Effects of caffeine on human health

Caffeine and neuropsychiatric symptoms in patients with dementia: A systematic review

BACKGROUND

The consumption of caffeine has well known effects on the behavior and sleep of healthy adults. Behavioral symptoms and sleeping difficulties are common in patients with dementia which may be affected by caffeine consumption. This systematic review examines the association between caffeine intake and neuropsychiatric symptoms in patients with dementia.

METHODS

In January 2019 an extensive search was conducted in Medline (PubMed), Embase, Emcare, Cochrane, PsychInfo, Web of Science and gray literature. Studies were included when they: i) investigated patients diagnosed with dementia, ii) reported neuropsychiatric symptoms, iii) used caffeine or coffee consumption as an intervention, and iv) reported associations between caffeine or coffee consumption and neuropsychiatric symptoms. Studies were excluded when they also included participants without a diagnosis of dementia, or presented a review or expert opinion. Two reviewers independently rated the studies and reached consensus on the appraisal.

RESULTS

Of the seven studies eligible for this review, four reported on sleeping difficulties and five on behavioral symptoms. There was no consistent effect of caffeine administration on neuropsychiatric symptoms: e.g., both high caffeine consumption and eliminating caffeine were associated with less apathy, the total Neuropsychiatric Inventory (Nursing Home) decreased after both coffee therapy and after eliminating caffeine, and both caffeine consumption and eliminating caffeine improved sleep.

CONCLUSION

These findings suggest that caffeine can either induce or reduce neuropsychiatric symptoms in individual patients with dementia. Therefore, in these patients, caffeine consumption requires a prudent individualized approach and further research on the effects of caffeine on individual neuropsychiatric symptoms is required.

Caffeine Intake During Pregnancy and Neonatal Anthropometric Parameters

Caffeine is a psychoactive substance that may affect the normal course of pregnancy, therefore its intake during that time should not exceed 200 mg/day. The aim of this study was to evaluate caffeine intake among pregnant women from the Warsaw region. The study was conducted among 100 pregnant women who delivered at the Department of Obstetrics, Gynecology and Oncology, Medical University of Warsaw. Caffeine intake from coffee, tea, and energy drinks was measured using a questionnaire. Direct interviewing was used, with all interviews conducted by the same dietitian. Multiple regression analysis was used to investigate the relationship between caffeine intake and anthropometric measurements of the newborns. Mean caffeine intake among pregnant women was 68 ± 51 mg/day. Only 2% of the respondents exceeded the safe dose of 200 mg. Tea (mostly black) was the source of 63% of all caffeine. No relationships were found between caffeine intake and neonatal weight, length, or head and chest circumference (p > 0.05). Caffeine intake in our study population was relatively low and did not negatively affect fetal growth.

Consumers' Perceptions of Coffee Health Benefits and Motives for Coffee Consumption and Purchasing

Coffee is popular worldwide and consumption is increasing, particularly in non-traditional markets. There is evidence that coffee consumption may have beneficial health effects. Consumers' beliefs in the health benefits of coffee are unclear. The study aimed at analyzing consumers' perceptions of coffee health benefits, consumption and purchasing motives of coffee consumers with positive perceptions of coffee health benefits, and willingness to pay for coffee with associated health claims. Data were collected through a face-to-face survey with consumers, resulting in a convenience sample of 250 questionnaires valid for data elaboration. Results were elaborated with factor analysis and logistic regression analysis. Findings revealed that a relevant minority of consumers believed that coffee could have positive health effects. The consumer with a positive perception of coffee health benefits is mostly male, young, works, is familiar with non-espresso-based coffee, consumes a limited amount of coffee (generally not for breakfast and often in social settings), and buys coffee at retail outlets. Consumers drink coffee for its energetic and therapeutic effects. Coffee consumption is still price-driven, but consumers are interested in purchasing coffee with associated health claims. There is the opportunity to improve the perception of coffee health benefits in consumers' minds.

Consumption of energy drinks among Turkish University students and its health hazards

Objective:

To determine the awareness, consumption patterns of energy drinks (ED) and health hazards among students at a Turkish University.

Methods:

This cross-sectional descriptive study was conducted by questionnaire method between in 2017 among Erciyes University students. Total 1257 students from the Faculties of Medicine, Communication and Physical Education and Sports College participated in the study. Pearson chi-square test, binary logistic regressions were used for statistical analysis. p <0.05 values were considered significant.

Results:

Students who tried at least once and consumed regularly ED were 52.5% and 15.7% respectively. Consuming regularly and trying ED were more common among students who were studying at Physical Education and Sports High school, male, smoking, alcohol consumer, doing regular physical activity. Mean age of students to start drinking ED was 15.1 years. Most common reason for ED consumption was; staying awake. Alcohol mixed energy drinks consumption rate was 37.6% among regular ED consumers. Most declared harmful effect was palpitation.

Conclusion:

ED consumption among Erciyes University students was widespread. Students should be informed about EDs’ hazards for health. Legal regulations regarding production, marketing and advertising of EDs must be reconsidered.

A randomized controlled trial of a manual-only treatment for reduction and cessation of problematic caffeine use

BACKGROUND

Caffeine Use Disorder was added to DSM-5 as a diagnosis for further research, but few studies have been conducted to identify effective treatments. This randomized, controlled clinical trial examined the efficacy of a manual-only treatment program for caffeine cessation and reduction among individuals seeking treatment for problematic caffeine use.

METHODS

Individuals meeting at least two proposed DSM-5 diagnostic criteria for Caffeine Use Disorder were randomly assigned to receive either immediate treatment or treatment delayed by 7 weeks. The treatment consisted of a manual containing information about caffeine and instructions for gradually reducing caffeine consumption over a period of 6 weeks, with no counseling or additional support. Caffeine consumption and caffeine-related distress were assessed before treatment, 7 weeks after receiving the treatment manual (end-of-treatment), and 20 weeks post-treatment.

RESULTS

The manual-only treatment resulted in significant reductions in participants' self-reported caffeine consumption and caffeine-related distress at end-of-treatment that were sustained at 20-weeks post-treatment. Salivary caffeine levels and community observers corroborated the self-reported reductions in caffeine consumption. Comparisons between the immediate and delayed treatment groups suggest the reductions in caffeine consumption were attributable to the manualized treatment rather than spontaneous with the passage of time.

CONCLUSIONS

The present study provides evidence that a gradual caffeine reduction and cessation program may be successfully implemented using a manual-only approach. This time- and cost-effective intervention may be easily adopted by practitioners with limited time or experience with behavioral interventions who want to encourage their patients to reduce caffeine consumption.

Intra-periaqueductal gray matter administration of orexin-A exaggerates pulpitis-induced anxiogenic responses and c-fos expression mainly through the interaction with orexin 1 and cannabinoid 1 receptors in rats

Different types of trigeminal pains are frequently associated with psychophysiological concerns. Orexin-A and orexin 1 receptor (OX1R) are involved in modulation of both trigeminal pain and anxiety responses. Ventrolateral periaqueductal gray matter (vlPAG), a controlling site for nociception and emotion, receives orexinergic inputs. Here, the role of vlPAG OX1Rs and their interaction with cannabinoid 1 (CB1) receptor was evaluated in anxiety-like behavior following capsaicin-induced dental pulp pain. Rats were cannulated in the vlPAG and orexin-A was injected at the doses of 0.17, 0.35 and 0.51 μg/rat prior to the induction of pain. The elevated plus maze (EPM) and open field (OF) tests were used for assessing the anxiety responses. In addition, the induction of c-fos, in the vlPAG, was investigated using immunofluorescence microscopy. Capsaicin-treated rats displayed significantly higher anxiogenic behavior on EPM and OF tests. Pretreatment with orexin-A (0.51 μg/rat) attenuated capsaicin-mediated nociception, while exaggerated anxiogenic responses (p < 0.05). In addition, orexin-A effects were diminished by the administration of OX1R (SB-334867, 12 μg/rat) and cannabinoid 1 (AM251, 4 μg/rat) receptor antagonists. Intradental capsaicin induced a significant increase in c-fos expression in the vlPAG that was exaggerated by orexin-A (0.51 μg/rat). Blockage of OX1R and CB1 receptors attenuated the effect of orexin-A on c-fos expression in capsaicin-treated rats. In conclusion, the data suggest that manipulation of OX1R and CB1 receptors in the vlPAG alters capsaicin-evoked anxiety like behaviors and c-fos induction in rats.

Common Ingredient Profiles of Multi-Ingredient Pre-Workout Supplements

Multi-ingredient pre-workout supplements are a popular class of dietary supplements which are purported to improve exercise performance. However, the composition of these products varies substantially between formulations, thus making comparisons challenging. Therefore, the purpose of this study was to identify a common ingredient profile of top-selling pre-workout supplements and to compare ingredient dosages to established efficacious values. The top 100 commercially available pre-workout products were analyzed for listed ingredients and amounts, if available, from the supplement facts panel. The mean ± SD number of ingredients per supplement (n = 100) was 18.4 ± 9.7 with 8.1 ± 9.9 of these ingredients included in a proprietary blend at undisclosed quantities. Relative prevalence and average amounts of the top ingredients amounted to: Beta-alanine (87%; 2.0 ± 0.8 g), Caffeine (86%; 254.0 ± 79.5 mg), Citrulline (71%; 4.0 ± 2.5 g), Tyrosine (63%; 348.0 ± 305.7 mg), Taurine (51%; 1.3 ± 0.6 g), and Creatine (49%; 2.1 ± 1.0 g). Nearly half (44.3%) of all ingredients were included as part of a proprietary blend with undisclosed amounts of each ingredient. The average amount of beta-alanine per serving size was below the recommended efficacious dose. The average caffeine content was near the low end for an effective relative dose for a 70 kg individual (3–6 mg·kg⁻¹ of bodyweight).

Fortification of Ground Roasted Coffees with Iron, Zinc, and Calcium Salts: Evaluation of Minerals Recovery in Filtered and Espresso Brews

Micronutrient deficiencies are of great public health and socioeconomic importance. Food fortification has been widely used as a simple low-cost resource to increase mineral intake. Considering that coffee is the most consumed food product worldwide, in this study, C. arabica and C. canephora seeds were roasted, ground, and fortified with three salts of iron, zinc, and calcium as part of the selection of appropriate mineral vehicles for fortification. After ranking the performance through a test by a trained tasters’ panel, only two salts for each mineral remained. Mineral recoveries were evaluated by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) in filtered (paper and nylon filters) and espresso brews. The best mean recoveries for each mineral in espresso brew prepared from fortified coffees were: 80.8% of iron as ferrous bisglycinate chelate, 75.4% of zinc as zinc lactate, and 72.1% of calcium as calcium lactate. These better ranked salts by the tasters’ panel. In filtered brews, mean recovery values of 51.1%, 47.6%, and 51.6% were obtained for the same mineral salts, respectively. No difference or very small differences were observed between species and types of filter. The results implications are discussed.

Machine-Learning Identification of the Sensing Descriptors Relevant in Molecular Interactions with Metal Nanoparticle-Decorated Nanotube Field-Effect Transistors

Carbon nanotube-based field-effect transistors (NTFETs) are ideal sensor devices as they provide rich information regarding carbon nanotube interactions with target analytes and have potential for miniaturization in diverse applications in medical, safety, environmental, and energy sectors. Herein, we investigate chemical detection with cross-sensitive NTFETs sensor arrays comprised of metal nanoparticle-decorated single-walled carbon nanotubes (SWCNTs). By combining analysis of NTFET device characteristics with supervised machine-learning algorithms, we have successfully discriminated among five selected purine compounds, adenine, guanine, xanthine, uric acid, and caffeine. Interactions of purine compounds with metal nanoparticle-decorated SWCNTs were corroborated by density functional theory calculations. Furthermore, by testing a variety of prepared as well as commercial solutions with and without caffeine, our approach accurately discerns the presence of caffeine in 95% of the samples with 48 features using a linear discriminant analysis and in 93.4% of the samples with only 11 features when using a support vector machine analysis. We also performed recursive feature elimination and identified three NTFET parameters, transconductance, threshold voltage, and minimum conductance, as the most crucial features to analyte prediction accuracy.

Potential nutraceutical and food additive properties and risks of coffee: a comprehensive overview

Coffee is a composite mixture of more than a thousand diverse phytochemicals like alkaloids, phenolic compounds, vitamins, carbohydrates, lipids, minerals and nitrogenous compounds. Coffee has multifunctional properties as a food additive and nutraceutical. As a nutraceutical, coffee has anti-inflammatory, anti-oxidant, antidyslipidemic, anti-obesity, type-2 diabetes mellitus (DM), and cardiovascular diseases (CVD), which can serve for the treatment and prevention of metabolic syndrome and associated disorders. On the other hand, as a food additive, coffee has antimicrobial activity against a wide range of microorganisms, inhibits lipid peroxidation (LPO), and can function as a prebiotic. The outcomes of different studies also revealed that coffee intake may reduce the incidence of numerous chronic diseases, like liver disease, mental health, and it also overcomes the all-cause mortality, and suicidal risks. In some studies, high intake of coffee is linked to increase CVD risk factors, like cholesterol, plasma homocysteine and blood pressure (BP). There is also a little evidence that associated the coffee consumption with increased risk of lung tumors in smokers. Among adults who consume the moderate amount of coffee, there is slight indication of health hazards with strong indicators of health benefits. Moreover, existing literature suggests that it may be cautious for pregnant women to eliminate the chances of miscarriages and impaired fetal growth. The primary purpose of this narrative review is to provide an overview of the findings of the positive impacts and risks of coffee consumption on human health. In conclusion, to date, the best available evidence from research indicates that drinking coffee up to 3-4 cups/day provides health benefits for most people.

Health Related Nutritional Knowledge and Dietary Behavior Regarding Caffeine Intake among High School Students in Yongin Region

Objectives

We aimed to examine health-related nutritional knowledge and dietary behavior related to caffeine intake among high school students (n = 310) in the Yongin region of Korea.

Methods

Data were collected using a face-to-face survey, and analyzed using chi-square test, t- test, and logistic regression analysis.

Results

The level of caffeine intake in respondents was divided into low (< 30 mg/d; n = 208) and high caffeine intake groups (> 30 mg/d; n = 102). Total nutritional knowledge related to bone disease was higher in the low intake group (score 2.75) than the high intake group (score 2.39; p < 0.05). The high intake group had lower scores for nutritional knowledge (score 0.70; p < 0.05) related to how caffeinated beverages affect sleep and for dietary behavior (score 3.25; p < 0.001), based on “I avoid caffeinated foods before sleep,” than the low intake group (nutritional knowledge score, 0.80; dietary behavior score, 3.76).

Conclusion

In the overall analysis, the low caffeine intake group had better nutritional knowledge related to bone and sleep health, and healthier dietary behavior related to sleep health compared with the high intake group.

Hourly and daily intake patterns among U.S. caffeinated beverage consumers based on the National Health and Nutrition Examination Survey (NHANES, 2013-2016)

Characterization of 'hour-of-day' or 'day-of-week' caffeine intake for the National Health and Nutrition Examination Survey (NHANES) population is limited. No study has focused on patterns from an individual perspective. The NHANES 2013-2016 survey respondents' dietary recalls were analyzed to gain a better understanding of caffeine intake patterns for different caffeinated beverage consumer types - defined by beverage type consumed and daily caffeine intake levels. Dominant caffeinated beverage consumers (≥143 mg) were identified by a reported daily caffeine intake level greater than or equal to the 50th percentile among those 1-80 y. Dominant caffeinated beverage consumers - irrespective of age groups investigated - typically reported the greatest caffeine intake early in the day from coffee. Analyses by consumer type, relevant age brackets and 'hour-of-day' or 'day-of-week' indicated that caffeinated beverage consumers generally do not cluster multiple caffeine intake events over short periods of time (i.e., less than fours). Dominant caffeinated beverage consumers appear to maintain a relatively stable daily caffeine intake by substitution of secondary sources of caffeine. Only a small fraction (4.1%) of individuals within 13-29 y respondents consumed caffeine at levels in excess of 400 mg/day, compared to 14% within the 30-80 y old survey respondent group.

Niacin, alkaloids and (poly)phenolic compounds in the most widespread Italian capsule-brewed coffees

Coffee is one of the most popular beverages worldwide and, nowadays, one of the most practical way for its preparation is by prepacked capsules. The aim of this study was comparing the content in caffeine, trigonelline, N-methylpyridinium (NMP), niacin, and chlorogenic acids of 65 different capsule-brewed coffees, commercialised by 5 of the most representative brands in Italy. Coffees were prepared from capsules following manufacturer’s instructions and analysed with an optimized UHPLC-MS/MS method able to assess all these phytochemicals in one single run. Inter-lot and capsule variability were also studied for a subset of coffee capsules. Except for decaffeinated coffees, caffeine amount accounted between 54 and 208 mg/serving. Regular espresso coffees showed higher trigonelline, NMP, and niacin concentrations than large (lungo) and decaffeinated samples, with average serving amounts of 17.96, 1.78, and 0.66 mg, respectively. Regarding chlorogenic acids, caffeoylquinic acids were the most relevant ones (20–117 mg/serving). Feruloylquinic acids were quantified between 8 and 50 mg/serving. Coumaroylquinic acids, hydroxycinnamate dimers, caffeoylshikimic acids, and caffeoylquinic lactones were also present at lower concentrations. Multivariate analysis provided comprehensive information on the phytochemical profile of the different types of coffee, showing a great variability among coffees with some brand-related insights. This study supports the need for accurately characterizing espresso coffees while investigating the beneficial effects of coffee on human health.

The Impact of Coffee and Its Selected Bioactive Compounds on the Development and Progression of Colorectal Cancer In Vivo and In Vitro

Coffee is one of the most popular beverages worldwide. Coffee contains bioactive compounds that affect the human body such as caffeine, caffeic acid, chlorogenic acids, trigonelline, diterpenes, and melanoidins. Some of them have demonstrated potential anticarcinogenic effects in animal models and in human cell cultures, and may play a protective role against colorectal cancer. Colorectal cancer (CRC) is the third leading cause of cancer-related mortality in the USA and other countries. Dietary patterns, as well as the consumption of beverages, may reduce the risk of CRC incidence. In this review, we focus on published epidemiological studies concerning the association of coffee consumption and the risk of development of colorectal cancer, and provide a description of selected biologically active compounds in coffee that have been investigated as potential cancer-combating compounds: Caffeine, caffeic acid (CA), chlorogenic acids (CGAs), and kahweol in relation to colorectal cancer progression in in vitro settings. We review the impact of these substances on proliferation, viability, invasiveness, and metastasis, as well as on susceptibility to chemo- and radiotherapy of colorectal cancer cell lines cultured in vitro.

Evaluation of a 24-Hour Caffeine Intake Assessment Compared with Urinary Biomarkers of Caffeine Intake among Young Adults in Canada

BACKGROUND

Caffeine is a widely consumed stimulant, and caffeine-containing products are increasingly available on the market. Few tools are available to capture caffeine intake, particularly among young adults. To estimate caffeine consumption in the previous 24 hours, the 24-Hour Caffeine Intake Recall (CIR-24) was modeled after the Automated Self-Administered 24-Hour Dietary Assessment Tool, using a brand-specific database of caffeine-containing foods, beverages, and supplements.

OBJECTIVE

To evaluate the accuracy of the CIR-24 compared with caffeine concentration biomarkers in urine and a caffeinated beverage intake frequency screener (CBQ) designed to assess usual intake among a young adult population in Canada.

DESIGN/PARTICIPANTS

In all, 79 young adults, aged 18 to 29 years, provided 24-hour urine samples and completed the CIR-24 and CBQ.

MAIN OUTCOME MEASURES

Excretion for caffeine and eight caffeine metabolites were quantified from urine samples using high-performance liquid chromatography-polarity switching electrospray ionization-tandem quadrupole mass spectrometry with stable isotope-labeled internal standards.

STATISTICAL ANALYSES PERFORMED

Pearson correlations and weighted κ coefficients were calculated for the self-report tools and caffeine biomarkers.

RESULTS

The CIR-24 was significantly positively associated with all caffeine biomarkers (r_p=0.28 to 0.52, κ=0.39 to 0.59), and the CBQ was significantly positively associated with all but one biomarker (r_p=0.21 to 0.40, κ=0.32 to 0.45). The CIR-24 yielded a higher mean intake of caffeine than the CBQ. There was strong linear correlation between the CIR-24 and CBQ (r_p=0.60, P<0.001), but poor agreement in absolute caffeine consumed (t=2.83, P=0.006); quartile ranking concordance was 0.44 (P<0.001). The CIR-24 performed better than the CBQ across all biomarkers in both linear correlation and quartile ranking.

CONCLUSIONS

Although both the CIR-24 and CBQ performed reasonably well in capturing caffeine intake compared with urinary biomarkers of caffeine consumption, the CIR-24 had stronger agreement than the CBQ. The results suggest that the CIR-24 is a promising tool for evaluating caffeine intake among this population.

Caffeine in the Diet: Country-Level Consumption and Guidelines

Coffee, tea, caffeinated soda, and energy drinks are important sources of caffeine in the diet but each present with other unique nutritional properties. We review how our increased knowledge and concern with regard to caffeine in the diet and its impact on human health has been translated into food-based dietary guidelines (FBDG). Using the Food and Agriculture Organization list of 90 countries with FBDG as a starting point, we found reference to caffeine or caffeine-containing beverages (CCB) in 81 FBDG and CCB consumption data (volume sales) for 56 of these countries. Tea and soda are the leading CCB sold in African and Asian/Pacific countries while coffee and soda are preferred in Europe, North America, Latin America, and the Caribbean. Key themes observed across FBDG include (i) caffeine-intake upper limits to avoid risks, (ii) CCB as replacements for plain water, (iii) CCB as added-sugar sources, and (iv) health benefits of CCB consumption. In summary, FBDG provide an unfavorable view of CCB by noting their potential adverse/unknown effects on special populations and their high sugar content, as well as their diuretic, psycho-stimulating, and nutrient inhibitory properties. Few FBDG balanced these messages with recent data supporting potential benefits of specific beverage types.

Daily Patterns of Caffeine Intake and the Association of Intake with Multiple Sociodemographic and Lifestyle Factors in US Adults Based on the NHANES 2007-2012 Surveys

BACKGROUND

Caffeine increases alertness when consumed in single servings of various products including coffee, tea, soft drinks, and energy drinks. Although not a nutrient, caffeine is consumed by 90% of the adult population in the United States.

OBJECTIVE

This study examined the daily pattern of caffeine intake and its relationship to multiple demographic variables.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) 2007-2012 (adults aged 19+ years; n=16,173) were used to determine the time of day at which caffeine is consumed and demographic factors associated with intake. Regression analyses characterized factors associated with caffeine intake including sex, age, ethnicity, education, smoking status, physical activity, employment status, total work hours, alcohol, and energy intake.

RESULTS

Mean adult per capita caffeine intake was 169±4 mg/d (mean±standard error). Most caffeine (70%) was consumed before noon, often at breakfast, and intake decreased progressively over the day, with little consumed after 9:00 pm. Intake was associated with age, ethnicity, smoking status, total calorie intake, and work hours (P<0.01) but not physical activity, economic status, education level, or employment status. Variables with the largest associations with intake were, respectively, ethnicity and age. Non-Hispanic black individuals consumed the smallest amounts (80±2 mg/d), non-Hispanic white individuals consumed the greatest amounts (194±3 mg/d), and Asian individuals (126±7 mg/d) and Hispanic individuals consumed intermediate amounts (127±3 mg/d). Middle-aged individuals (aged 50 to 54 years) consumed more caffeine (211±6 mg/d) than younger (107±4 mg/d, aged 20 to 24 years) and older individuals (153±4 mg/d, aged 75 to 79 years).

CONCLUSION

Most caffeine is consumed in the morning, when alertness is lowest, and very little in the evening before sleep. Ethnicity and age were the variables most strongly associated with intake; work hours, occupation, energy and alcohol intake, and smoking were also associated with intake. Because caffeine increases alertness, it is not surprising that its pattern of consumption and factors associated with its intake vary from those of most other food constituents.

Coffee variety, origin and extraction procedure: Implications for coffee beneficial effects on human health

We set up an efficient protocol for the rapid analysis of NMR spectra of green and roasted coffee extracts, enabling the automatic identification and quantification of metabolites in approximately two minutes per spectrum. This method allowed for the metabolic profiling and the subsequent evaluation of the content of bioactive compounds and antioxidant activity of coffee samples, depending on their species (Arabica and Robusta), geographical origin and extraction procedure (hydroalcoholic, espresso and moka). The hydroalcoholic extraction is the most efficient method in terms of yields of low molecular weight compounds (in particular chlorogenic acids), while moka extraction provides the highest amounts of melanoidins. Moreover, that the ratio between health-giving compounds (chlorogenic acids, trigonelline and choline) and caffeine is higher in Arabica coffees. The data collected provide useful insights for the selection of coffee raw material to be used in the preparation of coffee-based dietary supplements, nutraceuticals and functional beverages.

The clinical toxicology of caffeine: A review and case study

Caffeine is a widely recognized psychostimulant compound with a long history of consumption by humans. While it has received a significant amount of attention there is still much to be learned with respect to its toxicology in humans, especially in cases of overdose. A review of the history of consumption and the clinical toxicology of caffeine including clinical features, pharmacokinetics, toxicokinetics, a thorough examination of mechanism of action and management/treatment strategies are undertaken. While higher (i.e., several grams) quantities of caffeine are known to cause toxicity and potentially lethality, cases of mainly younger individuals who have experienced severe side effects and death despite consuming doses not otherwise known to cause such harm is troubling and deserves further study. An attempted case reconstruction is performed in an effort to shed light on this issue with a focus on the pharmacokinetics and pharmacodynamics of caffeine.

Looking beyond the mirror: Psychological distress; disordered eating, weight and shape concerns; and maladaptive eating habits in lawyers and law students

Research indicates that, in comparison to professionals and University students in other disciplines, lawyers and law students may be at greater risk of experiencing high levels of psychological distress. There is also a large body of literature supporting an association between stress, anxiety and depression and unhealthy eating. This article reports on the results of a study of Australian legal professionals and law students that evidence a positive association between psychological distress; disordered eating, weight and shape concerns; and maladaptive eating habits in lawyers and law students. Additionally, this study confirms a positive link between frequency of exercise and subjective physical well-being, that in turn is associated with enhanced emotional well-being. Based on the results of this study, we suggest simple yet effective strategies law firms and law schools might adopt to support the mental health of their staff and students.

The acute effects of plyometric and sled towing stimuli with and without caffeine ingestion on vertical jump performance in professional soccer players

Background

Post-activation potentiation (PAP) is the phenomenon by which muscular performance is enhanced in response to a conditioning stimulus. PAP has typically been evidenced via improved counter movement jump (CMJ) performance. This study examined the effects of PAP, with and without prior caffeine ingestion, on CMJ performance.

Methods

Twelve male professional soccer players (23 ± 5 years) performed two trials of plyometric exercises and sled towing 60 min after placebo or caffeine ingestion (5 mg.kg^− 1) in a randomized, counterbalanced and double-blinded design. CMJ performance was assessed at baseline and 1, 3 and 5 min after the conditioning stimulus (T1, T3 and T5, respectively).

Results

Two way ANOVA main effects indicated a significant difference in jump height after the PAP protocol (F[3, 11] = 14.99, P < 0.001, partial η2 = 0.577). Analysis also indicated a significant difference in CMJ performance across conditions, with caffeine eliciting a greater response (F[1, 11] = 10.12, P = 0.009, partial η2 = 0.479). CMJ height was increased at T1, T3 and T5 in caffeine condition (5.07%, 5.75% and 5.40%, respectively; P < 0.01) compared to baseline. In the placebo condition, jump performance was increased at T3 (4.94%; P < 0.01) only. Jump height was higher in caffeine condition on T1, T3 and T5 (P < 0.05) but not on baseline (P > 0.05) compared to placebo.

Conclusions

The results of this study suggest that acute plyometric and sled towing stimuli enhances jump performance and that this potentiation is augmented by caffeine ingestion in male soccer players.

Key Findings and Implications of a Recent Systematic Review of the Potential Adverse Effects of Caffeine Consumption in Healthy Adults, Pregnant Women, Adolescents, and Children

In 2016⁻2017, we conducted and published a systematic review on caffeine safety that set out to determine whether conclusions that were presented in the heavily cited Health Canada assessment, remain supported by more recent data. To that end, we reviewed data from 380 studies published between June 2001 and June 2015, which were identified from an initial batch of over 5000 articles through a stringent search and evaluation process. In the current paper, we use plain language to summarize our process and findings, with the intent of sharing additional context for broader reach to the general public. We addressed whether caffeine doses previously determined not to be associated with adverse effects by Health Canada (400 mg/day for healthy adults, 300 mg/day for pregnant women, 2.5 mg/kg body weight/day for adolescents and children, and 10 g/day for acute effects) remain appropriate for five outcome areas (acute toxicity, cardiovascular toxicity, bone & calcium effects, behavior, and development and reproduction) in healthy adults, pregnant women, adolescents, and children. We used a weight-of-evidence approach to draw conclusions for each of the five outcomes, as well as more specific endpoints within those outcomes, which considered study quality, consistency, level of adversity, and magnitude of response. In general, updated evidence confirms the levels of intake that were put forth by Health Canada in 2003 as not being associated with any adverse health effects, and our results support a shift in caffeine research from healthy to sensitive populations.

Recent progress in nanomaterial-based assay for the detection of phytotoxins in foods

Phytotoxins refers to toxic chemicals derived from plants. They include both secondary metabolites that are dose-dependently toxic and allergens that can cause anaphylactic shock in sensitive individuals. Detecting phytotoxins in foods is increasingly important. Conventional methods for detecting phytotoxins lack sufficient sensitivity and operational convenience. Nanomaterial-based determination assays show great competence in fast and accurate sensing of trace substances. In the present review, representative phytotoxin categories of alkaloids, cyanides, and proteins are discussed. Application of notable nanomaterials, e.g. carbon nanotubes, graphene oxide, magnetic nanoparticles, metal-based nanotools, and quantum dots, in specific sensing strategies to fit the physiochemical properties of the target toxins are summarized. Nanomaterials mainly play four roles in phytotoxin detection: 1) analyte enricher; 2) sensor structure mediator; 3) target recognizer or reactant; 4) signaling agent. Great achievements have been made in the detection of trace plant-derived toxins in food matrices, yet there are still challenges awaiting further investigation.

Consumer Awareness and Preferences Related to Taurine-Containing Drinks in Korean Female High School Students

The purpose of this cross-sectional study was to investigate awareness, consumption patterns, and preferences related to intake experience of taurine-containing drinks (TCD) in Korean female high school students. Study subjects were 335 female high school students residing in Incheon, Korea. Data were collected using self-administered questionnaires. A total of 249 students (74.3%) consumed TCD while 86 students (25.7%) did not. In the TCD consumption group, 66.7% of consumers drank TCD once every 2 or 3 months while most consumers consumed it during the examination period (57.4%). Regarding the effects of TCD intake, 45.8% of students cited 'relieve sleepiness' while 41.8% showed 'no effect'. According to self-reported school records, there were significant differences in intake time of TCD, effects of TCD intake, and degree of interest in TCD (p < 0.05). About 82.7% of all the subjects perceived TCD as an energy drink for fatigue recovery. Degree of interest in TCD (p < 0.001), degree of harmfulness to the body (p < 0.01), and improvement for learning-ability (p < 0.001) had significant effects on intake frequency of TCD. Regarding preferences, 'Vita 500' was preferred by 52.2% of subjects, 'Bacchas' by 20.1%, and 'Hot Six' by 17.3%. Although subjects preferred 'Vita 500' as a caffeine-free TCD, caffeine was perceived as the most abundant ingredients in TCD by 77.1% of subjects, taurine by 16.1%, and vitamin by 4.8%. These results show most Korean female high school students consumed TCD in order to stay awake during the examination periods. Therefore, nutritional education is needed to correct Korean high school students' consumption of TCD.

Overcoming the Limits of Flash Nanoprecipitation: Effective Loading of Hydrophilic Drug into Polymeric Nanoparticles with Controlled Structure

Flash nanoprecipitation (FNP) is a widely used technique to prepare particulate carriers based on various polymers, and it was proven to be a promising technology for the industrial production of drug loaded nanoparticles. However, up to now, only its application to hydrophobic compounds has been deeply studied and the encapsulation of some strongly hydrophilic compounds, such as caffeine, remains a challenge. Caffeine loaded poly-ε-caprolactone (PCL) nanoparticles were produced in a confined impinging jet mixer using acetone as the solvent and water as the antisolvent. Caffeine was dissolved either in acetone or in water to assess the effects of two different process conditions. Nanoparticles properties were assessed in terms of loading capacity (LC%), encapsulation efficiency (EE%), and in vitro release kinetics. Samples were further characterized by dynamic light scattering, scanning electron microscopy, X-ray photo electron spectroscopy, and infrared spectroscopy to determine the size, morphology, and structure of nanoparticles. FNP was proved an effective technique for entrapping caffeine in PCL and to control its release behavior. The solvent used to solubilize caffeine influences the final structure of the obtained particles. It was observed that the active principle was preferentially adsorbed at the surface when using acetone, while with water, it was embedded in the matrix structure. The present research highlights the possibility of extending the range of applications of FNP to hydrophilic molecules.

Caffeinated energy drink use by U.S. adolescents aged 13-17: A national profile

The present study examined the national prevalence and distribution of adolescent use of caffeinated energy drinks, assessing variations in sociodemographic characteristics, personality traits, lifestyles, and patterns of alcohol and caffeine use. A cross-sectional survey was conducted in May 2014, using a nationally representative sample of 1,032 U.S. early (aged 13-15; n = 602) and middle adolescents (aged 16-17; n = 430). Nearly two thirds of teens reported ever using energy drinks; 41% had done so recently, that is, in the past 3 months. Middle adolescents reported higher prevalences of both lifetime and recent use of energy drinks than early adolescents. Common situational contexts for use (e.g., compensating for lack of sleep or playing sports) differed by both gender and age cohort. In hierarchical logistic regression analyses, gender and geographic region significantly predicted both lifetime and recent use for early adolescents only, whereas age and race were significant predictors only for middle adolescents. For both age cohorts, odds of both lifetime and recent use increased with sensation-seeking score, lifetime alcohol use, and recent caffeinated soft drink use. Among early adolescents, grade point average predicted lifetime use only, whereas coffee and caffeine pill use predicted recent use only. Among middle adolescents, impulsivity and past sports participation predicted lifetime but not recent use. Our findings show that adolescent energy drink use is widespread and varies as a function of demographic, psychosocial, lifestyle, and substance use characteristics. Future research is needed to assess whether differences between early and middle adolescent use patterns are primarily developmental or cohort effects. (PsycINFO Database Record

Development and Characterization of Dapsone Cocrystal Prepared by Scalable Production Methods

In this study, the formation of caffeine/dapsone (CAF/DAP) cocrystals by scalable production methods, such as liquid-assisted grinding (LAG) and spray drying, was investigated in the context of the potential use of processed cocrystal powder for pulmonary delivery. A CAF/DAP cocrystal (1:1 M ratio) was successfully prepared by slow evaporation from both acetone and ethyl acetate. Acetone, ethyl acetate, and ethanol were all successfully used to prepare cocrystals by LAG and spray drying. The powders obtained were characterized by X-ray diffractometry (XRD), differential scanning calorimetry (DSC), thermogravimetry (TGA), and Fourier transform infrared spectroscopy (FTIR). Laser diffraction analysis indicated a median particle size (D₅₀) for spray-dried powders prepared from acetone, ethanol, and ethyl acetate of 5.4 ± 0.7, 5.2 ± 0.1, and 5.1 ± 0.0 μm respectively, which are appropriate sizes for pulmonary delivery by means of a dry powder inhaler. The solubility of the CAF/DAP cocrystal in phosphate buffer pH 7.4, prepared by spray drying using acetone, was 506.5 ± 31.5 μg/mL, while pure crystalline DAP had a measured solubility of 217.1 ± 7.8 μg/mL. In vitro cytotoxicity studies using Calu-3 cells indicated that the cocrystals were not toxic at concentrations of 0.1 and of 1 mM of DAP, while an in vitro permeability study suggested caffeine may contribute to the permeation of DAP by hindering the efflux effect. The results obtained indicate that the CAF/DAP cocrystal, particularly when prepared by the spray drying method, represents a possible suitable approach for inhalation formulations with applications in pulmonary pathologies.

Coffee consumption and purchasing behavior review: Insights for further research

This paper presents a systematic literature review of consumer research towards coffee with the objective to identify and categorize motives, preferences and attributes of coffee consumption and purchasing behavior. Research papers were analyzed in terms of main characteristics and components (study type, research methodology, sampling, and product type). The review gives a systematic overview of the heterogeneous group of concepts and approaches that have been used so far to examine consumer behavior towards coffee. Results provide a model of key determinants for coffee consumption that can be grouped into the categories, (1) personal preferences, (2) economic attributes, (3) product attributes, (4) context of consumption, and (5) socio-demographics. The findings also show that there is a strong focus on coffee sustainability.

Development and initial psychometric validation of the Brief-Caffeine Expectancy Questionnaire (B-CaffEQ)

Caffeine is the most widely available and consumed psychoactive substance in the United States. Extant work indicates that across substances, use expectancies play a marked role in the development and maintenance of consumption patterns. Despite a burgeoning line of etiological and intervention-oriented research focused on expectancies (e.g., alcohol), there is a limited literature regarding caffeine use effect expectancies, specifically. To facilitate this work, the Caffeine Expectancy Questionnaire (CaffEQ) was developed and psychometrically validated; however, the length of the CaffEQ (i.e., 47 items) may hinder widespread adoption of this tool. As such, the current study provides an initial psychometric validation of a brief, 20-item version-the Brief-Caffeine Expectancy Questionnaire (B-CaffEQ)-in a multiethnic sample of undergraduate students (N = 975). Results showed that the B-CaffEQ replicated the 7-factor structure of the original CaffEQ using both constrained (confirmatory factor analysis) and less constrained (exploratory structural equation modeling) structural models and evidenced good internal consistency across subscales. The B-CaffEQ also demonstrated concurrent validity with caffeine use frequency indices, replicated and extended convergent validity between caffeine expectancy subscales and related behavioral and psychological constructs, and demonstrated discriminant validity with other related, but notably distinct, stimulant use metrics (e.g., cocaine, Ritalin). Lastly, the B-CaffEQ appears to provide an invariant measure of expectancies across types of caffeine users. These findings indicate that the B-CaffEQ is a reliable assessment of caffeine use effect expectancies, with acceptable-to-good psychometric properties-comparable in length to other substance use expectancies measures-that may be more readily incorporated into research and clinical settings. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Dangerous mistake: an accidental caffeine overdose

Caffeine (1,3,7-trimethylxanthine) is a natural product commonly presented in food’s composition, beverages and medicinal products. Generally, it is thought to be safe under normal dosage, yet it can be fatal in case of severe intoxication. We report a case of a healthy 32-year-old woman who went to the local emergency department (ED) 30 min after ingesting, accidentally, 5000 mg of anhydrous caffeine for a preworkout supplement. At the ED, she presented an episode of presyncope followed by agitation. ECG showed polymorphic broad complex QRS tachycardia and arterial blood gas revealed metabolic acidaemia with severe hypokalemia. The dysrhythmia was successfully treated with intravenous propranolol. Acid–base and hydroelectrolytic disorders were also corrected. A persistent sinus tachycardia was observed in the first 2 days in the ward and 5 days later she was discharged asymptomatic with internal medicine follow-up.

Review of animal studies on the cardiovascular effects of caffeine

To address the safety of caffeine levels in energy drinks, we previously conducted a detailed evaluation of epidemiology studies in humans consuming coffee/caffeine, in which we assessed multiple health effects (unpublished). To further evaluate the effects of caffeine on the cardiovascular system, we turned to animal studies, which often use pure caffeine (not coffee), frequently at higher doses than those typical of human exposure. We identified key scientific studies and reviews in which effects of coffee or caffeine were evaluated in animals by conducting a comprehensive PubMed literature search and analyzing the results. We found that the human equivalent dose (HED) for the no observed adverse effect level (NOAEL) for cardiovascular effects was 260 mg caffeine (2-3 cups of coffee) for a single dose of caffeine for a 70-kg adult, while the lowest observed adverse effect level (LOAEL) was 770 mg (7-8 cups of coffee) for a 70-kg adult. Overall, the doses associated with possible adverse cardiovascular effects were more than either the amount of caffeine consumed over a 24-hour period in two regular energy shots (400 mg/day) or the amount in two extra strength energy shots (460 mg/day).

Caffeine use disorder: An item-response theory analysis of proposed DSM-5 criteria

INTRODUCTION

Caffeine is a common psychoactive substance with a documented addictive potential. Caffeine withdrawal has been included in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), but caffeine use disorder (CUD) is considered to be a condition for further study. The aim of the current study is (1) to test the psychometric properties of the Caffeine Use Disorder Questionnaire (CUDQ) by using a confirmatory factor analysis and an item response theory (IRT) approach, (2) to compare IRT models with varying numbers of parameters and models with or without caffeine consumption criteria, and (3) to examine if the total daily caffeine consumption and the use of different caffeinated products can predict the magnitude of CUD symptomatology.

METHODS

A cross-sectional study was conducted on an adult sample (N = 2259). Participants answered several questions regarding their caffeine consumption habits and completed the CUDQ, which incorporates the nine proposed criteria of the DSM-5 as well as one additional item regarding the suffering caused by the symptoms.

RESULTS

Factor analyses demonstrated the unidimensionality of the CUDQ. The suffering criterion had the highest discriminative value at a higher degree of latent trait. The criterion of failure to fulfill obligations and social/interpersonal problems discriminate only at the higher value of CUD latent factor, while endorsement the consumption of more caffeine or longer than intended and craving criteria were discriminative at a lower level of CUD. Total daily caffeine intake was related to a higher level of CUD. Daily coffee, energy drink, and cola intake as dummy variables were associated with the presence of more CUD symptoms, while daily tea consumption as a dummy variable was related to less CUD symptoms. Regular smoking was associated with more CUD symptoms, which was explained by a larger caffeine consumption.

CONCLUSIONS

The IRT approach helped to determine which CUD symptoms indicate more severity and have a greater discriminative value. The level of CUD is influenced by the type and quantity of caffeine consumption.

Age restriction warning label efficacy and high school student consumption of highly-caffeinated products

Age restriction warning labels (ARLs) are placed on highly-caffeinated food and drinks, such as Red Bull, to deter consumption by minors who are especially vulnerable to the risks of excessive caffeine consumption. Previous studies have shown that ARLs on media like TV programs and video games fail to discourage minors. However, it is unclear how ARLs on food and drink packages affect minors' purchasing behavior. High school students aged 14 to 17 years (n = 150, M_age = 15.2, 51% male) were asked to choose between seven novel product dyads (three food/drink dyads, two movie dyads, and two video game dyads); each dyad contained one product with an ARL and one without. Participants were then asked how ARLs and parental permissiveness of ARL products influenced their decision. Roughly half of the participants selected food and drink products with ARLs. Over two-thirds (69%) of the students reported that they were not discouraged by ARLs on highly caffeinated food and drinks. Participants reported their parents as significantly less permissive of age-restricted food and drink products than of age-restricted media merchandise (p < .01). Perceived parental permissiveness was not correlated with minors' perception of ARL or simulated product choice. Current ARLs on highly caffeinated food and drink items may be ineffective for adolescents and may actually increase product appeal. Pediatricians should educate patients and parents regarding the health risks of excessive caffeine consumption.

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Age restriction warning labels are displayed on highly caffeinated products.

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Warning labels failed to effectively deter minors from choosing marked products.

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Some minors stated warning labels encouraged their product choice.

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More research is needed to determine effective warning label wording for minors.

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Clinicians must warn teens against consumption of highly caffeinated products.

Pharmacological potential of methylxanthines: Retrospective analysis and future expectations

Methylated xanthines (methylxanthines) are available from a significant number of different botanical species. They are ordinarily included in daily diet, in many extremely common beverages and foods. Caffeine, theophylline and theobromine are the main methylxanthines available from natural sources. The supposedly relatively low toxicity of methylxanthines, combined with the many beneficial effects that have been attributed to these compounds through time, generated a justified attention and a very prolific ground for dedicated scientific reports. Methylxanthines have been widely used as therapeutical tools, in an intriguing range of medicinal scopes. In fact, methylxanthines have been/were medically used as Central Nervous System stimulants, bronchodilators, coronary dilators, diuretics and anti-cancer adjuvant treatments. Other than these applications, methylxanthines have also been hinted to hold other beneficial health effects, namely regarding neurodegenerative diseases, cardioprotection, diabetes and fertility. However, it seems now consensual that toxicity concerns related to methylxanthine consumption and/or therapeutic use should not be dismissed. Taking all the knowledge and expectations on the potential of methylxanthines into account, we propose a systematic look at the past and future of methylxanthine pharmacologic applications, discussing all the promise and anticipating possible constraints. Anyways, methylxanthines will still substantiate considerable meaningful research and discussion for years to come.