Role Of Caffeine Research Articles

Exploring the Role of Caffeine Use in Adult-ADHD Symptom Severity of US Army Soldiers.

There is a growing trend of using energy drinks and caffeinated beverages to improve cognitive performance that is widespread and well-studied among children and teenagers with Attention Deficit Hyperactive Disorder (ADHD), but little is known about adult ADHD (A-ADHD). As a consequence, the use of highly caffeinated drinks and their impact on ADHD symptoms are poorly understood. This is especially true in populations where A-ADHD and the use of these beverages are largely represented, such as in military samples. From the All Army Study (AAS) of the Army Study to Assess Risk and Resilience in Service members (STARRS) data, 1,239 A-ADHD soldiers and 17,674 peers without any psychiatric comorbidity were selected. The two groups were compared on: (1) the presence of substance use disorder (SUD) diagnosis both over their lifetime and in the previous 30 days; (2) patterns of alcohol and caffeine use using chi-square analyses. Lastly, the relationship between substance use and severity of A-ADHD symptoms was assessed using Pearson’s correlations. Soldiers with a diagnosis of A-ADHD had a higher prevalence of SUD diagnosis compared to their peers without psychiatric comorbidity. They also tended to use more alcohol, caffeine pills, energy drinks, and other caffeinated drinks. Alcohol use was positively correlated with A-ADHD symptoms; on the contrary, energy drinks, caffeine pills and other caffeinated drinks showed negative correlations with some aspects of A-ADHD symptomatology. The use of caffeinated compounds appears to be increased among military soldiers with ADHD, and they may help reducing A-ADHD symptoms and improve cognitive performance. These results suggest a possible role for caffeine as a potential pharmacological tool in the treatment of adult ADHD.

Antioxidant and Neuroprotective Effects of Caffeine against Alzheimer's and Parkinson's Disease: Insight into the Role of Nrf-2 and A2AR Signaling.

This paper reviews the results of studies conducted on the role of caffeine in the management of different neurological disorders, such as Parkinson’s disease (PD) and Alzheimer’s disease (AD). To highlight the potential role of caffeine in managing different neurodegenerative diseases, we identified studies by searching PubMed, Web of Science, and Google Scholar by scrutinizing the lists of pertinent publications. According to the collected overall findings, caffeine may reduce the elevated oxidative stress; inhibit the activation of adenosine A2A, thereby regulating the accumulation of Aβ; reduce the hyperphosphorylation of tau; and reduce the accumulation of misfolded proteins, such as α-synuclein, in Alzheimer’s and Parkinson’s diseases. The studies have suggested that caffeine has promising protective effects against different neurodegenerative diseases and that these effects may be used to tackle the neurological diseases and/or their consequences. Here, we review the ongoing research on the role of caffeine in the management of different neurodegenerative disorders, focusing on AD and PD. The current findings suggest that caffeine produces potent antioxidant, inflammatory, and anti-apoptotic effects against different models of neurodegenerative disease, including AD, PD, and other neurodegenerative disorders. Caffeine has shown strong antagonistic effects against the adenosine A2A receptor, which is a microglial receptor, and strong agonistic effects against nuclear-related factor-2 (Nrf-2), thereby regulating the cellular homeostasis at the brain by reducing oxidative stress, neuroinflammation, regulating the accumulation of α-synuclein in PD and tau hyperphosphorylation, amyloidogenesis, and synaptic deficits in AD, which are the cardinal features of these neurodegenerative diseases.

Regular and decaffeinated espresso coffee capsules: Unravelling the bioaccessibility of phenolic compounds and their antioxidant properties in milk model system upon in vitro digestion

Coffee is the most consumed beverage in the US and several other countries such as Brazil and Colombia. Coffee has been recognized for a myriad of health benefits including those arising from its antioxidant properties. However, to the best of our knowledge, there is no literature addressing the fate of phenolic compounds from espresso capsules considering the role of caffeine as well as the interaction with milk upon in vitro digestion. In this study, regardless of the sample (regular or decaffeinated espresso coffee capsule), oral and gastric digested samples showed lower contents of caffeine and phenolic acids than their undigested counterparts. In contrast, with recovery of up to 48%, only caffeic acid was present in the intestinal phase. Regular coffee samples showed a prooxidative action during the intestinal phase. In contrast, decaffeinated coffee prevented milk lipid peroxidation during the gastric and intestinal phases. A significant positive correlation existed between the caffeine concentration and the milk lipid peroxidation during the gastrointestinal phase. Thus, under the experimental conditions employed, decaffeinated coffee from commercial espresso capsules was considered the best choice in terms of prevention of the potential exposure of the gastrointestinal tract to products of milk lipid peroxidation.

What do we really know about the role of caffeine on urinary tract symptoms? A scoping review on caffeine consumption and lower urinary tract symptoms in adults.

The purpose of this scoping review was to map out the existing literature on caffeine intake and lower urinary tract symptoms (LUTS) in adults. In this scoping review, we searched for all studies available until June 2019 in MEDLINE, Embase, CINAHL, Cochrane Central Register, PsycINFO, LILACS, LiSSa, Web of Science, and Joanna Briggs Institute electronic databases, in addition to a hand search of the bibliographies of all relevant articles and a gray literature search. Both intervention studies on the effects of caffeine reduction in adults with LUTS and observational studies on the association between caffeine intake and LUTS-related outcomes in adults were included and assessed for methodological quality by two independent reviewers. Fourteen intervention and 12 observational studies were included. Overall, there was a decrease in urgency episodes (level of evidence 2, grade of recommendation B) and nocturnal enuresis episodes (4, C) with caffeine reduction. Observational studies reported an unclear association between caffeine intake and LUTS-related outcomes. Most importantly, this present review highlighted high heterogeneity in the studied populations, caffeine measures, and reported outcomes. There was also unknown or high risk of bias in most identified studies. Caffeine reduction appears to reduce LUTS. Future studies on caffeine reduction interventions should target populations with urgency and urge urinary incontinence, which show the most promising results, and include valid and reliable measures of caffeine intake and LUTS. Finally, future studies should also use reporting guidelines to ensure lower risk of bias.

0227 The Role of Caffeine in Mitigating Cognitive Deficits due to Sleep Deprivation

0227 The Role of Caffeine in Mitigating Cognitive Deficits due to Sleep Deprivation

Combination of Caffeine and Liver Albumin Plus Protects against Smoking-Induced Liver Injury in Rats

Background: A number of studies have revealed the hepatoprotective effect of coffee and tea. However, the role of caffeine on smoking-induced liver injury is not well elucidated. Liver Albumin Plus (LAP) is a liver supplement given in different liver diseases; to our knowledge, its role in smoking-induced liver injury is not clear. Objectives: This study aimed to find out the protective effect of caffeine and LAP alone and in combination in attenuation of smoking-induced liver injury. Methods: Thirty male albino rats were divided into a control group and a smoking group; the smoking group was then subdivided into a smoking group, a smoking + caffeine group, a smoking + LAP group, and a smoking + caffeine + LAP group. At the end of the experimental study, blood samples were collected for assessment of liver enzymes, alpha-fetoprotein (AFP), and interleukin 6, and livers were excised. Biochemical analysis of hydrogen peroxide (H₂O₂), superoxide dismutase (SOD), and hypoxia-inducible factor (HIF) as well as histological examination were done. Results: The results showed that smoking elevated liver enzymes, AFP, H₂O₂, and HIF and decreased SOD; histologically, deterioration of the liver was observed. On administration of caffeine, significant (p < 0.05) improvement in all measured parameters and preserved liver histological structure were observed, while intake of LAP alone showed some improvement. In combination, all liver parameters were improved and histological structure was preserved in contrast to each drug alone. Conclusion: It is better to give a combination of caffeine and LAP with cigarettes smoking to attenuate smoking-induced liver injury.

Role of caffeine and alcohol in the formation of glucose from starch-α-Amylase reaction: Application of a two-step model

Role of caffeine and alcohol in the formation of glucose from starch-α-Amylase reaction: Application of a two-step model

Caffeine, gravity, and baroreceptor function: the integration of diet and cardiovascular control.

We describe a simple, cost-effective experiment to demonstrate cardiovascular integration of heart rate and blood pressure to accommodate the environmental and dietary factors of gravity and caffeine. Specific learning objectives associated with this include understanding the effects of posture on blood pressure and heart rate, coupled with the role of caffeine in modifying this response. Inclusion of ECG measurements, coupled with heart rate variability analysis, added a demonstration of the contribution made by the autonomic nervous system under these conditions. We clearly demonstrate that the cardiac work, estimated as rate-pressure product, necessary to undertake the transition from supine to standing, is fixed for a given group of subjects. However, the individual contribution of heart rate and systolic pressure to the cardiac workload is subject to the external factors of gravity and caffeine. Such an activity also demonstrates additional benefits, including unstructured teaching opportunities to augment classroom learning associated with integrative physiology and also the discussion of ethical issues with regard to human experimentation.

Coffee with co-workers: role of caffeine on evaluations of the self and others in group settings.

This research explores the effect of consuming a moderate amount of commercially available caffeinated coffee on an individual's self-evaluated participation in a group activity and subsequent evaluations of the experience. Across two studies, results show that consuming a moderate amount of caffeinated coffee prior to indulging in a group activity enhances an individual's task-relevant participation in the group activity. In addition, subjective evaluations of the participation of other group members and oneself are also positively influenced. Finally, the positive impact of consuming a moderate amount of caffeinated coffee on the evaluation of participation of other group members and oneself is moderated by a sense of an increased level of alertness.

Caffeine: A Potential Protective Agent Against Cognitive Decline in Alzheimer's Disease.

Over the past few decades, caffeine has been well recognized as a stimulant whose effects can be detected particularly in the central nervous system. A stimulating effect of caffeine has been found useful in treating patients with many neurological disorders, including Alzheimer's disease (AD). AD is reported to be a rapidly increasing public health problem with lack of a remedial treatment. However, the assumed protective effects of caffeine against AD are of huge interest. This study substantiates caffeine's role as a potential prevention agent against AD through several epidemiological studies. More than 75% of available study reports support the opinion that caffeine has a favorable effect against cognitive decline and AD. Moreover, other studies have discussed the effect of caffeine drinking and concluded several positive effects on cognitive functioning. The present study, however, focuses more on the potential mechanisms by which caffeine diminishes effects as well as delays the onset of AD.

Caffeine Augments The Instruction of Anti-Inflammatory Macrophages by The Conditioned Medium of Mesenchymal Stem Cells.

Mesenchymal stem cells (MSCs) have been shown to produce adenosine, express adenosine receptors, and communicate with macrophages and other cells. However, there is no information about the role of caffeine, as a popular drink and adenosine antagonist, on the crosstalk between MSCs and immune cells. The aim of the current study is to evaluate the effects of the conditioned medium of MSCs treated with caffeine on macrophages. In this experimental study, MSCs were isolated from bone marrow of rats and pulsed with different concentrations of caffeine (0, 0.1, 0.5 and 1 mM) for 72 hours. The conditioned medium of MSCs was collected after 24 hours, then incubated with macrophages for 24 hours. Finally, the functions of the macrophages were evaluated. Conditioned medium of MSCs treated with caffeine significantly enhanced phagocytosis and simultaneously regressed expression of reactive oxygen species (ROS) and nitric oxide (NO) as well as IL-12 by macrophages compared to the supernatants of MSCs alone. The conditioned medium of MSCs pulsed with caffeine at low to moderate concentrations preserved the neutral red uptake by macrophages and elevated IL-10 secretion by macrophages. A high concentration of caffeine could interfere with the two latter effects of supernatants of MSCs on the macrophages. Collectively, caffeine treatment of MSCs appeared to augment the instruction of anti-inflammatory macrophages by conditioned medium of MSCs. These findings might offer new insight into the potential mechanisms that underlie the immunomodulatory and anti-inflammatory effects of caffeine.

Caffeine's influence on gambling behavior and other types of impulsivity

BackgroundYoung adulthood is a developmental period frequently associated with occurrence of impulsive behaviors including gambling. It is estimated that 73% of children and 87% of adults in the United States regularly use caffeine. Questions remain, however, concerning the role of caffeine in the development and maintenance of impulsive behaviors such as gambling. MethodsSixty-one young adults with at least some degree of disordered gambling were recruited from two Mid-Western university communities in the United States using media advertisements. Caffeine intake over the preceding month was quantified using the Caffeine Use Questionnaire. Clinician rating scales, questionnaires, and cognitive tests germane to impulsivity were completed. Relationships between caffeine intake and demographic, gambling symptom, and neurocognitive measures were evaluated using the statistical technique of partial least squares (PLS). ResultsAverage weekly caffeine intake in the gamblers was 1218.5mg (a figure higher than previously reported in the general population). PLS yielded an optimal model with one latent factor, which explained 14.8% of variation in demographic/clinical/cognitive measures and 32.3% of variation in caffeine intake. In this model, higher caffeine intake was significantly associated with earlier age at first gambling, higher personality-related impulsiveness, more nicotine consumption, older age, and more impulsive decision-making. ConclusionsThese data suggest a particularly strong relationship between caffeine intake, earlier age of first gambling, and certain types of impulsivity in gamblers. Providing education about healthy caffeine use may be especially valuable in gamblers. Future work should explore whether the relationship between caffeine use and gambling is due to a common predisposing factor (impulsive tendencies) or, rather, constitutes a form of self-medication in gamblers (or a means of sustaining gambling habits for longer).

A review of caffeine use as a risk or protective factor for women's health and pregnancy.

To provide a narrative synthesis of recently published studies on caffeine use as a risk or protective factor for health outcomes, with a focus on women's health and pregnancy. Based on predominantly observational studies, moderate caffeine intake has been shown to be a protective factor for liver cancer, certain bowel conditions, colorectal cancer, skin cancer, and regular menstrual cycle function. However, heavy consumption is a risk factor for osteoporosis, urinary incontinence, and poorer birth and child developmental outcomes. Residual confounding and issues surrounding retrospective self-reported intake are cited as key limitations in the majority of these studies. Moderate caffeine intake has been associated with lower risk of cardiovascular disease and metabolic syndrome; however, recent genetic epidemiology studies provide no evidence for a causal relationship. Greater inclusion of female participants in studies, and analysis of sex differences in the relationship between caffeine intake and certain health conditions, is necessary. The current literature suggests caffeine's role as a risk or protective factor differs across health conditions. Often, there are plausible biological mechanisms for this relationship. However, a continued precautionary stance is recommended until direct causal pathways are established. Review of recently published studies does not suggest that current intake guidelines for adults and for pregnant woman need to be modified.

Coffee, tea and melanoma risk: findings from the European Prospective Investigation into Cancer and Nutrition.

In vitro and animal studies suggest that bioactive constituents of coffee and tea may have anticarcinogenic effects against cutaneous melanoma; however, epidemiological evidence is limited to date. We examined the relationships between coffee (total, caffeinated or decaffeinated) and tea consumption and risk of melanoma in the European Prospective Investigation into Cancer and Nutrition (EPIC). EPIC is a multicentre prospective study that enrolled over 500,000 participants aged 25-70 years from ten European countries in 1992-2000. Information on coffee and tea drinking was collected at baseline using validated country-specific dietary questionnaires. We used adjusted Cox proportional hazards regression models to calculate hazard ratios (HR) and 95% confidence intervals (95% CI) for the associations between coffee and tea consumption and melanoma risk. Overall, 2,712 melanoma cases were identified during a median follow-up of 14.9 years among 476,160 study participants. Consumption of caffeinated coffee was inversely associated with melanoma risk among men (HR for highest quartile of consumption vs. non-consumers 0.31, 95% CI 0.14-0.69) but not among women (HR 0.96, 95% CI 0.62-1.47). There were no statistically significant associations between consumption of decaffeinated coffee or tea and the risk of melanoma among both men and women. The consumption of caffeinated coffee was inversely associated with melanoma risk among men in this large cohort study. Further investigations are warranted to confirm our findings and clarify the possible role of caffeine and other coffee compounds in reducing the risk of melanoma.

Role of caffeine as an inhibitor in aggregation of hydrophobic molecules: A molecular dynamics simulation study

Hydrophobic effect is one of the major driving forces in biomolecular interactions. Biological molecules such as proteins and nucleic acids contain numerous hydrophobic components, and their interactions play critical roles in protein folding-unfolding and protein aggregation. In our study, we have carried out molecular dynamics simulation to understand the effect of caffeine on hydrophobic aggregation of di-t-butyl-methane (DTBM) molecules. For this we consider aqueous solutions of a regime of caffeine:DTBM stoichiometric ratios. From the calculations of site-site radial distribution functions followed by the coordination number analyses and spatial distribution plots we have observed the disruption of hydrophobic moieties of DTBM aggregates in 10:1 or more stoichiometric ratio of caffeine:DTBM systems. Calculations of binding affinities, preferential interaction parameters, and effect of caffeine cluster's size on aggregation show that though the binding affinity of DTBM with itself is more when compared to that of caffeine-DTBM, with increasing caffeine number the former decreases. On the other hand, in the presence of higher number of caffeine molecules the formation of caffeine clusters takes place and these caffeine clusters form a hydrophobic environment in which DTBM molecule is encapsulated. The presence of a significant number of water molecules in this confinement also ensures the hydration of DTBM. Moreover, these caffeine clusters also act as barriers and physically block the DTBM molecules to interact with the like molecules leading to a disruption of DTBM aggregates in caffeine solution.

Caffeine Induces a Stimulant Effect and Increases Dopamine Release in the Nucleus Accumbens Shell Through the Pulmonary Inhalation Route of Administration in Rats.

Oral, intraperitoneal, or intravenous have been the common routes of administration used to study the behavioral and neurochemical pharmacology of caffeine, one of the most widely used psychoactive substances worldwide. We have reported that caffeine is an active adulterant frequently found in coca-paste (CP)-seized samples, a highly addictive form of smokable cocaine. The role of caffeine in the psychostimulant and neurochemical effects induced by CP remains under study. No preclinical animal studies have been performed so far to characterize the effects of caffeine when it is administered through the pulmonary inhalation route. Caffeine (10, 25, and 50mg) was volatilized and rats were exposed to one inhalation session of its vapor. The stimulant effect was automatically recorded and plasmatic levels of caffeine were measured. Caffeine capability (50mg) to increase extracellular dopamine (DA) levels in nucleus accumbens shell was also studied by in vivo microdialysis in non-anesthetized animals. A dose-dependent stimulant effect induced by volatilized caffeine was observed and this effect was directly related with caffeine plasmatic levels. A significant increase in the extracellular DA was achieved after 50mg of volatilized caffeine exposure. This is the first report showing pharmacological acute effects of caffeine through the pulmonary inhalation route of administration and suggests that this could be a condition under which caffeine can elevate its weak reinforcing effect and even enhance the psychostimulant effect and abuse liability of smokable adulterated psychostimulant drugs.

Caffeine toxicity in forensic practice: possible effects and under-appreciated sources.

Caffeine is considered a very safe stimulant and is widely consumed in a variety of forms, from pure caffeine to beverages and foods. Typically, death is only seen when gram quantities of caffeine are consumed, usually in suicide attempts. Even in this scenario, death is rare. However, there are special populations that need to be considered in forensic presentations, who may be at greater risk. These include poor metabolizers, people with liver disease, and people with cardiac conditions, who can die as a result of caffeine intake at levels well below what is ordinarily considered toxic. Also, caffeine intake may be hidden. For example, herbal medicines with substantial caffeine content may not disclose these concentrations on their product label. The role of caffeine in medicolegal deaths is yet to be defined, however, herbal medicines and herbal weight loss supplements may represent an underappreciated source of caffeine in this context.

Caffeine, a common active adulterant of cocaine, enhances the reinforcing effect of cocaine and its motivational value.

Caffeine is one of the psychoactive substances most widely used as an adulterant in illicit drugs, such as cocaine. Animal studies have demonstrated that caffeine is able to potentiate several cocaine actions, although the enhancement of the cocaine reinforcing property by caffeine is less reported, and the results depend on the paradigms and experimental protocols used. We examined the ability of caffeine to enhance the motivational and rewarding properties of cocaine using an intravenous self-administration paradigm in rats. Additionally, the role of caffeine as a primer cue during extinction was evaluated. In naïve rats, we assessed (1) the ability of the cocaine (0.250-0.125mg/kg/infusion) and caffeine (0.125-0.0625mg/kg/infusion) combination to maintain self-administration in fixed ratio (FR) and progressive ratio (PR) schedules of reinforcement compared with cocaine or caffeine alone and (2) the effect of caffeine (0.0625mg/kg/infusion) in the maintenance of responding in the animals exposed to the combination of the drugs during cocaine extinction. Cocaine combined with caffeine and cocaine alone was self-administered on FR and PR schedules of reinforcement. Interestingly, the breaking point determined for the cocaine + caffeine group was significantly higher than the cocaine group. Moreover, caffeine, that by itself did not maintain self-administration behavior in naïve rats, maintained drug-seeking behavior of rats previously exposed to combinations of cocaine + caffeine. Caffeine enhances the reinforcing effects of cocaine and its motivational value. Our results highlight the role of active adulterants commonly used in cocaine-based illicit street drugs.

Caffeine fostering of mycoparasitic fungi against phytopathogens

Caffeine (1,3,7-trimethixanthine) is a typical purine alkaloid produced in more than 80 plant species. Its biological role is considered to strengthen plant's defense capabilities, directly as a toxicant to biotic attackers (allelopathy) and indirectly as an activator of defense system (priming). Caffeine is actively secreted into rhizosphere through primary root, and possibly affects the structure of microbe community nearby. The fungal community in coffee plant rhizosphere is enriched with particular species, including Trichoderma family, a mycoparasite that attacks and kills phytopathogens by coiling and destroying their hyphae. In the present study, the caffeine response of 8 filamentous fungi, 4 mycoparasitic Trichoderma, and 4 prey phytopathogens, was examined. Results showed that allelopathic effect of caffeine on fungal growth and development was differential, being stronger on pathogens than on Trichoderma species. Upon confronting, the prey immediately ceased the growth, whereas the predator continued to grow, indicating active mycoparasitism to have occurred. Caffeine enhanced mycoparasitism up to 1.7-fold. Caffeine thus functions in a double-track manner against fungal pathogens: first by direct suppression of growth and development, and second by assisting their natural enemy. These observations suggest that caffeine is a powerful weapon in the arms race between plants and pathogens by fostering enemy's enemy, and we propose the idea of "caffeine fostering" as the third role of caffeine.

The role of caffeine as an inhibitor in the aggregation of amyloid forming peptides: a unified molecular dynamics simulation and experimental study

10 : 1 or more caffeine to SwP ratio can prevent the formation of β-sheet conformation.