Caffeinated energy drinks--a growing problem

Managing interactions between cognitive enhancers and other psychotropics

Polypharmacy is common in psychiatry. Usage of cognitive enhancers is increasing in the psychiatric population. Many clinicians are not familiar with these new psychoactive compounds. This paper reviews the potential drug-drug interactions when these cognitive enhancers are used together with psychotropic drugs and their confounding effects on diagnosis and clinical management.

Coffee and caffeine intake and male infertility: a systematic review

BACKGROUND

Semen quality, a predictor of male fertility, has been suggested declining worldwide. Among other life style factors, male coffee/caffeine consumption was hypothesized to influence semen parameters, but also sperm DNA integrity. To summarize available evidence, we performed a systematic review of observational studies on the relation between coffee/caffeine intake and parameters of male fertility including sperm ploidy, sperm DNA integrity, semen quality and time to pregnancy.

METHODS

A systematic literature search was performed up to November 2016 (MEDLINE and EMBASE). We included all observational papers that reported the relation between male coffee/caffeine intake and reproductive outcomes: 1. semen parameters, 2. sperm DNA characteristics, 3. fecundability. All pertinent reports were retrieved and the relative reference lists were systematically searched in order to identify any potential additional studies that could be included.

RESULTS

We retrieved 28 papers reporting observational information on coffee/caffeine intake and reproductive outcomes. Overall, they included 19,967 men. 1. Semen parameters did not seem affected by caffeine intake, at least caffeine from coffee, tea and cocoa drinks, in most studies. Conversely, other contributions suggested a negative effect of cola-containing beverages and caffeine-containing soft drinks on semen volume, count and concentration. 2. As regards sperm DNA defects, caffeine intake seemed associated with aneuploidy and DNA breaks, but not with other markers of DNA damage. 3. Finally, male coffee drinking was associated to prolonged time to pregnancy in some, but not all, studies.

CONCLUSIONS

The literature suggests that caffeine intake, possibly through sperm DNA damage, may negatively affect male reproductive function. Evidence from epidemiological studies on semen parameters and fertility is however inconsistent and inconclusive. Well-designed studies with predefined criteria for semen analysis, subject selection, and life style habits definition, are essential to reach a consistent evidence on the effect of caffeine on semen parameters and male fertility.

Energy drinks and alcohol-related risk among young adults

BACKGROUND

Energy drink consumption, with or without concurrent alcohol use, is common among young adults. This study sought to clarify risk for negative alcohol outcomes related to the timing of energy drink use.

METHODS

The authors interviewed a community sample of 481 young adults, aged 18-25, who drank alcohol in the last month. Past-30-day energy drink use was operationalized as no-use, use without concurrent alcohol, and concurrent use of energy drinks with alcohol ("within a couple of hours"). Negative alcohol outcomes included past-30-day binge drinking, past-30-day alcohol use disorder, and drinking-related consequences.

RESULTS

Just over half (50.5%) reported no use of energy drinks,18.3% reported using energy drinks without concurrent alcohol use, and 31.2% reported concurrent use of energy drinks and alcohol. Relative to those who reported concurrent use of energy drinks with alcohol, and controlling for background characteristics and frequency of alcohol consumption, those who didn't use energy drinks and those who used without concurrent alcohol use had significantly lower binge drinking, negative consequences, and rates of alcohol use disorder (P < .05 for all outcomes). There were no significant differences between the no-use and energy drink without concurrent alcohol groups on any alcohol-related measure (P > .10 for all outcomes).

CONCLUSIONS

Concurrent energy drink and alcohol use is associated with increased risk for negative alcohol consequences in young adults. Clinicians providing care to young adults could consider asking patients about concurrent energy drink and alcohol use as a way to begin a conversation about risky alcohol consumption while addressing 2 substances commonly used by this population.

Exploring infant feeding practices: cross-sectional surveys of South Western Sydney, Singapore, and Ho Chi Minh City

BACKGROUND

Infant feeding practices are known to influence the child's long-term health. Studies have associated obesity and other diseases with reduced breastfeeding and early introduction of high calorie beverages (HCBs). The rising prevalence of obesity is already a problem in most developed countries, especially Australia, but cultural differences are influential. Our aim is to examine and compare infant feeding practices and educational levels of respondents through questionnaires in three culturally different sites: Campbelltown (South Western Sydney), Australia, Singapore and Ho Chi Minh City, Vietnam (HCMC).

METHODS

Consenting parents and carers (aged ≥18 years old) of at least one child (≤6 years old) were recruited from paediatric clinics in Campbelltown, Singapore and HCMC. Participants completed an infant feeding practices questionnaire regarding breastfeeding, beverage and solid initiation in addition to the parent's ethnicity, age, and educational level. Data was analysed quantitatively using SPSS.

RESULTS

Two hundred eighty-three participants were recruited across the three sites, HCMC (n = 84), Campbelltown (n = 108), and Singapore (n = 91). 237 (82.6%) children were breastfed but in all only 100 (60.2%) were exclusively breastfed for five months or more. There was a statistical difference in rates of breast feeding between each region. HCMC (n = 18, 21.4%) had the lowest, followed by Campbelltown (n = 35, 32.4%), and then Singapore (n = 47, 51.7%). There was also a difference in rates of introduction of HCBs by 3 years of age, with those in HCMC (n = 71, 84.5%) were higher than Campbelltown (n = 71, 65.8%) and Singapore (n = 48, 52.8%). The educational level of respondents was lower in Vietnam where only 46.4% (n = 39) had completed post-secondary education, compared to 75.0% (n = 81) in Campbelltown and 75.8% (n = 69) in Singapore.

CONCLUSIONS

Rates of breast feeding were inversely correlated with rates of introduction of HCB and positively related to educational achievement. Vietnam had lowest rates of breast feeding, higher rates of introduction of HCBs, and lower rates of education. Given rising rates of obesity, there is a need for more effective programmes to promote breast feeding and restrict false advertising of HCBs.

The Taste of Caffeine

Many people avidly consume foods and drinks containing caffeine, despite its bitter taste. Here, we review what is known about caffeine as a bitter taste stimulus. Topics include caffeine's action on the canonical bitter taste receptor pathway and caffeine's action on noncanonical receptor-dependent and -independent pathways in taste cells. Two conclusions are that (1) caffeine is a poor prototypical bitter taste stimulus because it acts on bitter taste receptor-independent pathways, and (2) caffeinated products most likely stimulate "taste" receptors in nongustatory cells. This review is relevant for taste researchers, manufacturers of caffeinated products, and caffeine consumers.

The Safety of Ingested Caffeine: A Comprehensive Review

Caffeine is the most widely consumed psychoactive drug in the world. Natural sources of caffeine include coffee, tea, and chocolate. Synthetic caffeine is also added to products to promote arousal, alertness, energy, and elevated mood. Over the past decade, the introduction of new caffeine-containing food products, as well as changes in consumption patterns of the more traditional sources of caffeine, has increased scrutiny by health authorities and regulatory bodies about the overall consumption of caffeine and its potential cumulative effects on behavior and physiology. Of particular concern is the rate of caffeine intake among populations potentially vulnerable to the negative effects of caffeine consumption: pregnant and lactating women, children and adolescents, young adults, and people with underlying heart or other health conditions, such as mental illness. Here, we review the research into the safety and safe doses of ingested caffeine in healthy and in vulnerable populations. We report that, for healthy adults, caffeine consumption is relatively safe, but that for some vulnerable populations, caffeine consumption could be harmful, including impairments in cardiovascular function, sleep, and substance use. We also identified several gaps in the literature on which we based recommendations for the future of caffeine research.

A daily diary examination of caffeine mixed with alcohol among college students

OBJECTIVE

Caffeinated alcoholic beverage (CAB) use is associated with a range of substance-related problems. The majority of prior research on CABs is based on cross-sectional and retrospective reports, which do not account for intraindividual differences in use and may be subject to recall biases. The current research used a daily diary, within-subjects design to compare days where individuals simultaneously mixed alcohol with caffeine (CAB days) and days where individuals drank other types of alcohol (non-CAB days) on alcohol use outcomes. These relationships were tested further by examining the impact of the type of mixer (i.e., energy drink or cola-caffeinated).

METHOD

Participants were 122 (73.8% women) heavy drinking, college student CAB users. Mean age was 20.39 (SD = 2.08) years. Students completed a baseline questionnaire and up to 14 consecutive daily surveys about the previous night's drinking behavior.

RESULTS

Multilevel modeling results indicated that CAB days were associated with heavier alcohol use, regardless of mixer type. In addition, beyond amount of alcohol consumed the previous night and trait impulsivity, CAB days were linked with more alcohol-related problems, but only when the mixer was an energy drink. CAB days did not differ from non-CAB days on driving or sex after drinking.

CONCLUSIONS

This study was the first to demonstrate the unique risks posed by simultaneously consuming caffeine and alcohol in a within-subjects, daily diary design. Future research investigating use patterns may benefit from the use of fine-grained approaches in order to provide information relevant for CAB prevention and intervention efforts. (PsycINFO Database Record

Characteristics of university students who mix alcohol and energy drinks

OBJECTIVE

Research has identified correlates (eg, drug use, risky sex, smoking) of using alcohol mixed with energy drinks (AMEDs). Few studies have investigated common mental health-related concerns (eg, depression, sleep).

PARTICIPANTS

Alcohol-using college students (n = 380 never used AMEDs, n = 180 used AMEDs) were recruited in the study during the fall 2011 semester.

METHODS

The study examined demographics, substance use, depressive symptoms, and sleep problems in association with AMED use.

RESULTS

Multivariable logistic regression indicated that alcohol use severity (AOR = 1.24; 95% CI = 1.14+1.34), drug use severity (AOR = 1.20; 95% CI = 1.04-1.39), depressive symptoms (AOR = 1.06; 95% CI = 1.01-1.12), and smoking (AOR = 2.12; 95% CI = 1.22-3.68) were independently associated with AMED use; sleep problems were non-significant.

CONCLUSIONS

Administrators may consider policies regarding energy drink availability on campus, and campus health personnel may increase screening and education surrounding AMED use to reduce risks among students.

Energy drink use frequency among an international sample of people who use drugs: Associations with other substance use and well-being

OBJECTIVE

The study aims were to identify: i.) energy drink (ED), caffeine tablet, and caffeine intranasal spray use amongst a sample who report drug use, and ii.) the association between ED use frequency and demographic profile, drug use, hazardous drinking, and wellbeing.

METHOD

Participants (n=74,864) who reported drug use completed the online 2014 Global Drug Survey. They provided data on demographics, ED use, and alcohol and drug use, completed the Alcohol Use Disorders Identification Test (AUDIT) and Personal Wellbeing Index (PWI), and reported whether they wished to reduce alcohol use.

RESULTS

Lifetime ED, caffeine tablet and intranasal caffeine spray use were reported by 69.2%, 24.5% and 4.9%. Median age of ED initiation was 16 years. For those aged 16-37, median years using EDs increased from 4 to 17 years of consumption, where it declined thereafter. Greater ED use frequency was associated with: being male; under 21 years of age; studying; and past year caffeine tablet/intranasal spray, tobacco, cannabis, amphetamine, MDMA, and cocaine use. Past year, infrequent (1-4days) and frequent (≥5days) past month ED consumers reported higher AUDIT scores and lower PWI scores than lifetime abstainers; past month consumers were less likely to report a desire to reduce alcohol use.

CONCLUSIONS

ED use is part of a complex interplay of drug use, alcohol problems, and poorer personal wellbeing, and ED use frequency may be a flag for current/future problems. Prospective research is required exploring where ED use fits within the trajectory of other alcohol and drug use.

Regular energy drink consumption is associated with the risk of health and behavioural problems in adolescents

Consumption of energy drinks has become popular and frequent among adolescents across Europe. Previous research showed that regular consumption of these drinks was associated with several health and behavioural problems. The aim of the present study was to determine the socio-demographic groups at risk for regular energy drink consumption and to explore the association of regular energy drinks consumption with health and behavioural problems and negative school experiences in adolescents. Data from the Health Behaviour in School-aged Children Study conducted in 2014 in Slovakia were analysed. We assessed socio-demographic characteristics, energy drink consumption, health and behavioural problems and negative school experiences based on self-reports from 8977 adolescents aged 11-15 years (mean age/standard deviation 13/1.33; 50.0% boys). The prevalence of regular energy drink consumption in the present sample was 20.6% (95%CI: 20%-21%). Regular energy drink consumption was more frequent among boys and older adolescents. Adolescents with a medium-level family affluence were less likely to drink energy drinks regularly. Adolescents who consumed energy drinks regularly had more health and behavioural problems and negative school experiences.

CONCLUSION

Adolescents drinking energy drinks are at risk of a wide range of negative outcomes and should be specifically addressed by preventive interventions. What is Known • Energy drink consumption has become popular and frequent among adolescents across Europe. • There is growing evidence that energy drink consumption is related to negative social, emotional and health outcomes, but only a few studies have explored this relationship in adolescents. What is New • Regular energy drink consumption was more frequent among boys and adolescents reporting low family affluence and increased with age. • Adolescents reporting regular energy drink consumption were in higher risk to suffer from health and behavioural problems and negative school experiences.

Randomized Controlled Trial of High-Volume Energy Drink Versus Caffeine Consumption on ECG and Hemodynamic Parameters

Background

Caffeine in doses <400 mg is typically not considered arrhythmogenic, but little is known about the additional ingredients in energy drinks. We evaluated the ECG and blood pressure (BP) effects of high‐volume energy drink consumption compared with caffeine alone.

Methods and Results

This was a randomized, double‐blind, controlled, crossover study in 18 young, healthy volunteers. Participants consumed either 946 mL (32 ounces) of energy drink or caffeinated control drink, both of which contained 320 mg of caffeine, separated by a 6‐day washout period. ECG, peripheral BP, and central BP measurements were obtained at baseline and 1, 2, 4, 6, and 24 hours post study drink consumption. The time‐matched, baseline‐adjusted changes were compared. The change in corrected QT interval from baseline in the energy drink arm was significantly higher than the caffeine arm at 2 hours (0.44±18.4 ms versus −10.4±14.8 ms, respectively; P=0.02). The QTc changes were not different at other time points. While both the energy drink and caffeine arms raised systolic BP in a similar fashion initially, the systolic BP was significantly higher at 6 hours when compared with the caffeine arm (4.72±4.67 mm Hg versus 0.83±6.09 mm Hg, respectively; P=0.01). Heart rate, diastolic BP, central systolic BP, and central diastolic BP showed no evidence of a difference between groups at any time point. Post energy drink, augmentation index was lower at 6 hours.

Conclusions

The corrected QT interval and systolic BP were significantly higher post high‐volume energy drink consumption when compared with caffeine alone. Larger clinical trials validating these findings and evaluation of noncaffeine ingredients within energy drinks are warranted.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02023723.

Categorizing food-related illness: Have we got it right?

Since the 1950s food safety hazards have been categorized simply as (micro) biological, chemical or physical hazards with no clear differentiation between those that cause acute and chronic harm. Indeed international risk assessment methods, including hazard analysis critical control point (HACCP) use these criteria. However, the spectrum of food related illness continues to grow now encompassing food allergy and intolerance, obesity, type 2 diabetes, stroke, heart disease, cancer as well as food poisoning, foodborne illness and food contamination. Therefore over a half-century later is this the time to redefine the spectrum of what constitutes food related illness? This paper considers whether such "redefinition" of food related intoxicating and infectious agents would provide more targeted policy instruments and lead to better risk assessment and thus mitigation of such risk within the food supply chain.

Effects of caffeine on alcohol reinforcement: beverage choice, self-administration, and subjective ratings

RATIONALE

Combining alcohol and caffeine is associated with increased alcohol consumption, but no prospective experimental studies have examined whether added caffeine increases alcohol consumption.

OBJECTIVES

This study examined how caffeine alters alcohol self-administration and subjective reinforcing effects in healthy adults.

METHODS

Thirty-one participants completed six double-blind alcohol self-administration sessions: three sessions with alcohol only (e.g., beverage A) and three sessions with alcohol and caffeine (e.g., beverage B). Participants chose which beverage to consume on a subsequent session (e.g., beverage A or B). The effects of caffeine on overall beverage choice, number of self-administered drinks, subjective ratings (e.g., Biphasic Alcohol Effects Scale), and psychomotor performance were examined.

RESULTS

A majority of participants (65%) chose to drink the alcohol beverage containing caffeine on their final self-administration session. Caffeine did not increase the number of self-administered drinks. Caffeine significantly increased stimulant effects, decreased sedative effects, and attenuated decreases in psychomotor performance attributable to alcohol. Relative to nonchoosers, caffeine choosers reported overall lower stimulant ratings and reported greater drinking behavior prior to the study.

CONCLUSIONS

Although caffeine did not increase the number of self-administered drinks, most participants chose the alcohol beverage containing caffeine. Given the differences in subjective ratings and pre-existing differences in self-reported alcohol consumption for caffeine choosers and nonchoosers, these data suggest that decreased stimulant effects of alcohol and heavier self-reported drinking may predict subsequent choice of combined caffeine and alcohol beverages. These predictors may identify individuals who would benefit from efforts to reduce risk behaviors associated with combining alcohol and caffeine.

Consumption of Caffeinated Energy Drinks Among Youth and Young Adults in Canada

The growing market for caffeinated energy drinks (CEDs) has caused concern about excessive caffeine intake and potential adverse effects, particularly among young people. The current study examined patterns of CED consumption among youth and young adults in Canada, using data from a national online survey conducted in October 2014. Data from a non-probability sample of 2040 respondents aged 12-24 from a consumer panel was weighted to national proportions; measures of CED consumption were estimated, including prevalence, excessive daily consumption, and context for use (locations and reasons). Separate logistic regression models for two outcomes, past-week consumption and "ever" exceeding two energy drinks in a day (as per common guidance), were conducted to examine associations with demographic variables (sex, age, geographic region, race/ethnicity, and language). Overall, 73.6% of respondents reported "ever" consuming energy drinks; 15.6% had done so in the past week. Any consumption of energy drinks in the past week was more prevalent among males, Aboriginal respondents (vs. white only or mixed/other), and residents of British Columbia. Among "ever-consumers," 16.0% reported ever consuming more than two energy drinks in a day. Exceeding two in a day was more prevalent among older respondents (young adults aged 18-24), aboriginal respondents (vs. white only), and British Columbia residents. While the majority of youth and young adults had consumed energy drinks, about half were "experimental" consumers (i.e., consumed ≤ 5 drinks in their lifetime). Approximately one in six consumers had exceeded the usual guidance for maximum daily consumption, potentially increasing their risk of experiencing adverse effects.

Consumption of energy drinks among Québec college students

OBJECTIVES

Consumption of energy drinks (ED) raises concerns because of adverse health effects possibly linked with high levels of caffeine and sugar intake. The study looks at the scope of ED consumption as well as some of the associated characteristics.

METHODS

Thirty-six public colleges in the Canadian province of Québec agreed to participate in a descriptive cross-sectional study (n = 36). In February 2013, participating colleges invited their students to answer an online questionnaire on consumption of ED, alcoholic ED (AED), and ED in combination with other psychotropic drugs. A descriptive and correlational analysis was carried out. Logistic regressions explored associations between ED consumption and associated characteristics.

RESULTS

Of the students who successfully completed the questionnaire and participated in the study (n = 10,283), a low proportion consumed ED (9.1%; n = 935) and/or AED (1.1%; n = 109) at least once a week in the previous month. Although low in proportion, a number of participants reported having used ED with other stimulant psychoactive substances (n = 247) and ≥3 ED/day (n = 193) or ≥3 AED/occasion (n = 167), which can pose a risk for serious adverse effects. Weekly ED consumption was associated with consumption of ≥20 cups of coffee/week, smoking, excessive use of alcohol and past use of cannabis, glues or solvents and amphetamines.

CONCLUSION

A majority of respondents are not heavy users of ED, AED, or ED with drugs. Yet, the profiles of ED consumption potentially harmful to health that characterize some participants indicate that the potential health consequences of such behaviour are of concern.

Psychopathology Related to Energy Drinks: A Psychosis Case Report

Energy drinks (ED) are nonalcoholic beverages that have caffeine as their most common active substance. The rapid expansion of ED consumption has created concern in the scientific community as well as in the public opinion. We report a psychotic episode probably triggered by ED abuse in a young adult without previous psychotic disorders. We have reviewed the literature regarding the relationship between caffeine, energy drinks, and psychopathology. Few articles have been published about mental health effects of energy drinks and caffeine abuse. Nevertheless, this relationship has been suggested, specifically with anxiety disorders, manic episodes, suicide attempts, psychotic decompensation, and substance use disorder. ED consumption could represent a global public health problem because of the potential severe adverse effects in mental and physical health. To our knowledge, this article is probably the first case of psychosis related to ED abuse in an individual without previous psychotic disorders.

Measurement of caffeine and its three primary metabolites in human plasma by HPLC-ESI-MS/MS and clinical application

Caffeine is a mild stimulant with significant potential for abuse, being consumed in larger doses with the widespread availability of energy drinks and by novel routes of administration such as inspired powder, oral sprays and electronic cigarettes. How these recent changes in caffeine consumption affecting caffeine disposition and abuse potential is of growing concern. In the study of caffeine disposition in humans, it is common to only measure the caffeine concentration; however, caffeine's three major metabolites (paraxanthine, theobromine and theophylline) retain central nervous system stimulant activity that may contribute to the overall pharmacological activity and toxicity. Therefore, it would be scientifically more rigorous to measure caffeine and its major metabolites in the evaluation of caffeine disposition in human subjects. Herein, we report a method for the simultaneous quantification of caffeine and its three major metabolites in human plasma by high-performance liquid chromatography coupled to electrospray tandem mass spectrometry (HPLC-ESI-MS/MS). Human plasma samples were treated by simple protein precipitation and the analytes were separated using a 6 min gradient program. Precision and accuracy were well within in the 15% acceptance range. The simple sample preparation, short runtime, sensitivity and the inclusion of caffeine's major metabolites make this assay methodology optimal for the study of caffeine's pharmacokinetics and pharmacodynamics in human subjects.

Pilot Study of Veterinary Student Mindset and Association with Academic Performance and Perceived Stress

Individuals with a growth mindset believe that all failures are opportunities and that their baseline intelligence and talent can be used for continuous improvement. Individuals with a fixed mindset believe that baseline intelligence and talent cannot be developed. A growth mindset is associated with greater academic success and greater resilience in the face of failure or stress. Second-year veterinary students completed three surveys to determine mindset, perceived levels of stress, and life change score. Of 57 students, 70% had a strong growth mindset or a growth mindset with some fixed ideas. No students had a strong fixed mindset. Mindset was not correlated with GPA or perceived stress level. Colleges of veterinary medicine can assist students by providing resources and training for stress management, including training in how to further develop a growth mindset.

Relationship Between Energy Drink Consumption and Nutrition Knowledge in Student-Athletes

OBJECTIVE

To identify the relationships between energy drink consumption, nutrition knowledge, and socio-demographic characteristics in a convenience sample of student-athletes.

DESIGN

Cross-sectional.

SETTING

Online survey.

PARTICIPANTS

A total of 194 student-athletes (112 female and 82 male).

MAIN OUTCOME MEASURES

Socio-demographic characteristics, knowledge of human nutrition, energy drink consumption habits.

ANALYSIS

Chi-square tests of independence, independent t tests, and hierarchical regression analyses were applied.

RESULTS

Most student-athletes in the sample (85.5%) did not consume energy drinks, but those who did tended to be male (P = .004), had lower overall knowledge of nutrition (P = .02), and had a lower grade point average (P < .001) than did nonusers. Also, energy drink consumption was associated with the overall nutrition knowledge score when adjusted for socio-demographic characteristics, with nonusers having greater nutrition knowledge (P = .007) than users.

CONCLUSIONS AND IMPLICATIONS

Student-athletes tend to refrain from energy drink use but those who use it have a tendency to have lower nutrition knowledge than do nonusers. Therefore, nutrition education targeted toward student-athletes should encompass the consumption of energy drinks because limited evidence shows the benefits of collegiate athletes consuming energy drinks.

Longitudinal bone growth is impaired by direct involvement of caffeine with chondrocyte differentiation in the growth plate

We showed previously that caffeine adversely affects longitudinal bone growth and disrupts the histomorphometry of the growth plate during the pubertal growth spurt. However, little attention has been paid to the direct effects of caffeine on chondrocytes. Here, we investigated the direct effects of caffeine on chondrocytes of the growth plate in vivo and in vitro using a rapidly growing young rat model, and determined whether they were related to the adenosine receptor signaling pathway. A total of 15 male rats (21 days old) were divided randomly into three groups: a control group and two groups fed caffeine via gavage with 120 and 180 mg kg-1  day-1 for 4 weeks. After sacrifice, the tibia processed for the analysis of the long bone growth and proliferation of chondrocytes using tetracycline and BrdU incorporation, respectively. Caffeine-fed animals showed decreases in matrix mineralization and proliferation rate of growth plate chondrocytes compared with the control. To evaluate whether caffeine directly affects chondrocyte proliferation and chondrogenic differentiation, primary rat chondrocytes were isolated from the growth plates and cultured in either the presence or absence of caffeine at concentrations of 0.1-1 mm, followed by determination of the cellular proliferation or expression profiles of cellular differentiation markers. Caffeine caused significant decreases in extracellular matrix production, mineralization, and alkaline phosphatase activity, accompanied with decreases in gene expression of the cartilage-specific matrix proteins such as aggrecan, type II collagen and type X. Our results clearly demonstrate that caffeine is capable of interfering with cartilage induction by directly inhibiting the synthetic activity and orderly expression of marker genes relevant to chondrocyte maturation. In addition, we found that the adenosine type 1 receptor signaling pathway may be partly involved in the detrimental effects of caffeine on chondrogenic differentiation, specifically matrix production and mineralization, as evidenced by attenuation of the inhibitory effects of caffeine by blockade of this receptor. Thus, our study provides novel information on the integration of caffeine and adenosine receptor signaling during chondrocyte maturation, extending our understanding of the effect of caffeine at a cellular level on chondrocytes of the growth plate.

Caffeinated Beverage Consumption Rates and Reported Sleep in a United States Navy Ship

Ship crews live and work in an environment characterized by extreme sleep deprivation. In an attempt to maintain alertness, crewmembers frequently consume caffeinated beverages and energy drinks. As part of a broader study, this work assesses the consumption of caffeinated beverages and investigates the association between caffeinated beverage consumption and reported sleep amount. Crewmembers of a U.S. Navy aircraft carrier (N=767; age 18-49 years) completed a survey with questions pertaining to demographics, exercise frequency, average sleep duration, caffeine beverage consumption, the Epworth Sleepiness Scale (ESS), and the Fatigue Severity Scale (FSS). Results show that the sample of active duty personnel slept approximately six hours per night. Most respondents (~90%) reported using at least one type of caffeinated beverage (~55% coffee, ~50% soft drinks, ~35% energy drinks, and ~35% tea). The participants who reported drinking caffeinated drinks had an average weekly caffeine intake of 812±917 mg (MD=540), ranging from 30 to 9210 mg. Crewmembers who consumed more than 1,270 mg of caffeine weekly (equivalent to 180 mg daily) reported sleeping 5.79±1.17 hours, whereas crewmembers that drank less than 1,270 mg of caffeine reported sleeping 6.17±1.07 hours (p<0.001). Overall, our study shows widespread use of caffeine among active duty crewmembers in our sample. Our results suggest that caffeine intake – in the form of coffee, tea, caffeinated soft drinks, or energy drinks – is associated with sleep and may interfere with sleep patterns while working at sea. Future efforts should be directed at exploring causal relationships involved in this phenomenon. Better understanding of causal links will enable appropriate guidance for better sleep hygiene in the maritime operational environment.

Energy drinks – consumption and awareness among students of Medical University of Lublin

Energy drinks (ED), containing caffeine, taurine and another substances, are one of the more frequently used legal stimulants. Still, because these can endanger consumers’ health, it is thought that their marketing should be legally controlled.

In our study, we analyzed the frequency of energy drink consumption, as well as the knowledge held about these drinks among medicine and dentistry students of the Medical University of Lublin. In the study, 131 students participated, and the study was done in the form of a survey. The results of this indicate that 81 students (61.83%) declared a daily consumption, and most respondents (78.48%) stated at least a one time consumption of 250 to 749 ml of energy drink. What is more, 26.25% of respondents combined ED with other substances, most frequently with coffee and alcohol. Regarding knowledge of ED effects, contents and side effects, more males than females actively sought and held this information. Furthermore, more than half of all respondents believed that the availability of EDs in Poland should be limited.

Our study showed that the awareness of the effects and mechanisms of action of EDs, among the questioned students is relatively high. Nevertheless, they frequently consume EDs and combine these with other stimulants.

A Survey of Energy Drink Consumption Patterns Among College Students at a Mostly Hispanic University

Background: The purpose of this study was to determine energy drink (ED) consumption patterns among Hispanic college students. We measured the prevalence and frequency of ED consumption according to gender, degree programs, and specific university-related and social situations. In addition, we assessed the frequency of consumption of EDs mixed with alcoholic beverages. Methods: A total of 508 college students from the University of Puerto Rico, the largest Hispanic institution of higher education statewide, completed an online questionnaire. Results: Twenty-one percent of participants reported consuming EDs with the majority consuming EDs either occasionally (every 2-3 months) or at least once or twice a month. Men were found to be more likely to consume EDs than women. Undergraduate students were found less likely to consume EDs than graduate students. Most students consumed EDs while studying and during social activities. More than one-third of participants that consume EDs admitted mixing them with an alcoholic beverage. Graduate students were found to consume EDs mixed with alcohol more often. Conclusions: The majority of students consumed EDs occasionally and while studying. Most side effects reported after consuming EDs were similar to previous findings. The higher consumption of EDs and of EDs mixed with alcohol by students in graduate programs could be explained by a higher and more complex study load requiring longer periods of wakefulness and concentration. Future studies looking at the consumption patterns of EDs in more competitive graduate programs such as medical and/or dentistry school should be considered.

Energy Drink Use Patterns Among Young Adults: Associations with Drunk Driving

BACKGROUND

Highly caffeinated "energy drinks" (ED) are commonly consumed and sometimes mixed with alcohol. Associations between ED consumption, risk-taking, and alcohol-related problems have been observed. This study examines the relationship between ED consumption-both with and without alcohol-and drunk driving.

METHODS

Data were derived from a longitudinal study of college students assessed annually via personal interviews. In Year 6 (modal age 23; n = 1,000), participants self-reported their past-year frequency of drunk driving, ED consumption patterns (frequency of drinking alcohol mixed with energy drinks [AmED] and drinking energy drinks without alcohol [ED]), alcohol use (frequency, quantity), and other caffeine consumption. Earlier assessments captured suspected risk factors for drunk driving. Structural equation modeling was used to develop an explanatory model for the association between ED consumption patterns and drunk driving frequency while accounting for other suspected risk factors.

RESULTS

More than half (57%) consumed ED at least once during the past year. Among ED consumers, 71% drank AmED and 85% drank ED alone; many (56%) engaged in both styles of ED consumption while others specialized in one or the other (29% drank ED alone exclusively, while, 15% drank AmED exclusively). After accounting for other risk factors, ED consumption was associated with drunk driving frequency in 2 ways. First, a direct path existed from ED frequency (without alcohol) to drunk driving frequency. Second, an indirect path existed from AmED frequency through alcohol quantity to drunk driving frequency.

CONCLUSIONS

Among this sample, ED consumption with and without alcohol was common, and both styles of ED consumption contributed independently to drunk driving frequency. Results call for increased attention to the impact of different patterns of ED consumption on alcohol-related consequences, such as drunk driving.

Consuming energy drinks at the age of 14 predicted legal and illegal substance use at 16

AIM

This study examined whether consuming energy drinks at the age of 14 predicted substance use at 16.

METHODS

We followed 621 youths from an area of Switzerland who completed a longitudinal online survey in both 2012 and 2014 when they were 14 and 16 years of age. At 14, participants, who were divided into nonenergy drink users (n = 262), occasional users (n = 183) and regular users (n = 176), reported demographic, health-related and substance use data. Substance use at 16 was assessed through logistic regression using nonusers as the reference group and controlling for significant variables at 14.

RESULTS

At the bivariate level, energy drink consumption was associated with substance use at both 14 and 16. Energy drink consumers were also more likely to be male, older, less academic, sleep less on schooldays and live in an urban area. In the multivariate analysis, smokers, alcohol misusers and cannabis users at the age of 16 were significantly more likely to have been regular energy drink users at the age of 14.

CONCLUSION

Consuming energy drinks at 14 years of age predicted using legal and illegal substances at 16. Health providers should screen young adolescents for energy drink use and closely monitor weekly users.

Clinical Symptoms and Adverse Effects Associated With Energy Drink Consumption in Adolescents

OBJECTIVE

The aims of the study were to determine the prevalence of energy drink consumption by adolescents, to identify associated clinical symptoms and adverse effects, and to gain an understanding to the motivation behind its consumption.

METHODS

A prospective, questionnaire-based study was conducted at 2 emergency departments from June 2011 to June 2013. The questionnaire was distributed to a convenience sample of adolescents aged 12 to 18 years. Stratification was performed on the basis of frequency of consumption: frequent consumption (at least once a month) and infrequent consumption (less frequent than once a month).

RESULTS

Data analysis was performed on 612 completed questionnaires. Two hundred two responders (33%) were considered frequent energy drink consumers. Frequent consumers were more likely to be involved in high-risk behaviors and more likely to consume other caffeinated drinks. In the previous 6 months, frequent energy drink consumers were more likely to report headache (76%), anger (47%), and increased urination (24%) and were more likely to require medical evaluation for headache (41%) and difficulty breathing (22%). Frequent energy drink consumers were more likely to believe that energy drinks "help me do better in school" (12%), "help me do better in sports" (35%), "are just for fun" (46%), "help me stay up at night" (67%), and "make me concentrate/focus better" (34%).

CONCLUSIONS

Clarifying common misconceptions associated with energy drink consumption, especially in high-risk adolescents and frequent energy drink consumers, may decrease the frequency of symptoms experienced by adolescents, such as headache and difficulty breathing, requiring medical evaluation.

Caffeine consumption patterns and determinants among adolescents in Serbia

BACKGROUND

The number of adolescents who use caffeine is constantly increasing. As juvenile age is vulnerable, it is reasonable to expect that they will differently perceive reason and react to caffeine use than adults, and be more prone to unwanted physiological and psychological consequences of its consumption.

AIM

Analysis of the scope and pattern of caffeine consumption among adolescents in Serbia.

STUDY DESIGN

The cross-sectional survey was implemented in the study population of 191 Serbian adolescents during 2010.

RESULTS

The median daily intake of caffeine was 95.6 mg. The major source of caffeine was brewed coffee, and the most common reasons for caffeine intake were leisure, peer influence, or habit. Only 57.6% of the subjects were aware that caffeine is present in consumed beverages. Sex affected the pattern, but not the overall level, of caffeine consumption. No association between caffeine consumption and smoking status, frequency of caffeine use in the family, or negative personal experience with caffeine effects was observed.

CONCLUSION

Our investigation provides first and rather detailed insight into caffeine-containing beverage consumption scope and pattern among Serbian adolescents. For accurate estimation and analysis of caffeine intake in this population, randomized studies with prospective longitudinal design, caffeine content measurement, and more subjects involved are warranted.

Association between energy drink intake, sleep, stress, and suicidality in Korean adolescents: energy drink use in isolation or in combination with junk food consumption

BACKGROUND

A considerable amount of research suggests that the frequent use of caffeinated energy drinks may be associated with undesirable effects, particularly so in children and adolescents. This study aimed to investigate the associations between energy drink intake and mental health problems, in isolation or in combination with junk food consumption, in a nationally representative sample of Korean adolescents.

METHODS

Data from the 2015 Korean Youth Risk Behavior Web-Based Survey, collected from 68,043 adolescents aged 12-18 years (mean age 15.09 ± 1.72 years), were analyzed. Questionnaires were administered to collect information related to dietary behavior including energy drink intake and junk food consumption. Single item measures of sleep dissatisfaction, stress, depression, suicidal ideation, suicide plan, and suicide attempt were also administered. Associations between energy drink intake and sleep dissatisfaction, perceived severe stress, persistent depressive mood, and suicidality were investigated, and a multivariate approach was taken so that additional variance from demographic and lifestyle factors could be controlled for statistically.

RESULTS

Energy drink intake was significantly associated with sleep dissatisfaction (adjusted odd ratios [AORs] = 1.64 and 1.25), severe stress (AORs = 2.23 and 1.38), depressive mood (AOR = 2.59 and 1.51), suicidal ideation (AORs = 3.14 and 1.43), suicide plan (AORs = 4.65 and 1.78), and suicide attempt (AORs = 6.79 and 1.91), with a higher risk for more frequent use of energy drinks (≥5 times/wk) than for less frequent use (1-4 times/wk). The detrimental effect of energy drinks on mental health was particularly prominent in frequent junk food consumers.

CONCLUSIONS

Our data suggest that energy drink intake had detrimental effects related to stress, sleep dissatisfaction, mood, and suicidality, in isolation or in combination with junk food consumption, in Korean adolescents. However, the cross-sectional study design prevents our ability to assess causal relationships.

Pharmacokinetic analysis and comparison of caffeine administered rapidly or slowly in coffee chilled or hot versus chilled energy drink in healthy young adults

Context: There is a paucity of data describing the impact of type of beverage (coffee versus energy drink), different rates of consumption and different temperature of beverages on the pharmacokinetic disposition of caffeine. Additionally, there is concern that inordinately high levels of caffeine may result from the rapid consumption of cold energy drinks. Objective: The objective of this study was to compare the pharmacokinetics of caffeine under various drink temperature, rate of consumption and vehicle (coffee versus energy drink) conditions. Materials: Five caffeine (dose = 160 mg) conditions were evaluated in an open-label, group-randomized, crossover fashion. After the administration of each caffeine dose, 10 serial plasma samples were harvested. Caffeine concentration was measured via liquid chromatography–mass spectrometry (LC–MS), and those concentrations were assessed by non-compartmental pharmacokinetic analysis. The calculated mean pharmacokinetic parameters were analyzed statistically by one-way repeated measures analysis of variance (RM ANOVA). If differences were found, each group was compared to the other by all pair-wise multiple comparison. Results: Twenty-four healthy subjects ranging in age from 18 to 30 completed the study. The mean caffeine concentration time profiles were similar with overlapping SDs at all measured time points. The ANOVA revealed significant differences in mean C_max and V_d ss/F, but no pair-wise comparisons reached statistical significance. No other differences in pharmacokinetic parameters were found. Discussion: The results of this study are consistent with previous caffeine pharmacokinetic studies and suggest that while rate of consumption, temperature of beverage and vehicle (coffee versus energy drink) may be associated with slightly different pharmacokinetic parameters, the overall impact of these variables is small. Conclusion: This study suggests that caffeine absorption and exposure from coffee and energy drink is similar irrespective of beverage temperature or rate of consumption.

Energy Drinks and Their Impact on the Cardiovascular System: Potential Mechanisms

Globally, the popularity of energy drinks is steadily increasing. Scientific interest in their effects on cardiovascular and cerebrovascular systems in humans is also expanding and with it comes a growing number of case reports of adverse events associated with energy drinks. The vast majority of studies carried out in the general population report effects on blood pressure and heart rate. However, inconsistencies in the current literature render it difficult to draw firm conclusions with regard to the effects of energy drinks on cardiovascular and cerebrovascular variables. These inconsistencies are due, in part, to differences in methodologies, volume of drink ingested, and duration of postconsumption measurements, as well as subject variables during the test. Recent well-controlled, randomized crossover studies that used continuous beat-to-beat measurements provide evidence that cardiovascular responses to the ingestion of energy drinks are best explained by the actions of caffeine and sugar, with little influence from other ingredients. However, a role for other active constituents, such as taurine and glucuronolactone, cannot be ruled out. This article reviews the potentially adverse hemodynamic effects of energy drinks, particularly on blood pressure and heart rate, and discusses the mechanisms by which their active ingredients may interact to adversely affect the cardiovascular system. Research areas and gaps in the literature are discussed with particular reference to the use of energy drinks among high-risk individuals.

Adolescent intake of caffeinated energy drinks does not affect adult alcohol consumption in C57BL/6 and BALB/c mice

The rise in marketing and mass consumption of energy drink products by adolescents poses a largely unknown risk on adolescent development and drug reward. Yet, with increasing reports of acute health issues present in young adults who ingest large quantities of energy drinks alone or in combination with alcohol, the need to elucidate these potential risks is pressing. Energy drinks contain high levels of caffeine and sucrose; therefore, exposure to energy drinks may lead to changes in drug-related behaviors since caffeine and sucrose consumption activates similar brain pathways engaged by substances of abuse. With a recent study observing that adolescent caffeine consumption increased cocaine sensitivity, we sought to investigate how prolonged energy drink exposure in adolescence alters alcohol use and preference in adulthood. To do so, we utilized three different energy drink exposure paradigms and two strains of male mice (C57BL/6 and BALB/c) to monitor the effect of caffeine exposure via energy drinks in adolescence on adult alcohol intake. These paradigms included two models of volitional consumption of energy drinks or energy drink-like substances and one model of forced consumption of sucrose solutions with different caffeine concentrations. Following adolescent exposure to these solutions, alcohol intake was monitored in a limited-access, two-bottle choice between water and increasing concentrations of alcohol during adulthood. In none of the three models or two strains of mice did we observe that adolescent 'energy drink' consumption or exposure was correlated with changes in adult alcohol intake or preference. While our current preclinical results suggest that exposure to large amounts of caffeine does not alter future alcohol intake, differences in caffeine metabolism between mice and humans need to be considered before translating these results to humans.

Perceived stress and dietary choices: The moderating role of stress management

Many college students exhibit unhealthy eating behaviors, consuming large quantities of high-fat foods and few fruits and vegetables. Perceived stress has been linked to daily dietary choices among college students; however, this work has been conducted among predominantly white, female populations. The role of perceived stress management in moderating this relationship is unclear. This study investigated the relationship between perceived stress and dietary choices among a diverse sample of male and female college freshmen and assessed whether perceived ability to manage stress moderated this relationship. 613 students from a large, public university completed an online survey which assessed past week consumption of various foods and beverages (e.g. soda, fast food, fruits, vegetables), as well as perceived stress and ability to manage stress. Hierarchical linear regression examined the association between perceived stress and past week dietary choices, and the moderating effect of perceived ability to manage stress, controlling for demographic variables. Perceived stress was positively associated with past week soda, coffee, energy drink, salty snack, frozen food, and fast food consumption (p<0.05). Perceived stress management moderated the relationship between stress and sweet snack consumption. Individuals who reported low ability to manage stress consumed greater amounts. Findings indicate greater stress is associated with poor dietary choices among college freshmen. The relationship between stress and sweet snack consumption was exacerbated among those who reported low ability to manage stress. It may be important for college nutrition education programs to focus on the relationship between stress and diet and promote effective stress management techniques.

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

RATIONALE

Caffeine is one of the psychoactive substances most widely used as an adulterant in illicit drugs, such as cocaine. Animal studies have demonstrated that caffeine is able to potentiate several cocaine actions, although the enhancement of the cocaine reinforcing property by caffeine is less reported, and the results depend on the paradigms and experimental protocols used.

OBJECTIVES

We examined the ability of caffeine to enhance the motivational and rewarding properties of cocaine using an intravenous self-administration paradigm in rats. Additionally, the role of caffeine as a primer cue during extinction was evaluated.

METHODS

In naïve rats, we assessed (1) the ability of the cocaine (0.250-0.125 mg/kg/infusion) and caffeine (0.125-0.0625 mg/kg/infusion) combination to maintain self-administration in fixed ratio (FR) and progressive ratio (PR) schedules of reinforcement compared with cocaine or caffeine alone and (2) the effect of caffeine (0.0625 mg/kg/infusion) in the maintenance of responding in the animals exposed to the combination of the drugs during cocaine extinction.

RESULTS

Cocaine combined with caffeine and cocaine alone was self-administered on FR and PR schedules of reinforcement. Interestingly, the breaking point determined for the cocaine + caffeine group was significantly higher than the cocaine group. Moreover, caffeine, that by itself did not maintain self-administration behavior in naïve rats, maintained drug-seeking behavior of rats previously exposed to combinations of cocaine + caffeine.

CONCLUSIONS

Caffeine enhances the reinforcing effects of cocaine and its motivational value. Our results highlight the role of active adulterants commonly used in cocaine-based illicit street drugs.

Unique Behavioral and Neurochemical Effects Induced by Repeated Adolescent Consumption of Caffeine-Mixed Alcohol in C57BL/6 Mice

The number of highly caffeinated products has increased dramatically in the past few years. Among these products, highly caffeinated energy drinks are the most heavily advertised and purchased, which has resulted in increased incidences of co-consumption of energy drinks with alcohol. Despite the growing number of adolescents and young adults reporting caffeine-mixed alcohol use, knowledge of the potential consequences associated with co-consumption has been limited to survey-based results and in-laboratory human behavioral testing. Here, we investigate the effect of repeated adolescent (post-natal days P35-61) exposure to caffeine-mixed alcohol in C57BL/6 mice on common drug-related behaviors such as locomotor sensitivity, drug reward and cross-sensitivity, and natural reward. To determine changes in neurological activity resulting from adolescent exposure, we monitored changes in expression of the transcription factor ΔFosB in the dopaminergic reward pathway as a sign of long-term increases in neuronal activity. Repeated adolescent exposure to caffeine-mixed alcohol exposure induced significant locomotor sensitization, desensitized cocaine conditioned place preference, decreased cocaine locomotor cross-sensitivity, and increased natural reward consumption. We also observed increased accumulation of ΔFosB in the nucleus accumbens following repeated adolescent caffeine-mixed alcohol exposure compared to alcohol or caffeine alone. Using our exposure model, we found that repeated exposure to caffeine-mixed alcohol during adolescence causes unique behavioral and neurochemical effects not observed in mice exposed to caffeine or alcohol alone. Based on similar findings for different substances of abuse, it is possible that repeated exposure to caffeine-mixed alcohol during adolescence could potentially alter or escalate future substance abuse as means to compensate for these behavioral and neurochemical alterations.

Caffeine alters the behavioural and body temperature responses to mephedrone without causing long-term neurotoxicity in rats

Administration of caffeine with 3,4-methylenedioxymethamphetamine (MDMA) alters the pharmacological properties of MDMA in rats. The current study examined whether caffeine alters the behavioural and neurochemical effects of mephedrone, which has similar psychoactive effects to MDMA. Rats received either saline, mephedrone (10 mg/kg), caffeine (10 mg/kg) or combined caffeine and mephedrone intraperitoneally twice weekly on consecutive days for three weeks. Locomotor activity (days 1 and 16), novel object discrimination (NOD, day 2), elevated plus maze (EPM) exploration (day 8), rectal temperature changes (day 9) and pre-pulse inhibition (PPI) of acoustic startle response (day 15) were assessed. Seven days after the final injection, brain regions were collected for the measurement of 5-hydroxytryptamine (5-HT), dopamine and their metabolites. Combined caffeine and mephedrone further enhanced the locomotor response observed following either drug administered alone, and converted mephedrone-induced hypothermia to hyperthermia. Co-administration also abolished mephedrone-induced anxiogenic response on the EPM, but had no effect on NOD or PPI. Importantly, no long-term neurotoxicity was detected following repeated mephedrone alone or when co-administered with caffeine. In conclusion, the study suggests a potentially dangerous effect of concomitant caffeine and mephedrone, and highlights the importance of taking polydrug use into consideration when investigating the acute adverse effect profile of popular recreational drugs.

Energy drink use is associated with alcohol and substance use in eighth, tenth, and twelfth graders

The increasing prevalence of energy drink (ED) use and its link with negative behaviors and adverse health outcomes has garnered much attention. Use of EDs combined with alcohol among college students has been of particular interest. It is unclear if these relationships develop in the context of college, or if similar associations exist in younger individuals. The present study examined associations between ED consumption patterns and other substance use in an adolescent, school-based sample. Participants were N = 3743 students attending 8th, 10th or 12th grade in a suburban central Virginia public school system who completed a prevention needs assessment survey in 2012. Chi-square analyses and logistic regressions were used to compare rates of alcohol, tobacco and other drug use across three ED use groups: moderate/heavy (12.6%), light (30.5%), and non-users (57%). Over 40% of the sample reported recent (past month) ED use, with males more likely to report moderate/heavy ED use than females (14.0% and 11.1%, respectively; p = 0.02). After adjusting for gender and grade, ED use group predicted lifetime alcohol, tobacco and other drug use (all p < 0.001). Moderate/heavy ED users were most likely and ED non-users were least likely to report using each of the 13 substances in the survey, with light ED users intermediate to the other two groups. Moderate/heavy ED users were consistently most likely to report licit and illicit substance use. Additional research is needed to better understand which adolescents are at greatest risk for adverse health behaviors associated with ED use.

Impact of alcohol and alcohol mixed with energy drinks on non-medical prescription stimulant use in a nationally representative sample of 12th-grade students

BACKGROUND AND OBJECTIVES

Approximately 30% of high school students use energy drinks. Alcohol use and alcohol mixed with energy drink use (AmED) is associated with risky behavior, including non-medical prescription stimulant use. We assessed alcohol-only, AmED and non-medical prescription stimulant use among 12th grade students in the U.S. using a nationally representative secondary data from the 2012 Monitoring the Future Study.

METHODS

Wilcoxon-Mann-Whitney tests and logistic regression analyses were used to determine differences in non-medical prescription stimulant use by students who used alcohol-only versus AmED and to identify covariates of non-medical prescription stimulant use. Pearson-product moment coefficients were used to determine strength of variable relationships.

RESULTS

Significant differences were found in frequency of Ritalin (p < .001, Cohen's d = .23) and Adderall (p < .001, Cohen's d = .32) use between alcohol-only students and AmED students. Greater frequency of AmED use was also associated with greater frequency of Ritalin use (r = .293, p < .001) and Adderall use (r = .353, p < .001). Males (b = .138, OR = 1.148) were more likely to use prescription stimulants non-medically than females.

DISCUSSION AND CONCLUSIONS

This study highlights the need to better understand influences on non-medical prescription stimulant, energy drink and AmED use, as the combined effects of stimulants contained in energy drinks and the depressant effects of alcohol appear to be associated with increased non-medical prescription stimulant use.

SCIENTIFIC SIGNIFICANCE

Research on the influential factors related to energy drinks, alcohol, and non-medical prescription stimulants will help practitioners to more appropriately design prevention and intervention strategies addressing these high-risk behaviors. (Am J Addict 2016;25:378-384).

Impact of Acute Energy Drink Consumption on Blood Pressure Parameters: A Meta-analysis

OBJECTIVE

Hospitalizations associated with energy drinks have increased in the past decade. Whereas energy drinks are suspected to cause hemodynamic effects, the magnitude of risk remains controversial. We evaluated the effects of acute energy drink consumption on systolic and diastolic blood pressure (SBP and DBP) and heart rate (HR).

DATA SOURCES

A search in PubMed, Cumulative Index of Nursing and Allied Health Literature, and Cochrane database through December 31, 2015, was performed.

STUDY SELECTION AND DATA EXTRACTION

Prospective clinical studies assessing the effects of commercially available energy drinks on BP and HR were included. A weighted mean change from baseline was calculated using the DerSimonian and Laird random-effects model for all end points.

DATA SYNTHESIS

In all, 15 studies were included, encompassing a total of 340, 322, and 340 individuals for SBP, DBP, and HR, respectively. SBP and DBP increased significantly by 4.44 mm Hg (95% CI = 2.71 to 6.17; Cochrane Q P = 0.001) and 2.73 mm Hg (95% CI = 1.52 to 3.95; Cochrane Q P = 0.050), respectively. HR changed nonsignificantly by 0.80 beats per minute (95% CI = -1.26 to 2.87; Cochrane Q P < 0.001). The largest change in SBP was seen with drinks administering ≥200 mg of caffeine (6.44 mm Hg, 95% CI = 4.62 to 8.27).

CONCLUSIONS

Our results indicate that acute consumption of caffeinated energy drinks significantly raises SBP and DBP. Further investigation of the ingredients in energy drinks and the impact of chronic energy drink consumption is warranted.

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

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

Acute effects of energy drinks in medical students

PURPOSE

To determine the acute effects of a variety of recognized energy drinks on medical students, based on the hypothesis that these beverages may affect negatively cardiovascular parameters, stress levels and working memory.

METHODS

Eighty young healthy medical students were included in the study. 62.5 % of the participants were male, and the age mean was 21.45 years. Each person was evaluated via measurement of systolic and diastolic blood pressure, electrocardiogram (ECG), heart rate, oxygen saturation, breath rate, temperature, STAI score (to assess anxiety state), salivary cortisol and N-back task score (to determine cognitive enhancement). These evaluations were performed before and following the intake of either carbonated water or one of three energy drinks containing caffeine in similar concentrations and an undetermined energy blend; A contained less sugar and no taurine.

RESULTS

Thirty-minute SBP increased significantly in the A and C groups. The B group exhibited a diminution of the percentage of the 1-h SBP increase, an increase of 1-h DBP and QTc shortening. HR showed an increase in the percent change in the A and C groups. Cortisol salivary levels increased in the B group. The STAI test score decreased in the C group. The percent change in N-back scores increased in the A group.

CONCLUSIONS

The data reinforce the need for further research on the acute and chronic effects of energy drinks to determine the actual risks and benefits. Consumers need to be more informed about the safety of these energy drinks, especially the young student population.