M C Cornelis et al, 2017. Targeted proteomic analysis of habitual coffee consumption, Journal of Internal Medicine, published online.

ABSTRACT:

BACKGROUND:
Coffee drinking has been implicated in mortality and a variety of diseases but potential mechanisms underlying these associations are unclear. Large-scale systems epidemiological approaches may offer novel insights to mechanisms underlying associations of coffee with health.

OBJECTIVE:
We performed an analysis of known and novel protein markers linked to cardiovascular disease and their association with habitual coffee intake in the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS, n=816) and followed-up top proteins in the Uppsala Longitudinal Study of Adult Men (ULSAM, n=635) and EpiHealth (n=2418).

METHODS:
In PIVUS and ULSAM, coffee intake was measured by 7-day dietary records while a computer-based food frequency questionnaire was used in EpiHealth. Levels of up to 80 proteins were assessed in plasma by a proximity extension assay.

RESULTS:
Four protein-coffee associations adjusted for age, sex, smoking and BMI, met statistical significance in PIVUS (FDR<5%, P<2.31×10-3 ): leptin (LEP), chitinase-3-like protein 1 (CHI3L), Tumor necrosis factor (TNF) receptor 6 and TNF-related apoptosis-inducing ligand. The inverse association between coffee intake and LEP replicated in ULSAM (β, -0.042 SD per cup of coffee, P=0.028) and EpiHealth (β, -0.025 SD per time of coffee, P=0.004). The negative coffee-CHI3L association replicated in EpiHealth (β, -0.07, P=1.15×10-7 ), but not in ULSAM (β, -0.034, P=0.16).

CONCLUSIONS:
The current study supports an inverse association between coffee intake and plasma LEP and CHI3L1 levels. The coffee-CHI3L1 association is novel and warrants further investigation given links between CHI3L1 and health conditions that are also potentially influenced by coffee.

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B J Distelberg et al, 2017. The Effect of Coffee and Caffeine on Mood, Sleep, and Health-Related Quality of Life, Journal of Caffeine Research, Volume 7, Number 2.

ABSTRACT:

Objective: The study sought to measure the effects of caffeinated and decaffeinated coffee on affective mood, sleep, and health-related quality of life (HRQL). Methods: Forty-nine healthy participants between the ages of 18 and 45 took part in a randomized, doubleblind, longitudinal study with decaffeinated coffee as the control. The participants began with a 5-day washout period, followed by a 5-day treatment phase, and concluded with a 5-day washout phase. Data were analyzed with repeated-measures analysis of covariance and ordinary least-squares mediational analysis. Results: The caffeinated coffee treatment group showed significant direct effects on sleep, anxiety, and stress-based domains of HRQL. In addition, mediational analysis showed that the more global domains of HRQL were affected indirectly through reduced sleep quality/quantity and through increases in anxiety. No significant changes were noted in the decaffeinated treatment group. Conclusions: Given the strong effect of caffeine on sleep and anxiety, as well as the indirect effect on HRQL in this study, it might be beneficial for individuals with stress responsive illnesses to refrain from high doses of caffeine. Further studies should examine the effects of caffeine in individuals with various stress-related illnesses. The results of caffeine on depression are contrary to previous studies, and further evaluations should examine variations of effects based on dosages and different populations (major depression diagnoses as well as healthy populations).

 

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T J Doty et al, 2017. Limited efficacy of caffeine and recovery costs during and following 5 days of chronic sleep restriction: Caffeine and Sleep Restriction, Sleep, published online ahead of print.

ABSTRACT

OBJECTIVES:
To investigate the effects of caffeine on psychomotor vigilance and sleepiness during sleep restriction and following subsequent recovery sleep.

METHODS:
Participants were N=48 healthy good sleepers. All participants underwent 5 nights of sleep satiation [time-in-bed (TIB): 10 hrs], followed by 5 nights of sleep restriction (TIB: 5 hrs), and 3 nights of recovery sleep (TIB: 8 hrs) in a sleep laboratory. Caffeine (200 mg) or placebo was administered in the form of chewing gum at 0800 and 1200 hrs each day during the sleep restriction phase. Participants completed hourly 10-min psychomotor vigilance tests (PVTs) and a modified Maintenance of Wakefulness Test approximately every 4 hours during the sleep restriction and recovery phases.

RESULTS:
Caffeine maintained objective alertness compared to placebo across the first three days of sleep restriction, but this effect was no longer evident by the fourth day. A similar pattern of results was found for MWT sleep latencies, such that those in the caffeine group (compared to placebo) did not show maintenance of wakefulness relative to baseline after the second night of restriction. Compared to placebo, participants in the caffeine condition displayed slower return to baseline in alertness and wakefulness across the recovery sleep period. Lastly, the caffeine group showed greater N3 sleep duration during recovery.

CONCLUSIONS:
Caffeine appears to have limited efficacy for maintaining alertness and wakefulness across 5 days of sleep restriction. Perhaps more importantly, there may be recovery costs associated with caffeine use following conditions of prolonged sleep loss.

 

The post T J Doty et al, 2017. Limited efficacy of caffeine and recovery costs during and following 5 days of chronic sleep restriction: Caffeine and Sleep Restriction, Sleep, published online ahead of print. appeared first on Coffee and Health.