Characterization of fine-flavor cocoa in parent-hybrid combinations using metabolomics approach.

Fine-flavored cocoa is generally characterized by fresh bean color and sensory characteristics. However, these methods cannot be applied to progenies/hybrids because their colors may vary depending on their parents. Additionally, sensory evaluation lacks universal quality standards, necessitating robust complementary characterization methods. This study aimed to characterize the fine-flavor cacao in parent-hybrid combinations using widely targeted Gas Chromatography-Mass Spectrometry (GC-MS) and bean phenotype analysis. Fine-flavored cacao exhibits white-bean characteristics and a lighter color than forastero. Conversely, the hybrids displayed varying percentages of fresh bean color. Caffeine and organic acids (malic acid, fumaric acid, citric acid, lactic acid, and tartaric acid) were found to correspond to the characteristics of fine-flavored cacao. Each parent-hybrid combination demonstrated distinct flavor characteristics, with the ICCRI03-hybrid emerging as a promising clone, exhibiting flavor characteristics similar to those of its female parent (fine-flavor cacao). This information on flavor characteristics will be beneficial for further fine-flavored cacao selection.

Simultaneous analysis of caffeine and paraxanthine provides potentially useful indexes in the treatment of acute caffeine intoxication.

Caffeine (CFF) is efficiently absorbed after ingestion, and approximately 80% of ingested CFF is metabolized to paraxanthine (PXT). Although PXT has approximately twice the adenosine receptor antagonist activity of CFF, there are few reports measuring the metabolite concentrations during CFF intoxication. Furthermore, no studies have examined the efficacy of hemodialysis (HD) on PXT or the indicators that contribute to treatment strategies for patients with acute CFF intoxication. This study analyzed the association between CFF and PXT blood levels, the blood biochemical data, and the vital signs of 27 cases with information on CFF intake and elapsed time data. It was found that HD was not as effective as CFF against PXT in CFF intoxication; however, HD was effective in cases with relatively high PXT concentrations (>10 µg/mL). Simultaneous analysis of CFF and PXT would make it possible to estimate the time elapsed from CFF intake and the risk of hyperCKemia, which may develop in cases left untreated for a prolonged period after ingestion. Therefore, the measurement of PXT, in addition to CFF, is expected to provide useful information for understanding the pathogenesis of CFF intoxication and the development of treatment strategies of acute CFF intoxication.

Effects of coffee intake on skeletal muscle microvascular reactivity at rest and oxygen extraction during exercise: a randomized cross-over trial.

PURPOSE: The effects of coffee ingestion on skeletal muscle microvascular function are not well understood. This study aimed to investigate the acute effects of coffee intake with varying levels of caffeine on skeletal muscle microvascular reactivity at rest and oxygen extraction during maximal incremental exercise in physically active individuals. METHODS: Twenty healthy young male participants were administered coffee with low caffeine (3 mg/kg body weight; LC), high caffeine (6 mg/kg body weight; HC), and placebo (decaf) in different sessions. Skeletal muscle reactivity indexes, including tissue saturation index 10s slope (TSI10) and TSI half time recovery (TSI ½) following 5-minute ischemia were measured at rest and were measured at baseline and post-coffee consumption using near-infrared spectroscopy (NIRS). Post-coffee intake, NIRS was also used to measure microvascular oxygen extraction during exercise via maximal incremental exercise. Peak oxygen consumption and peak power output (Wpeak) were simultaneously evaluated. RESULTS: Post-coffee consumption, TSI10 was significantly higher in the LC condition compared to placebo (p = 0.001) and significantly higher in the HC condition compared to placebo (p < 0.001). However, no difference was detected between LC and HC conditions (p = 0.527). HC condition also showed significant less TSI ½ compared to placebo (p = 0.005). However, no difference was detected for microvascular oxygen extraction during exercise, despite the greater Wpeak found for HC condition (p < 0.001) compared to placebo. CONCLUSION: Coffee ingestion with high caffeine level (6 mg/kg body weight) significantly enhanced skeletal muscle reactivity at rest. However, the improvement of exercise performance with coffee intake is not accompanied by alterations in muscle oxygen extraction.

The Prophylactic Effect of Acetaminophen and Caffeine on Post Dural Puncture Headache after Spinal Anesthesia for Cesarean Section: A Randomized Double-Blind Clinical Trial.

Background: Post-dural puncture headache (PDPH) is the most common complication following spinal anesthesia among parturients undergoing cesarean section surgery. The purpose of this study was to evaluate the effectiveness of acetaminophen and caffeine in preventing PDPH. Methods: This double-blind, randomized clinical trial was conducted on 96 obstetric women, who were candidates for elective cesarean section. Following the randomization of participants into two groups, participants in the intervention group received tablets of acetaminophen (500 mg)+caffeine (65 mg), and participants in the control group received placebo tablets orally 2 hours before spinal anesthesia induction and then every 6 hours after surgery up to 24 hours. All parturients were evaluated for frequency and intensity of PDPH every 6 hours until 24 hours after surgery and then 48 and 72 hours after surgery. Overall satisfaction during the first 72 hours of postpartum was evaluated. The data were analyzed using SPSS software. P<0.05 was considered statistically significant. Results: Participants in the intervention group were 70% less likely to experience PDPH after spinal anesthesia (OR=0.31 P=0.01, 95% CI [0.12-0.77]). They also experienced significantly milder headaches 18 hours, 48 hours, and 72 hours later. Participants in the intervention group reported higher levels of satisfaction at the end of the study (P=0.01). No side effects related to the intervention were reported. Conclusion: Prophylactic administration of acetaminophen+caffeine decreases 70% the risk of PDPH and significantly attenuates pain intensity in obstetric patients who underwent spinal anesthesia for cesarean section.

The impact of freeze-dried Baiyedancong-Oolong tea aqueous extract containing bioactive compounds on the activities of CYP450 enzymes, the transport capabilities of P-gp and OATs, and transcription levels in mice.

In this study, (-)-epigallocatechin gallate (EGCG) and caffeine extracted from freeze-dried autumn Baiyedancong Oolong tea (FBOT) were orally administered to mice for 7 consecutive days to explore the effects of BOT and its bioactive compounds on the activities and transcription levels of CYP450 enzymes, intestinal effluence transporter P-gp, and renal ingestion Organic Anion Transporters (OATs). Concurrently, EGCG and caffeine enhanced the activities of CYP3A, CYP2E1, and CYP2C37 in the liver of mice, while impairing the transport capabilities of P-gp and OATs. Reduced levels of MDR1 encoding P-gp transcription in the small intestine and renal OAT1 and OAT3 revealed that transcription was involved in the regulation of CYP450, P-gp, and OATs. The reduced transcription level of liver CYP2E1 suggested that CYP2E1 activity may have been elevated due to alternative mechanisms, but not through transcription. The absorption, metabolism, and excretion of drugs may be influenced by the daily consumption or high-dose administration of BOT and its related products, in which EGCG and caffeine may make great contributions.

Strigolactone enhances tea plant adaptation to drought and Phyllosticta theicola petch by regulating caffeine content via CsbHLH80.

Strigolactones (SLs) play crucial roles in both plant growth and stress responses. However, their impact on the secondary metabolites of woody plants remains elusive. Here, we found that exogenous strigolactone analogue GR24 positively regulates tea plant flavor secondary metabolites, concurrently inhibiting caffeine biosynthesis and promoting the accumulation of caffeine catabolic pathway products. In this process, SL directly or indirectly inhibits the expression of CsSAMSs by inducing CsbHLH80, thereby reducing caffeine biosynthesis. Furthermore, CsbHLH80 enhances caffeine degradation, leading to increased allantoin. Under normal conditions, heightened allantoin reduces abscisic acid (ABA) accumulation. This inhibition reverses under drought stress. Increased ABA significantly enhances tea plant tolerance to both drought and Phyllosticta theicola Petch. In summary, this study offers novel insights for improving tea plant adaptation and quality in arid regions, particularly emphasizing the selection of stress-tolerant varieties and the refinement of production measures with a focus on high-quality production and environmentally friendly biological control methods.

Metabolomic profiling of in vitro and in situ grown Nilgiris tea reveals unique signatures for breeding decaffeinated varieties.

This study was begun by establishing an in vitro culture in UPASI 9, a Nilgiris tea clone (Camellia sinensis) by optimising various factors. Anatomical studies demonstrated that use of lower carbendazim concentration for sterilisation (0.2%) produced viable and healthy explants for callus initiation. To confirm the genetic consistency of the regenerated plants, gene-specific SSR markers were developed and utilised. GC-MS was employed to analyse volatile metabolites extracted from callus, stem, micro shoots, and leaves of the UPASI 9 tea genotype. The results revealed distinct compositions of metabolites in each sample. More interestingly, caffeine was exclusively detected in leaf samples but absent in all other investigated tissues, despite the presence of Tea Caffeine Synthase (TCS) gene-specific SSRs. Thus, this study provided unique information on the absence of caffeine in in vitro grown Nilgiris tea clone, UPASI 9, as decaffeinated tea has a unique niche in the global market.

New Insight for Enhanced Topical Targeting of Caffeine for Effective Cellulite Treatment: In Vitro Characterization, Permeation Studies, and Histological Evaluation in Rats.

Cellulite (CLT) is one of the commonly known lipodystrophy syndromes affecting post-adolescent women worldwide. It is topographically characterized by an orange-peel, dimpled skin appearance hence, it is an unacceptable cosmetic problem. CLT can be modulated by surgical procedures such as; liposuction and mesotherapy. But, these options are invasive, expensive and risky. For these reasons, topical CLT treatments are more preferred. Caffeine (CA), is a natural alkaloid that is well-known for its prominent anti-cellulite effects. However, its hydrophilicity hinders its cutaneous permeation. Therefore, in the present study CA was loaded into solid lipid nanoparticles (SLNs) by high shear homogenization/ultrasonication. CA-SLNs were prepared using Compritol® 888 ATO and stearic acid as solid lipids, and span 60 and brij™35, as lipid dispersion stabilizing agents. Formulation variables were adjusted to obtain entrapment efficiency (EE > 75%), particle size (PS < 350 nm), zeta potential (ZP < -25 mV) and polydispersity index (PDI < 0.5). CA-SLN-4 was selected and showed maximized EE (92.03 ± 0.16%), minimized PS (232.7 ± 1.90 nm), and optimum ZP (-25.15 ± 0.65 mV) and PDI values (0.24 ± 0.02). CA-SLN-4 showed superior CA release (99.44 ± 0.36%) compared to the rest CA-SLNs at 1 h. TEM analysis showed spherical, nanosized CA-SLN-4 vesicles. Con-LSM analysis showed successful CA-SLN-4 permeation transepidermally and via shunt diffusion. CA-SLN-4 incorporated into Noveon AA-1® hydrogel (CA-SLN-Ngel) showed accepted physical/rheological properties, and in vitro release profile. Histological studies showed that CA-SLN-Ngel significantly reduced mean subcutaneous fat tissue (SFT) thickness with 4.66 fold (p = 0.035) and 4.16 fold (p = 0.0001) compared to CA-gel, at 7th and 21st days, respectively. Also, significant mean SFT thickness reduction was observed compared to untreated group with 4.83 fold (p = 0.0005) and 3.83 fold (p = 0.0043), at 7th and 21st days, respectively. This study opened new avenue for CA skin delivery via advocating the importance of skin appendages. Hence, CA-SLN-Ngel could be a promising nanocosmeceutical gel for effective CLT treatment.

Mendelian randomization analysis of maternal coffee consumption during pregnancy on offspring neurodevelopmental difficulties in the Norwegian Mother, Father and Child Cohort Study (MoBa).

BACKGROUND: Previous observational epidemiological studies have suggested that coffee consumption during pregnancy may affect fetal neurodevelopment. However, results are inconsistent and may represent correlational rather than causal relationships. The present study investigated whether maternal coffee consumption was observationally associated and causally related to offspring childhood neurodevelopmental difficulties (NDs) in the Norwegian Mother, Father and Child Cohort Study. METHODS: The observational relationships between maternal/paternal coffee consumption (before and during pregnancy) and offspring NDs were assessed using linear regression analyses (N = 58694 mother-child duos; N = 22 576 father-child duos). To investigate potential causal relationships, individual-level (N = 46 245 mother-child duos) and two-sample Mendelian randomization (MR) analyses were conducted using genetic variants previously associated with coffee consumption as instrumental variables. RESULTS: We observed positive associations between maternal coffee consumption and offspring difficulties with social-communication/behavioral flexibility, and inattention/hyperactive-impulsive behavior (multiple testing corrected p < 0.005). Paternal coffee consumption (negative control) was not observationally associated with the outcomes. After adjusting for potential confounders (smoking, alcohol, education and income), the maternal associations attenuated to the null. MR analyses suggested that increased maternal coffee consumption was causally associated with social-communication difficulties (individual-level: beta = 0.128, se = 0.043, p = 0.003; two-sample: beta = 0.348, se = 0.141, p = 0.010). However, individual-level MR analyses that modelled potential pleiotropic pathways found the effect diminished (beta = 0.088, se = 0.049, p = 0.071). Individual-level MR analyses yielded similar estimates (heterogeneity p = 0.619) for the causal effect of coffee consumption on social communication difficulties in maternal coffee consumers (beta = 0.153, se = 0.071, p = 0.032) and non-consumers (beta = 0.107, se = 0.134, p = 0.424). CONCLUSIONS: Together, our results provide little evidence for a causal effect of maternal coffee consumption on offspring NDs.

Coffee substitutes: A review of the technology, characteristics, application, and future perspective.

Despite being one of the most frequently consumed beverages worldwide, there are concerns that excessive consumption of coffee can have adverse effects, especially concerning the addictive and stimulating effects of the alkaloid caffeine, which contributes to coffee's popularity. It is known to increase the risk of hypertension and heart rate among predisposed individuals, adversely affecting the nervous system. Even though they differ in nature from those found in coffee, coffee substitutes can be considered economically and health-wise as a favorable alternative to natural coffee brews. This review summarizes the state-of-the-art varieties of plants used as coffee substitutes and discusses their production technology, chemical composition, nutritional properties, health benefits, economic challenges, and rationale for choosing the plant as a substitute for coffee. Various instant products and coffee substitute blends are also available on the market especially based on different kinds of plants and herbs like ginger, rye, date pits, quinoa, lupine, chicory, barley, rye, oak, and so on. These coffee substitutes have several advantages especially having no caffeine and containing different beneficial phytochemicals, although the results of the difference between the levels of harmful compounds in coffee and coffee substitutes were contradictory. Therefore, it is no wonder that the development of coffee substitutes, which are beverages that are able to mimic the taste and aroma of coffee, is on the rise at present.

Metabolomic insights into idiopathic xerostomia: The central role of caffeine metabolism in salivary biochemistry.

OBJECTIVE: This study aims to delineate the salivary metabolomic profile of patients with idiopathic xerostomia using untargeted metabolomics techniques, with the goal of addressing the lack of clear diagnostic markers and providing insights into the pathophysiological mechanisms of the condition. DESIGN: In this observational, cross-sectional study, saliva samples from 33 patients with idiopathic xerostomia and 34 healthy controls were analyzed using Ultra Performance Liquid Chromatography Quadrupole Time of Flight Mass Spectrometry (UPLC-QTOF MS). Metabolomic profiling was complemented by multivariate statistical analysis to differentiate between affected individuals and controls. RESULTS: Metabolomic analysis delineated a pronounced differentiation between patients with idiopathic xerostomia and healthy controls. A total of 195 metabolites displayed significant differential expression, each with a variable importance in projection (VIP) greater than 1 and a P-value less than 0.05. Pathway enrichment analysis, according to the Kyoto Encyclopedia of Genes and Genomes (KEGG), identified 22 metabolites that participated in 18 distinct metabolic pathways. Among these, the caffeine metabolism pathway, characterized by notable alterations in impact values (VIP, P-value, Log2-fold change, Rich factor), emerged as the most significantly disrupted, underscoring its potential role in the pathophysiology of idiopathic xerostomia (P = 0.0000395). CONCLUSIONS: The salivary metabolomic profiling revealed distinct alterations in idiopathic xerostomia, with a significant reduction in caffeine metabolism pathways, underscoring potential neuropathic involvement. This study advances our understanding of the metabolic alterations in xerostomia, suggesting that salivary metabolomics may offer viable biomarkers for diagnosing and understanding the etiology of idiopathic xerostomia. Future research should focus on therapeutic targeting of these metabolic disturbances and evaluating their reversibility with treatment.

Caffeine intake from foods and beverages and trends among Chinese children and adolescents: 2004-2018.

BACKGROUND: The popularity of caffeinated foods and beverages poses risks of high caffeine exposure among Chinese children and adolescents. Nevertheless, there is a lack of national assessments on their caffeine consumption. OBJECTIVE: To estimate daily caffeine intake and analyze time trends among Chinese children and adolescents. METHODS: The study subjects were participants of the China Health and Nutrition Survey in 2004, 2006, 2009 and 2011, and the National Food and Beverage Consumption Survey in 2014 and 2018. Caffeine content was determined using chromatographic instrument. The Monte Carlo simulation was utilized to estimate daily caffeine intake and the Kruskal-Wallis test was used to analyze differences between population characteristics. To examine yearly trends in caffeine intake from 2004 to 2018, the partial Mann-Kendall test was applied. RESULTS: The median daily caffeine intake of Chinese children and adolescents was 0.17 (95%CI: 0.15-0.20) mg/kg BW/day. Main contributors were tea (55.52%), sodas (19.52%) and tea beverages (10.37%). Approximately 4.68% of individuals consumed caffeine exceeding 2.5 mg/kg BW/day. Higher caffeine intake was observed in adolescents aged 12-17 years, males, and consumers residing in northeastern China. While no significant overall yearly trends in caffeine intake were detected from 2004 to 2018, there was an increase in intake driven by beverage consumption between 2006 and 2014. CONCLUSION: This study provided a national assessment of caffeine consumption among Chinese children and adolescents. Caffeinated beverages like tea, soda, and tea beverages emerged as major contributors to caffeine intake. These findings could contribute to the regulation of caffeine consumption and the promotion of healthy habits among children and adolescents.

Quantitative mapping of renal oxygen consumption using pseudo-continuous arterial spin labeling and quantitative susceptibility mapping in humans.

PURPOSE: To propose a new method for quantitatively mapping the renal metabolic rate of oxygen (RMRO2) and to evaluate the proposed method using a caffeine challenge. THEORY AND METHODS: Pseudo-continuous arterial spin labeling (pCASL) and QSM sequences were used to obtain MR images in the kidney. Six healthy volunteers were scanned on caffeine and control days. The pCASL and QSM images were registered using DICOM information and rigid translation. The Fick principle was applied to estimate RMRO2. The results on caffeine and control days were compared to evaluate the capability of the proposed method to estimate renal oxygen consumption. A paired t-test was used to assess the statistical significance. RESULTS: Estimated renal blood flow (RBF), QSM, and RMRO2 maps were consistent with those reported in the literature. RMRO2 values were higher than the cerebral metabolic rate of oxygen (CMRO2) and were significantly reduced on the caffeine days compared to the control days, consistent with findings from non-MRI literature. CONCLUSION: The feasibility of measuring renal oxygen consumption using pCASL and QSM images was demonstrated. To the best of our knowledge, this work provides quantitative maps of renal oxygen consumption in humans for the first time. The results were consistent with the literature, including the statistically significant reduction in renal oxygen consumption with caffeine challenge. These findings suggest the potential utility of our technique in measuring renal oxygen consumption noninvasively, especially for patients with complications associated with contrast agents.

Consumption of a Coffee Rich in Phenolic Compounds May Improve the Body Composition of People with Overweight or Obesity: Preliminary Insights from a Randomized, Controlled and Blind Crossover Study.

This study analyzes the effects on body composition and variables related to metabolic syndrome of two coffees with different degree of roasting and phenolic content. Sixty participants with body mass index between 25 and 35 kg/m2 and a median age of 51.0 years (Interquartile range 46.3-56) were recruited. The study was a controlled, randomized, single-blind crossover trial consisting in drinking three cups/day of roasted coffee (RC) or lightly roasted coffee (LRC) during 12 weeks with 2-week wash-out stages before each coffee intervention. LRC contained ≈400 mg of hydroxycinnamic acids and ≈130 mg of caffeine per 200 mL/cup while RC contained ≈150 mg of hydroxycinnamic acids and ≈70 mg of caffeine per 200 mL/cup. Along the study, in each of the six visits, blood pressure, body composition by bioimpedance, anthropometric measurements, and blood biochemistry were analyzed. The mean differences and p values were calculated using a linear mixed model (JASP.v.0.18.0.3). A total of 38 participants completed the study. After the consumption of both coffees, fat mass and body fat percentage (LRC: -1.4%, p < 0.001; RC: -1.0%, p = 0.005) were reduced, whereas muscle mass and muscle mass percentage slightly increased (LRC: 0.8%, p < 0.001; RC: 0.7%, p = 0.002). The decrease in fat percentage was greater with LRC compared to RC (-0.8%; p = 0.029). There were no significant changes in metabolic syndrome variables or in body weight. In conclusion, LRC was slightly superior at inducing changes in body composition.

Matcha Does Not Affect Electroencephalography during Sleep but May Enhance Mental Well-Being: A Randomized Placebo-Controlled Clinical Trial.

Although theanine in matcha improves sleep quality and cognitive function, the caffeine in green tea is thought to worsen sleep quality. Therefore, this study investigated the factors behind the observed improvements in subjective sleep quality in matcha. A placebo-controlled randomized double-blind parallel-group study was conducted on healthy Japanese men and women aged 27-64 years. After 4 weeks of consuming 2.7 g of matcha daily (containing 50.3 mg theanine, 301.4 mg catechins, and 71.5 mg caffeine), no significant differences were observed between the control and matcha groups on total sleep time, sleep latency, wake after sleep onset, or sleep efficiency measured by electroencephalography (EEG). However, the sleep questionnaire Oguri-Shirakawa-Azumi Sleep Inventory, the Middle-age and Aged version (OSA-MA), administered immediately after waking showed a trend toward increased satisfaction with sleep time (p < 0.1), and EEG measurements indicated significantly shortened wake-up times after waking with matcha intake (p < 0.05). The Beck Depression Inventory-II scores also tended to decrease (p < 0.1). The continuous intake of matcha may offer improved subjective sleep quality and emotional stability despite not offering significant changes in objective sleep parameters.

Impact of Coffee Intake on Measures of Wellbeing in Mice.

Coffee intake is increasingly recognized as a life-style factor associated with the preservation of health, but there is still a debate on the relative effects of caffeinated and decaffeinated coffee. We now tested how the regular drinking of caffeinated and decaffeinated coffee for 3 weeks impacted on the behavior of male and female adult mice. Males drinking caffeinated coffee displayed statistically significant lower weight gain, increased sensorimotor coordination, greater motivation in the splash test, more struggling in the forced swimming test, faster onset of nest building, more marble burying and greater sociability. Females drinking caffeinated coffee displayed statistically significant increased hierarchy fighting, greater self-care and motivation in the splash test and faster onset of nest building. A post-hoc two-way ANOVA revealed sex-differences in the effects of caffeinated coffee (p values for interaction between the effect of caffeinated coffee and sex) on the hierarchy in the tube test (p = 0.044; dominance), in the time socializing (p = 0.044) and in the latency to grooming (p = 0.048; selfcare), but not in the marble burying test (p = 0.089). Intake of decaffeinated coffee was devoid of effects in males and females. Since caffeine targets adenosine receptors, we verified that caffeinated but not decaffeinated coffee intake increased the density of adenosine A1 receptors (A1R) and increased A1R-mediated tonic inhibition of synaptic transmission in the dorsolateral striatum and ventral but not dorsal hippocampus, the effects being more evident in the ventral hippocampus of females and striatum of males. In contrast, caffeinated and decaffeinated coffee both ameliorated the antioxidant status in the frontal cortex. It is concluded that caffeinated coffee increases A1R-mediated inhibition in mood-related areas bolstering wellbeing of both males and females, with increased sociability in males and hierarchy struggling and self-care in females.

Acute caffeine administration impaired spatial working memory in habitual coffee/tea drinkers: A randomized, placebo-controlled, double-blind study.

BACKGROUND: Although coffee consumption is widespread worldwide, a recent study showed that acute intake of caffeine negatively affects working memory (WM) performance on n-back tasks among habitual caffeine consumers. However, there is a scarcity of double-blind, placebo-controlled studies that assess the spatial WM (SWM) effects of caffeine using spatial span tasks. Therefore, the present study aimed to examine the effects of acute caffeine administration (200 mg, PO) on SWM and verbal WM (VWM) among habitual caffeine consumers. METHODS: The effects of caffeine on working memory (WM) was evaluated through the administration of backward digit span and spatial span tasks under a delay-dependent condition (0, 4, 8, and 6 s) in a randomized, double-blind, placebo-controlled study involving 18 healthy participants. This data is derived from our previous published study. The total scores obtained and the maximum scores achieved were the primary outcome variables of the study. RESULTS: Caffeine had a significant impact on SWM (maximum obtained, p = 0.013; for total scored, p = 0.007) in a delay-independent manner. However, there were no significant main effects of caffeine on VWM (p = 0.82 for maximum obtained, p = 0.56 for total scored). CONCLUSION: Overall, the present findings contradict the commonly held belief that caffeine improves cognitive performance and suggest that acute administration of caffeine may impair SWM in habitual coffee/tea drinkers. CLINICAL TRIAL REGISTRATION NUMBER: CT-2018-CTN-02561 (Therapeutic Goods Administration Clinical Trial Registry) and ACTRN12618001292268 (The Australian New Zealand Clinical Trials Registry).

Association between coffee and tea consumption and the risk of dementia in individuals with hypertension: a prospective cohort study.

Many studies have shown that drinking coffee and tea may be associated with the risk of hypertension and dementia. Limited research exists on their impact on dementia risk in hypertensive patients. This study aimed to determine the association between coffee and tea consumption and the risk of dementia development in hypertensive population by utilizing Cox proportional risk modeling with 453,913 participants from a UK biobank. Our findings reveal a J-shaped and U-shaped association between the risk of all-cause dementia and the consumption of coffee and tea respectively in hypertensive people. The hypertensive patients who drink 0.5-1 cup of coffee or 4-5 cups of tea per day have the lowest risk of dementia. A U-shaped relationship was observed between daily caffeine consumption and the risk of developing all-cause dementia and vascular dementia in the hypertensive population. Furthermore, the significant association between the amount of coffee and tea consumed and the risk of all-cause and vascular dementia were more likely to be found in hypertensive patients than in the non-hypertensive population.

Caffeine-Induced Psychosis: A Case Report and Review of Literature.

A 51-year-old female, with no previous history of psychosis, presented to the Emergency Department with an acute psychotic episode in the context of excess caffeine consumption. Caffeine is an adenosine antagonist. An antagonist of adenosine can lead to the release of dopamine into the synaptic cleft, which can induce psychotic symptoms in vulnerable individuals. The patient had consumed caffeine in the form of up to eight energy drinks daily. She experienced persecutory delusions alongside auditory and visual hallucinations. She did not have a history of psychotic disorder but did have a history of generalized anxiety disorder. Upon cessation of caffeine, her symptoms resolved within five days. She remained caffeine-free and symptom-free 18 months later when reviewed in the community. This case highlights the potential psychiatric consequences of excessive caffeine consumption and identifies the need to screen for excessive consumption of caffeine in individuals presenting with new psychotic symptoms or worsening of pre-existing psychotic symptoms.

Risperidone suppresses caffeine-induced hyperthermia and hyperactivity in rats.

Caffeine, a methylxanthine alkaloid, works as a nonselective adenosine receptor antagonist. It is the most widely used psychostimulant drug worldwide. However, caffeine overdose can lead to acute intoxication, posing a clinical problem. Hyperthermia and hyperactivity are associated issues with acute caffeine intoxication; however, no definitive treatment exists. This study aimed to assess the ability of risperidone to attenuate caffeine-induced hyperthermia and hyperactivity while elucidating the unknown mechanisms of caffeine intoxication. The rats received intraperitoneal injections of saline, risperidone (0.25 mg/kg, 0.5 mg/kg), WAY-100635, ketanserin, haloperidol, sulpiride, or SCH 23390, 5 min after the administration of caffeine (25 mg/kg). Subcutaneous temperature and activity counts were measured using nano tag ® for up to 90 min. In vivo microdialysis was used to determine the effect of risperidone on caffeine-induced elevation of dopamine (DA), serotonin (5-HT), and noradrenaline (NA) concentrations in the anterior hypothalamus. Rats were injected with caffeine (25 mg/kg), followed by saline or risperidone (0.5 mg/kg) 5 min later. The levels of DA, 5-HT, and noradrenaline were measured every 15 min for up to 90 min after caffeine administration. Risperidone and 5-HT2A receptor antagonist ketanserin attenuated caffeine-induced hyperthermia and hyperactivity. Haloperidol and dopamine D1 antagonist SCH-23390 exacerbated hyperthermia without any effect on the hyperactivity. In the microdialysis study, risperidone treatment further attenuated caffeine-induced 5-HT elevation, but not DA and NA. Our results indicate that risperidone attenuates caffeine-induced hyperthermia and hyperactivity by blocking 5-HT2A receptor activity and may be potentially useful for treating caffeine intoxication.