0
selected
-
1.
The effects of caffeine ingestion on isokinetic muscular strength: A meta-analysis.
Grgic, J, Pickering, C
Journal of science and medicine in sport. 2019;(3):353-360
Abstract
OBJECTIVES The aims of this paper are threefold: (1) to summarize the research examining the effects of caffeine on isokinetic strength, (2) pool the effects using a meta-analysis, and (3) to explore if there is a muscle group or a velocity specific response to caffeine ingestion. DESIGN Meta-analysis. METHODS PubMed/MEDLINE, Scopus, and SPORTDiscus were searched using relevant terms. The PEDro checklist was used for the assessment of study quality. A random-effects meta-analysis of standardized mean differences (SMDs) was done. RESULTS Ten studies of good and excellent methodological quality were included. The SMD for the effects of caffeine on strength was 0.16 (95% CI=0.06, 0.26; p=0.003; +5.3%). The subgroup analysis for knee extensor isokinetic strength showed a significant difference (p=0.004) between the caffeine and placebo conditions with SMD value of 0.19 (95% CI=0.06, 0.32; +6.1%). The subgroup analysis for the effects of caffeine on isokinetic strength of other, smaller muscle groups indicated no significant difference (p=0.092) between the caffeine and placebo conditions. The subgroup analysis for knee extensor isokinetic strength at angular velocities of 60°s-1 and 180°s-1 showed a significant difference between the caffeine and placebo conditions; however, no significant effect (p=0.193) was found at an angular velocity of 30°s-1. CONCLUSIONS This meta-analysis demonstrates that acute caffeine ingestion caffeine may significantly increase isokinetic strength. Additionally, this meta-analysis reports that the effects of caffeine on isokinetic muscular strength are predominantly manifested in knee extensor muscles and at greater angular velocities.
-
2.
Are low doses of caffeine as ergogenic as higher doses? A critical review highlighting the need for comparison with current best practice in caffeine research.
Pickering, C, Kiely, J
Nutrition (Burbank, Los Angeles County, Calif.). 2019;:110535
Abstract
Caffeine is a popular and widely consumed sporting ergogenic aid. Over the years, the effects of different caffeine doses have been researched, with the general consensus being that 3 to 6 mg/kg of caffeine represents the optimal dose for most people. Recently, there has been increased attention placed on lower (≤3 mg/kg) caffeine doses, with some research suggesting these doses are also ergogenic. However, a critical consideration for athletes is not merely whether caffeine is ergogenic at a given dose, but whether the consumed dose provides an optimized performance benefit. Following this logic, the aim of this review was to identify a potential oversight in the current research relating to the efficacy of lower caffeine doses. Although low caffeine doses do appear to bestow ergogenic effects, these effects have not been adequately compared with the currently accepted best practice dose of 3 to 6 mg/kg. This methodological oversight limits the practical conclusions we can extract from the research into the efficacy of lower doses of caffeine, as the relative ergogenic benefits between low and recommended doses remains unclear. Here, we examine existing research with a critical eye, and provide recommendations both for those looking to use caffeine to enhance their performance, and those conducting research into caffeine and sport.
-
3.
Association between obstructive sleep apnea and alcohol, caffeine and tobacco: A meta-analysis.
Taveira, KVM, Kuntze, MM, Berretta, F, de Souza, BDM, Godolfim, LR, Demathe, T, De Luca Canto, G, Porporatti, AL
Journal of oral rehabilitation. 2018;(11):890-902
Abstract
The aim of this systematic review was to answer the focused question, "Is there an association between obstructive sleep apnea (OSA) and alcohol, caffeine or tobacco use?" Five electronic databases (Cinahl, Literatura Latth American and Caribbean, PubMed, Scopus, Web of Science) and 3 grey literature (Google Acadêmico, ProQuest, OpenGrey) were searched, as well as search on reference list of included papers and contacts with study authors. Observational studies were included. The Meta-Analysis of Statistics Assessment and Review Instrument (MAStARI) tool assessed the potential risk of bias (RoB) among the studies, while the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach determined the level of evidence. Meta-Analysis was performed with RevMan 5.3 software. Among 3,442 identified studies, 14 were included. Eleven studies were classified as moderate RoB and 3 as high RoB. Meta-analysis showed OSA has no association with tobacco and presented a positive association with alcohol. The odds ratio for OSA increased almost 1.33 times (95% confidence interval [CI]; 1.10-1.62) for alcohol users. There was insufficient published data to evaluate whether OSA is associated with caffeine. The overall quality of evidence ranged from low to very low. OSA was associated with the use of alcohol, however there is not enough evidence to confirm the association with tobacco or caffeine. Due to the very low GRADE level of evidence, caution should be applied when considering these findings.
-
4.
Caffeine: A Potential Protective Agent Against Cognitive Decline in Alzheimer's Disease.
Hussain, A, Tabrez, ES, Mavrych, V, Bolgova, O, Peela, JR
Critical reviews in eukaryotic gene expression. 2018;(1):67-72
Abstract
Over the past few decades, caffeine has been well recognized as a stimulant whose effects can be detected particularly in the central nervous system. A stimulating effect of caffeine has been found useful in treating patients with many neurological disorders, including Alzheimer's disease (AD). AD is reported to be a rapidly increasing public health problem with lack of a remedial treatment. However, the assumed protective effects of caffeine against AD are of huge interest. This study substantiates caffeine's role as a potential prevention agent against AD through several epidemiological studies. More than 75% of available study reports support the opinion that caffeine has a favorable effect against cognitive decline and AD. Moreover, other studies have discussed the effect of caffeine drinking and concluded several positive effects on cognitive functioning. The present study, however, focuses more on the potential mechanisms by which caffeine diminishes effects as well as delays the onset of AD.
-
5.
The Effect of Acute Caffeine Ingestion on Endurance Performance: A Systematic Review and Meta-Analysis.
Southward, K, Rutherfurd-Markwick, KJ, Ali, A
Sports medicine (Auckland, N.Z.). 2018;(8):1913-1928
Abstract
BACKGROUND Caffeine is a widely used ergogenic aid with most research suggesting it confers the greatest effects during endurance activities. Despite the growing body of literature around the use of caffeine as an ergogenic aid, there are few recent meta-analyses that quantitatively assess the effect of caffeine on endurance exercise. OBJECTIVES To summarise studies that have investigated the ergogenic effects of caffeine on endurance time-trial performance and to quantitatively analyse the results of these studies to gain a better understanding of the magnitude of the ergogenic effect of caffeine on endurance time-trial performance. METHODS A systematic review was carried out on randomised placebo-controlled studies investigating the effects of caffeine on endurance performance and a meta-analysis was conducted to determine the ergogenic effect of caffeine on endurance time-trial performance. RESULTS Forty-six studies met the inclusion criteria and were included in the meta-analysis. Caffeine has a small but evident effect on endurance performance when taken in moderate doses (3-6 mg/kg) as well as an overall improvement following caffeine compared to placebo in mean power output (3.03 ± 3.07%; effect size = 0.23 ± 0.15) and time-trial completion time (2.22 ± 2.59%; effect size = 0.41 ± 0.2). However, differences in responses to caffeine ingestion have been shown, with two studies reporting slower time-trial performance, while five studies reported lower mean power output during the time-trial. CONCLUSION Caffeine can be used effectively as an ergogenic aid when taken in moderate doses, such as during sports when a small increase in endurance performance can lead to significant differences in placements as athletes are often separated by small margins.
-
6.
[Caffeine: traditional and new therapeutic indications and use as a dermatological model drug].
Bors, L, Bajza, Á, Kocsis, D, Erdő, F
Orvosi hetilap. 2018;(10):384-390
Abstract
Coffee consumption had already been described in the 15th century. The spreading of coffee drinking was not only a consequence of its delicious aromatic taste, but also of its pharmacological effects, especially due to its caffeine content. In this review, the mechanisms behind its complex stimulatory effects and the latest studies on the possible new therapeutic indications of caffeine are summarized. Several papers reported the neuroprotective (in Alzheimer's and Parkinson's disease) and hepatoprotective profiles of caffeine, and we show the most promising new results about its preventive properties in dermal malignancies. These findings were described both in cell cultures and in vivo. The application of caffeine and coffee in cosmetology and dermatological products is based on their antioxidant property and on the above-mentioned beneficial effects. Caffeine is also presented here as a dermatological model drug due to its hydrophilic profile. It can be used for designing and comparing different novel drug formulations, although beside the transcellular route, the follicular and transappendageal pathways play also important roles in its skin penetration. Taken together, caffeine molecule has many recently discovered beneficial pharmacological effects, but one should be careful with its excessive consumption. It can result in several adverse events if overdosed and in case of regular intake of high doses, after abandonment, withdrawal symptoms may appear. Orv Hetil. 2018; 159(10): 384-390.
-
7.
Does coffee affect the bowel function after caesarean section?
Rabiepoor, S, Yas, A, Navaei, J, Khalkhali, HR
European journal of obstetrics, gynecology, and reproductive biology. 2018;:96-99
Abstract
OBJECTIVES Postoperative ileus is a common consequence of abdominal surgery, which tends to prolong the duration of hospital stay and imposes considerable economic costs on healthcare system. Coffee is proved to have positive effects on gastrointestinal motility index in healthy young adults. Thus, the present study aims to examine effects of coffee on bowel function after caesarean section. MATERIAL AND METHOD A total number 100 patients after elective caesarean section were randomly assigned before surgery into control and intervention groups. The intervention group received 100cc coffee at 8, 12 and 20h after the surgery, while the control group received 100cc hot water at the same intervals. First bowel sound, first passage of flatus, first defecation, and length of stay after surgery were compared in the two groups. FINDINGS Mean time to first flatus passage was recorded in the control (22.54±5.09h) and intervention (17.28±4.44h) groups and showed to be statistically significant (p=-0.000). However, average time of first defecation (intervention 37.22±16.31h; control 36.82±16.5h; p=0.647) and mean time of hospital stay of patients (intervention 30.08±9.50h; control 32.16±11.82h; p=0.518) and first bowel sound (intervention 5.84±1.41h; control 6.16±1.33h; p=-0.326) were not statistically significant. DISCUSSION Drinking coffee after a caesarean section reduces time to first flatus in patients. Nevertheless, further studies are needed to examine effects of coffee on ileus after elective caesarean section.
-
8.
Early Caffeine: Essentials for the Neonatal Nurse.
Rostas, SE
The Journal of perinatal & neonatal nursing. 2018;(4):300-302
-
9.
Caffeine controversies.
Gentle, SJ, Travers, CP, Carlo, WA
Current opinion in pediatrics. 2018;(2):177-181
Abstract
PURPOSE OF REVIEW Caffeine use in preterm infants has endured several paradigms: from standard of care to possible neurotoxin to one of the few medications for which there is evidence of bronchopulmonary dysplasia (BPD) risk reduction. The purpose of the review is to analyze this dynamic trajectory and discuss controversies that still remain after decades of caffeine use. RECENT FINDINGS Following concerns for caffeine safety in preterm infants, a large randomized controlled trial demonstrated a reduction in BPD and treatment for patent ductus arteriosus. The lower rate of death or neurodevelopmental impairment noted at 18-21 months was not statistically different at later timepoints; however, infants in the caffeine group had lower rates of motor impairment at 11-year follow-up. The time of caffeine therapy initiation is now substantially earlier, and doses used are sometimes higher that previously used, but there are limited data to support these practices. SUMMARY Caffeine therapy for apnea of prematurity (AOP) remains one of the pillars of neonatal care, although more evidence to support dosing and timing of initiation and discontinuation are needed.
-
10.
Caffeine and Physiological Responses to Submaximal Exercise: A Meta-Analysis.
Glaister, M, Gissane, C
International journal of sports physiology and performance. 2018;(4):402-411
Abstract
The aim of this study was to carry out a systematic review and meta-analysis of the effects of caffeine supplementation on physiological responses to submaximal exercise. A total of 26 studies met the inclusion criteria of adopting double-blind, randomized crossover designs that included a sustained (5-30 min) fixed-intensity bout of submaximal exercise (constrained to 60-85% maximal rate of oxygen consumption) using a standard caffeine dose of 3-6 mg·kg-1 administered 30-90 min prior to exercise. Meta-analyses were completed using a random-effects model, and data are presented as raw mean difference (D) with associated 95% confidence limits (CLs). Relative to placebo, caffeine led to significant increases in submaximal measures of minute ventilation (D = 3.36 L·min-1; 95% CL, 1.63-5.08; P = .0001; n = 73), blood lactate (D = 0.69 mmol·L-1; 95% CL, 0.46-0.93; P < .00001; n = 208), and blood glucose (D = 0.42 mmol·L-1; 95% CL, 0.29-0.55; P < .00001; n = 129). In contrast, caffeine had a suppressive effect on ratings of perceived exertion (D = -0.8; 95% CL, -1.1 to -0.6; P < .00001; n = 147). Caffeine had no effect on measures of heart rate (P = .99; n = 207), respiratory exchange ratio (P = .18; n = 181), or oxygen consumption (P = .92; n = 203). The positive effects of caffeine supplementation on sustained high-intensity exercise performance are widely accepted, although the mechanisms to explain that response are currently unresolved. This meta-analysis has revealed clear effects of caffeine on various physiological responses during submaximal exercise, which may help explain its ergogenic action.