The Effect of Caffeine Consumed Before Competition on Heart Rate, Trigger Squeeze Time and Shooting Score in Air Pistol Athletes

Background: Caffeine consumption may adversely affect the performance of athletes in some sports. Aim: The aim of this study was to investigate the effects of caffeine drink consumed before competitions by air pistol athletes on their heart rate, trigger squeeze times and shooting scores. Methods: : In the study, caffeinated and caffeine-free measurements were applied on the same athletes. Following the evaluation, a total of 20 elite athletes, including 10 women with a mean age of 23.6±4.7 and 10 men with a mean age of 25.9±4.8 who had at least 2 years sports history, participated voluntarily in the study. The study was planned as a single blind. All athletes shot 10 times before both measurements. By random method, the athletes consumed Coffee with 3mg/kg caffeine or decaf coffee before the measurement. After 1 week, the same athletes were given coffee which was not given in the previous measurement before the measurement. A total of 80 shots were fired at 15, 30 and 60 minutes after both measurements. Following the evaluation, heart rates, trigger squeeze times and shooting scores of the athletes were recorded. Wilcoxon test to compare the differences between the measurements at two different times on the same group and Mann-Whitney U test to examine the differences in independent groups were used. Results: When the differences between the measurements of all male and female athletes were examined, it was found that there was an increase in their heart rate and trigger squeeze times 15, 30 and 60 minutes after caffeinated coffee consumption, and this difference was statistically significant (p<0.05). Besides there was a significant decrease in 15, 30 and 60 minute shooting scores of female athletes, and 15 and 30 minute shooting scores of male athletes (p<0.05). Conclusion: As a result of the study, it was observed that the use of caffeine had a negative effect on the performance of air pistol athletes. Therefore, it can be said that people interested in air pistol discipline should not consume coffee or caffeine-containing beverages within 1-2 hours before the competition, if they consume, their heart rate will increase and their aiming during shooting will be more difficult and trigger-squeezing times will be extended. Keywords: Air pistol, Caffeine, Heart rate, Shooting

Caffeine, Coffee, Tea and Risk of Rheumatoid Arthritis: Systematic Review and Dose- Response Meta-analysis of Prospective Cohort Studies

Objective: Prospective cohort studies on coffee, tea and caffeine in relation to the risk of rheumatoid arthritis (RA) have shown conflicting results. The aim of this study was to conduct a dose–response meta-analysis of cohort studies on the association between dietary caffeine, different types of coffee and tea consumption and the risk of RA.Methods: PubMed/Medline, Scopus and EMBASE were searched up to July 2021 to identify relevant studies that had considered different types of coffee (caffeinated or decaffeinated), tea or caffeine exposure with RA as the main, or one of the, outcome(s). Two authors independently screened 742 publications. Finally, 5 prospective cohort studies were included in our meta-analysis. Pooled relative risks (RRs) were calculated by using a fixed-effects model. We also performed linear and non-linear dose-response analyses to examine the dose-response relations. Results: Comparing extreme categories, we found a positive, significant association between coffee (RR: 1.30; 95% CI: 1.04-1.62; I2 = 0%, n = 5) and decaffeinated coffee (RR: 1.89; 95% CI: 1.35-2.65; I2 =38.1%, n =3) consumption and risk of RA. One additional cup of coffee consumed per day was associated with an increased risk of RA by 6% (95% CI: 1.02-1.10; I2 = 0%;). This increase in the risk of RA for one cup/d of decaffeinated coffee was 11% 95% CI: 1.05-1.18; I2 = 38). No significant association was observed between caffeinated coffee, tea or caffeine intake and the risk of RA.Conclusion: We found that a higher intake of coffee and decaffeinated coffee was associated with increased risk of RA. No significant association between caffeinated coffee, tea or caffeine intake and the risk of RA was observed.

Coffee break has no impact on laparoscopic skills: a randomized double-blinded placebo-controlled parallel-group trial

Background Coffee is a widely consumed beverage. Surgeons often drink coffee before performing surgery. Caffeine intake leads to tremor which might have a negative effect on surgeons’ fine motor skills. Methods A double-blinded parallel-group trial was conducted in order to investigate if caffeinated coffee intake has a negative effect on laparoscopic skills and increases tremor, regardless of previous coffee consumption. 118 participants were selected during a congress of the German Society of Surgery. Exclusion criteria were immaturity and no given consent. Participants and investigators were blinded. Participants were randomized with a 1:1 allocation into interventional group receiving caffeinated coffee or placebo group receiving decaffeinated coffee. The motor skills were tested with two validated laparoscopic exercises at a laparoscopy simulator (LapSim®) before and 30 min after coffee intake. Data on influencing factors were recorded in a standardized questionnaire and tested for equal distribution in both groups. In both exercises four parameters were recorded: left and right hand path length and angular path. Their differences and the resulting effect scores were calculated for both groups as primary outcome to test which group showed greater improvement on the second round of exercises. Registration number DRKS00023608, registered retrospectively. Results Fifty nine subjects were assigned to each the interventional (54 analyzed) and placebo group (53 analyzed) with 11 drop outs. There was no significant difference between the placebo and interventional group in the two exercises in effect score 30 min after coffee intake [mean (SD); 38.58 (10.66) vs. 41.73 (7.40) and 113.09 (28.94) vs. 116.59 (25.63)]. A significant improvement from first to second measurement in the first exercise could be observed for both groups, demonstrating the training effect. Conclusion In our study, we verified that additional caffeinated coffee intake, e.g., during a coffee break, does not lead to deterioration of laparoscopic fine motor skills.

Coffee Consumption Modulates Amoxicillin-Induced Dysbiosis in the Murine Gut Microbiome

The microbiome is essential for host health, and perturbations resulting from antibiotic use can lead to dysbiosis and disease. Diet can be a powerful modulator of microbiome composition and function, with the potential to mitigate the negative effects of antibiotic use. Thus, it is necessary to study the impacts of diet and drug interactions on the gut microbiome. Coffee is a commonly consumed beverage containing many compounds that have the potential to affect the microbiome, including caffeine, polyphenols, and fiber. We supplemented mice with caffeinated and decaffeinated coffee in conjunction with amoxicillin, and used 16S rRNA amplicon sequencing of fecal samples to investigate changes in diversity and composition of the murine fecal microbiome. We found that antibiotics, regardless of coffee supplementation, caused significant disruption to the murine fecal microbiome, enriching for Proteobacteria, Verrucomicrobia, and Bacteroidetes, but reducing Firmicutes. While we found that coffee alone did not have a significant impact on the composition of the fecal microbiome, coffee supplementation did significantly affect relative abundance metrics in mice treated with amoxicillin. After caffeinated coffee supplementation, mice treated with amoxicillin showed a smaller increase in Proteobacteria, specifically of the family Burkholderiaceae. Correspondingly we found that in vitro, Burkholderia cepacia was highly resistant to amoxicillin, and that it was inhibited by concentrations of caffeine and caffeinated coffee comparable to levels of caffeine in murine ceca. Overall, this work shows that coffee, and possibly the caffeine component, can impact both the microbiome and microbiome members during antibiotic exposure.

Consumption of caffeinated beverages and kidney function decline in an elderly Mediterranean population with metabolic syndrome

It remains unclear whether caffeinated beverages could have deleterious renal effects in elderly population with underlying comorbid conditions. We investigated the associations between coffee, tea, or caffeine intake and 1-year changes in glomerular filtration rate (eGFR) in a large Spanish cohort of overweight/obese elderly with metabolic syndrome (MetS). This prospective analysis includes 5851 overweight/obese adults (55–75 years) with MetS from the PREDIMED-Plus study. We assessed coffee, tea, and caffeine consumption from a validated food-frequency questionnaire and creatinine-based eGFR using the Chronic Kidney Disease Epidemiology Collaboration equation. Multivariate-adjusted regression models were applied to test associations between baseline coffee, tea, or caffeine intake and 1-year eGFR changes. Caffeinated coffee (> 2 cups/day) and tea (at least 1 cup/day) drinkers had 0.88 and 0.93 mL/min/1.73 m2 greater eGFR decrease respectively, compared to those with less than 1 cup/day of coffee consumption or non-tea drinkers. Furthermore, caffeinated coffee consumption of > 2 cups/day was associated with 1.19-fold increased risk of rapid eGFR decline > 3 mL/min/1.73 m2 (95% CI 1.01–1.41). Similarly, individuals in the highest (median, 51.2 mg/day) tertile of caffeine intake had a 0.87 mL/min/1.73 m2 greater eGFR decrease. Decaffeinated coffee was not associated with eGFR changes. In conclusion, higher consumption of caffeinated coffee, tea, and caffeine was associated with a greater 1-year eGFR decline in overweight/obese adults with MetS.

Coffee Consumption and All-Cause, Cardiovascular, and Cancer Mortality in an Adult Mediterranean Population

We assessed the association between usual coffee consumption and all-cause, cardiovascular (CV), and cancer mortality in an adult population in Spain, taking into account both the amount and type of coffee consumed. We used baseline data on coffee consumption and other personal variables, and the number of deaths during an 18-year follow-up period, for 1567 participants aged 20 years and older from the Valencia Nutrition Study in Spain. Total, caffeinated, and decaffeinated coffee consumption was assessed using a validated food frequency questionnaire. Cox regression models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). During the 18-year follow-up period, 317 died; 115 due to CV disease and 82 due to cancer. Compared with no-consumption, the consumption of ≤1 cup per day and >1 cup per day of coffee was associated with a lower risk of all-cause mortality, HR = 0.73 (95% CI: 0.56–0.97) and HR 0.56 (95% CI: 0.41–0.77), respectively. A lower cancer mortality was observed among drinkers of more than 1 cup per day compared with nondrinkers, HR 0.41 (95% CI 0.20–0.86). Regarding the type of coffee, only the overall consumption of caffeinated coffee was associated with lower all-cause mortality at 12 and 18 years of follow-up, HR = 0.66 (95% CI:0.46–0.94) and HR = 0.59 (95% CI: 0.44–0.79), respectively. In conclusion, this study suggests that the moderate consumption of coffee, particularly caffeinated coffee (range 1–6.5 cups per day), is associated with a lower all-cause and cancer mortality after a long follow-up period. No significant association was found between coffee consumption and CVD mortality.

Effects of Different Doses of Caffeinated Coffee on Muscular Endurance, Cognitive Performance, and Cardiac Autonomic Modulation in Caffeine Naive Female Athletes

Caffeine is widely consumed among elite athletes for its well-known ergogenic properties, and its ability to increase exercise performance. However, studies to date have predominantly focused on the anhydrous form of caffeine in male participants. The aim of the study was to investigate the effect of caffeinated coffee ingestion on lower-upper body muscular endurance, cognitive performance, and heart rate variability (HRV) in female athletes. A total of 17 participants (mean ± standard deviation (SD): age = 23 ± 2 years, body mass = 64 ± 4 kg, height = 168 ± 3 cm) in a randomized cross-over design completed three testing sessions, following the ingestion of 3 mg/kg/bm of caffeine (3COF), 6 mg/kg/bm of caffeine (6COF) provided from coffee or decaffeinated coffee (PLA) in 600 mL of hot water. The testing results included: (1) repetition number for muscular endurance performance; (2): reaction time and response accuracy for cognitive performance; (3): HRV parameters, such as standard deviation of normal-to-normal (NN) intervals (SDNN), standard deviation of successive differences (SDSD), root mean square of successive differences (RMSSD), total power (TP), the ratio of low- and high-frequency powers (LF/HF), high-frequency power (HF), normalized HF (HFnu), low-frequency power (LF), and normalized LF (LFnu). A one-way repeated measures ANOVA revealed that 3COF (p = 0.024) and 6COF (p = 0.036) improved lower body muscular endurance in the first set as well as cognitive performance (p = 0.025, p = 0.035 in the post-test, respectively) compared to PLA. However, no differences were detected between trials for upper body muscular endurance (p = 0.07). Lastly, all HRV parameters did not change between trials (p > 0.05). In conclusion, ingesting caffeinated coffee improved lower body muscular endurance and cognitive performance, while not adversely affecting cardiac autonomic function.