The Safety of Ingested Caffeine: A Comprehensive Review

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

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

Occurrence, distribution, and ecological risk assessment of pharmaceuticals and personal care products in the surface water of Lipu River, China

Pharmaceuticals and Personal Care Products (PPCPs) are inadvertently released into the aquatic environment, causing detrimental effects on aquatic ecosystem. There is an urgent need of an in-deep investigation on contamination information of PPCPs in aquatic environment as well as the ecological risks to the aquatic ecosystem. This study was carried out in Lipu River basin, China, to investigate the distribution pattern and ecological risks of PPCPs. Results showed that PPCPs pollution is ubiquitous, 29 out of 30 targeted PPCPs were detected in Lipu River. Fourteen PPCPs were detected with a frequency of 100% in all water samples, and ten PPCPs were detected with a frequency of more than 80%. The cumulated PPCPs concentrations ranged from 33.30 ng/L to 99.60 ng/L, with a median value of 47.20 ng/L in Lipu River. Caffeine, flumequine, nifedipine, and lomefloxacin were the predominant PPCPs in study area. Caffeine showed high ecological risk, five and seven individual PPCP showed medium and low ecological risk to algae.

Evaluation of the responsiveness pattern to caffeine through a smart data-driven ECG non-linear multi-band analysis

This study aimed to explore more efficient ways of administering caffeine to the body by investigating the impact of caffeine on the modulation of the nervous system's activity through the analysis of electrocardiographic signals (ECG). An ECG non-linear multi-band analysis using Discrete Wavelet Transform (DWT) was employed to extract various features from healthy individuals exposed to different caffeine consumption methods: expresso coffee (EC), decaffeinated coffee (ED), Caffeine Oral Films (OF_caffeine), and placebo OF (OF_placebo). Non-linear feature distributions representing every ECG minute time series have been selected by PCA with different variance percentages to serve as inputs for 23 machine learning models in a leave-one-out cross-validation process for analyzing the behavior differences between ED/EC and OF_placebo/OF_caffeine groups, respectively, over time. The study generated 50-point accuracy curves per model, representing the discrimination power between groups throughout the 50 min. The best model accuracies for ED/EC varied between 30 and 70 %, (using the decision tree classifier) and OF_placebo/OF_caffeine ranged from 62 to 84 % (using Fine Gaussian). Notably, caffeine delivery through OFs demonstrated effective capacity compared to its placebo counterpart, as evidenced by significant differences in accuracy curves between OF_placebo/OF_caffeine. Caffeine delivery via OFs also exhibited rapid dissolution efficiency and controlled release rate over time, distinguishing it from EC. The study supports the potential of caffeine delivery through Caffeine OFs as a superior technology compared to traditional methods by means of ECG analysis. It highlights the efficiency of OFs in controlling the release of caffeine and underscores their promise for future caffeine delivery systems.

Impact of carbonated beverages on early onset of osteoporosis: A narrative review

Background: Processed and semi-processed foods are getting popular in the diets of the Western population. The Western diet is almost coupled with consuming carbonated beverages, either alcoholic or nonalcoholic. The presence of sugar, caffeine, and alcohol in different carbonated beverages and detrimental dietary patterns are leading causes of obesity, diabetes, and periodontal diseases in the young population. Aims: This article aims to review the impact of carbonated beverages on early onset of osteoporosis. Methods: A nonsystematic literature review searches in PubMed and Google Scholar electronic databases with predefined terms relating to carbonated beverages, caffeine intake, childhood obesity, osteoporosis, and bone softness. Results: Bone diseases significantly increase due to early exposure to caffeine and phosphoric acid in the pubertal period. Musculoskeletal growth is a dynamic and complex process, and bone mass achievement is of great importance in this process. According to the global burden of diseases, bone disorders consist of "6.8% of total disability-adjusted life-years." The consumption of soft drinks and their impact on bone accretion and bone mineral density in the young population is under research in the current literature on osteoporotic disorders. Since bone is a metabolically active tissue, it's in constant reconstruction mode. This process is regulated by genetic, hormonal, nutritional, and physical factors. Any imbalance in one of these processes might lead to mineral deposition and osteoporosis. Conclusion: Habitual intake of carbonated drinks with added sugars and caffeine is associated with increased body weight and bone fragility; stringent regulations are needed for proper education.

Elimination of Toxic Solvents from Analytical Methods in Food Analysis: Caffeine Determination in Tea as an Example

This study presents an innovative method for caffeine determination in tea, employing ethanol as the sole organic solvent for both SPE sample preparation and chromatographic analysis. This approach aligns with green chemistry principles, as confirmed by a comparative study highlighting ethanol's safety and eco-friendliness compared to traditional solvents. The experiments validate ethanol's efficacy in caffeine extraction and chromatographic analysis, minimizing environmental impact and eliminating toxicity risks. Utilizing a reduced chromatography column enhances the method's efficiency and sustainability, resulting in a low limit of quantitation (0.125 μg/mL) and good reproducibility (RSD < 2.5%). Based on tea from the Polish market, the findings reveal the caffeine content (19.29-37.69 mg/g) and endorse ethanol's role in enhancing sustainable chemical analysis in food science.

The Impact of Stress and Social Determinants on Diet in Cardiovascular Prevention in Young Women

The prevention of cardiovascular diseases is a fundamental pillar for reducing morbidity and mortality caused by non-communicable diseases. Social determinants, such as socioeconomic status, education, neighborhood, physical environment, employment, social support networks, and access to health care, play a crucial role in influencing health outcomes and health inequities within populations. Social determinants and stress in women are interconnected factors that can significantly impact women's health and well-being. Pregnancy is a good time to engage young women and introduce them to beneficial behaviors, such as adopting essential life skills, especially diet, and learning stress management techniques. Stress influences diet, and women are more likely to engage in unhealthy eating behaviors such as emotional eating or coping with stress with food. Strong action is needed to improve women's lifestyle starting at a young age considering that this lays the foundation for a lower cardiovascular risk in adults and the elderly. The objective of this review is to examine cardiovascular primary prevention in young healthy women, focusing particularly on unresolved issues and the influence of social determinants, as well as the correlation with stressors and their influence on diet.

Estimate the prevalence of daily caffeine consumption, caffeine use disorder, caffeine withdrawal and perceived harm in Iran: a cross-sectional study

One of the informal diagnoses in DSM-5 is Caffeine Use Disorder (CUD). CUD and high levels of caffeine consumption could impact mental health conditions. This study aimed to estimate the prevalence of CUD, caffeine consumption, caffeine-related harms, and related psychiatric symptoms in Iran. A cross-sectional survey with a convenience sample of 1228 adults were conducted in Iran. Caffeine consumption was assessed across 20 products in Iran. Caffeine Use Disorder Questionnaire (CUDQ), Caffeine Withdrawal Symptoms Questionnaire (CWSQ), 14-item Caffeine-related Harm Screening (CHS), and Symptom Checklist-25 (SCL-25) were used in the present study. We used SPSS (desktop version 26.0) to analyze the data using descriptive statistics, chi-square, and the least significant difference (LSD) post hoc test. The daily average caffeine consumption was 146.67 mg. The prevalence of CUD and caffeine withdrawal (C.W.) were estimated at 19.5% and 46.62%, respectively. Also, 12.9% of responders received CUD and C.W.s simultaneously. The prevalence of CUD was higher in men than females (25.08% vs. 13.93%). 95% of participants (n = 1166) reported using at least one caffeine product yesterday. Moreover, the most reported caffeine-related harms were the desire for sugar (42.9%), insomnia (39.3%), and caffeine dependence (38.3%). Age significantly correlates with CUD (- 0.07) and daily caffeine intake (0.08). Moreover, all SCL-90 subscales had a significant correlation with daily caffeine intake. Finally, responders at younger ages reported higher levels of CUD and caffeine consumption than older adults(P < 0.05). High rates of C.W. and CUD in the Iranian population suggest that it is necessary to develop evidence-based treatments.

Prenatal caffeine consumption and neurobehavioral disorders - A systematic review

Studies have suggested associations between gestational exposure to caffeine and adverse outcomes, however the evidence is still limited. Therefore, a systematic review was conducted to investigate the association between prenatal caffeine exposure and neurobehavioral disorders. The MEDLINE (PubMed), EMBASE, Scopus, Web of Science, and LILACS databases were searched. Observational studies involving women with documented caffeine consumption during pregnancy were eligible for inclusion. The outcomes evaluated were behavioral and intellectual development, Attention Deficit Hyperactivity Disorder, and related behaviors. The data were analyzed by qualitative synthesis. The ROBINS-I tool was employed to assess the risk of bias, and the certainty of evidence was evaluated using GRADE (PROSPERO: CRD42023421164). The search yielded fourteen studies that met the inclusion/exclusion criteria. The sample size among pregnant women ranged from 173 to 64,189, and among children ranged from 88 to 49,190. Maternal caffeine consumption during pregnancy ranged from 0 to 1000 mg/day, with the highest levels observed during mid-pregnancy. Seven studies indicated a potential association between prenatal caffeine exposure and neurobehavioral/neurodevelopment deficits, one study showed that prenatal caffeine exposure improved peer problems, and six studies did not show a significant effect of prenatal caffeine consumption on neurobehavioral disorders. The included studies were classified as moderate for the risk of bias and with very low certainty of evidence. Thus, the evidence is insufficient to confirm with certainty that the prenatal caffeine exposure leads to neurobehavioral disorders. Studies heterogenicity, as well as their variable quality and the presence of several confounding factors, generate uncertainty.

Using caffeine as a chemical means to induce flow states

Flow is an intrinsically rewarding state characterised by positive affect and total task absorption. Because cognitive and physical performance are optimal in flow, chemical means to facilitate this state are appealing. Caffeine, a non-selective adenosine receptor antagonist, has been emphasized as a potential flow-inducer. Thus, we review the psychological and biological effects of caffeine that, conceptually, enhance flow. Caffeine may facilitate flow through various effects, including: i) upregulation of dopamine D1/D2 receptor affinity in reward-associated brain areas, leading to greater energetic arousal and 'wanting'; ii) protection of dopaminergic neurons; iii) increases in norepinephrine release and alertness, which offset sleep-deprivation and hypoarousal; iv) heightening of parasympathetic high frequency heart rate variability, resulting in improved cortical stress appraisal, v) modification of striatal endocannabinoid-CB1 receptor-signalling, leading to enhanced stress tolerance; and vi) changes in brain network activity in favour of executive function and flow. We also discuss the application of caffeine to treat attention deficit hyperactivity disorder and caveats. We hope to inspire studies assessing the use of caffeine to induce flow.

Caffeine intake in adults with cardiovascular diseases; A cross-sectional study

Background: Caffeine in the safe dose range has been associated with a reduction in the risk of chronic diseases. There is evidence that caffeine intake has both protective and negative effects on cardiovascular diseases. Aim: This study aimed to investigate caffeine intake in cardiovascular patients. Methods: The study sample was selected from individuals who applied to the Cardiology policlinic of Tekirdağ Namık Kemal University Hospital. A questionnaire was applied using face-to-face interview method to determine their demographic information, nutritional status and anthropometric measurements. Moreover, the nutritional status of the participants was determined by the Food Frequency Questionnaire and the type of cardiovascular disease was determined by a physician. The blood parameters of the sample for the last three months were questioned. The sample has been ninety people of whom fifty cardiovascular diseases (CVDs) were diagnosed and forty were non-diagnosed (ND). Results: The mean age of individuals (n = 90) was 43.2 ± 14.4. The BMI and waist circumference of the CVDs group were statistically significantly higher than the ND group (p < 0.001). While the total caffeine consumption of the ND group was 209.34 ± 143.85 mg/day, consumption of the CVDs group was 209.99 ± 196.76 mg/day. LDL cholesterol and total cholesterol did not show statistically significant difference between the two groups. However, HDL cholesterol was significantly higher in the ND group (p ≤ 0.001). Conclusion: Present results show that daily caffeine consumption may partially affect blood parameters associated with cardiovascular diseases, especially in the presence of coronary artery disease.

Caffeine intake and its association with nutrition, sleep, and physical activity among schoolchildren in the United Arab Emirates: a national cross-sectional study

PURPOSE

Recent surveys indicate a significant increase in total caffeine intake among schoolchildren. Limited research has been published concerning the total intake of caffeine among schoolchildren in the Middle East and Gulf Cooperation Council (GCC) countries, including the UAE.

METHODS

This cross-sectional survey estimated the total caffeine intake from foods and beverages among 10,275 schoolchildren in the UAE. Caffeine intakes were related to the European Food Safety Authority's level of no safety concern (3.0 mg/kg BW) and level of effects on sleep (1.4 mg/kg BW).

RESULTS

More than half (56.2%) of the students consumed more than 100 mg (the upper limit allowed) of caffeine from dietary sources. High intake of caffeine (> 100 mg/day) was significantly associated (p = 0.001) with reduced sleep duration, difficulty falling asleep, infrequent exercising, using smart devices for more than 2 h a day, getting a lower GPA, skipping breakfast, eating fewer servings of vegetables than recommended, frequent consumption of fast food and more frequent snack consumption.

CONCLUSION

Excessive intake of caffeine from different dietary sources coexists with unhealthy dietary and lifestyle behaviors and sleep problems. Tailoring educational programs and intervention strategies is warranted to correct the unhealthy intake of caffeine and the associated unhealthy dietary and lifestyle behaviors among schoolchildren in the UAE.

Does dietary intake of caffeine have an effect on transient global amnesia?

AIM

Amnesia is a cognitive disorder that may lead to memory loss. Caffeine is a psychoactive substance which have an effect on memory and cognitive functions. This study aimed to assess the association of transient global amnesia (TGA) with dietary intake of caffeine.

METHODS

This cross-sectional study was conducted on the Sabzevar Persian cohort data of 258 patients with TGA and 520 healthy individuals in Sabzevar, Iran. The Nutritional data were gathered in face-to-face interviews using a valid Food Frequency Questionnaire. Different models of logistic regression were used to determine the association between TGA and dietary caffeine intake after adjusting the confounders including age, sex, education, job, marital status, physical activity, BMI, and calorie intake.

RESULTS

There was no significant difference in terms of dietary calorie intake of (2279.5 ± 757.9 vs. 2365.5 ± 799.5, p = 0.19), protein (70.79 ± 25.27 vs. 72.94 ± 24.83, p = 0.31), fat (59.97 ± 23.79 vs. 60.13 ± 26.38, p = 0.93), carbohydrate (376 ± 134 vs. 393.1 ± 137.8, p = 0.14), and caffeine (196.4 ± 127.9 vs. 186.3 ± 128.5, p = 0.36) between the groups. No significant association was found between TGA and dietary intake of caffeine (OR: 0.99, 95% CI: 0.99-1.01, p = 0.36). The results did not change after adjusting the confounders.

CONCLUSIONS

No significant association was found between TGA and dietary intake of caffeine. Further prospective studies are required to confirm this finding.

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

BACKGROUND AND AIMS

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Effects of Caffeine-Taurine Co-Ingestion on Endurance Cycling Performance in High Temperature and Humidity Environments

BACKGROUND

Taurine (TAU) and caffeine (CAF), as common ergogenic aids, are known to affect exercise performance; however, the effects of their combined supplementation, particularly in high temperature and humidity environments, have not been studied.

HYPOTHESIS

The combination of TAU and CAF will have a greater effect on endurance cycle performance and improve changes in physiological indicators during exercise compared with TAU or CAF supplementation alone and placebo.

STUDY DESIGN

Single-blind crossover randomized controlled study.

LEVEL OF EVIDENCE

Level 1.

METHODS

Twelve university students majoring in physical education volunteered to receive 4 different supplement ingestions: (1) placebo (maltodextrin), (2) TAU, (3) CAF, (4) TAU + CAF. After a 7-day washout period, participants completed a time to exhaustion (TTE) test in the heat (35°C, 65% relative humidity).

RESULTS

All experimental groups improved TTE compared with the placebo group. Peak and mean power of countermovement jump were significantly higher in the CAF group compared with the placebo group before the exhaustion exercise (P = 0.02, d = 1.2 and P = 0.04, d = 1.1, respectively). Blood lactate was significantly lower after the exhaustion test in the TAU group compared with the CAF (P < 0.01, d = 0.8) and TAU + CAF (P < 0.01, d = 0.7) groups. Core temperature in the TAU group was significantly reduced in the placebo group later in the exhaustion test (P < 0.01, d = 1.9).

CONCLUSION

In high temperature and humidity environments, acute TAU, CAF, and combined supplementation all improved TTE and did not affect recovery from lower limb neuromuscular fatigue compared with placebo, with TAU having the best effect. Combined supplementation failed to exhibit superimposed performance.

CLINICAL RELEVANCE

The results provide suggestions for the effects of TAU, CAF, and their combined intake on exercise performance in high temperature and humidity environments.

Effect of Caffeine on the Inflammatory-Dependent Changes in the GnRH/LH Secretion in a Female Sheep Model

Caffeine is one of the most widely consumed psychoactive drugs in the world. It easily crosses the blood-brain barrier, and caffeine-interacting adenosine and ryanodine receptors are distributed in various areas of the brain, including the hypothalamus and pituitary. Caffeine intake may have an impact on reproductive and immune function. Therefore, in the present study performed on the ewe model, we decided to investigate the effect of peripheral administration of caffeine (30 mg/kg) on the secretory activity of the hypothalamic-pituitary unit which regulates the reproductive function in females during both a physiological state and an immune/inflammatory challenge induced by lipopolysaccharide (LPS; 400 ng/kg) injection. It was found that caffeine stimulated (p < 0.01) the biosynthesis of gonadotropin-releasing hormone (GnRH) in the hypothalamus of ewe under both physiological and inflammatory conditions. Caffeine also increased (p < 0.05) luteinizing hormone (LH) secretion in ewes in a physiological state; however, a single administration of caffeine failed to completely release the LH secretion from the inhibitory influence of inflammation. This could result from the decreased expression of GnRHR in the pituitary and it may also be associated with the changes in the concentration of neurotransmitters in the median eminence (ME) where GnRH neuron terminals are located. Caffeine and LPS increased (p < 0.05) dopamine in the ME which may explain the inhibition of GnRH release. Caffeine treatment also increased (p < 0.01) cortisol release, and this stimulatory effect was particularly evident in sheep under immunological stress. Our studies suggest that caffeine affects the secretory activity of the hypothalamic-pituitary unit, although its effect appears to be partially dependent on the animal's immune status.

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

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

Circadian neurogenetics and its implications in neurophysiology, behavior, and chronomedicine

The circadian rhythm affects multiple physiological processes, and disruption of the circadian system can be involved in a range of disease-related pathways. The genetic underpinnings of the circadian rhythm have been well-studied in model organisms. Significant progress has been made in understanding how clock genes affect the physiological functions of the nervous system. In addition, circadian timing is becoming a key factor in improving drug efficacy and reducing drug toxicity. The circadian biology of the target cell determines how the organ responds to the drug at a specific time of day, thus regulating pharmacodynamics. The current review brings together recent advances that have begun to unravel the molecular mechanisms of how the circadian clock affects neurophysiological and behavioral processes associated with human brain diseases. We start with a brief description of how the ubiquitous circadian rhythms are regulated at the genetic, cellular, and neural circuit levels, based on knowledge derived from extensive research on model organisms. We then summarize the latest findings from genetic studies of human brain disorders, focusing on the role of human clock gene variants in these diseases. Lastly, we discuss the impact of common dietary factors and medications on human circadian rhythms and advocate for a broader application of the concept of chronomedicine.

Concentration-effect relationships of plasma caffeine on EEG delta power and cardiac autonomic activity during human sleep

Acute caffeine intake affects brain and cardiovascular physiology, yet the concentration-effect relationships on the electroencephalogram and cardiac autonomic activity during sleep are poorly understood. To tackle this question, we simultaneously quantified the plasma caffeine concentration with ultra-high-performance liquid chromatography, as well as the electroencephalogram, heart rate and high-frequency (0.15-0.4 Hz) spectral power in heart rate variability, representing parasympathetic activity, with standard polysomnography during undisturbed human sleep. Twenty-one healthy young men in randomized, double-blind, crossover fashion, ingested 160 mg caffeine or placebo in a delayed, pulsatile-release caffeine formula at their habitual bedtime, and initiated a 4-hr sleep opportunity 4.5 hr later. The mean caffeine levels during sleep exhibited high individual variability between 0.2 and 18.4 μmol L-1 . Across the first two non-rapid-eye-movement (NREM)-rapid-eye-movement sleep cycles, electroencephalogram delta (0.75-2.5 Hz) activity and heart rate were reliably modulated by waking and sleep states. Caffeine dose-dependently reduced delta activity and heart rate, and increased high-frequency heart rate variability in NREM sleep when compared with placebo. The average reduction in heart rate equalled 3.24 ± 0.77 beats per minute. Non-linear statistical models suggest that caffeine levels above ~7.4 μmol L-1 decreased electroencephalogram delta activity, whereas concentrations above ~4.3 μmol L-1 and ~ 4.9 μmol L-1 , respectively, reduced heart rate and increased high-frequency heart rate variability. These findings provide quantitative concentration-effect relationships of caffeine, electroencephalogram delta power and cardiac autonomic activity, and suggest increased parasympathetic activity during sleep after intake of caffeine.

Vegan/vegetarian diet and human milk donation: An EMBA survey across European milk banks

The nutritional adequacy of human milk (HM) from vegan/vegetarian mothers has been a matter of debate, and a variety of recommendations regarding the eligibility of these mothers as human milk donors exists. According to the latest evidence, HM from vegans/vegetarians is similar in its composition to that from omnivores, however, some differences may be observed regarding vitamin B12 and omega-3 fatty acids concentrations. Maternal supplementation of these compounds has been proven effective in increasing their HM concentration. With this survey, we aimed to explore the practices currently in use in European human milk banks (HMBs) regarding potential donors following vegan/vegetarian diets. The online survey was distributed to European HMBs between January and July 2022. A total of 188 HMBs were contacted, and 118 replied (response rate 63%). Vegan and vegetarian mothers were recommended supplements of vitamin B12 to be accepted as donors in 27% and 26% of HMBs, respectively. Additional omega-3 fatty acid supplementation was required in 8% HMBs. In the remaining HMBs, these mothers were either systematically excluded or included regardless of supplementation. The dosage of the recommended supplements was extremely variable. Fifty-one percent of HMBs were following recommendations to guide their practice, national or local recommendations mainly. Great variability in European HMBs practices towards potential donors following vegan/vegetarian diets exists. Some of these practices can result in loss of donors and/or in potential nutritional deficiencies. Standardised evidence-based recommendations on this issue and their implementation in daily HMB practice are needed.

The SAFE study: Stress and fatigue control by exercise: Acute and long-term effects of aerobic exercise in lactating employed mothers

BACKGROUND

Stress and fatigue experienced by lactating employed mothers can affect mothers' and babies' mental and physical health detrimentally. Aerobic exercise is known to control stress and fatigue, but the dosages of the exercises needed to maintain long-term effects are still under investigation.

OBJECTIVE

This study aimed to investigate the acute and long-term effects of aerobic exercise on controlling stress and fatigue in lactating, employed mothers.

METHODS

This randomized control study involved sixty lactating, employed mothers suffering from stress and fatigue. They were divided into two groups: Group A received five sessions of 30-minute aerobic training on a treadmill per week, in addition to lifestyle modification advice for six weeks. Group B received the same lifestyle routine advice for the same duration without being trained. Assessments of stress and fatigue levels were done before, after 6 weeks, and after 6 months from the baseline assessments using the Perceived Stress Scale (PSS-10) and Fatigue Assessment Scale (FAS), respectively.

RESULTS

Post-six-week comparisons within and between both groups showed a significant decline in PSS-10 and FAS in group A compared with group B (p < 0.001); however, after six months of follow-up, there were statistically significant effects within groups only (p < 0.05) and no statistically significant difference between groups at both variables (p > 0.05).

CONCLUSION

Aerobic exercises for 6 weeks can induce an acute but not long-term effect on stress and fatigue control in lactating-employed mothers. Future research is needed to tailor the exercise prescription needed to maintain training's long-term benefits.

Caffeine intake during pregnancy and adverse outcomes: An integrative review

Caffeine intake during pregnancy is common. Caffeine crosses the placenta, raising concerns about its possible deleterious effects on the developing embryo/fetus. Studies on this subject show conflicting results, and still there is no consensus on the recommended dose of caffeine during pregnancy. We performed an integrative review with studies from six databases, using broad MESH terms to allow the identification of publications that addressed the outcomes of caffeine use during pregnancy, with no date limit for publications, in English and Portuguese language. The research returned 16,192 articles. After removing duplicates, screening by title, abstract and full-text, we evaluated 257 and included 59 articles. We found association between caffeine intake and pregnancy loss, low birth weight, cardiac and genital anomalies, higher body mass, and neurodevelopmental and neurobehavioral outcomes. The effects were often dose dependent. No association with prematurity has been demonstrated, but one study showed a small reduction in gestational age with increasing doses of caffeine intake. Defining a safe dose for caffeine intake during pregnancy is a challenging task due to the heterogeneity in study designs and results, as well as the difficulty of reliably assessing the amount of caffeine consumed. In some studies, exposures below the recommended level of caffeine intake during pregnancy (200 mg/day), as suggested by the guidelines, were associated with pregnancy loss, low birth weight, cardiac and genital anomalies, higher body mass, and neurodevelopmental and neurobehavioral outcomes. Well-designed studies with reliable quantification of caffeine intake are needed to assess the safety of low doses during pregnancy.

Complementary and alternative supplements: a review of dermatologic effectiveness for androgenetic alopecia

Background

Androgenetic alopecia (AGA) is a dermatologic condition with no current cure. Treatments such as minoxidil have been proven to be effective; however, the side effects can be unpleasant. As a result, the utilization of natural remedies for treatment has increased over the years. There is limited scientific evidence that addresses the efficacy of these supplements in combating AGA.

Methods

A review was conducted of the effectiveness of popular complementary and alternative medicines (CAMs) in adult patients experiencing AGA. A literature search was performed for the period of 1993 to 2023 using PubMed, Embase, Google Scholar, Web of Science, and Cochrane.

Results

Natural ingredients like pumpkin seed oil, saw palmetto, melatonin extract, caffeine extract, and rosemary oil were effective in treating AGA either when compared to baseline or a definite AGA Western medication, such as minoxidil. These natural agents also presented minimal side effects.

Conclusion

Certain CAMs can be promising for hair loss treatment. There is a need for more scientific research to better explore the efficacy of currently identified CAMs in treating AGA.

Caffeinated Soda Intake in Children Is Associated with Neurobehavioral Risk Factors for Substance Misuse

BACKGROUND AND OBJECTIVES

Use of psychotropic substances in childhood has been associated with both impulsivity and other manifestations of poor executive function as well as escalation over time to use of progressively stronger substances. However, how this relationship may start in earlier childhood has not been well explored. Here, we investigated the neurobehavioral correlates of daily caffeinated soda consumption in preadolescent children and examined whether caffeinated soda intake is associated with a higher risk of subsequent alcohol initiation.

METHODS

Using Adolescent Brain Cognitive Development study data (N = 2,092), we first investigated cross-sectional relationships between frequent caffeinated soda intake and well-known risk factors of substance misuse: impaired working memory, high impulsivity, and aberrant reward processing. We then examined whether caffeinated soda intake at baseline predicts more alcohol sipping at 12 months follow-up using a machine learning algorithm.

RESULTS

Daily consumption of caffeinated soda was cross-sectionally associated with neurobehavioral risk factors for substance misuse such as higher impulsivity scores and lower working memory performance. Furthermore, caffeinated soda intake predicted a 2.04 times greater likelihood of alcohol sipping after 12 months, even after controlling for rates of baseline alcohol sipping rates.

CONCLUSIONS

These findings suggest that previous linkages between caffeine and substance use in adolescence also extend to younger initiation, and may stem from core neurocognitive features thought conducive to substance initiation.

Loneliness Is Associated With Problematic Internet Use but Not With the Frequency of Substance Use: A Czech Cross-Sectional Study

Objectives: This study aimed to assess the associations between loneliness and the frequency of substance use and problematic Internet use (PIU) in different age groups. Methods: Data were collected in April 2021 from a sample of 1,293 participants with main characteristics close to a nationally representative sample (mean age = 50.1 ± 15.4 years; 56% male). We measured loneliness with the Three-Item Loneliness Scale (TILS), PIU with the General Problematic Internet Use Scale-2 (GPIUS-2) and the frequency of drugs, alcohol, smoking or caffeine consumption. Spearman's correlation, the t-test, and one-way and multivariate linear regression models were used to analyze the data. Results: In our study, 43.8% of respondents reported moderate to severe levels of loneliness. Loneliness was associated with the severity of PIU [F (3, 1,277) = 15.25, p < 0.001], with higher loneliness corresponding to higher PIU. No significant relationship was found between loneliness and drugs, alcohol, smoking or caffeine consumption. Conclusion: Regardless of age, loneliness is associated with PIU but not with the frequency of substance use. Professional help for lonely people should focus on problematic Internet use in all age groups.

Extraction methods, physiological activities and high value applications of tea residue and its active components: a review

Tea is a traditional plant beverage originating from China as one of the most popular beverages worldwide, which has been an important companion in modern society. Nevertheless, as the waste after tea processing, tea residues from agriculture, industry and kitchen waste are discarded in large quantities, resulting in waste of resources and environmental pollution. In recent years, the comprehensive utilization of tea residue resources has attracted people's attention. The bioactive components remaining in tea residues demonstrate a variety of health benefits and can be recycled using advanced extraction processes. Furthermore, researchers have been devoted to converting tea residues into derivatives such as biosorbents, agricultural compost, and animal feeds through thermochemical techniques and biotechnology. This review summarized the chemical composition and physiological activities of bioactive components from tea residue. The extraction methods of bioactive components in tea residue were elucidated and the main high-value applications of tea residues were proposed. On this basis, the utilization of tea residues can be developed from a single way to a multi-channel or cascade way to improve its economic efficiency. Novel applications of tea residues in different fields, including food development, environmental remediation, energy production and composite materials, are of far-reaching significance. This review aims to provide new insights into developing the utilization of tea residue using a comprehensive strategy and exploring the mechanism of active components from tea residue on human health and their potential applications in different areas.HighlightsThe composition and function of tea residue active components were introduced.The extraction methods of active components from tea residue were proposed.The main high-value applications of tea residues were summarized.The current limitations and future directions of tea residue utilization were concluded.

Association between tea drinking and disability levels in older Chinese adults: a longitudinal analysis

Objective

As the global population ages, disability among the elderly presents unprecedented challenges for healthcare systems. However, limited research has examined whether dietary interventions like tea consumption may alleviate and prevent disability in older adults. As an important dietary therapy, the health benefits of tea drinking have gained recognition across research disciplines. Therefore, this study aimed to investigate the association between tea drinking habits and disability levels in the elderly Chinese population.

Methods

Leveraging data from the 2008 to 2018 waves of the Chinese Longitudinal Healthy Longevity Survey, we disaggregated tea drinking frequency and activities of daily living (ADL) measures and deployed fixed-effect ordered logit models to examine the tea-disability association for the first time. We statistically adjusted for potential confounders and conducted stratified analyses to assess heterogeneity across subpopulations.

Results

Multivariable fixed-effect ordered logistic regression suggested tea drinking has protective effects against ADL disability. However, only daily tea drinking was associated with lower risks of basic activities of daily living (BADL) disability [odds ratio (OR) = 0.61; 95% confidence interval (CI), 0.41-0.92] and lower levels of instrumental activities of daily living (IADL) disability (OR = 0.78; 95% CI, 0.64-0.95). Stratified analyses indicated heterogeneous effects across age and income groups. Daily tea drinking protected against BADL (OR = 0.26 and OR = 0.28) and IADL disability (OR = 0.48 and OR = 0.45) for adults over 83 years old and high-income households, respectively.

Conclusion

We found that drinking tea almost daily was protective against disability in elderly people, warranting further research into optimal dosages. Future studies should utilize more rigorous causal inference methods and control for confounders.

Methylliberine Ingestion Improves Various Indices of Affect but Not Cognitive Function in Healthy Men and Women

This study assessed the acute effects of oral methylliberine (DynamineTM) supplementation on cognitive function and indices of well-being. This was a double-blind, randomized, within-subject crossover trial. In total, 25 healthy men and women (33.5 ± 10.7 yr, 172.7 ± 8.6 cm, 73.3 ± 11.0 kg) underwent pretesting before ingesting methylliberine (100 mg) or a placebo (PLA) for 3 days. On the fourth day, the participants were tested before their fourth dose (baseline) and every hour post-ingestion for 3 h. After a one-week washout period, the participants repeated testing with the alternate investigational product. The testing battery consisted of vitals, Stroop test, Trail Making Test-B, and visual analog scales that assessed various indices of well-being. Mixed factorial ANOVAs with repeated measures were used to assess all variables. There were significant (p ≤ 0.050) interactions in terms of concentration, motivation, and mood. Methylliberine improved concentration at 1 and 3 h, motivation at 3 h, and mood at 1, 2, and 3 h (p ≤ 0.050). Methylliberine improved energy, sustained energy, and mood in all participants to a greater extent than PLA at 1 h and 3 h relative to baseline (p ≤ 0.050). PLA improved motivation at 1 and 2 h and mood at 2 h (p ≤ 0.050). Methylliberine improved concentration, well-being, and the ability to tolerate stress to a greater extent than PLA at 3 h relative to baseline (p ≤ 0.050). Women observed elevations in sustained energy at 1 and 3 h (p ≤ 0.050) with methylliberine vs. PLA. Methylliberine had a negligible influence on cognitive function and vitals (p > 0.050), and no adverse events were reported. Methylliberine significantly improved subjective feelings of energy, concentration, motivation, and mood, but not cognitive function. PLA improved motivation and mood at hours 1 and 2, while methylliberine sustained these benefits for longer. Methylliberine also improved concentration, well-being, and the ability to tolerate stress to a greater degree than PLA, while having no detrimental effects on vital signs. Methylliberine also seemed to have a positive impact on sustained energy in women.

Caffeine Consumption and Depression, Anxiety, and Stress Levels Among University Students in Medina: A Cross-Sectional Study

Introduction Caffeine is a psychoactive stimulant frequently found in coffee, tea, energy drinks, and some medications. Various mental health challenges, including stress, anxiety, and depression, commonly affect college students. Moreover, an individual's mental and physical health can be significantly impacted by stress, anxiety, and depression. However, the impact of caffeine on mental health, particularly its association with depressive and anxiety symptoms, remains inconclusive. Thus, this study aimed to evaluate the amount of caffeine consumed by university students and its association with depression, anxiety, and stress levels. Material and method This cross-sectional study was performed on Taibah University students in Medina from both health-related and non-health-related colleges. We used a self-administrated questionnaire composed of four sections: the informed consent section; sociodemographic information; the Depression, Anxiety, and Stress Scale (DASS-21), which assessed the depression, anxiety, and stress levels; and a caffeine-measuring questionnaire, which reported daily caffeine intake in milligrams per day. Result This cross-sectional study examined a 520 convenience sample of Taibah University students with an age range from 17 to 29 years. The majority of the participants were single (95.2%), most of them were female (73.8%), and slightly more than half (51.5%) were recruited from health-related colleges. According to the study's DASS-21 score results, 45.8% of the students had extremely severe stress, 61% had extremely severe anxiety, and 51% had extremely severe depression. The most frequently reported sources of daily caffeine among the participants were Arabic coffee (69.6%), specialty coffee (57.5%), black tea (56.3%), cola (48.7%), and regular coffee (48.5%). The overall daily amount of consumed caffeine ranged from zero to 4276.7 mg/oz. However, no significant association was found between the severity of the DASS-21 score and the daily consumption of caffeine among Taibah University students. Conclusion Our study shows no significant association between the severity of depression, anxiety, and stress and daily caffeine consumption among university students. This proves the opposite of the theory that high levels of caffeine consumption can be correlated to high levels of depression, stress, and anxiety.

Assessment of caffeine intake in groups of pregnant and breastfeeding women: A cross-sectional analysis

BACKGROUND & AIMS

Caffeine is commonly consumed by pregnant and breastfeeding women. The maximum safe dose of caffeine in their diet is 200 mg per day, according to the European Food Safety Authority. The purpose of this study was to assess the consumption of caffeinated products by pregnant and breastfeeding women, as well as to estimate their caffeine intake.

METHODS

The number of subjects who qualified for the study was 1112 women, of whom 401 were pregnant and 711 were breastfeeding. The research was conducted with the use of a questionnaire, which included information about food frequency and history of consumption of caffeinated products during the past 3 days.

RESULTS

The median (interquartile range) daily caffeine intake among pregnant women was 114.5 (57.6-202.8) mg, and the level of caffeine intake increased with the duration of pregnancy (p < 0.001). For breastfeeding women it was 193.7 (100.5-324.8) mg/d. The majority of participants (58.9%) were not able to correctly identify the safe amount of caffeine in their diets. It was observed that the intake of 73.8% of pregnant women and 51.9% of breastfeeding women fit within the safe range (0-200 mg/d). The main sources of caffeine were ground coffee, black tea, and instant coffee. For 63,6% of women knowledge about nutrition and supplementation came most often from blogs and social media run by medical professionals. Pleasure was the main reason for drinking coffee and tea.

CONCLUSION

Most pregnant women did not exceed the recommended maximum daily dose of caffeine, while breastfeeding women often did.

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

Background

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

Objective

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

Methods

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

Results

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

Conclusion

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

Caffeine exacerbates seizure-induced death via postictal hypoxia

Sudden unexpected death in epilepsy (SUDEP) is the leading epilepsy-related cause of premature mortality in people with intractable epilepsy, who are 27 times more likely to die than the general population. Impairment of the central control of breathing following a seizure has been identified as a putative cause of death, but the mechanisms underlying this seizure-induced breathing failure are largely unknown. Our laboratory has advanced a vascular theory of postictal behavioural dysfunction, including SUDEP. We have recently reported that seizure-induced death occurs after seizures invade brainstem breathing centres which then leads to local hypoxia causing breathing failure and death. Here we investigated the effects of caffeine and two adenosine receptors in two models of seizure-induced death. We recorded local oxygen levels in brainstem breathing centres as well as time to cessation of breathing and cardiac activity relative to seizure activity. The administration of the non-selective A1/A2A antagonist caffeine or the selective A1 agonist N6-cyclopentyladenosine reveals a detrimental effect on postictal hypoxia, providing support for caffeine modulating cerebral vasculature leading to brainstem hypoxia and cessation of breathing. Conversely, A2A activation with CGS-21680 was found to increase the lifespan of mice in both our models of seizure-induced death.

Characteristics of Chitosan Films with the Bioactive Substances-Caffeine and Propolis

Chitosan is a natural and biodegradable polymer with promising potential for biomedical applications. This study concerns the production of chitosan-based materials for future use in the medical industry. Bioactive substances-caffeine and ethanolic propolis extract (EEP)-were incorporated into a chitosan matrix to increase the bioactivity of the obtained films and improve their mechanical properties. Acetic and citric acids were used as solvents in the production of the chitosan-based films. The obtained materials were characterized in terms of their antibacterial and antifungal activities, as well as their mechanical properties, including tensile strength and elongation at break. Moreover, the chemical structures and surface morphologies of the films were assessed. The results showed that the solution consisting of chitosan, citric acid, caffeine, and EEP exhibited an excellent antiradical effect. The activity of this solution (99.13%) was comparable to that of the standard antioxidant Trolox (92.82%). In addition, the film obtained from this solution showed good antibacterial activity, mainly against Escherichia coli and Enterococcus faecalis. The results also revealed that the films produced with citric acid exhibited higher activity levels against pathogenic bacteria than the films obtained with acetic acid. The antimicrobial effect of the chitosan-based films could be further enhanced by adding bioactive additives such as caffeine and propolis extract. The mechanical tests showed that the solvents and additives used affected the mechanical properties of the films obtained. The film produced from chitosan and acetic acid was characterized by the highest tensile strength value (46.95 MPa) while the chitosan-based film with citric acid showed the lowest value (2.28 MPa). The addition of caffeine and propolis to the film based on chitosan with acetic acid decreased its tensile strength while in the case of the chitosan-based film with citric acid, an increase in strength was observed. The obtained results suggested that chitosan films with natural bioactive substances can be a promising alternative to the traditional materials used in the medical industry, for example, as including biodegradable wound dressings or probiotic encapsulation materials.

A Determination of the Caffeine Content in Dietary Supplements According to Green Chemistry Principles

Caffeine is a natural psychoactive substance that belongs to a group of chemical compounds called purine alkaloids. Caffeine is found in various plants such as coffee, tea, cocoa, guarana, and yerba mate. It is often added to dietary supplements for its ability to increase metabolism and aid in weight loss. To determine the caffeine content in dietary supplements, a novel UHPLC method was developed, compatible with the rules of green analytical chemistry. The developed method used only water and ethanol for sample preparation and chromatographic separation on a short C18 column. The obtained method confirmed that caffeine may be analyzed using only environmentally friendly solvents, ethanol, and water. The developed method is characterized by its low limit of quantitation, equal to 0.047 µg/mL, and good reproducibility (a relative standard deviation lower than 1.1%). The obtained results show that the caffeine content in tested dietary supplements is 4-35% higher than the declared amount in most cases. In comparison, the caffeine content of the drug determined using this method was performed with an accuracy of 0.4% RSD.

Maternal dietary caffeine consumption and risk of birth defects in the National Birth Defects Prevention Study, 1997-2011

BACKGROUND

Caffeine consumption is common during pregnancy, but published associations with birth defects are mixed. We updated estimates of associations between prepregnancy caffeine consumption and 48 specific birth defects from the National Birth Defects Prevention Study (NBDPS) for deliveries from 1997 to 2011.

METHODS

NBDPS was a large population-based case-control study conducted in 10 U.S. states. We categorized self-reported total dietary caffeine consumption (mg/day) from coffee, tea, soda, and chocolate as: <10, 10 to <100, 100 to <200, 200 to <300, and ≥ 300. We used logistic regression to estimate adjusted odds ratios (aORs [95% confidence intervals]). Analyses for defects with ≥5 exposed case children were adjusted for maternal race/ethnicity, age at delivery, body mass index, early pregnancy cigarette smoking and alcohol use, and study site.

RESULTS

Our analysis included 30,285 case and 11,502 control children, with mothers of 52% and 54%, respectively, reporting consuming <100 mg caffeine, and 11% of mothers of both cases and controls reported consuming ≥300 mg per day. Low (10 to <100 mg/day) levels of prepregnancy caffeine consumption were associated with statistically significant increases in aORs (1.2-1.7) for 10 defects. Associations with high (≥300 mg/day) levels of caffeine were generally weaker, except for craniosynostosis and aortic stenosis (aORs = 1.3 [1.1-1.6], 1.6 [1.1-2.3]).

CONCLUSIONS

Given the large number of estimates generated, some of the statistically significant results may be due to chance and thus the weakly increased aORs should be interpreted cautiously. This study supports previous observations suggesting lack of evidence for meaningful associations between caffeine consumption and the studied birth defects.

G protein-coupled receptors in neurodegenerative diseases and psychiatric disorders

Neuropsychiatric disorders are multifactorial disorders with diverse aetiological factors. Identifying treatment targets is challenging because the diseases are resulting from heterogeneous biological, genetic, and environmental factors. Nevertheless, the increasing understanding of G protein-coupled receptor (GPCR) opens a new possibility in drug discovery. Harnessing our knowledge of molecular mechanisms and structural information of GPCRs will be advantageous for developing effective drugs. This review provides an overview of the role of GPCRs in various neurodegenerative and psychiatric diseases. Besides, we highlight the emerging opportunities of novel GPCR targets and address recent progress in GPCR drug development.

Determinants of pupils' energy drink consumption - Findings from a Hungarian primary school

Consumption of energy drinks is harmful in childhood and adolescence, and its increasing popularity makes it a public health threat in this age group. Our study aimed to assess energy drink (ED) consumption and identify the context and determinants of its consumption at a Hungarian primary school. A mixed-method approach was used for the research, including a survey filled in by 157 10-15-year-old pupils and World Café workshops (WCWs) involving pupils, home-room teachers, and Parental Council representatives (N = 39). The Jamovi 2.2.5. The software was used to perform descriptive statistics and logistic regression, and a causal loop diagram was created based on the results of the WCWs. The survey results revealed that almost one-third of the pupils consumed EDs regularly, and most daily consumers drank high amounts (500ml). Most students considered ED consumption unhealthy, yet every fifth drank them. Buying breakfast on the way to school increased the odds of ED consumption almost threefold. According to the WCWs' findings, the determinants of ED consumption were embedded in two critical contextual sets; one was the need for energy and concentration boost and the Perception of high social acceptance of ED consumption. Our results suggest that interventions to reduce students' ED consumption need to include increased parents' involvement in controlling their children's screen time and encouraging them to provide breakfast at home for their children. There is also an urgent need to restrict the marketing of EDs and strictly regulate access to EDs for under-18s.

Psychometric evaluation of the Chinese version of Sleep Health Index in pregnant women

OBJECTIVE

The aim of this study was to investigate the psychometric properties of the Chinese version of the Sleep Health Index (SHI-C) among pregnant women.

DESIGN

Cross-sectional design.

SETTING

Outpatient clinic of three hospitals in China.

PARTICIPANTS

Pregnant women (N = 264) aged between 18 and 45 years were recruited via convenience sampling.

METHODS

The Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS) and Insomnia Severity Index (ISI) were used to measure sleep quality, daytime sleepiness, and insomnia, respectively. The Fatigue Assessment Scale (FAS) and the Edinburgh Postnatal Depression Scale (EPDS) were used to measure fatigue and depression, respectively. Structural validity was assessed via confirmatory factor analysis (CFA). Concurrent and convergent validity were assessed using bivariate correlation analyses. Known-group validity was assessed by comparing the SHI-C score between different groups. Cronbach's α was calculated for reliability.

FINDINGS

The average sample age was 30.6 years old and their average score of SHI-C was 86.4 (SD 8.2). Based on PSQI, ISI, and ESS, 43.6%, 32.2%, and 26.9% had poor sleep quality, insomnia, and excessive daytime sleepiness, respectively. The SHI-C total and sleep quality sub-index scores had moderate to strong correlations with both PSQI (r=-0.542, p<0.01; r=-0.648, p<0.01) and ISI (r=-0.692, p<0.01; r=-0.752, p<0.01). The SHI-C total and sleep quality sub-index scores were significantly associated with ESS, FAS, and EPDS (r=-0.171 to -0.276; p<0.01). The SHI-C total score was higher in the second trimester and among those who were working, never drank coffee, or took a nap every day. The Cronbach's α of the SHI-C total and the sleep quality sub-index were 0.723 and 0.806, respectively. The Cronbach's α of sleep duration and disordered sleep sub-indices were 0.594 and 0.545, respectively.

KEY CONCLUSIONS

Overall, the SHI-C has good validity and acceptable reliability among the pregnant population in China. It can be a useful tool for the assessment of sleep health. More research is warranted to refine the sleep duration and disordered sleep sub-indices.

IMPLICATIONS FOR PRACTICE

The use of SHI-C would facilitate the assessment of sleep health among pregnant women, which could contribute to the promotion of perinatal care.

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

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

Awake and Alert: Examining the Portrayal of Energy Drinks on TikTok

PURPOSE

Energy drinks (EDs) are not recommended for minors' consumption due to a myriad of health risks, but marketing initiatives persist. This study explored the promotion of EDs on TikTok, a platform frequented by children and adolescents.

METHODS

197 highly viewed videos from the four top ED-related hashtags on TikTok were coded for engagement variables, user information, sponsorship status, video content, and sentiment toward EDs.

RESULTS

Of the 197 videos analyzed (combined 70 + million views), 29% disclosed sponsorship and 22% featured a child/adolescent. ED consumption appeared in 46% of videos, with 15% depicting hazardous consumption. Most videos (67%) had a positive sentiment toward EDs.

DISCUSSION

ED-related TikTok videos are positively framed, have high engagement, and are not restricted for viewing by minors. As the platform's underage user-base grows, such videos may encourage heightened consumption. Given the known health risks, effective age-gated content restrictions are needed to reduce minors' exposure.

Long-term Pu-erh tea consumption improves blue light-induced depression-like behaviors

Blue light emitted by smartphones and tablets at night increases the risk of depression. Pu-erh tea has been reported to reduce the risk of depression by regulating tryptophan metabolism, but its underlying protective mechanism on depression induced by blue light at night (BLAN) remains unclear. In this work, two groups of C57BL6/J mice were given water or 0.25% (w/v) Pu-erh tea for 120 days, followed by a 45-day BLAN treatment (400 lux blue light between 21:00 and 23:00) to simulate blue light emitted from electronic equipment. Our results indicated that BLAN induced depression-like behaviors and gut microbiota disorders in healthy mice. Pu-erh tea intake significantly reshaped the gut microbiome (especially Bifidobacterium) and regulated the metabolism of short-chain fatty acids (SCFAs) which protected the integrity of the intestinal barrier. This improvement further reduced blood-brain barrier (BBB) damage and alleviated neuroinflammation by inhibiting MyD88/NF-κB pathways which finally regulated neurotransmitters such as brain-derived neurotrophic factor (BDNF) and serotonin (5-hydroxytryptamine, 5-HT). Collectively, 0.25% (w/v) Pu-erh tea has the potential to prevent BLAN-induced depression-like behaviors by reshaping the gut microbiota and increasing the generation of SCFAs via the gut-brain axis.

Prevalence, characteristics, and factors associated with caffeine-withdrawal headache during the first day of Ramadan

BACKGROUND

Data regarding prevalence, characteristics, and factors associated with caffeine-withdrawal headache are lacking. This work aimed to study the prevalence of caffeine-withdrawal headache among caffeine consumers during Ramadan's first day and describe its characteristics and associated factors.

METHODS

This analytical cross-sectional study targeted 755 caffeine consumers eligible to fast on the first day of Ramadan. Two methodological approaches were followed: an online open survey and a face-to-face interview. Using an adjusted form of food frequency questionnaire, eligible participants were requested to report their intake of caffeine-containing products during the last week of Shaaban month, the month preceding Ramadan.

RESULTS

The prevalence of caffeine-withdrawal headache on the first day of Ramadan was 419 (55.5%), with 95% confidence interval (CI; 51.9-59.0%). The headache in the majority of the participants was throbbing in character (249/419, 59.4%), diffuse (146/419, 34.8%), and moderate in intensity (227/419, 54.2%). Participants who developed caffeine-withdrawal headache had significantly higher body mass index (27.2 ± 5.1 vs. 26.3 ± 5 [mean ± standard deviation], p-value = 0.012), daily caffeine intake, mg (316 [185.2-537.8] vs. 144.4 [60.0-312.4] [median interquartile range (IQR)], p-value < 0.001), and caffeine intake mg/kg body weight (4.7 [2.6-7.2] vs. 1.9 [0.8-4.4] [median (IQR)], p-value < 0.001) than participants who did not develop it. Mild, moderate, and severe caffeine use disorder were found to have adjusted associations with developing caffeine-withdrawal headache. They increased the odds of headache by 5.3 (95% CI = 3.40-8.3), 10.2 (95% CI = 5.9-17.5), and 15.5 (95% CI = 9.0-26.8) times, respectively. The optimal cut-off value of daily caffeine intake/Kg body weight was determined at 1.97 mg/kg with an area under the curve of 0.722 and sensitivity and specificity of 85.1% and 50.2%, respectively.

CONCLUSION

Daily caffeine intake/kg body weight and caffeine use disorder are significantly associated with a caffeine-withdrawal headache.

Successful Use of Continuous Veno-Venous Haemodialysis in a Case of Potential Lethal Caffeine Intoxication

Here we describe the case of a potentially lethal caffeine intoxication after the reported ingestion of 10 g of caffeine. Due to hemodynamic instability with tachycardia and hypertension with an insufficient effect of continuous labetalol infusion, the patient was started on continuous veno-venous haemodialysis (CVVHD). After successful treatment for 15 h, CVVHD could be discontinued, and the patient was discharged home the next day. This case report is the first to report the use of CVVHD as a haemodialysis modality in the case of caffeine intoxication and illustrate the effect on caffeine clearance. We stress the importance of an early recognition of caffeine intoxication, so that haemodialysis can be considered in the case of a potentially lethal intoxication.

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

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

The duration of caffeine treatment plays an essential role in its effect on sleep and circadian rhythm

Sleep is regulated by the homeostatic system and the circadian clock. Caffeine intake promotes wakefulness in Drosophila. In humans, caffeine is consumed on a daily basis and hence it is important to understand the effect of prolonged caffeine intake on both circadian and homeostatic regulation of sleep. Furthermore, sleep changes with age and the impact of caffeine on age-dependent sleep fragmentation are yet to be understood. Hence in the present study, we examined the effect of short exposure to caffeine on homeostatic sleep and age-dependent sleep fragmentation in Drosophila. We further assessed the effect of prolonged exposure to caffeine on homeostatic sleep and circadian clock. The results of our study showed that short exposure to caffeine reduces sleep and food intake in mature flies. It also enhances sleep fragmentation with increasing age. However, we have not assessed the effect of caffeine on food intake in older flies. On the other hand, prolonged caffeine exposure did not exert any significant effect on the duration of sleep and food intake in mature flies. Nevertheless, prolonged caffeine ingestion decreased the morning and evening anticipatory activity in these flies indicating that it affects the circadian rhythm. These flies also exhibited phase delay in the clock gene timeless transcript oscillation and exhibited either behavioral arrhythmicity or a longer free-running period under constant darkness. In summary, the results of our studies showed that short exposure to caffeine increases the sleep fragmentation with age whereas prolonged caffeine exposure disrupts the circadian clock.

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

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

The effect of caffeine on subsequent sleep: A systematic review and meta-analysis

The consumption of caffeine in response to insufficient sleep may impair the onset and maintenance of subsequent sleep. This systematic review and meta-analysis investigated the effect of caffeine on the characteristics of night-time sleep, with the intent to identify the time after which caffeine should not be consumed prior to bedtime. A systematic search of the literature was undertaken with 24 studies included in the analysis. Caffeine consumption reduced total sleep time by 45 min and sleep efficiency by 7%, with an increase in sleep onset latency of 9 min and wake after sleep onset of 12 min. Duration (+6.1 min) and proportion (+1.7%) of light sleep (N1) increased with caffeine intake and the duration (-11.4 min) and proportion (-1.4%) of deep sleep (N3 and N4) decreased with caffeine intake. To avoid reductions in total sleep time, coffee (107 mg per 250 mL) should be consumed at least 8.8 h prior to bedtime and a standard serve of pre-workout supplement (217.5 mg) should be consumed at least 13.2 h prior to bedtime. The results of the present study provide evidence-based guidance for the appropriate consumption of caffeine to mitigate the deleterious effects on sleep.

Quantitative proteomics reveals common and unique molecular mechanisms underlying beneficial effects of caffeine and trigonelline on human hepatocytes

Caffeine and trigonelline are the major bioactive compounds in coffee. Caffeine alone or combined with other coffee compounds shows hepatoprotective effects. However, molecular mechanisms underlying such hepatoprotective effects remain unclear. We therefore addressed molecular effects of caffeine and trigonelline on human hepatocytes using quantitative proteomics followed by bioinformatic analyses to obtain topological and functional significance. HepG2 cells were treated with 100 μM caffeine or trigonelline for 24-h and evaluated by quantitative proteomics using nanoLC-ESI-LTQ-Orbitrap MS/MS. A total of 26 and 25 significantly altered proteins were identified in caffeine-treated and trigonelline-treated cells, respectively, compared with control cells. Topological analyses revealed that ribosomal and translation regulatory proteins predominantly served as the hub proteins associated with protein clusters. Functional analyses also revealed that these two bioactive compounds shared some molecular mechanisms via induction of translational processes. There were also other unique molecular functions and biological processes triggered or suppressed by either caffeine or trigonelline. These data highlight common and unique molecular mechanisms underlying the hepatoprotective effects of caffeine and trigonelline that may be useful for future clinical applications.

PGRMC1: An enigmatic heme-binding protein

Progesterone Receptor Membrane Component 1 (PGRMC1) is a heme-binding protein that has been implicated in a wide range of cell and tissue functions, including cytochromes P450 activity, heme homeostasis, cancer, female reproduction, and protein quality control. Despite an extensive body of literature, a relative lack of mechanistic insight means that how PGRMC1 functions in these different aspects of biology is largely unknown. This review provides an overview of the PGRMC1 literature, highlighting what information is rigorously supported by experimental evidence and where additional investigation is warranted. The central role of PGRMC1 in supporting cytochrome P450 activity is discussed at length. Building on existing models of PGRMC1 function, a speculative model is proposed using the reviewed literature in which PGRMC1 functions as a heme chaperone to shuttle heme from its site of synthesis in the mitochondrion to other subcellular compartments. By spotlighting knowledge gaps, this review will motivate investigators to better understand this enigmatic protein.

Coffee consumption, health benefits and side effects: a narrative review and update for dietitians and nutritionists

Coffee is one of the most popular beverages worldwide; however, its impact on health outcomes and adverse effects is not fully understood. The current review aims to establish an update about the benefits of coffee consumption on health outcomes highlighting its side effects, and finally coming up with an attempt to provide some recommendations on its doses. A literature review using the PubMed/Medline database was carried out and the data were summarized by applying a narrative approach using the available evidence based on the literature. The main findings were the following: first, coffee may contribute to the prevention of inflammatory and oxidative stress-related diseases, such as obesity, metabolic syndrome and type 2 diabetes; second, coffee consumption seems to be associated with a lower incidence of several types of cancer and with a reduction in the risk of all-cause mortality; finally, the consumption of up to 400 mg/day (1-4 cups per day) of caffeine is safe. However, the time gap between coffee consumption and some drugs should be taken into account in order to avoid interaction. However, most of the data were based on cross-sectional or/and observational studies highlighting an association of coffee intake and health outcomes; thus, randomized controlled studies are needed in order to identify a causality link.

Caffeine Delays Ethanol-Induced Sedation in Drosophila

Caffeine and ethanol are among the most widely available and commonly consumed psychoactive substances. Both interact with adenosine receptor-mediated signaling which regulates numerous neurological processes including sleep and waking behaviors. In mammals, caffeine is an adenosine receptor antagonist and thus acts as a stimulant. Conversely, ethanol is a sedative because it promotes GABAergic neurotransmission, inhibits glutamatergic neurotransmission, and increases the amount of adenosine in the brain. Despite seemingly overlapping interactions, not much is known about the effect of caffeine on ethanol-induced sedation in Drosophila. In this study, using Drosophila melanogaster as a model, we show that caffeine supplementation in food delays the onset of ethanol-induced sedation in males and females of different strains. The resistance to sedation reverses upon caffeine withdrawal. Heterozygous adenosine receptor mutant flies are resistant to sedation. These findings suggest that caffeine and adenosine receptors modulate the sedative effects of ethanol in Drosophila.