Effects of caffeine on human health

Paraxanthine provides greater improvement in cognitive function than caffeine after performing a 10-km run

RATIONALE

Intense exercise promotes fatigue and can impair cognitive function, particularly toward the end of competition when decision-making is often critical for success. For this reason, athletes often ingest caffeinated energy drinks prior to or during exercise to help them maintain focus, reaction time, and cognitive function during competition. However, caffeine habituation and genetic sensitivity to caffeine (CA) limit efficacy. Paraxanthine (PX) is a metabolite of caffeine reported to possess nootropic properties. This study examined whether ingestion of PX with and without CA affects pre- or post-exercise cognitive function.

METHODS

12 trained runners were randomly assigned to consume in a double-blind, randomized, and crossover manner 400 mg of a placebo (PL); 200 mg of PL + 200 mg of CA; 200 mg of PL + 200 mg of PX (ENFINITY®, Ingenious Ingredients); or 200 mg PX + 200 mg of CA (PX+CA) with a 7-14-day washout between treatments. Participants donated fasting blood samples and completed pre-supplementation (PRE) side effects questionnaires, the Berg-Wisconsin Card Sorting Test (BCST), and the Psychomotor Vigilance Task Test (PVTT). Participants then ingested the assigned treatment and rested for 60 minutes, repeated tests (PRE-EX), performed a 10-km run on a treadmill at a competition pace, and then repeated tests (POST-EX). Data were analyzed using General Linear Model (GLM) univariate analyses with repeated measures and percent changes from baseline with 95% confidence intervals.

RESULTS

BCST correct responses in the PX treatment increased from PRE-EX to POST-EX (6.8% [1.5, 12.1], p = 0.012). The error rate in the PL (23.5 [-2.8, 49.8] %, p = 0.078) and CA treatment (31.5 [5.2, 57.8] %, p = 0.02) increased from PRE-EX values with POST-EX errors tending to be lower with PX treatment compared to CA (-35.7 [-72.9, 1.4] %, p = 0.059). POST-EX perseverative errors with PAR rules were significantly lower with PX treatment than with CA (-26.9 [-50.5, -3.4] %, p = 0.026). Vigilance analysis revealed a significant interaction effect in Trial #2 mean reaction time values (p = 0.049, η p 2 = 0.134, moderate to large effect) with POST-EX reaction times tending to be faster with PX and CA treatment. POST-EX mean reaction time of all trials with PX treatment was significantly faster than PL (-23.2 [-43.4, -2.4] %, p = 0.029) and PX+CA (-29.6 [-50.3, -8.80] %, p = 0.006) treatments. There was no evidence that PX ingestion adversely affected ratings of side effects associated with stimulant intake or clinical blood markers.

CONCLUSIONS

Results provide some evidence that pre-exercise PX ingestion improves prefrontal cortex function, attenuates attentional decline, mitigates cognitive fatigue, and improves reaction time and vigilance. Adding CA to PX did not provide additional benefits. Therefore, PX ingestion may serve as a nootropic alternative to CA.

Common questions and misconceptions about caffeine supplementation: what does the scientific evidence really show?

Caffeine is a popular ergogenic aid that has a plethora of evidence highlighting its positive effects. A Google Scholar search using the keywords "caffeine" and "exercise" yields over 200,000 results, emphasizing the extensive research on this topic. However, despite the vast amount of available data, it is intriguing that uncertainties persist regarding the effectiveness and safety of caffeine. These include but are not limited to: 1. Does caffeine dehydrate you at rest? 2. Does caffeine dehydrate you during exercise? 3. Does caffeine promote the loss of body fat? 4. Does habitual caffeine consumption influence the performance response to acute caffeine supplementation? 5. Does caffeine affect upper vs. lower body performance/strength differently? 6. Is there a relationship between caffeine and depression? 7. Can too much caffeine kill you? 8. Are there sex differences regarding caffeine's effects? 9. Does caffeine work for everyone? 10. Does caffeine cause heart problems? 11. Does caffeine promote the loss of bone mineral? 12. Should pregnant women avoid caffeine? 13. Is caffeine addictive? 14. Does waiting 1.5-2.0 hours after waking to consume caffeine help you avoid the afternoon "crash?" To answer these questions, we performed an evidence-based scientific evaluation of the literature regarding caffeine supplementation.

Effects of post-fermentation addition of green tea extract for sulfur dioxide replacement on Sauvignon Blanc wine phenolic composition, antioxidant capacity, colour, and mouthfeel attributes

This study examines the feasibility of replacing SO2 in a New Zealand Sauvignon Blanc wine with a green tea extract. The treatments included the control with no preservatives (C), the addition of green tea extract at 0.1 and 0.2 g/L (T1 and T2), and an SO2 treatment at 50 mg/L (T3). Five monomeric phenolic compounds were detected in the green tea extract used for the experiment, and their concentrations ranged in the order (-)-epigallocatechin gallate > (-)-epigallocatechin > (-)-epicatechin > (-)-epicatechin gallate > gallic acid. At the studied addition rates, these green tea-derived phenolic compounds contributed to ∼70% of the antioxidant capacity (ABTS), ∼71% of the total phenolic index (TPI), and ∼ 84% of tannin concentration (MCPT) of the extract dissolved in a model wine solution. Among wine treatments, T1 and T2 significantly increased the wine's colour absorbance at 420 nm, MCPT, gallic acid and total monomeric phenolic content. TPI and ABTS were significantly higher in wines with preservatives (i.e., T2 > T1 ≅ T3 > C, p < 0.05). These variations were observed both two weeks after the treatments and again after five months of wine aging. Additionally, an accelerated browning test and a quantitative sensory analysis of wine colour and mouthfeel attributes were performed after 5 months of wine aging. When exposed to excessive oxygen and high temperature (50 °C), T1 and T2 exhibited ∼29% and 24% higher browning capacity than the control, whereas T3 reduced the wine's browning capacity by ∼20%. Nonetheless, the results from sensory analysis did not show significant variations between the treatments. Thus, using green tea extract to replace SO2 at wine bottling appears to be a viable option, without inducing a negative impact on the perceptible colour and mouthfeel attributes of Sauvignon Blanc wine.

The Association Between Caffeine Consumption and Academic Success in Makkah Region, Saudi Arabia

BACKGROUND

 The consumption of caffeinated beverages has increased significantly, particularly, among young adults. They use caffeinated drinks for a variety of reasons. The most popular reason is to enhance mental alertness by improving brain function, wakefulness, and productivity. The high prevalence rate of caffeinated drinks among young adults may affect their academic performance level.

METHODOLOGY

 A descriptive cross-sectional study based on an electronic questionnaire via Google Forms, conducted in February 2022 after the biomedical ethics committee obtained the ethical approval at Umm Al-Qura University (UQU), College of Medicine, Makkah, Saudi Arabia, the sample size was 593 medical students in Makkah region.

RESULTS

 A total number of 593 medical students participated in this study, most of the medical students who participated (47.20%) had average GPA of 85%-95%. The largest number of medical students (45.30%) consume only one cup of caffeinated beverages per day. We reported no association between caffeinated beverages consumption and academic performance.

CONCLUSION

 Our study demonstrates that caffeinated beverages are a popular practice among medical college students. Majority of the medical students in Makkah region consume coffee as the most popular drink, while energy drinks are considered to be the least consumed drink, but energy drinks are easily affordable and available. Therefore, primary prevention of excessive consumption of caffeine is essential.

Polythiophene-wrapped Chitosan Nanofibrils with a Bouligand Structure toward Electrochemical Macroscopic Membranes

Exploring structural biomimicry is a great opportunity to replicate hierarchical frameworks inspired by nature in advanced functional materials for boosting new applications. In this work, we present the biomimetic integration of polythiophene into chitosan nanofibrils in a twisted Bouligand structure to afford free-standing macroscopic composite membranes with electrochemical functionality. By considering the integrity of the Bouligand structure in crab shells, we can produce large, free-standing chitosan nanofibril membranes with iridescent colors and flexible toughness. These unique structured features lead the chitosan membranes to host functional additives to mimic hierarchically layered composites. We used the iridescent chitosan nanofibrils as a photonic platform to investigate the host-guest combination between thiophene and chitosan through oxidative polymerization to fabricate homogeneous polythiophene-wrapped chitosan composites. This biomimetic incorporation fully retains the twisted Bouligand organization of nanofibrils in the polymerized assemblies, thus giving rise to free-standing macroscopic electrochemical membranes. Our further experiments are the modification of the biomimetic polythiophene-wrapped chitosan composites on a glassy carbon electrode to design a three-electrode system for simultaneous electrochemical detection of uric acid, xanthine, hypoxanthine, and caffeine at trace concentrations.

Caffeine Ameliorates Age-Related Hearing Loss by Downregulating the Inflammatory Pathway in Mice

OBJECTIVE

Age-related hearing loss (ARHL), also known as presbycusis, is a debilitating sensory impairment that affects the elderly population. There is currently no ideal treatment for ARHL. Long-term caffeine intake was reported to have anti-aging effects in many diseases. This study is to identify whether caffeine could ameliorate ARHL in mice and analyze its mechanism.

METHODS

Caffeine was administered in drinking water to C57BL/6J mice from the age of 3 months to 12 months. The body weight, food intake and water intake of the mice were monitored during the experiment. The metabolic indicators of serum were detected by ELISA. The function of the hearing system was evaluated by ABR and hematoxylin and eosin staining of the cochlea. Genes' expression were detected by Q-PCR, immunofluorescencee and Western blot.

RESULTS

The results showed that the ARHL mice exhibited impaired hearing and cochlear tissue compared with the young mice. However, the caffeine-treated ARHL mice showed improved hearing and cochlear tissue morphology. The expression of inflammation-related genes, such as TLR4, Myd88, NF-κB, and IL-1β, was significantly increased in the cochleae of ARHL mice compared with young mice but was down-regulated in the caffeine-treated cochleae.

CONCLUSIONS

Inflammation is involved in ARHL of mice, and long-term caffeine supplementation could ameliorate ARHL through the down-regulation of the TLR4/NF-κB inflammation pathway. Our findings provide a new idea for preventing ARHL and suggest new drug targets for ARHL treatment.

Prevalence of energy drink consumption world-wide: A systematic review and meta-analysis

BACKGROUND AND AIMS

The increasing market for energy drinks (EDs) in recent years, as well as the health risks caused by their consumption, prompt calls to estimate the prevalence of ED use among different countries. This systematic review and meta-analysis aimed to synthesize the prevalence of ED use in different continents and age groups.

METHOD

We searched two databases (i.e. PubMed and PsycInfo) on 31 March 2023 to identify studies reporting the prevalence of ED use. A total of 192 studies (196 distinct samples; n = 1 120 613; 53.37% males) from the United States, Europe, Asia, Oceania and Africa were included in the analysis. A random-effects model was applied to estimate the overall pooled prevalence at several time-periods. Subgroup analyses were performed to provide prevalence based on continent and age group. The quality of articles was assessed using Joana Brigg's Institute (JBI) critical appraisal checklist. Measurements included prevalence of ED use (i.e. life-time, past 12 months, past 30 days, past 7 days and daily use), continent and age group (i.e. children, adolescents, young adults and adults).

RESULTS

The life-time ED use world-wide-pooled prevalence was estimated to be 54.7% [95% confidence interval (CI) = 48.8-60.6; I2  = 99.80], 43.4% (95% CI = 36.1-50.6; I2  = 99.92) in the past 12 months, 32.3% (95% CI = 28.8-35.8; I2  = 99.82) in the past 30 days, 21.6% (95% CI = 18.7-24.5; I2  = 99.95) in the past 7 days and 8.82% (95% CI = 6.3-11.4; I2  = 99.95) daily ED use. Subgroups analyses showed significant differences in ED life-time use within age groups (P = 0.002) and continents (P = 0.035).

CONCLUSIONS

The world-wide prevalence of energy drink use appears to be high, particularly among adolescents and young adults.

Molecular docking targeting autophagy pathway mediate abrogation of NASH by specific functional foods: update review

Autophagy is a very well-conserved self-digestive mechanism that transports unwanted or disposable cytoplasmic debris to lysosomes for destruction, including misfolded proteins and damaged organelles. Advanced liver illnesses can develop from the prevalent clinical condition known as non-alcoholic steatohepatitis (NASH). There is no effective treatment, is still unclear. Therefore, in order to create novel therapeutics, it is necessary to comprehend the pathogenic pathways causing disease onset and progression. Natural components from medicinal plants are currently the subject of a larger number of studies since they provide fresh promise for NASH. This review provided an overview of the aetiology of NASH, in addition the role of natural products as alternative or complementary therapeutic agent for management of NASH via autophagy induction. It was concluded that, alternative and complementary supplement of natural functional food as Arabica coffee that rich with chlorogenic acid targeting autophagy mechanism mediate amelioration effect of NASH.

Addressing nutritional issues and eating behaviours among university students: a narrative review

University life is a critical period for establishing healthy eating habits and attitudes. However, university students are at risk of developing poor eating habits due to various factors, including economic conditions, academic stress and lack of information about nutritional concepts. Poor diet quality leads to malnutrition or overnutrition, increasing the risk of preventable diseases. Food environments on university campuses also play a significant role in shaping the dietary habits of students, with the availability of and accessibility to healthy food options being important factors influencing food choices and overall diet quality. Disordered eating habits and body dissatisfaction are prevalent among university students and can lead to eating disorders. Income and living arrangements also influence dietary habits, with low household income and living alone being associated with unhealthy eating habits. This study is a narrative review that aimed to address nutritional issues and eating behaviours, specifically among university students. We investigated the eating behaviours of university students, including their dietary patterns, food choices and food environments. The objective of this review was to provide insights into the nutritional issues and eating behaviours of university students, with the aim of identifying target areas for intervention to improve the overall health and wellbeing among college students. University food environments need to be restructured to promote healthy eating, including the availability, accessibility, affordability and labelling of healthy foods, and policies to limit the availability of unhealthy foods and drinks on campus.

Counteracting mental fatigue for athletes: a systematic review of the interventions

The deleterious effects of mental fatigue (MF) on athletes have been carefully studied in various sports, such as soccer, badminton, and swimming. Even though many researchers have sought ways to ameliorate the negative impact of MF, there is still a lack of studies that review the interventions used to counteract MF among athletes. This review aims to report the current evidence exploring the effects of interventions on MF and sport-specific performance, including sport-specific motor performance and perceptual-cognitive skills. Web of Science, Scopus, PubMed, and SPORTDicus (EBSCOhost) were combed through to find relevant publications. Additionally, the references and Google Scholar were searched for any grey literature. For the current review, we included only randomized controlled trials that involved athletes, a primary task to induce MF, interventions to counter MF with comparable protocols, and the outcomes of sport-specific motor performance and perceptual-cognitive skill. The selection criteria resulted in the inclusion of 10 articles. The manipulations of autonomous self-control exertion, person-fit, nature exposure, mindfulness, and transactional direct current stimulation showed that positive interventions counteract MF and improve sport-specific performance in different domains, including strength, speed, skill, stamina, and perceptual-cognitive skills. The selected interventions could significantly counteract MF and improve subsequent sport-specific performance. Moreover, self-regulation and attention resources showed the importance of the potential mechanisms behind the relevant interventions.

The caffeine dilemma: unraveling the intricate relationship between caffeine use disorder, caffeine withdrawal symptoms and mental well-being in adults

OBJECTIVE

This study aimed to explore the relationship between caffeine use disorder (CUD), caffeine withdrawal symptoms and the prevalence of depression, anxiety and stress (DASS) in adults.

DESIGN

The study utilised a cross-sectional design to assess the relationships between CUD, caffeine withdrawal symptoms and DASS.

SETTING

Participants' CUD was evaluated through the Caffeine Use Disorder Questionnaire (CUDQ), while the Depression Anxiety Stress Scale-21 (DASS-21) measured DASS levels. Caffeine withdrawal symptoms and total caffeine intake were calculated based on self-reported consumption of caffeine-rich products.

PARTICIPANTS

The study involved 618 participants with an average age of 27·8 (sd 7·8) years.

RESULTS

Participants consumed an average of 461·21 (sd 11·09) mg/d of caffeine, showing a positive correlation between CUD and total caffeine intake. The risk of CUD increased alongside levels of DASS. Individuals with caffeine withdrawal symptoms had higher CUDQ and DASS scores. A multiple linear regression model revealed significant associations between total caffeine intake (P < 0·001) and DASS-21 score (P < 0·001) with CUDQ score.

CONCLUSIONS

The study concluded that caffeine, while recognised for its potential health benefits, also exhibits properties that may lead to addiction. The development of caffeine use disorder and cessation of caffeine intake can increase DASS levels in adults, indicating the need for awareness and appropriate interventions in public health nutrition.

Extrapolating the Coffee and Caffeine (1,3,7-Trimethylxanthine) Effects on Exercise and Metabolism-A Concise Review

The consumption of coffee and caffeine (1,3,7-trimethylxanthine) is part of many cultures worldwide. Their properties include serving as a neurostimulant aid, enhancing energy substrate levels, and improving general exercise performance. Both present therapeutic effects that can also be used to control chronic and metabolic diseases due to four mechanisms: adenosine receptor antagonism, increased catecholamine concentrations, a phosphodiesterase inhibitor, and a stimulator of calcium-release channels. Despite the individual genetic variabilities, distinct mechanisms have been demonstrated to improve physical performance, thermogenesis, lipolysis, insulin sensitivity, and hormonal modulation. Thus, coffee consumption and caffeine supplementation may enhance physical and mental performance and may improve metabolic variables, reducing oxidative stress, inflammation, and insulin resistance. Current data reveal vital aspects of coffee and caffeine consumption in specific populations, although further studies are needed to define clinical interventions with caffeine in obesity and chronic conditions.

Current therapeutic targets and multifaceted physiological impacts of caffeine

Caffeine, which shares consubstantial structural similarity with purine adenosine, has been demonstrated as a nonselective adenosine receptor antagonist for eliciting most of the biological functions at physiologically relevant dosages. Accumulating evidence supports caffeine's beneficial effects against different disorders, such as total cardiovascular diseases and type 2 diabetes. Conversely, paradoxical effects are also linked to caffeine ingestion in humans including hypertension-hypotension and tachycardia-bradycardia. These observations suggest the association of caffeine action with its ingested concentration and/or concurrent interaction with preferential molecular targets to direct explicit events in the human body. Thus, a coherent analysis of the functional targets of caffeine, relevant to normal physiology, and disease pathophysiology, is required to understand the pharmacology of caffeine. This review provides a broad overview of the experimentally validated targets of caffeine, particularly those of therapeutic interest, and the impacts of caffeine on organ-specific physiology and pathophysiology. Overall, the available empirical and epidemiological evidence supports the dose-dependent functional activities of caffeine and advocates for further studies to get insights into the caffeine-induced changes under specific conditions, such as asthma, DNA repair, and cancer, in view of its therapeutic applications.

Higher caffeine consumption is associated with insufficient sleep time in Brazilian adults (CUME study)

We aimed to evaluate the association between caffeine intake and sleep time in Brazilian adults. This cross-sectional study was conducted with 6,356 participants from the Cohort of Universities of Minas Gerais (CUME Study). Data was collected through an online self-report questionnaire. Of the total, 31.9% of the participants had insufficient sleep. Women were found to sleep less than men (64.1 vs. 35.9%; p < 0.001), as well as being more likely to consume higher doses of caffeine (55.2%, p < 0.001). Coffee (35.7%), dark chocolate (25.2%), milk chocolate (15.2%), and diet soda (11.0%) were the foods that more contributed to caffeine intake. Individuals in the highest quartile of caffeine intake (87.0 - 572.0 mg/day) had a 19% higher prevalence of insufficient sleep compared with the lowest quartile (PR: 1.19; 95%CI: 1.08 - 1.31). Future studies are needed to investigate the genetic and hormonal factors involved in the interindividual response in this population.

Coffee Consumption Behavior in Young Adults: Exploring Motivations, Frequencies, and Reporting Adverse Effects and Withdrawal Symptoms

Background

Coffee consumption by young people has increased dramatically over the last decades as there are substantial evidence of the physiological, cognitive, and emotional effects of coffee consumption. To reduce the risk of consuming related harm, it is necessary to understand the consumer's motivation for its use.

Objective

This study aimed to investigate coffee consumption behavior in young adults, assess the type of coffee consumption, explore motivation, document adverse effects and withdrawal symptoms of coffee intake.

Methods

A sample of 923 young adults were recruited voluntarily to complete a set of measures examining motivations, adverse effects, and withdrawal symptoms of coffee intake. Logistic regression analysis was performed to determine the association between coffee consumption and all independent variables. A p-value of 0.005 was considered as statistically significant.

Results

The results indicate that more than half of the participants consumed coffee. Coffee consumers were more like to be male, young adults, unmarried, poor sleep pattern (3-5 hours), and smokers. Main motivations of coffee intake were those related to reinforcing effects. The prevalence of dripper coffee consumption (85.59%) was observed to be highest with 20.1% participants consuming coffee in 2-3 times per day. Participants experienced restlessness, shaky, excited, difficulty in falling sleep, and fast heart beat as adverse effects of coffee consumption. Withdrawal symptoms such as headache, mood change, and tiredness were also noticed after consuming a high amount of coffee. Gender (p < 0.005), age (p < 0.003), family income (p < 0.004), BMI (p < 0.002) and sleeping pattern (p < 0.005) were found important variables associated with coffee intake.

Conclusion

The association reported in this study may allow for the implementation of appropriate strategies to address behaviors towards excessive coffee consumption and its link to an increased risk of poor health.

The effect of coffee on contralateral suppression of transient evoked otoacoustic emissions

Background: Coffee is a popular non-alcoholic beverage consumed by humans across the world. It contains caffeine, which is a type of stimulant of the central nervous system. In the auditory system, it has a positive effect on auditory brainstem response and perception of speech in noise. Further, caffeine has an inhibitory effect in the cochlea, but studies have rarely investigated its effect on otoacoustic emissions (OAEs) in humans. OAEs are low-intensity sounds produced by the cochlea, which could be recorded in the ear canal. The present study was carried out to investigate the effect of coffee on transient evoked otoacoustic emission (TEOAE) and contralateral suppression of TEOAE. Method: A total of 52 young adults participated in the study. A cross-over study design was used for the present investigation. The TEOAE and contralateral suppression of TEOAE were recorded before and after consumption of coffee and milk. The contralateral suppression of TEOAE was measured by presenting white noise to the contralateral ear at 40, 50, and 60 dB sound pressure level (SPL). Results: The mean amplitude of TEOAE before and after consumption of coffee was similar in both ears. Further, the mean contralateral suppression of TEOAE was slightly larger after consumption of coffee in both ears. However, the mean difference was not significant in both the ears. Conclusions: Based on the findings of present study, coffee has no significant effect on the amplitude of TEOAE and contralateral suppression of TEOAE.

Effect of caffeine and other xanthines on liver sinusoidal endothelial cell ultrastructure

Xanthines such as caffeine and theobromine are among the most consumed psychoactive stimulants in the world, either as natural components of coffee, tea and chocolate, or as added ingredients. The present study assessed if xanthines affect liver sinusoidal endothelial cells (LSEC). Cultured primary rat LSEC were challenged with xanthines at concentrations typically obtained from normal consumption of xanthine-containing beverages, food or medicines; and at higher concentrations below the in vitro toxic limit. The fenestrated morphology of LSEC were examined with scanning electron and structured illumination microscopy. All xanthine challenges had no toxic effects on LSEC ultrastructure as judged by LSEC fenestration morphology, or function as determined by endocytosis studies. All xanthines in high concentrations (150 μg/mL) increased fenestration frequency but at physiologically relevant concentrations, only theobromine (8 μg/mL) showed an effect. LSEC porosity was influenced only by high caffeine doses which also shifted the fenestration distribution towards smaller pores. Moreover, a dose-dependent increase in fenestration number was observed after caffeine treatment. If these compounds induce similar changes in vivo, age-related reduction of LSEC porosity can be reversed by oral treatment with theobromine or with other xanthines using targeted delivery.

Natural Rubber/Hexagonal Mesoporous Silica Nanocomposites as Efficient Adsorbents for the Selective Adsorption of (-)-Epigallocatechin Gallate and Caffeine from Green Tea

(-)-Epigallocatechin gallate (EGCG) is a bioactive component of green tea that provides many health benefits. However, excessive intake of green tea may cause adverse effects of caffeine (CAF) since green tea (30-50 mg) has half the CAF content of coffee (80-100 mg). In this work, for enhancing the health benefits of green tea, natural rubber/hexagonal mesoporous silica (NR/HMS) nanocomposites with tunable textural properties were synthesized using different amine template sizes and applied as selective adsorbents to separate EGCG and CAF from green tea. The resulting adsorbents exhibited a wormhole-like silica framework, high specific surface area (528-578 m2 g-1), large pore volume (0.76-1.45 cm3 g-1), and hydrophobicity. The NR/HMS materials adsorbed EGCG more than CAF; the selectivity coefficient of EGCG adsorption was 3.6 times that of CAF adsorption. The EGCG adsorption capacity of the NR/HMS series was correlated with their pore size and surface hydrophobicity. Adsorption behavior was well described by a pseudo-second-order kinetic model, indicating that adsorption involved H-bonding interactions between the silanol groups of the mesoporous silica surfaces and the hydroxyl groups of EGCG and the carbonyl group of CAF. As for desorption, EGCG was more easily removed than CAF from the NR/HMS surface using an aqueous solution of ethanol. Moreover, the NR/HMS materials could be reused for EGCG adsorption at least three times. The results suggest the potential use of NR/HMS nanocomposites as selective adsorbents for the enrichment of EGCG in green tea. In addition, it could be applied as an adsorbent in the filter to reduce the CAF content in green tea by up to 81.92%.

An analysis of codon utilization patterns in the chloroplast genomes of three species of Coffea

BACKGROUND

The chloroplast genome of plants is known for its small size and low mutation and recombination rates, making it a valuable tool in plant phylogeny, molecular evolution, and population genetics studies. Codon usage bias, an important evolutionary feature, provides insights into species evolution, gene function, and the expression of exogenous genes. Coffee, a key crop in the global tropical agricultural economy, trade, and daily life, warrants investigation into its codon usage bias to guide future research, including the selection of efficient heterologous expression systems for coffee genetic transformation.

RESULTS

Analysis of the codon utilization patterns in the chloroplast genomes of three Coffea species revealed a high degree of similarity among them. All three species exhibited similar base compositions, with high A/T content and low G/C content and a preference for A/T-ending codons. Among the 30 high-frequency codons identified, 96.67% had A/T endings. Fourteen codons were identified as ideal. Multiple mechanisms, including natural selection, were found to influence the codon usage patterns in the three coffee species, as indicated by ENc-GC3s mapping, PR2 analysis, and neutral analysis. Nicotiana tabacum and Saccharomyces cerevisiae have potential value as the heterologous expression host for three species of coffee genes.

CONCLUSION

This study highlights the remarkable similarity in codon usage patterns among the three coffee genomes, primarily driven by natural selection. Understanding the gene expression characteristics of coffee and elucidating the laws governing its genetic evolution are facilitated by investigating the codon preferences in these species. The findings can enhance the efficacy of exogenous gene expression and serve as a basis for future studies on coffee evolution.

Caffeine Consumption and Its Potential Health Effects on Saudi Adolescents in Jazan

Background Caffeine is the most popular product consumed globally in different types and amounts by various age groups. This study aimed to identify caffeine consumption patterns among adolescents in Jazan and explore related health effects. Methodology A cross-sectional study was conducted in Jazan on adolescents between 12 and 18 years of age. The consumption of coffee and caffeinated products and their potential health effects were evaluated using a self-reported online questionnaire. The data were analyzed using software for descriptive and inferential statistics. Results A total of 718 participants were enrolled in this study, with the age group of 16-18 years constituting the highest percentage (48.9%). Nearly 94% of the participants consumed coffee or caffeinated products, with 57% consuming the products infrequently. About 6.6% consumed coffee or caffeinated products more than three times daily, and about half of the participants used medium-sized cups. The most consumed type of caffeinated beverage was Arabic coffee, followed by tea, soft drinks, and Nescafe. Education level and age group showed a significant correlation with consumption patterns. The most common health effects of caffeine consumption were headaches, irregular sleep, and nausea, which were statistically related to age group, gender, and comorbid conditions. Conclusions Consumption of coffee and caffeinated beverages was relatively high among adolescents in this study. Further research on the habits of Saudi adolescent consumers, particularly across different areas of the country, is required.

Coffee intake and risk of diabetic nephropathy: a Mendelian randomization study

Rationale and objective

A causal relationship concerning coffee intake and diabetic nephropathy (DN) is controversial. We conducted a Mendelian randomization study to assess the causal nature of these associations.

Methods

40 independent single nucleotide polymorphisms (SNPs) associated with coffee intake were selected from the UK Biobank study. Summary-level data for diabetic nephropathy were obtained from publicly available genome-wide association studies (GWAS) and the FinnGen consortium. Inverse variance weighted (IVW), MR-Egger, and weighted median (WM) methods were used to examine a causal association. Sensitivity analyses included Cochran's Q test, the intercept of MR-Egger, MR-PRESSO, and the Outlier method. Leave-One-Out sensitivity analyses were also conducted to reduce the heterogeneity.

Results

Our current study demonstrated positive associations of genetically predicted coffee intake with diabetic nephropathy (OR=1.939; P = 0.045 and type 2 diabetes with renal complications (OR = 2.787, P= 0.047). These findings were robust across several sensitivity analyses.

Conclusions

This study found a positive correlation between coffee consumption and the risk of diabetic nephropathy using genetic data. For a more accurate and trustworthy conclusion, subgroup analysis on coffee intake, including preparing method, variety of coffee, and quantity, is required.

Association of Coffee and Tea Intake with Bone Mineral Density and Hip Fracture: A Meta-Analysis

Background and Objectives: Osteoporosis is characterized by low bone mass and high bone fragility. Findings regarding the association of coffee and tea intake with osteoporosis have been inconsistent. We conducted this meta-analysis to investigate whether coffee and tea intake is associated with low bone mineral density (BMD) and high hip fracture risk. Materials and Methods: PubMed, MEDLINE, and Embase were searched for relevant studies published before 2022. Studies on the effects of coffee/tea intake on hip fracture/BMD were included in our meta-analysis, whereas those focusing on specific disease groups and those with no relevant coffee/tea intake data were excluded. We assessed mean difference (MD; for BMD) and pooled hazard ratio (HR; for hip fracture) values with 95% confidence interval (CI) values. The cohort was divided into high- and low-intake groups considering the thresholds of 1 and 2 cups/day for tea and coffee, respectively. Results: Our meta-analysis included 20 studies comprising 508,312 individuals. The pooled MD was 0.020 for coffee (95% CI, -0.003 to 0.044) and 0.039 for tea (95% CI, -0.012 to 0.09), whereas the pooled HR was 1.008 for coffee (95% CI, 0.760 to 1.337) and 0.93 for tea (95% CI, 0.84 to 1.03). Conclusions: Our meta-analysis results suggest that daily coffee or tea consumption is not associated with BMD or hip fracture risk.

Position statement on nutrition therapy for overweight and obesity: nutrition department of the Brazilian association for the study of obesity and metabolic syndrome (ABESO-2022)

Obesity is a chronic disease resulting from multifactorial causes mainly related to lifestyle (sedentary lifestyle, inadequate eating habits) and to other conditions such as genetic, hereditary, psychological, cultural, and ethnic factors. The weight loss process is slow and complex, and involves lifestyle changes with an emphasis on nutritional therapy, physical activity practice, psychological interventions, and pharmacological or surgical treatment. Because the management of obesity is a long-term process, it is essential that the nutritional treatment contributes to the maintenance of the individual's global health. The main diet-related causes associated with excess weight are the high consumption of ultraprocessed foods, which are high in fats, sugars, and have high energy density; increased portion sizes; and low intake of fruits, vegetables, and grains. In addition, some situations negatively interfere with the weight loss process, such as fad diets that involve the belief in superfoods, the use of teas and phytotherapics, or even the avoidance of certain food groups, as has currently been the case for foods that are sources of carbohydrates. Individuals with obesity are often exposed to fad diets and, on a recurring basis, adhere to proposals with promises of quick solutions, which are not supported by the scientific literature. The adoption of a dietary pattern combining foods such as grains, lean meats, low-fat dairy, fruits, and vegetables, associated with an energy deficit, is the nutritional treatment recommended by the main international guidelines. Moreover, an emphasis on behavioral aspects including motivational interviewing and the encouragement for the individual to develop skills will contribute to achieve and maintain a healthy weight. Therefore, this Position Statement was prepared based on the analysis of the main randomized controlled studies and meta-analyses that tested different nutrition interventions for weight loss. Topics in the frontier of knowledge such as gut microbiota, inflammation, and nutritional genomics, as well as the processes involved in weight regain, were included in this document. This Position Statement was prepared by the Nutrition Department of the Brazilian Association for the Study of Obesity and Metabolic Syndrome (ABESO), with the collaboration of dietitians from research and clinical fields with an emphasis on strategies for weight loss.

Espresso Science: Laser-Based Diamond Thin-Film Waveguide Sensors for the Quantification of Caffeine

Diamond thin-film waveguides with a nanocrystalline diamond layer of approximately 20 μm thickness were used in the mid-infrared regime in combination with quantum cascade lasers to detect the IR signature of caffeine. The diamond thin-film waveguides were fundamentally characterized with respect to their morphological properties via AFM and SEM. Theoretical simulations confirmed the feasibility of using a larger sensing area of approximately 50 mm² compared to conventionally used strip waveguides. A comprehensive and comparative analysis confirmed the performance of the diamond thin-film-waveguide-based sensing system vs data obtained via conventional attenuated total reflection Fourier transform infrared spectroscopy using a single-bounce diamond internal reflection element. Hence, the utility of innovative diamond thin-film-waveguide-based sensors coupled with quantum cascade laser light sources has been confirmed as an innovative analytical tool, which may be used in a wide range of application scenarios, ranging from environmental to medical sensing, taking advantage of the robustness and inertness of nanocrystalline diamond.

A multiway spectral analysis model to monitor the kinetic chlorination reaction of caffeine and determine its content in commercial liquid and solid drinks

A multiway data analysis model, namely parallel factor analysis (PARAFAC) was proposed to decompose a three-way array of second-order kinetic UV measurements, for the chlorination reaction of caffeine with NaOCl, into a set of the spectra, time, and concentration matrices. The multiway resolution provided the simultaneous estimation of spectral, kinetic, and quantitative analysis of caffeine. The ability of the PARAFAC tool was checked by analyzing the validation samples in the presence of interferences. The added recovery and relative standard deviations for caffeine in the spiked samples were calculated as 99.1%-99.5% and 0.52%-1.34% for Iced Coffee Black liquid coffee (ICB), 99.5%-103.0% and 0.42%-1.03% for Jacobs Monarch Gold 100% Instant Coffee (JMG) and 99.5%-101.4% and 0.11%-0.13% for Çaykur Black Filter (Süzen) Bag Tea (BTB). Caffeine in commercial drinks was analyzed using the concentration matrices of the PARAFAC application. The PARAFAC results were statistically compared to those obtained by the developed UPLC method.

Salivary clearance of caffeine in children

Background

Measurement of salivary caffeine (1,3,7-trimethylpurine-2,6-dione or 1,3,7-trimethylxanthine) clearance can, in principle, be used to assess hepatic function, diagnose chronic hepatic disease and conduct investigations of substrates of hepatic cytochrome P450 (CYP) isozymes in children, without recourse to venepuncture. However, little is known about childhood sexual dimorphism of hepatic CYP isoforms. Furthermore, the association, if any, between salivary caffeine clearance and age in children has not hitherto been established. The aims of this study were to assess whether salivary caffeine clearance differs between boys and girls and whether it varies with age during childhood.

Methods

Following at least 24 h' abstinence from dietary caffeine, nine boys (mean (standard error) age 9.6 (1.1) y) and eight girls (mean age 11.0 (1.2) y), none of whom was a smoker or suffered from chronic hepatic disease, ingested an oral caffeine dose titrated by body mass, namely 3 mg kg-1. Salivary samples collected two and 14 h later underwent spectrophotometric caffeine analysis.

Results

The boys and the girls were age matched. The mean caffeine clearance in the boys was 2.47 (0.33) mL min-1 kg-1, while that in the girls was 2.20 (0.31) mL min-1 kg-1 (p = 0.56). The salivary caffeine clearance was negatively correlated with age (r = -0.59, p = 0.01).

Conclusion

Stratification by sex appears to be unnecessary when considering childhood salivary caffeine clearance or when conducting investigations in children of CYP1A2 and xanthine oxidase substrates. Furthermore, childhood salivary caffeine clearance is negatively correlated with age.

Trends of caffeine intake from food and beverage among Chinese adults: 2004-2018

Caffeine is a kind of psychostimulant that naturally exist in foods. The benefits and risks of caffeine depend on the dose. Moreover, the intake of caffeine from dietary sources in China has seldom been assessed. We calculated the dietary caffeine intake of Chinese adult consumers from 2004 to 2018 and analyzed its consumption trends by using data from the China Health and Nutrition Survey and the National Food and Beverage Consumption Survey. Caffeine contents in different dietary items were determined by HPLC. Monte Carlo simulations were applied to estimate caffeine intake. Mann-Kendall trend test and linear regression were used to analyze the trend of caffeine consumption. Among 79,173 individuals, 3972 (5%) of the adult Chinese population consumed caffeine between 2004 and 2018. The average caffeine intake was 123 mg/day for male consumers and 116 mg/day for female consumers. The median and P75 caffeine intake raised over the 14 years. Traditional tea leaves, coffee and sodas are the main sources of caffeine intake. Our findings indicate that most Chinese adults consumed caffeine within the safe level (400 mg/day), but the caffeine consumption has shown an increasing trend in recent 14 years.

Relationship between caffeine intake and small for gestational age and preterm birth: a dose-response meta-analysis

Our meta-analysis aimed to determine the dose-response relationship between caffeine intake and risk of small for gestational age (SGA) and preterm birth (PB). A systematic search of PubMed, Web of science and Scopus was done from inception to January 2023 using relevant keywords. All case-control and cohort studies reported in English were included if the exposure of interest was caffeine intake during pregnancy, the outcome of interest was spontaneous SGA and PB, and multivariable-adjusted odds ratios (ORs) or risk ratios were provided or could be calculated. In all, 22 studies (15 cohort studies and seven case-control studies) were included in this review. Examining the association of caffeine intake with risk of PB, no significant relationship was found (Pooled ES: 1.04; 95% CI: 0.95 to 1.14, P = 0.019). Findings from this meta-analysis demonstrated that caffeine intake had a significantly higher risk of SGA respectively (Pooled ES: 1.28; 95% CI: 1.16 to 1.41, P < 0.001). A dose-response analysis proposed that an increase of 100 mg caffeine per day was associated with a 13% greater risk of SGA. This study confirmed that caffeine intake raises the risk of SGA. However, the risk of PB was not found to be reliably associated with maternal caffeine consumption.

Secondary School Students and Caffeine: Consumption Habits, Motivations, and Experiences

Adolescents may be particularly vulnerable to the effects of caffeine due to a lack of tolerance, their small size, changing brain physiology, and increasing independence. Concerns about adolescent caffeine consumption relate to potentially serious physiological and psychological effects following consumption. Motivations driving caffeine intake are not well understood among adolescents but are important to understand to reduce harmful behavioural patterns. This study explored caffeine consumption habits (sources, amount, frequency) of New Zealand adolescents; and factors motivating caffeine consumption and avoidance. The previously validated caffeine consumption habits questionnaire (CaffCo) was completed by 216 participants (15-18 years), with most (94.9%) consuming at least one caffeinated product daily. Chocolate, coffee, tea, and kola drinks were the most consumed sources. The median caffeine intake was 68 mg·day^-1. Gender (boy) and being employed influenced the source, but not the quantity of caffeine consumed. One-fifth (21.2%) of adolescents consumed more than the recommended European Food Safety Authority (EFSA) safe level (3 mg·kg^-1·day^-1). Taste, energy, and temperature were the main motivators for consumption, and increased energy, excitement, restlessness, and sleep disturbances were reported effects following caffeine consumption. This study provides information on caffeinated product consumption among New Zealand adolescents, some of whom consumed caffeine above the EFSA safe level. Public health initiatives directed at adolescents may be important to reduce potential caffeine-related harm.

Regulatory Effects and Molecular Mechanisms of Tea and Its Active Compounds on Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD), the most common chronic liver disease, is a multifactorial disease resulting from the interaction between environment, genetic background, and metabolic stress. Most treatments for NAFLD include dietary intervention and exercise show limited efficacy due to the complex mechanisms involved in NAFLD. Meanwhile, drug therapy is accompanied by serious side effects. The development of high-efficiency natural supplements is a sustainable strategy for the prevention and treatment of NAFLD. As the second most consumed beverage, tea has health benefits that have been widely recognized. Nevertheless, the intervention of tea active compounds in NAFLD has received limited attention. Tea contains abundant bioactive compounds with potential effects on NAFLD, such as catechins, flavonoids, theanine, tea pigments, and tea polysaccharides. We reviewed the intrinsic and environmental factors and pathogenic mechanisms that affect the occurrence and development of NAFLD, and summarized the influences of exercise, drugs, diet, and tea drinking on NAFLD. On this basis, we further analyzed the potential effects and molecular regulatory mechanisms of tea active compounds on NAFLD and proposed future development directions. This review hopes to provide novel insights into the development and application of tea active compounds in the prevention and treatment of NAFLD.

Tryptophan and Substance Abuse: Mechanisms and Impact

Addiction, the continuous misuse of addictive material, causes long-term dysfunction in the neurological system. It substantially affects the control strength of reward, memory, and motivation. Addictive substances (alcohol, marijuana, caffeine, heroin, methamphetamine (METH), and nicotine) are highly active central nervous stimulants. Addiction leads to severe health issues, including cardiovascular diseases, serious infections, and pulmonary/dental diseases. Drug dependence may result in unfavorable cognitive impairments that can continue during abstinence and negatively influence recovery performance. Although addiction is a critical global health challenge with numerous consequences and complications, currently, there are no efficient options for treating drug addiction, particularly METH. Currently, novel treatment approaches such as psychological contingency management, cognitive behavioral therapy, and motivational enhancement strategies are of great interest. Herein, we evaluate the devastating impacts of different addictive substances/drugs on users' mental health and the role of tryptophan in alleviating unfavorable side effects. The tryptophan metabolites in the mammalian brain and their potential to treat compulsive abuse of addictive substances are investigated by assessing the functional effects of addictive substances on tryptophan. Future perspectives on developing promising modalities to treat addiction and the role of tryptophan and its metabolites to alleviate drug dependency are discussed.

Long-Term Cola Intake Does Not Cause Evident Pathological Alterations in the Femoral Bone Microstructure: An Animal Study in Adult Mice

Short-term animal experiments and association studies in humans have shown that cola intake may have a detrimental impact on bone mineral density (BMD); however, other bone parameters have not been investigated. This study examined the effects of long-term cola consumption on the femoral bone microstructure using adult mice (n = 32) as an animal model, which were divided into water and cola groups depending on whether they received water or cola along with a standard rodent diet for 6 months. Micro-computed tomography revealed that cola intake did not significantly affect all measured parameters characterizing trabecular bone mass and microarchitecture, as well as cortical microarchitecture and geometry in both sexes, although a slight deterioration of these parameters was noted. Cola consumption also resulted in a slightly, statistically insignificant worsening of bone mechanical properties. In contrast to female mice, males receiving cola had a lower area of primary osteons' vascular canals. Nevertheless, long-term cola intake did not cause evident pathological alterations in the femur of adult mice, possibly due to a balanced diet and no restriction of physical activity. Therefore, the adverse effects of cola consumption on BMD, the only bone parameter studied so far, may be caused by other risk and lifestyle factors.

Determination of Caffeine, Theobromine, and Theophylline by HPLC-DAD in Beverages Commonly Consumed in Lima, Peru

The purpose of this study was to determine the content of caffeine, theobromine, and theophylline by high-performance liquid chromatography with diode-array detection (HPLC-DAD) in beverages commonly consumed in Lima, Peru. The samples were divided into 6 groups (herbal teas, coffee powder, chocolate milks, soft drinks, sports drinks, and energy drinks) which included the five most commonly consumed beverages of the different groups. Caffeine was mainly identified in the soft drink and energy drink groups, with the latter having a more significant value (10.38 ± 0.01 vs. 95.50 ± 3.48 mg/L, respectively). In herbal teas, caffeine showed the highest content (0.47 ± 0.01 to 4.91 ± 0.05 mg/L), despite theophylline being a characteristic compound of tea leaves. Sports drinks presented very low caffeine levels (0.03 ± 0.01 to 0.05 ± 0.01 mg/L), and theobromine (0.48 ± 0.01 to 6.00 ± 0.02) was also identified. Caffeine (4.09 ± 0.01 to 5.70 ± 0.01 mg/L) and theobromine (1.70 ± 0.01 to 12.24 ± 0.01 mg/L) were found in the five commercial brands of chocolate milk evaluated. Moreover, the group of coffee powder samples had the highest level of caffeine content (49.25 ± 0.24 to 964.40 ± 4.93 mg/100 g). The results obtained in this study provide reliable information on the composition and quantification of methylxanthines in the beverages most consumed in Lima and impact consumer knowledge.

Effect of Caffeine on Colonic Manometry in Children

OBJECTIVES

Coffee and caffeinated products have been widely consumed for many centuries. Previous adult studies have suggested that both coffee and decaffeinated beverages induce colonic motility. However, no study has been conducted in pediatrics, and the role of caffeine alone in pediatric colonic motility needs to be explored.

METHODS

A prospective study of pediatric patients undergoing standard colonic motility testing that were able to consume caffeinated coffee, decaffeinated coffee, and caffeine tablet during colonic manometry. Patients who had a gastrocolonic reflex and high amplitude propagated contractions (HAPCs) in response to intraluminal administration of bisacodyl in the colon were included in the final analyses.

RESULTS

Thirty-eight patients were recruited, 22 of which were excluded, 11 due to abnormal studies (no HAPC seen in response to intraluminal response to bisacodyl), and 11 due to inability to consume all study agents or complete the study. Sixteen patients met criteria for final analyses. Intracolonic bisacodyl produced a larger area under the curve (AUC) compared to all other agents. Caffeinated coffee resulted in a higher AUC, motility index (MI), and time to HAPC compared with decaffeinated coffee ( P < 0.05). There was no significant difference between caffeinated coffee and caffeine tablet, or caffeine tablet and decaffeinated coffee.

CONCLUSIONS

Caffeine is indeed a colonic stimulant; however, other components of caffeinated and non-caffeinated beverages likely induce colonic response and require further evaluation for possible use as a colonic stimulant.

Caffeine levels and dietary intake in smokers with schizophrenia and bipolar disorder

Caffeine is one of the most widely used psychoactive drugs in the United States. High rates of caffeine use have been observed in adult smokers as well as those with serious mental illness. The current secondary analysis aimed to extend previous findings demonstrating high caffeine intake in schizophrenia by examining dietary intake of caffeine and serum caffeine levels in outpatient smokers with schizophrenia (SCZ), bipolar disorder (BP) and control smokers with no psychiatric diagnoses (CON). Two hundred forty-eight adult smokers (SCZ=80; BP=80; CON=88) were included in the current study. Adult smokers with schizophrenia, bipolar disorder, and no psychiatric diagnoses were 40.85 (SD = 11.90) years old on average and all participants were current smokers (∼20 cigarettes per day). Twenty-four hour self-reported caffeine intake (in mg) was highest among individuals with bipolar disorder (median=195.3), followed by adults with schizophrenia (median=155.0) and controls (median=131.7). Participants with bipolar disorder also had the highest serum caffeine levels (in ng/ml; median=1725), followed by those with schizophrenia (median=1194) and controls (median=613.2).  These results provide additional evidence of high caffeine intake among adults with schizophrenia and extend findings by identifying even higher rates of caffeine use in those with bipolar disorder. The current study suggests that caffeine intake is higher among subgroups of patients with serious mental illness.

Assessment of caffeine consumption behavior among Jazan University students in the south of Saudi Arabia: A cross-sectional study

Caffeine is a central nervous system stimulant. High consumption levels of caffeine can lead to intoxication and serious side effects. Saudi Arabia is witnessing a rise in the commercialization and consumption of caffeine. Young adults such as university students may exhibit high levels of caffeine consumption. This investigation aims to assess caffeine consumption habits among a sample of Jazan University students in the south of Saudi Arabia. This study was a cross-sectional investigation that utilized multistage sampling to recruit the students. Data was collected via a self-administered questionnaire that measured student demographics, their frequency of consuming caffeine-containing food, portion sizes, and patterns of consumption during different times of the day. Caffeine consumption levels were estimated based on a cutoff point of 400 mg per day. A chi-squared test was used to investigate the association between levels of caffeine consumption and measured study characteristics. A sample of 964 students was recruited with a mean age of 21.8 years. The most frequently consumed product among the recruited students was coffee (32%), followed by chocolate bars (16%) and soft drinks (12%). The median total consumed caffeine amount was 185 mg per day. 194 (20%) students of the sample exceeded the recommended level of daily caffeine consumption (>400 mg/day). Among the measured demographics, only the year of study was associated with caffeine consumption (P value of .003), suggesting that students in their earlier years of university are likely to exceed the recommended daily consumption of caffeine in comparison with those who are in their later years of study. Our investigation identified high levels of caffeine consumption among some students. The findings imply the need to enhance the awareness of students who exceed the recommended daily intake of caffeine regarding the harmful impacts of caffeine toxicity.

Prevalence of Voice Problems and Associated Risk Factors Among Tamil-Speaking Imams

PURPOSE

Voice of Professional Voice Users (PVUs) are of particular interest to practicing Speech-Language Pathologists. There is a dearth of studies concerning the prevalence of voice disorders and the associated risk factors among Tamil-speaking Imams. We address this research gap using non-experimental survey research.

METHODS

A questionnaire was framed by reviewing earlier literature. The derived questionnaire was administered to one hundred Tamil-speaking Imams actively involved in religious service in Tamil Nadu. We analyzed the obtained responses quantitatively and qualitatively. We also examined the effect of age on the prevalence of voice disorders and associated risk factors.

RESULTS

Based on survey responses, the career prevalence of voice problems among Tamil-speaking Imams was as high as 89%, and the point prevalence was 64%. The general health status of the Imams were good. However, vocal health was not satisfactory. This study identified several factors that contribute to voice problems, such as constant use of loud voice, acid reflux, unhealthy vocal habits, and insufficient hydration. A positive aspect observed during this study was the absence of smoking and consumption of alcohol among Imams. Even though the Imams presented good awareness of the voice production mechanism, they reported not seeking medical help when facing a voice problem. Current findings report a minimal impact of age-related differences on associated risk factors for voice disorders among the Imams.

CONCLUSIONS

Voice disorders are prevalent among Tamil-speaking Imams. Several risk factors leading to voice disorders among these individuals need to be addressed.

Intake of Food Supplements, Caffeine, Green Tea and Protein Products among Young Danish Men Training in Commercial Gyms for Increasing Muscle Mass

Sixty-three men (15-35 years of age) regularly training in Danish gyms and supplement users were interviewed about the use of supplemental protein and food supplements, intake of caffeine- and (-)-epigallocathechin-3-gallate (EGCG)-containing supplements and beverages and any experienced adverse effects. Protein powder (60%), fish oil (54%) and multivitamin/mineral supplements (41%) were the most popular products. The daily supplementary protein intake (mean 0.42 g/kg body weight, users only) in adult men contributed substantially to their protein intake and exceeded the recommended allowance (0.83 g/kg body weight) for six adult participants (14%). Thirty-eight percent of the adult men exceeded the daily caffeine intake presumed to be safe (400 mg) with coffee as the main contributor. Thirty percent drank green tea and among this percentage, two participants had an extreme daily intake (1.5 and 2 -L). EGCG intake could not be estimated from the food supplements due to the lack of label information. Eighteen participants (29%) reported having experienced adverse effects but seventeen did not consult a physician or report the adverse effect to the Danish food authority. The most common adverse effects were insomnia, shaking, headache and palpitations, itching of the skin and stinging. Pre-workout products accounted for 53% of the adverse effects. Three adverse effects came after intake of two brands of supplements known to have contained substances such as 1,3-dimethylamine or derivatives of phenylethylamines previously having caused serious adverse effects.

Association of urinary caffeine and caffeine metabolites with bone mineral density in children and adolescents

In epidemiological research, the link between coffee consumption and bone mineral density (BMD) is still debated. Moreover, there hasn't been any research on the relationship between urine caffeine and caffeine metabolites and BMD. This study aimed to investigate if there was a connection between urine caffeine and its metabolites and BMD in people between the ages of 8 and 19. Using data from the National Health and Nutrition Examination Survey 2009 to 2014, multivariate logistic regression models were utilized to investigate the association between urinary caffeine and caffeine metabolites and total BMD. Fitted smoothing curves and generalized additive models were also used. A total of 1235 adolescents were included in this analysis, after controlling for various variables, we found that the association between urinary theophylline and total BMD was negative, whereas the association between urinary paraxanthine, theobromine and caffeine and total BMD was positive. In our study, an inverted U-shaped association between urinary paraxanthine and urinary caffeine was found with BMD in women. In this cross-sectional study, the correlation between urinary caffeine and its metabolites and total BMD differed by sex and race. More studies are needed to confirm the results of this study and to investigate the underlying causes.

Recent Advances in Electrochemical Sensors for Caffeine Determination

The determination of target analytes at very low concentrations is important for various fields such as the pharmaceutical industry, environmental protection, and the food industry. Caffeine, as a natural alkaloid, is widely consumed in various beverages and medicines. Apart from the beneficial effects for which it is used, caffeine also has negative effects, and for these reasons it is very important to determine its concentration in different mediums. Among numerous analytical techniques, electrochemical methods with appropriate sensors occupy a special place since they are efficient, fast, and entail relatively easy preparation and measurements. Electrochemical sensors based on carbon materials are very common in this type of research because they are cost-effective, have a wide potential range, and possess relative electrochemical inertness and electrocatalytic activity in various redox reactions. Additionally, these types of sensors could be modified to improve their analytical performances. The data available in the literature on the development and modification of electrochemical sensors for the determination of caffeine are summarized and discussed in this review.

Caffeine-loaded nano/micro-carriers: Techniques, bioavailability, and applications

Caffeine, as one of the most consumed bioactive compounds globally, has gained considerable attention during the last years. Considering the bitter taste and adverse effects of high levels of caffeine consumption, it is crucial to apply a strategy for masking the caffeine's bitter taste and facilitating its programmable deliverance within a long time. Other operational parameters such as food processing parameters, exposure to sunlight and oxygen, and gastrointestinal digestion could also degrade the phenolic compounds in general and caffeine in special. To overcome these challenges, various nano/micro-platforms have been fabricated, including lipid-based (e.g., nanoliposomal vehicles; nanoemulsions, double emulsions, Pickering emulsions; microemulsions; niosomal vehicles; solid lipid nanoparticles and nanostructured lipid carriers), as well as biopolymeric (e.g., nanoparticles; hydrogels, organogels, oleogels; nanofibers and nanotubes; protein-polysaccharide nanocomplexes, conjugates; cyclodextrin inclusion complexes) and inorganic (e.g., gold and silica nanoparticles) nano/micro-structures. In this review, the findings on various caffeine-loaded nano/micro-carriers and their potential applications in functional food products/supplements will be discussed. Also, the controlled release and bioavailability of encapsulated caffeine will be given, and finally, the toxicity and safety of encapsulated caffeine will be presented.

Treatment of Lethal Caffeine Overdose with Haemodialysis: A Case Report and Review

Caffeine, chemically 1,3,7-trimethylxanthine, is the most widely consumed central nervous system stimulant in the world with pleiotropic effects on the cardiovascular, pulmonary, and renal systems. The advent of over the counter (OTC) caffeine formulations has opened the window for potential toxicity, either by inadvertent or intentional overdosing. We present the case of a patient who attempted suicide by caffeine overdose treated with emergent haemodialysis and a review of the literature.

Matrix-Specific Effects on Caffeine and Chlorogenic Acid Complexation in a Novel Extract of Whole Coffea arabica Coffee Cherry by NMR Spectroscopy

Coffee cherry is a rich source of caffeine and chlorogenic acids. In this study we investigate the structural analysis of caffeine-enriched whole coffee cherry extracts, CEWCCE by using ¹H and ¹³C NMR spectroscopy. The changes in ¹H chemical shift data in NMR spectra of CEWCCE compared to pure caffeine indicated the formation of complexes between caffeine and chlorogenic acids in aqueous solution. The effect of complexation on the peak position of caffeoylquinic acid and caffeine resonance with increasing addition of caffeine was investigated. 2D NOESY experiments show the presence of cross-peaks that are due to the proximity of chlorogenic acid and caffeine molecules in stable complexes in protic solvents. The quantification data of caffeine by ¹H qNMR was found to be in close agreement with the data obtained by HPLC analysis.

Caffeine consumption within British fencing athletes

The ergogenic effects of caffeine are well documented, yet despite the potential benefits of supplementation, there is a lack of understanding of caffeine habits and supplementation within fencing. British fencers (n = 136) completed a Web-based questionnaire, exploring self-reported caffeine consumption, reasons for use and education. Fencers (94.1%) habitually consumed caffeine, primarily due to the taste of the products (93.8%). Respondents ingested 183.4 ± 137.5 mg of caffeine daily, with a significant difference between age groups (p &lt; 0.05). Many respondents (30.1%) consumed caffeine 60 mins prior/during fencing training and/or competition with the main reason highlighted as cognitive performance enhancement. Respondents ingested 140.8 ± 104.6 mg of caffeine during training/competition, mainly as energy drinks, bars, and powders. Education on caffeine supplementation was low (25.7%), with significant associations between age groups (p &lt; 0.05). Evidence implies caffeine toxicity has been experienced by 35% of fencers, highlighting the need for education on caffeine consumption. To conclude there is evidence of caffeine supplementation in fencing, primarily to magnify cognitive performance. However, there is a requirement for targeted education on caffeine supplementation to fencers, so that negative side effects and potential anti-doping infringements can be avoided.

Anti-biofilm activity of caffeine against uropathogenic E. coli is mediated by curli biogenesis

Biofilms are assemblages of sessile microorganisms that form an extracellular matrix around themselves and mediate attachment to surfaces. The major component of the extracellular matrix of Uropathogenic E. coli and other Enterobacteriaceae are curli fibers, making biofilms robust and resistant to antimicrobials. It is therefore imperative to screen antibiofilm compounds that can impair biofilm formation. In the present study, we investigated the curli-dependent antibiofilm activity of caffeine against UPEC strain CFT073 and commensal strain E. coli K-12MG1655.Caffeine significantly reduced the biofilm formation of both UPEC and E. coli K-12 by 86.58% and 91.80% respectively at 48 mM caffeine as determined by Crystal Violet assay. These results were further confirmed by fluorescence microscopy and Scanning Electron Microscope (SEM). Caffeine significantly reduced the cytotoxicity and survivability of UPEC. Molecular docking analysis revealed a strong interaction between caffeine and curli regulator protein (Csg D) of E. coli. The qRT-PCR data also showed significant downregulation in the expression of CsgBA and the CsgDEFG operon at both 24 mM and 48 mM caffeine. The findings revealed that caffeine could inhibit E. coli biofilm formation by regulating curli assembly and thus may be used as an alternative therapeutic strategy for the treatment of chronic E. coli biofilm-related infections.

Enhanced decomposition of caffeine by water plasma combined with mist generator: Effect of operational parameter and decomposition pathway

Water plasma coupled with mist generator was introduced to perform the decomposition of caffeine (CAF) wastewater. The mist-shaped water molecule was directly used for plasma-forming gas with no additional gas. The influence of arc current on the decomposition of CAF was elucidated in detail. With the increase of input power from 0.8 to 1.1 kW according to arc current, the removal efficiency of total organic carbon (TOC) and CAF increased, reaching 91.1 and 99.8% at 9.5 A, respectively. H₂, CO, CO₂, and N₂ were major effluent gaseous species, of which the H₂ generation was more than 40% for all conditions. The concentration of nitrate in the effluent liquids was the highest at 9.5 A due to a higher oxidation environment. The H, O, and OH as reactive species formed via the dissociation of water molecules were demonstrated, and the plasma temperatures were at over 5000 K. The detailed decomposition pathway was deduced based on eleven intermediate products identified in this process. Electron impact and hydroxyl radical were found to take leading roles in the decomposition of CAF.

Development of a Caffeine Content Table for Foods, Drinks, Medications and Supplements Typically Consumed by the Brazilian Population

Background: The lack of a national table informing the caffeine contents in foods, drinks, dietary supplements, and medications sold in Brazil added to the noncompulsory disclosure of caffeine contents on labels of food products makes it difficult to estimate caffeine consumption in the Brazilian population. Therefore, this study aimed to develop the Brazilian Caffeine Content Table (BraCaffT). Methods: A systematic search for caffeine levels in foods, drinks, recipes, supplements, and medications was performed through a literature review, afterward collecting data from the United States Department of Agriculture Food Data Central, information from manufacturers’ and websites, and the Brazilian official medication guide. Subsequently, data systematization was performed in a spreadsheet with standardized values presented in mg of caffeine per 100 g or 100 mL of food or drink and a capsule or pill for medications and some dietary supplements. Results: The BraCaffT presents 57 items, divided into 11 categories: coffees, teas and infusions, cocoa powder, chocolates, cocoa-based beverages, desserts, soft drinks, energy drinks, guaraná powder, dietary supplements, and medications. Conclusions: The BraCaffT emerges as an instrument of great relevance and wide applicability in clinical contexts, in academic research, and as a database for the Brazilian population to better understand the amounts of caffeine in foods, drinks, dietary supplements, and medications consumed daily favoring a safe intake.

Dietary supplements for lipedema

Lipedema is a chronic disease that mostly manifests in females as the abnormal distribution of subcutaneous adipose connective tissue, usually coupled with bruising, pain, and edema. Lipedema molecular pathophysiology is currently not clear, but several studies suggest that genetics and hormonal imbalance participate in lipedema pathogenesis. Women with lipedema present in some cases with elevated body mass index, and the appearance of obesity in addition to lipedema, where the obesity can cause serious health issues as in lipedema-free individuals with obesity, such as diabetes and cardiovascular disorders. Unlike obesity, lipedema tissue does not respond well to diet or physical exercise alone. Therefore, in this review we discuss the effect of various dietary supplements that, along with diet and physical exercise, cause fat burning and weight loss, and which could potentially be important in the treatment of lipedema. Indeed, an effective fat burner should convert stored fats into energy, mobilize and break down triglycerides in adipocytes, boost metabolism and inhibit lipogenesis. Common ingredients of fat burning supplements are green tea, caffeine, chromium, carnitine, and conjugated linoleic acid. The use of fat burners could act synergistically with a healthy diet and physical exercise for decreasing adipose tissue deposition in patients with lipedema and resolve related health issues. The effects of fat burners in human studies are sometimes contradictory, and further studies should test their effectiveness in treating lipedema.

Caffeine. A critical review of contemporary scientific literature

Caffeine is a secondary metabolite extensively studied for its stimulatory properties and presumed association with specific pathologies. This alkaloid is typically consumed through coffee, tea, and other plant products but is also an additive in many medications and confectionaries. Nonetheless, despite its worldwide consumption and acceptance, there is controversial evidence as to whether its effects on the central nervous system should be interpreted as stimulatory or as an addiction in which typical withdrawal effects are canceled out with its daily consumption. The following discussion is the product of an extensive review of current scientific literature, which aims to describe the most salient topics associated with caffeine's purpose in nature, biosynthesis, metabolism, physiological effects, toxicity, extraction, industrial use and current plant breeding approaches for the development of new caffeine deficient varieties as a more economical option to the industrially decaffeinated coffees currently available to caffeine intolerant consumers. Keywords: biosynthesis, decaffeination, extraction, metabolism, physiological effects, plant breeding.