in young
(a), middle-aged (B) and elderly (C) participants. Basal values
are serum samples obtained before the intake of the cherry
product or the placebo, assay values are serum samples taken
on the last day of a 5-day product intake or placebo intake, and
post-assay values are serum samples obtained after the
termination of the assay. data are expressed as pg/ml. each
value represents the mean ± SeM from ten participants
*P < 0.05 with respect to their corresponding basal values.
The decline in melatonin secretion with age has been
suggested as one of the major reasons for increased sleep
disruption in elderly people (42). Thus, different studies have
correlated age-related disturbances in sleep/wake cycle with
decreases in melatonin output (43, 44), which is also in
accordance with other studies reporting a negative, significant
correlation between urinary excretion of aMT6-s and age (45,
46). in this sense, the ingestion of the JVCP not only induced
sleep-enhancing effects in young and middle-aged volunteers,
but also produced a highly noticeable improvement on sleep of
elderly participants, as reported by substantial increases in all
seven different sleep parameters assayed. likewise, after the
consumption of the JVCP, the most remarkable increase in
urinary aMT6-s was also found in elderly participants, thus
highlighting the potential usefulness of this cherry-based
foodstuff to prevent or alleviate some disorders related to the
decline in melatonin and, consequently, linked to old age.
Several cytokines and their receptors are present and
biologically active in normal healthy brain (20), acting locally
within the cortex to alter the eeG delta power (indicative of
A JERTE VALLEY CHERRY PRODUCT PROVIDES BENEFICIAL EFFECTS ON SLEEP QUALITY
The Journal of Nutrition, Health & Aging©
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558
nreM intensity) (47, 48). in this sense, it has been reported
that il-1β circulating levels increase at the onset of sleep (49).
Moreover, il-1β enhances the firing rate of hypothalamic
sleep-active neurons while it inhibits wake-active neurons (50).
likewise, alterations in circulating levels of TnF-α have been
corroborated in patients suffering from sleep disturbances (51).
our results showed that circulating levels of the pro-
somnogenic cytokines il-1β, TnF-α and il-8, measured at
1.00 am, were enhanced after the consumption of the JVCP
and, therefore, these findings may also account for the sleep-
promoting effects of the JVCP. Given that cytokine production
and melatonin levels are interrelated, we hypothesized that the
rise in pro-somnogenic cytokines at night may be due to the
enhancement of melatonin levels because of the ingestion of the
melatonin-enriched JVCP. in fact, melatonin is known to
exhibit immunomodulatory actions that are mainly mediated
through the modulation of cytokine production (52) via binding
to specific receptors expressed by different immune cells (53).
Furthermore, this indole has been shown to stimulate the
production of il-1β, il-2, il-12, il-6, iFn-γ, as well as
enhancing TnF-α levels (54-56).
one potential methodological weakness of our study is the
small sample size, as it may have limited statistical power to
detect between-group differences. nonetheless, based on the
results of the post hoc power analysis, it seems that such a
sample size provided sufficient statistical power to study the
effect of the JVCP on sleep quality. Taking together, our
findings suggest that the consumption of the JVCP twice a day,
as lunch and dinner dessert, was positive in improving some
sleep parameters, particularly in advancing age. However,
given the moderate size of the population studied herein, the
actual clinical significance of this JVCP on sleep disorders
remains to be corroborated in a much bigger clinical studysummarize the content into a scipt