Effects of caffeine on human health

Caffeine intake enhances the benefits of sodium glucose transporter 2 inhibitor

BACKGROUND

The effect of sodium glucose transporter 2 (SGLT-2) inhibitors is dependent on the glomerular filtration rate. It has been reported that caffeine intake increases glomerular filtration rate. However, the effect of caffeine intake on urinary glucose excretion in patients who take SGLT-2 inhibitors is unclear.

METHODS

Six patients with type 2 diabetes took part in a randomized, open-label, crossover pilot study. The patients took SGLT-2 inhibitors (ipragliflozin) for 9 days. On day 3, 6 and 9, the patients were assigned to one of three studies: Water 500, patients drank 500 mL of water in 3 h; Water 1500, patients drank 1500 mL of water in 3 h; and Caffeine 500, patients drank 500 mL of water with 400 mg of caffeine in 3 h. In all of the studies, the patients' urine was collected over a 6-h period. In addition, we enrolled 60 patients with type 2 diabetes who newly took SGLT-2 inhibitors in a 3-month follow-up cohort study to investigate the effect of caffeine intake on glucose control. Caffeine intake was evaluated using questionnaires.

RESULTS

The 6-h median (interquartile range) urinary glucose excretion was 9.5 (8.5-9.7) g in Water 500, 12.2 (10.3-27.2) g in Water 1500 and 15.7 (11.4-21.4) g in Caffeine 500 (p = 0.005 vs Water 500). In the cohort study, multiple regression analysis demonstrated that log (caffeine intake) was associated with a change in HbA_1c (β = -0.299, p = 0.043) after adjusting for covariates.

CONCLUSIONS

Caffeine intake enhanced the effect of SGLT-2 inhibitors. Copyright © 2016 John Wiley & Sons, Ltd.

Dose- and time-related effects of caffeine on the testis in immature male rats

We previously showed that prepubertal chronic caffeine exposure adversely affected the development of the testes in male rats. Here we investigated dose- and time-related effects of caffeine consumption on the testis throughout sexual maturation in prepubertal rats. A total of 80 male SD rats were randomly divided into four groups: controls and rats fed 20, 60, or 120 mg caffeine/kg/day, respectively, via gavage for 10, 20, 30, or 40 days. Preputial separation was monitored daily before the rats were sacrificed. Terminal blood samples were collected for hormone assay, and testes were grossly evaluated and weighed. One testis was processed for histological analysis, and the other was collected to isolate Leydig cells. Caffeine exposure significantly increased the relative weight of the testis in a dose-related manner after 30 days of exposure, whereas the absolute testis weight tended to decrease at the 120 mg dose of caffeine. The mean diameter of the seminiferous tubules and height of the germinal epithelium significantly decreased in the caffeine-fed groups after 40 days of caffeine exposure, which was accompanied by a reduced BrdU incorporation rate in germ cells. In addition, caffeine intake significantly reduced in vivo and ex vivo testosterone production in a dose-related manner. Our results demonstrate that caffeine exposure during sexual maturation alter the testicular microarchitecture and also slow germ cell proliferation even at the 20 mg dose level. Furthermore, caffeine may act directly on Leydig cells and interfere with testosterone production in a dose-related manner, consequently delaying onset of sexual maturation.

Extended exposure to sugar and/or caffeine produces distinct behavioral and neurochemical profiles in the orbitofrontal cortex of rats: Implications for neural function

Caffeine is a psychostimulant commonly consumed with high levels of sugar. The increased availability of highly caffeinated, high sugar energy drinks could put some consumers at risk of being exposed to high doses of caffeine and sugar. Notably, research that has examined the consequences of this combination is limited. Here, we explored the effect of chronic exposure to caffeine and/or sugar on behavior and protein levels in the orbitofrontal cortex (OFC) of rats. The OFC brain region has been implicated in neuropsychiatric conditions, including obesity and addiction behaviors. Adult male Sprague-Dawley rats were treated for 26 days with control, caffeine (0.6 g/L), 10% sugar, or combination of both. Locomotor behavior was measured on the first and last day of treatment, then 1 week after treatment. Two hours following final behavioral testing, brains were rapidly removed and prepared for proteomic analysis of the OFC. Label-free quantitative shotgun analysis revealed that 21, 12, and 23% of proteins identified in the OFC were differentially expressed by sugar and/or caffeine. The results demonstrate that the intake of high levels of sugar and/or low to moderate levels of caffeine has different behavioral consequences. Moreover, each treatment results in a unique proteomic profile with different implications for neural health.

Implication of caffeine consumption and recovery on the reproductive functions of adult male Wistar rats

BACKGROUND

This study assessed the impact of caffeine consumption and recovery on reproductive functions and fertility of Wistar rats.

METHODS

Thirty-five adult male Wistar rats were divided into seven groups of five rats each. Group A (control) received distilled water (vehicle), while groups B, C, and D were treated orally with 10 mg/kg body weight (BW), 20 mg/kg BW, and 40 mg/kg BW caffeine, respectively, for 30 days. Groups E, F, and G were treated orally with 10 mg/kg BW, 20 mg/kg BW, and 40 mg/kg BW caffeine, respectively, for 30 days and then allowed to recover for another 30 days.

RESULTS

Caffeine caused a decrease in body weight, while recovery groups showed appreciable increase in body weight during recovery. Relative weight of seminal vesicle, prostate, and epididymis decreased dose dependently during treatment but increased during recovery. The liver and kidney weight increased during treatment but reduced during recovery. Sperm count was significantly decreased in both treated and recovery groups. Initial decrease in sperm viability and volume was appreciably reversed during recovery period. Serum level of testosterone increased at high doses, while serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) showed significant decrease. Histological sections of testis in treated groups showed mild congestion of the interstitial blood vessel and subcapsular congestion. However, there was no subcapsular congestion in the recovery groups. All rats in both treated and recovery groups had 100% fertilization success from fertility study.

CONCLUSIONS

Suggestively, caffeine treatment for 4 weeks could impair body, reproductive organs weight, sperm characteristics, LH/FSH level, and also testicular cyto-architecture. Effects appeared, however, reversible after caffeine withdrawal.

Structure-Bioactivity Relationships of Methylxanthines: Trying to Make Sense of All the Promises and the Drawbacks

Methylxanthines are a group of phytochemicals derived from the purine base xanthine and obtained from plant secondary metabolism. They are unobtrusively included in daily diet in common products as coffee, tea, energetic drinks, or chocolate. Caffeine is by far the most studied methylxanthine either in animal or epidemiologic studies. Theophylline and theobromine are other relevant methylxanthines also commonly available in the aforementioned sources. There are many disseminated myths about methylxanthines but there is increased scientific knowledge to discuss all the controversy and promise shown by these intriguing phytochemicals. In fact, many beneficial physiologic outcomes have been suggested for methylxanthines in areas as important and diverse as neurodegenerative and respiratory diseases, diabetes or cancer. However, there have always been toxicity concerns with methylxanthine (over)consumption and pharmacologic applications. Herein, we explore the structure-bioactivity relationships to bring light those enumerated effects. The potential shown by methylxanthines in such a wide range of conditions should substantiate many other scientific endeavors that may highlight their adequacy as adjuvant therapy agents and may contribute to the advent of functional foods. Newly designed targeted molecules based on methylxanthine structure may originate more specific and effective outcomes.

Effects of Caffeine on Exercise Responses and Performance in Children and Youth

Extensive research has been performed investigating the effects of caffeine during exercise in adults with many reviews published in just the past 10 years. Limited research has been conducted in children despite the fact that they are one of the fastest growing consumers of caffeine. In light of the limited research, in writing this review no inclusion or exclusion criteria were used, as the aim of the review is to provide as wide a research base as possible. This review will present the data that has systematically investigated the acute effects of caffeine in children and youth during exercise.

The Safety, Pharmacokinetics, and Nervous System Effects of Two Natural Sources of Caffeine in Healthy Adult Males

This double‐blind crossover clinical trial randomized 12 adult males to receive 200 mg of caffeine from a green coffee extract, a guayusa leaf extract, and a synthetic control to compare their safety, absorption, and effect on neurotransmitters. The results showed no statistically significant changes in blood pressure or heart rate from baseline to 120 min postdose of each natural source compared with changes from baseline in the control (0.094 < = P < = 0.910). The ratios of C_max, AUC_0‐4, and AUC_0‐∞ of each natural source to the control were bioequivalent by US Food and Drug Administration standards (90% CI within 80–125%). The guayusa leaf extract stimulated a significantly lower increase in epinephrine compared with the control (+0.5 vs. +2.78 μg/gCr, P = 0.04), while the green coffee extract provoked an increase in epinephrine similar to the control (+3.21 vs. +2.78 μg/gCr, P = 0.569). Implications for future clinical research are discussed.

Beneficial Role of Coffee and Caffeine in Neurodegenerative Diseases: A Minireview

Coffee is among the most widespread and healthiest beverages in the world. Coffee typically contains more caffeine than most other beverages, and is widely and frequently consumed. Thus, it contributes significantly to the overall caffeine consumption within the general population, particularly in adults. Controversies regarding its benefits and risks still exist as reliable evidence is becoming available supporting its health-promoting potential. Several lines of evidence have highlighted the beneficial effects towards several disease conditions including Type II diabetes, hepatitis C virus, hepatocellular carcinoma, nonalcoholic fatty liver disease and neurodegenerative disorders such as Alzheimer's disease (AD), Parkinson's disease (PD) and Amyotrophic Lateral Sclerosis (ALS). The health-promoting properties of coffee are largely attributed to its rich phytochemistry, including caffeine, chlorogenic acid, caffeic acid, and hydroxy hydroquinone. In this minireview, an attempt has been made to discuss the various evidences which are mainly derived from animal and cell models. Various mechanisms chiefly responsible for the beneficial effects of caffeine have also been briefly outlined. A short note on the undesirable effects of excessive coffee intakes is also presented.

Review of the Evidence that Transcranial Electromagnetic Treatment will be a Safe and Effective Therapeutic Against Alzheimer's Disease

We have demonstrated in multiple studies that daily, long-term electromagnetic field (EMF) treatment in the ultra-high frequency range not only protects Alzheimer's disease (AD) transgenic mice from cognitive impairment, but also reverses such impairment in aged AD mice. Moreover, these beneficial cognitive effects appear to be through direct actions on the AD process. Based on a large array of pre-clinical data, we have initiated a pilot clinical trial to determine the safety and efficacy of EMF treatment to mild-moderate AD subjects. Since it is important to establish the safety of this new neuromodulatory approach, the main purpose of this review is to provide a comprehensive assessment of evidence supporting the safety of EMFs, particularly through transcranial electromagnetic treatment (TEMT). In addition to our own pre-clinical studies, a rich variety of both animal and cell culture studies performed by others have underscored the anticipated safety of TEMT in clinical AD trials. Moreover, numerous clinical studies have determined that short- or long-term human exposure to EMFs similar to those to be provided clinically by TEMT do not have deleterious effects on general health, cognitive function, or a variety of physiologic measures-to the contrary, beneficial effects on brain function/activity have been reported. Importantly, such EMF exposure has not been shown to increase the risk of any type of cancer in human epidemiologic studies, as well as animal and cell culture studies. In view of all the above, clinical trials of safety/efficacy with TEMT to AD subjects are clearly warranted and now in progress.

Adherence to the Mediterranean Diet and Lifestyle Characteristics of University Students in Cyprus: A Cross-Sectional Survey

Objective. To assess dietary-related habits among young adults. Design and Setting. Dietary habits were assessed cross-sectionally, using a self-completed questionnaire in 193 students enrolled in public and private universities in Cyprus. Adherence to the Mediterranean diet was evaluated using the validated KIDMED index. BMI was estimated based on weight and height measurements. Results. The mean BMI was 23.31 (±3.98). The mean adherence score to the Mediterranean diet was 6.0 (IQR 4 to 8), with 26.9% of students being classified as high adherers and 21.8% as low adherers to the Mediterranean diet. About 32% of students consumed a second serving of fruit and vegetables more than once a day, whereas 26% reported going more than once a week to a fast-food restaurant and 31% consumed sweets and candy several times a day. On the other hand, 76% of participants reported consumption of at least two dairy products daily and 88% use olive oil at home. The majority consume coffee 2-3 times per day. Conclusions. Results support a shift from traditional healthy diets to more unhealthy eating patterns. However, we also report a high dairy intake and use of olive oil. Tailored-made strategies targeting the young adult population could be warranted.

A Review of Natural Stimulant and Non-stimulant Thermogenic Agents

Obesity and overweight are major health issues. Exercise and calorie intake control are recognized as the primary mechanisms for addressing excess body weight. Naturally occurring thermogenic plant constituents offer adjunct means for assisting in weight management. The controlling mechanisms for thermogenesis offer many intervention points. Thermogenic agents can act through stimulation of the central nervous system with associated adverse cardiovascular effects and through metabolic mechanisms that are non-stimulatory or a combination thereof. Examples of stimulatory thermogenic agents that will be discussed include ephedrine and caffeine. Examples of non-stimulatory thermogenic agents include p-synephrine (bitter orange extract), capsaicin, forskolin (Coleus root extract), and chlorogenic acid (green coffee bean extract). Green tea is an example of a thermogenic with the potential to produce mild but clinically insignificant undesirable stimulatory effects. The use of the aforementioned thermogenic agents in combination with other extracts such as those derived from Salacia reticulata, Sesamum indicum, Lagerstroemia speciosa, Cissus quadrangularis, and Moringa olifera, as well as the use of the carotenoids as lutein and fucoxanthin, and flavonoids as naringin and hesperidin can further facilitate energy metabolism and weight management as well as sports performance without adverse side effects. © 2016 The Authors Phytotherapy Research published by John Wiley & Sons Ltd.

Readability and content analysis of lifestyle education resources for weight management in Australian general practice

BACKGROUND

Weight management education is one of the key strategies to assist patients to manage their weight. Educational resources provide an important adjunct in the chain of communication between practitioners and patients. However, one in five Australian adults has low health literacy. The purpose of this study was to assess the readability and analyse the content of weight management resources.

METHODS

This study is based on the analysis of 23 resources found in the waiting rooms of ten Sydney-based general practices and downloaded from two clinical software packages used at these practices. The reading grade level of these resources was calculated using the Flesch Reading Ease, Flesch-Kincaid Grade Level, Fry Readability Graph, and the Simplified Measure of Gobbledygook. Resources' content was analysed for the presence of dietary, physical activity, and behaviour change elements, as recommended by the Clinical practice guidelines for the management of overweight and obesity in adults, adolescents, and children in Australia.

RESULTS

The resources' average reading grade level was for a 10(th) grader (9.5 ± 1.8). These findings highlight that the average reading grade level was two grades higher than the recommended reading grade level for health education resources of 8th grade level or below. Seventy percent of resources contained dietary and behaviour change elements. Physical activity was included in half of the resources. Two messages were identified to be inconsistent with the guidelines and three messages had no scientific basis.

CONCLUSION

A body of evidence now exists that supports the need to develop evidence-based education resources for weight management that place low demand on literacy, without compromising content accuracy. The findings from this study suggest that there is significant room for improvement in the educational resources provided in general practices.

Effects of Trigonelline, an Alkaloid Present in Coffee, on Diabetes-Induced Disorders in the Rat Skeletal System

Diabetes increases bone fracture risk. Trigonelline, an alkaloid with potential antidiabetic activity, is present in considerable amounts in coffee. The aim of the study was to investigate the effects of trigonelline on experimental diabetes-induced disorders in the rat skeletal system. Effects of trigonelline (50 mg/kg p.o. daily for four weeks) were investigated in three-month-old female Wistar rats, which, two weeks before the start of trigonelline administration, received streptozotocin (60 mg/kg i.p.) or streptozotocin after nicotinamide (230 mg/kg i.p.). Serum bone turnover markers, bone mineralization, and mechanical properties were studied. Streptozotocin induced diabetes, with significant worsening of bone mineralization and bone mechanical properties. Streptozotocin after nicotinamide induced slight glycemia increases in first days of experiment only, however worsening of cancellous bone mechanical properties and decreased vertebral bone mineral density (BMD) were demonstrated. Trigonelline decreased bone mineralization and tended to worsen bone mechanical properties in streptozotocin-induced diabetic rats. In nicotinamide/streptozotocin-treated rats, trigonelline significantly increased BMD and tended to improve cancellous bone strength. Trigonelline differentially affected the skeletal system of rats with streptozotocin-induced metabolic disorders, intensifying the osteoporotic changes in streptozotocin-treated rats and favorably affecting bones in the non-hyperglycemic (nicotinamide/streptozotocin-treated) rats. The results indicate that, in certain conditions, trigonelline may damage bone.

Impact of an Energy Drink on the Structure of Stomach and Pancreas of Albino Rat: Can Omega-3 Provide a Protection?

BACKGROUND AND OBJECTIVES

A controversy developed between the benefits of energy drinks (EDs) versus the possible health threats since its revolution. Lack of information was a call to assess the effect of chronic consumption of Power Horse (PH) as one of the EDs, on the structure of pancreas and fundic mucosa of stomach in rats, and possible protective role of Omega-3.

MATERIALS AND METHODS

Thirty two adult male albino rats were divided equally into 4 groups; control received group which only received a standard diet, Omega-3 group, PH group which given PH and PH plus Omega-3 group received both PH plus Omega-3 for 4 weeks. Biochemical assessment of blood glucose, serum insulin, gastrin, tumor necrosis factor alpha (TNF-α) and inducible nitric oxide synthetase (iNOS) was performed. The antioxidant activity and histopathological examination of both pancreatic tissue and fundic mucosa of stomach were assessed.

RESULTS

Administration of PH significantly increased serum insulin and glucose levels while it significantly reduced serum gastrin level compared to control. PH also caused oxidants/antioxidants imbalance in both pancreas and fundic mucosa. The latter revealed degenerative changes and increased apoptosis which was evident by increased caspase-3 immunoexpression. Pancreas exhibited signs of β-cells overstimulation. Fundic mucosa showed reduced number of parietal cells, gastrin hormone expression compared to control group. Omega-3 administration could alleviate, to some extent, these changes. It significantly decreased TNF-α, iNOS and reduced glutathione (GSH) as well as significantly increasing superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities compared to the group which received PH alone.

CONCLUSION

Power Horse intake significantly injures islet cells, pancreatic acini as well as the glandular cells of the fundic mucosa. Omega-3 decreases these detrimental effects mostly through its antioxidant and anti-inflammatory action.

Breakfast and Energy Drink Consumption in Secondary School Children: Breakfast Omission, in Isolation or in Combination with Frequent Energy Drink Use, is Associated with Stress, Anxiety, and Depression Cross-Sectionally, but not at 6-Month Follow-Up

A considerable amount of research suggests that breakfast omission and the frequent use of caffeinated energy drinks may be associated with undesirable effects, and particularly so in children and adolescents. The current paper presents cross-sectional and longitudinal data from the Cornish Academies Project to investigate the effects of consuming energy drinks and missing breakfast on stress, anxiety, and depression in a cohort of secondary school children from the South West of England. Questionnaires were administered at two time-points (spaced 6 months apart) to collect information relating to diet and lifestyle over the previous 6 months. Demographic and school data were acquired through the School Information Management System, and single-item measures of stress, anxiety, and depression were administered at the second time-point only. Associations between breakfast and energy drink consumption and stress, anxiety, and depression were investigated, and a multivariate approach was taken so that additional variance from diet, demography, and lifestyle could be controlled for statistically. Cross-sectional analyses showed that breakfast omission was consistently associated with negative outcomes, and that this was largely observed for both those who frequently consumed energy drinks and those who did not. However, cross-lag analyses showed that neither breakfast omission or energy drink consumption, alone or in combination, was predictive of stress, anxiety, or depression at 6-month follow-up. This suggests that associations between breakfast and mental health may be bi-directional rather than breakfast being the causal factor.

General and Genetic Toxicology of Guayusa Concentrate (Ilex guayusa)

Tea from the leaves of guayusa (Ilex guayusa) has a long history of consumption by Ecuadorian natives in regions where the plant is indigenous. The tea contains the methylxanthines caffeine and theobromine as well as chlorogenic acids, flavonoids, and sugars. Various studies were performed to evaluate the general and genetic toxicology of a standardized liquid concentrate of guayusa (GC). Guayusa concentrate was found to be negative in in vitro genotoxicity tests including the Ames test and a chromosome aberration study in human lymphocytes. The oral median lethal dose (LD50) of GC was >5,000 mg/kg for female rats. Guayusa concentrate was administered to male and female rats in a 90-day subchronic study at 1,200, 2,500, and 5,000 mg/kg/d of GC and a caffeine-positive control at 150 mg/kg/d corresponding to the amount of caffeine in the high-dose GC group. Effects observed in the GC-treated groups were comparable to those in the caffeine control group and included reductions in body weights, food efficiency, triglycerides values, and fat pad weights and increases in blood chemistry values for serum aspartate aminotransferase, serum alanine aminotransferase, and cholesterol and adaptive salivary gland hypertrophy. No signs of incremental toxicity due to any other components of guayusa were observed. The studies indicate no harmful effects of GC in these test systems.

Caffeine: cognitive and physical performance enhancer or psychoactive drug?

Caffeine use is increasing worldwide. The underlying motivations are mainly concentration and memory enhancement and physical performance improvement. Coffee and caffeine-containing products affect the cardiovascular system, with their positive inotropic and chronotropic effects, and the central nervous system, with their locomotor activity stimulation and anxiogenic-like effects. Thus, it is of interest to examine whether these effects could be detrimental for health. Furthermore, caffeine abuse and dependence are becoming more and more common and can lead to caffeine intoxication, which puts individuals at risk for premature and unnatural death. The present review summarizes the main findings concerning caffeine’s mechanisms of action (focusing on adenosine antagonism, intracellular calcium mobilization, and phosphodiesterases inhibition), use, abuse, dependence, intoxication, and lethal effects. It also suggests that the concepts of toxic and lethal doses are relative, since doses below the toxic and/or lethal range may play a causal role in intoxication or death. This could be due to caffeine’s interaction with other substances or to the individuals' preexisting metabolism alterations or diseases.

Caffeine: Friend or Foe?

The debate on the safety of and regulatory approaches for caffeine continues among various stakeholders and regulatory authorities. This decision-making process comes with significant challenges, particularly when considering the complexities of the available scientific data, making the formulation of clear science-based regulatory guidance more difficult. To allow for discussions of a number of key issues, the North American Branch of the International Life Sciences Institute (ILSI) convened a panel of subject matter experts for a caffeine-focused session entitled "Caffeine: Friend or Foe?," which was held during the 2015 ILSI Annual Meeting. The panelists' expertise covered topics ranging from the natural occurrence of caffeine in plants and interindividual metabolism of caffeine in humans to specific behavioral, reproductive, and cardiovascular effects related to caffeine consumption. Each presentation highlighted the potential risks, benefits, and challenges that inform whether caffeine exposure warrants concern. This paper aims to summarize the key topics discussed during the session.

Approaches to the Development of Human Health Toxicity Values for Active Pharmaceutical Ingredients in the Environment

Management of active pharmaceutical ingredients (API) in the environment is challenging because these substances represent a large and diverse group of compounds. Advanced wastewater treatment technologies that can remove API tend to be costly. Because of the potential resources required to address API in the environment, there is a need to establish environmental benchmarks that can serve as targets for treatment and release. To date, there are several different approaches that have been taken to derive human health toxicity values for API. These methods include traditional risk assessment approaches that calculate "safe" doses using experimental data and uncertainty (safety) factors; point of departure (POD), which starts from a therapeutic human dose and applies uncertainty factors; and threshold of toxicological concern (TTC), a generic approach that establishes threshold values across broad classes of chemicals based on chemical structure. To evaluate the use of these approaches, each of these methods was applied to three API commonly encountered in the environment: acetaminophen, caffeine, and chlorpromazine. The results indicate that the various methods of estimating toxicity values produce highly varying doses. Associated doses are well below typical intakes, or toxicity thresholds cannot be derived due to a lack of information. No uniform approach can be applied to establishing thresholds for multiple substances. Rather, an individualized approach will need to be applied to each target API.

Caffeine consumption and self-assessed stress, anxiety, and depression in secondary school children

Previous research suggests that effects of caffeine on behaviour are positive unless one is investigating sensitive groups or ingestion of large amounts. Children are a potentially sensitive subgroup, and especially so considering the high levels of caffeine currently found in energy drinks. The present study used data from the Cornish Academies Project to investigate associations between caffeine (both its total consumption, and that derived separately from energy drinks, cola, tea, and coffee) and single-item measures of stress, anxiety, and depression, in a large cohort of secondary school children from the South West of England. After adjusting for additional dietary, demographic, and lifestyle covariates, positive associations between total weekly caffeine intake and anxiety and depression remained significant, and the effects differed between males and females. Initially, effects were also observed in relation to caffeine consumed specifically from coffee. However, coffee was found to be the major contributor to high overall caffeine intake, providing explanation as to why effects relating to this source were also apparent. Findings from the current study increase our knowledge regarding associations between caffeine intake and stress, anxiety, and depression in secondary school children, though the cross-sectional nature of the research made it impossible to infer causality.

Cognitive Performance and Mood Following Ingestion of a Theacrine-Containing Dietary Supplement, Caffeine, or Placebo by Young Men and Women

Theacrine is a purine alkaloid found primarily in the leaves of the Camellia Kucha plant and is now included within dietary supplements. To compare the effects of a theacrine-containing dietary supplement with caffeine and placebo on energy and mood, as well as objective measures of cognitive performance, heart rate, and blood pressure, 10 healthy men (20.8 ± 0.7 years) and 10 healthy women (22.2 ± 1.1 years) ingested the dietary supplement TheaTrim (Purus Labs; containing a branded form of theacrine (Teacrine™) and caffeine (150 mg)), caffeine only (150 mg), or a placebo on three different days, separated by approximately one week. Before, and for up to 4 h following, ingestion of the assigned condition, subjects completed a subjective assessment of energy and mood, as well as tests of cognitive performance (trail making test (TMT), digit symbol substitution test (DSST)), and reaction time. Heart rate and blood pressure were measured. No condition or interaction effects were noted for TMT, DSST, or reaction time, despite a trend for improvement in selected variables with both TheaTrim and caffeine treatment. Condition effects or trends were noted for subjective feelings, with values for attentive, alert, focused, and energetic higher for TheaTrim than for placebo and caffeine, while values for lethargic and groggy were lower for TheaTrim than for placebo and caffeine. Heart rate and blood pressure were largely unaffected by treatment. These data indicate that TheaTrim treatment does not result in a statistically significant improvement in cognitive performance but may favorably impact multiple subjective feelings related to energy and mood.

Effects of Yerba Mate (IIex paraguariensis) on Histomorphometry, Biomechanics, and Densitometry on Bones in the Rat

Yerba mate (Ilex paraguariensis) is a xanthine-containing beverage, which is also rich in caffeine. Because caffeine has a negative impact on bone mineral density (BMD) mainly associated with low calcium (Ca) diets, there would be expected a negative effect of yerba mate on bone. In this study, Sprague-Dawley rats were used and randomly assigned into four groups (n = 6/group): Control + Ca 0.2 g %; Control + Ca 0.9 g %; Yerba + Ca 0.2 g %; Yerba + Ca 0.9 g %. At the end of the experiment, tibias and femurs were obtained for BMD, morphometric, histomorphometric, and biomechanical analyses. While there was no difference in bone parameters between rats with and without yerba mate consumption, a negative effect of low Ca diet was observed in BMD, morphometric, histomorphometric, and biomechanical results. Interaction between Ca content in the diet and yerba mate was only found in trabecular bone volume, which would indicate that the negative effect of low Ca intake on bone volume is reversed in part by yerba mate infusion. However, yerba mate was not able to reverse the negative effect of low Ca content on biomechanical properties and trabecular connectivity. In summary, at least in our study, yerba mate would not have a negative effect on bone and would be safe for the bone health of consumers.

Public Concern about the Sale of High-Caffeine Drinks to Children 12 Years or Younger: An Australian Regulatory Perspective

Background. Dietary exposure to high caffeine is a health risk for children. Governments are considering measures to restrict the sale of formulated caffeinated beverages (FCB) to children. Objectives. To investigate community concern about sales of high-caffeine drinks to children among Western Australian adults and describe Australian and New Zealand regulatory processes regarding FCB. Methods. Data from the 2009 and 2012 Department of Health's Nutrition Monitoring Survey Series of 2,832 Western Australians aged 18–64 years was pooled with descriptive and ordinal logistic regression analysis performed. Current regulatory processes for FCB are reported. Results. Most (85%) participants were concerned about the sale of high-caffeine drinks to children; 77.4% were very concerned in 2012 compared to 66.5% in 2009, p < .008. Females and those living with children had higher concern (odds ratio (OR) 2.11; 95% confidence interval (CI) 1.44–3.10; OR 2.16; 95% CI 1.51–3.09, resp., p < .001). Concern increased with each year of age (OR 1.04; 95% CI 1.02, 1.05, p < .001). Conclusions. Community concern regarding sale of high-caffeine energy drinks to children is high and increasing. Being female and living with children were associated with greater concern. These findings support the Australian and New Zealand regulatory controls of FCB, including labelling, promotion, and advertising to children.

The impact of neuroscience on society: cognitive enhancement in neuropsychiatric disorders and in healthy people

In addition to causing distress and disability to the individual, neuropsychiatric disorders are also extremely expensive to society and governments. These disorders are both common and debilitating and impact on cognition, functionality and wellbeing. Cognitive enhancing drugs, such as cholinesterase inhibitors and methylphenidate, are used to treat cognitive dysfunction in Alzheimer's disease and attention deficit hyperactivity disorder, respectively. Other cognitive enhancers include specific computerized cognitive training and devices. An example of a novel form of cognitive enhancement using the technological advancement of a game on an iPad that also acts to increase motivation is presented. Cognitive enhancing drugs, such as methylphenidate and modafinil, which were developed as treatments, are increasingly being used by healthy people. Modafinil not only affects 'cold' cognition, but also improves 'hot' cognition, such as emotion recognition and task-related motivation. The lifestyle use of 'smart drugs' raises both safety concerns as well as ethical issues, including coercion and increasing disparity in society. As a society, we need to consider which forms of cognitive enhancement (e.g. pharmacological, exercise, lifelong learning) are acceptable and for which groups (e.g. military, doctors) under what conditions (e.g. war, shift work) and by what methods we would wish to improve and flourish.

Urine testing for antipsychotics: a pilot trial for a method to determine detection levels

OBJECTIVE

The goal of the present study was to demonstrate that the analytical assay of interest can detect antipsychotics in human urine specimens.

METHOD

Forty inpatients treated with haloperidol, quetiapine, risperidone, or olanzapine were recruited to participate in a one visit study. During the study visit, demographic and clinical information was collected as well as one urine sample that was forwarded to the Ameritox Laboratory and assayed for the presence of antipsychotic medications and/or metabolites. Urine samples were analyzed to determine detection sensitivity for four antipsychotic medications and their metabolites (risperidone, quetiapine, olanzapine, and/or haloperidol) using Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry.

RESULTS

All urine samples produced positive results for the antipsychotic(s) the participants were known to be taking. Urine concentrations (level of quantification) for parent drugs ranged from <25-417 ng/mL for haloperidol, <25-4017 ng/mL for quetiapine, 0-997 ng/mL for risperidone, and 57-700 ng/mL for olanzapine.

CONCLUSION

The analytical assay produced by Ameritox, Ltd using Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry can qualitatively detect antipsychotics in human urine specimens. The present study highlights the potential utility of the urine assay to help monitor adherence to antipsychotic medications.

The role of coffee consumption on the 10-year (2004-2014) Acute Coronary Syndrome (ACS) incidence among cardiac patients: the GREECS observational study

The association between long-term coffee consumption and 10-year cardiovascular disease incidence among Acute Coronary Syndrome (ACS) patients was evaluated. From 2003 to 2004, 2172 ACS consecutive patients from six major Greek hospitals were enrolled. During 2013-2014, the 10-year follow-up was performed (88% participation rate) and recurrent fatal or non-fatal ACS was recorded. Baseline coffee consumption (cups/day) was assessed using a semi-quantitative Food Frequency Questionnaire. Multi adjusted analysis revealed that 1-2 cups of coffee/day versus no consumption had an adverse effect on the ACS incidence [odds ratio (OR) = 1.35, 95% confidence interval (CI) 1.01, 1.79]. In subgroup analysis, with hypertension as strata, only the normotensive reached significance. Odds ratios for 1-2 and ≥3 cups relative to no consumption were [OR = 1.66, 95% CI 1.07, 2.60] and [OR = 1.86, 95% CI 1.06, 3.27], respectively, after controlling for potential confounders. Thus, avoidance of coffee may be of high importance to ameliorate disease prognosis among cardiac patients.

No Enhancement of 24-Hour Visuomotor Skill Retention by Post-Practice Caffeine Administration

Caffeine is widely consumed throughout the world and appears to indirectly facilitate learning and memory through effects on attention and motivation. Animal work indicates that post-training caffeine administration augments inhibitory avoidance memory, spatial memory, and object memory. In humans, post-training caffeine administration enhances the ability to discern between familiar images and new, similar images. However, the effect of post-training caffeine administration on motor memory has not been examined. Therefore, we tested two groups of low caffeine consumers (average weekly consumption ≤500 mg) in a double-blind, placebo-controlled study involving acquisition of a continuous isometric visuomotor tracking skill. On Day 1, subjects completed 5 blocks (150 repetitions) of training on the continuous isometric visuomotor skill and subsequently ingested either 200 mg of caffeine or placebo. On day 2, subjects completed an additional 5 blocks of training. Day 1 mean performance and performance variability were both similar between groups, suggesting that both groups acquired the motor skill similarly. For mean performance on Day 2, patterns of re-learning, mean performance learning magnitudes, mean performance learning rates, and mean performance retention magnitudes were all similar between groups. For performance variability on Day 2, there was a small trend towards increased variability in the caffeine group during re-learning, but performance variability learning magnitudes and performance variability retention magnitudes did not differ between groups. Because motor skill acquisition can also be conceptualized as a reduction in performance variability, these results suggest that there may be a small negative effect of post-practice caffeine administration on memory of a newly-learned visuomotor skill. Overall, we found no evidence to suggest that post-training caffeine administration enhances 24-hour retention of a newly-learned continuous visuomotor skill, and these results support the notion that memory-enhancing effects of post-training caffeine ingestion may be task-specific.

Trends in intake and sources of caffeine in the diets of US adults: 2001-2010

BACKGROUND

Coffee and tea are traditional sources of caffeine in the diet, but other sources, such as energy drinks, are now available. Because risks and benefits of caffeine use are dose dependent, the public health consequences of caffeine consumption cannot be determined without data on amounts currently consumed by the US population.

OBJECTIVE

The objective was to obtain an up-to-date, nationally representative estimate of caffeine consumption in adults.

DESIGN

Dietary intake data from NHANES from 2001 to 2010 for adults ≥19 y of age were used (n = 24,808). Acute and usual intake of caffeine was estimated from all caffeine-containing foods and beverages. Trends in consumption and changes in sources of caffeine were also examined.

RESULTS

Eighty-nine percent of the adult US population consumed caffeine, with equal prevalence in men and women. Usual mean ± SE per capita caffeine consumption when nonusers were included was 186 ± 4 mg/d, with men consuming more than women (211 ± 5 vs. 161 ± 3 mg/d, P < 0.05). Usual intake in consumers was 211 ± 3 mg/d, with 240 ± 4 mg/d in men and 183 ± 3 mg/d in women (P < 0.05); 46% was consumed in a single consumption event. In consumers, acute 90th and 99th percentiles of intake were 436 and 1066 mg/d, respectively. Consumption was highest in men aged 31-50 y and lowest in women aged 19-30 y. Beverages provided 98% of caffeine consumed, with coffee (∼64%), tea (∼16%), and soft drinks (∼18%) predominant sources; energy drinks provided <1%, but their consumption increased substantially from 2001 to 2010.

CONCLUSIONS

Although new caffeine-containing products were introduced into the US food supply, total per capita intake was stable over the period examined.

Effects of energy drinks on blood pressure, heart rate, and electrocardiographic parameters: An experimental study on healthy young adults

Objective:

To evaluate the effects of the consumption of energy drinks on cardiovascular parameters in a group of healthy young individuals.

Methods:

In a quasi-experimental study, 44 healthy adult participants aged between 15 and 30 years were evaluated. The blood pressure (BP) as well as electrocardiographic indices, including heart rate (HR), PR interval, QRS duration, corrected QT (QTc) interval, and ST-T changes were recorded before consumption of a caffeine-containing energy drink and at the specific time points over a 4-h test duration.

Results:

We found statistically significant HR decline (p=0.004) and more frequent ST-T changes (p=0.004) after the participants consumed the energy drink. However, readings for systolic BP (p=0.44), diastolic BP (p=0.26), PR interval (p=0.449), QRS duration (p=0.235), and QTc interval (p=0.953) showed no significant change post-consumption.

Conclusion:

In conclusion, we demonstrated that the consumption of energy drinks could contribute to HR decline and ST-T change in healthy young adults.