Caffeine and cardiovascular diseases: critical review of current research

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.

Effects of caffeine on cerebral blood flow

OBJECTIVE

The objective of the present study is to evaluate whether, after caffeine ingestion, there are variations in blood velocity of the middle cerebral arteries in clinically healthy young people as well as to evaluate whether this variation is dependent on the administered dose.

METHODS

We used transcranial Doppler ultrasonography to record blood velocities of the middle cerebral arteries in three groups of 15 clinically healthy young adults each: no caffeine, a45 mg, and 120 mg of caffeine groups. Transcranial Doppler ultrasonography provided simultaneous bilateral velocity of the middle cerebral arteries measurements while participants performed functional tests (hyperventilation and hypoventilation orders) and three cognitive activities (test 1, short-term memory; test 2, solving a vocabulary problem; and test 3, solving a math problem) each in 31-s tests with 1-min rests between them. Participants were assessed before and 30 min after caffeine ingestion.

RESULTS

There was a significant decrease in mean velocity, peak systolic velocity, end-diastolic velocity, and heart rate after high caffeine intake, except in hyperventilation, which was only observed in peak systolic velocity. With the intake of a lower dose, significant decreases were seen with hypoventilation and with test 1. In hyperventilation, there was only a significant decrease in end-diastolic velocity and heart rate; in test 2, it was found in mean velocity and peak systolic velocity; and in test 3, only in heart rate.

CONCLUSION

With this study, we conclude that caffeine influences the cardiovascular system acutely, interfering with the velocity of the middle cerebral arteries, causing its decrease. We also conclude that this acute effect causes vasodilation of the cerebral arteries, more accentuated with higher doses of caffeine.

Is Coffee and Tea a Threat or Ally to Cardiovascular Health?

Tea and coffee have become ingrained in our daily lives and have become the most widely consumed drinks after water. Their effects vary on an individual basis depending upon the amount of daily consumption, genetic polymorphisms, and the presence of comorbidities. Non-habitual individuals experience an initial, brief increase in blood pressure due to caffeine's vasoactive effects. Caffeine also appears to be protective against arrhythmias and heart failure. Along with having a generally cardioprotective profile, they have also demonstrated to have a favorable impact on insulin resistance and reduced risk of diabetes mellitus. Physicians often practice caution and advise patients with known cardiovascular diseases to refrain from drinking caffeine; however, studies have shown that drinking two to three cups a day has either no or some beneficial effects on both patients with or without cardiac disorders like arrhythmias. This article focuses on the effects of tea and coffee on the cardiovascular system as well as the potential mechanisms involved.

The effects of caffeine supplementation on blood pressure in adults: A systematic review and dose-response meta-analysis

BACKGROUND AND AIMS

Hypertension is a serious complication linked to a higher risk for organs. Caffeine is a natural component that affects the cardiovascular system, while the mechanisms of its effects are not fully established. Therefore, we aimed to examine the impact of caffeine supplementation on blood pressure (BP) by conducting a systematic review and dose-response meta-analysis of randomized controlled clinical trials (RCTs).

METHODS AND RESULTS

We searched online databases using relevant keywords up to July 2022 to identify RCTs using caffeine on systolic (SBP) and diastolic BP (DBP) in adults. Inclusion criteria were adult participants ≥18 years old for subjects, examining the effect of caffeine supplementation on BP, and RCTs studies. A random-effects model was used to estimate the weighted mean difference (WMD) and 95% confidence (CI). The pooled of 11 effect sizes analysis of 8 studies demonstrated significant increases in SBP (WMD:1.94 mmHg; 95%CI:0.52, 3.35; p = 0.007) and DBP (WMD:1.66 mmHg; 95% CI:0.75, 2.57; p = 0.000) after caffeine supplementation. The subgroup analysis showed that caffeine supplementation more effectively increased SBP and DBP in males than females. Moreover, meta-regression analysis demonstrated a significant relationship between the dose of caffeine intake and changes in SBP (p = 0.000), DBP (p = 0.000), and duration of the trial in SBP (p = 0.005), and DBP (p = 0.001). The non-linear dose-response analysis detected the dosage of supplementation >400 mg/day is effective for increasing DBP (p = 0.034), and the duration of supplementation of more than nine weeks makes increasing in both SBP and DBP.

CONCLUSION

This meta-analysis shows that caffeine supplementation significantly increased SBP and DBP in adults.

Current therapeutic targets and multifaceted physiological impacts of caffeine

Caffeine, which shares consubstantial structural similarity with purine adenosine, has been demonstrated as a nonselective adenosine receptor antagonist for eliciting most of the biological functions at physiologically relevant dosages. Accumulating evidence supports caffeine's beneficial effects against different disorders, such as total cardiovascular diseases and type 2 diabetes. Conversely, paradoxical effects are also linked to caffeine ingestion in humans including hypertension-hypotension and tachycardia-bradycardia. These observations suggest the association of caffeine action with its ingested concentration and/or concurrent interaction with preferential molecular targets to direct explicit events in the human body. Thus, a coherent analysis of the functional targets of caffeine, relevant to normal physiology, and disease pathophysiology, is required to understand the pharmacology of caffeine. This review provides a broad overview of the experimentally validated targets of caffeine, particularly those of therapeutic interest, and the impacts of caffeine on organ-specific physiology and pathophysiology. Overall, the available empirical and epidemiological evidence supports the dose-dependent functional activities of caffeine and advocates for further studies to get insights into the caffeine-induced changes under specific conditions, such as asthma, DNA repair, and cancer, in view of its therapeutic applications.

Coffee consumption and associations with blood pressure, LDL-cholesterol and echocardiographic measures in the general population

Coffee, next to water the most widespread beverage, is attributed both harmful and protective characteristics concerning cardiovascular health. This study aimed to evaluate associations of coffee consumption with cardiac biomarkers, echocardiographic, electrocardiographic parameters and major cardiovascular diseases. We performed a cross-sectional analysis of 9009 participants of the population-based Hamburg City Health Study (HCHS), enrolled between 2016 and 2018 median age 63 [IQR: 55; 69] years. Coffee consumption was classified into three groups: < 3 cups/day (low), 3-4 cups/day (moderate), > 4 cups/day (high). In linear regression analyses adjusted for age, sex, body mass index, diabetes, hypertension, smoking, and additives, high coffee consumption correlated with higher LDL-cholesterol (β = 5.92; 95% CI 2.95, 8.89; p < 0.001). Moderate and high coffee consumption correlated with lower systolic (β = - 1.91; 95% CI - 3.04, - 0.78; p = 0.001; high: β = - 3.06; 95% CI - 4.69, - 1.44; p < 0.001) and diastolic blood pressure (β = - 1.05; 95% CI - 1.67, - 0.43; p = 0.001; high: β = - 1.85; 95% CI - 2.74, - 0.96; p < 0.001). Different levels of coffee consumption did neither correlate with any investigated electrocardiographic or echocardiographic parameter nor with prevalent major cardiovascular diseases, including prior myocardial infarction and heart failure. In this cross-sectional analysis, high coffee consumption correlated with raised LDL-cholesterol levels and lower systolic and diastolic blood pressure. However, major cardiovascular diseases including heart failure and its diagnostic precursors were not associated with coffee consumption, connoting a neutral role of coffee in the context of cardiovascular health.

The Potential of Spent Coffee Grounds in Functional Food Development

Coffee is a popular and widely consumed beverage worldwide, with epidemiological studies showing reduced risk of cardiovascular disease, cancers and non-alcoholic fatty liver disease. However, few studies have investigated the health effects of the post-brewing coffee product, spent coffee grounds (SCG), from either hot- or cold-brew coffee. SCG from hot-brew coffee improved metabolic parameters in rats with diet-induced metabolic syndrome and improved gut microbiome in these rats and in humans; further, SCG reduced energy consumption in humans. SCG contains similar bioactive compounds as the beverage including caffeine, chlorogenic acids, trigonelline, polyphenols and melanoidins, with established health benefits and safety for human consumption. Further, SCG utilisation could reduce the estimated 6-8 million tonnes of waste each year worldwide from production of coffee as a beverage. In this article, we explore SCG as a major by-product of coffee production and consumption, together with the potential economic impacts of health and non-health applications of SCG. The known bioactive compounds present in hot- and cold-brew coffee and SCG show potential effects in cardiovascular disease, cancer, liver disease and metabolic disorders. Based on these potential health benefits of SCG, it is expected that foods including SCG may moderate chronic human disease while reducing the environmental impact of waste otherwise dumped in landfill.

Caffeine-loaded nano/micro-carriers: Techniques, bioavailability, and applications

Caffeine, as one of the most consumed bioactive compounds globally, has gained considerable attention during the last years. Considering the bitter taste and adverse effects of high levels of caffeine consumption, it is crucial to apply a strategy for masking the caffeine's bitter taste and facilitating its programmable deliverance within a long time. Other operational parameters such as food processing parameters, exposure to sunlight and oxygen, and gastrointestinal digestion could also degrade the phenolic compounds in general and caffeine in special. To overcome these challenges, various nano/micro-platforms have been fabricated, including lipid-based (e.g., nanoliposomal vehicles; nanoemulsions, double emulsions, Pickering emulsions; microemulsions; niosomal vehicles; solid lipid nanoparticles and nanostructured lipid carriers), as well as biopolymeric (e.g., nanoparticles; hydrogels, organogels, oleogels; nanofibers and nanotubes; protein-polysaccharide nanocomplexes, conjugates; cyclodextrin inclusion complexes) and inorganic (e.g., gold and silica nanoparticles) nano/micro-structures. In this review, the findings on various caffeine-loaded nano/micro-carriers and their potential applications in functional food products/supplements will be discussed. Also, the controlled release and bioavailability of encapsulated caffeine will be given, and finally, the toxicity and safety of encapsulated caffeine will be presented.

Clinical Effect of Electroacupuncture on Acute Sleep Deprivation and Event-Related Potential Affecting the Inhibition Control of the Brain: Study Protocol for a Randomized Controlled Trial

Background

Acute sleep deprivation (ASD) can effect mood, attention, memory, alertness and metabolism. Especially, it is often accompanied by cognitive impairment of the brain. Acupuncture is safe and effective for improving cognitive function, but its underlying mechanism is not fully understood. In this study, an event-related potential (ERP) technique will be employed to measure the behavioral, cognitive, and physiological changes produced by electroacupuncture intervention after ASD.

Methods

We will recruit 60 healthy subjects. The participants will be randomly divided into a treatment group, a control group, a sham electroacupuncture group and a blank group, at a 1:1:1:1 ratio. The primary outcome will be determined by the change from baseline to 36 h in the MoCA score. The secondary results include the amplitude and latency of ERP N2 and P3, Go-hit rates, Go-RTs, No-Go-FA rates, the WCST, the Digit Span Subtest of the WAIS, the ESS score and FS-14. The 15 healthy subjects will not receive acupuncture treatment and ASD, but will receive EEG records and cognition functions test at the beginning and end of the experiment. Electroacupuncture intervention will be performed for 30 min once every 12 h, a total of three times. ERP measurements and other tests will be performed after baseline and ASD, and the statistician and outcome evaluator will be blinded to treatment allocation.

Discussion

This study is expected to investigate the effectiveness of electroacupuncture in improving cognition for ASD.

Trial Registration

ChiCTR2200055999.

Development of machine learning prediction models to explore nutrients predictive of cardiovascular disease using Canadian linked population-based data

Machine learning may improve use of observational data to understand the nutritional epidemiology of cardiovascular disease (CVD) through better modelling of non-linearity, non-additivity, and dietary complexity. Our objective was to develop machine learning prediction models for exploring how nutrients are related to CVD risk and to evaluate their predictive performance. We established a population-based cohort from the Canadian Community Health Survey and measured CVD incidence and mortality from 2004 to 2018 using administrative databases of national hospital discharges and deaths. Predictors included 61 nutrition variables and fourteen socioeconomic, demographic, psychological, and behavioural variables. Conditional inference forest models were interpreted and evaluated by permutation feature importance, accumulated local effects, and predictive discrimination and calibration. A total of 12 130 individuals were included in the study. Use of supplements, caffeine, and alcohol were the most important nutrition variables for prediction of CVD. Supplement use was associated with decreased risk, caffeine was associated with increasing risk, and alcohol had a u-shaped association with risk. The model had an out-of-sample c-statistic of 0.821 (95% confidence interval = 0.801-0.842). Exploratory findings included both known and novel associations and predictive performance was competitive, suggesting that further application of machine learning to nutritional epidemiology may help elucidate risks and improve predictive models. Novelty: Machine learning prediction models were developed for CVD using dietary data. Models were interpreted with interpretable machine learning techniques, revealing diverse associations between diet and CVD. Models achieved comparable or superior predictive performance to existing CVD risk prediction models.

Mental Performance and Sport: Caffeine and Co-consumed Bioactive Ingredients

The plant defence compound caffeine is widely consumed as a performance enhancer in a sporting context, with potential benefits expected in both physiological and psychological terms. However, although caffeine modestly but consistently improves alertness and fatigue, its effects on mental performance are largely restricted to improved attention or concentration. It has no consistent effect within other cognitive domains that are important to sporting performance, including working memory, executive function and long-term memory. Although caffeine's central nervous system effects are often attributed to blockade of the receptors for the inhibitory neuromodulator adenosine, it also inhibits a number of enzymes involved both in neurotransmission and in cellular homeostasis and signal propagation. Furthermore, it modulates the pharmacokinetics of other endogenous and exogenous bioactive molecules, in part via interactions with shared cytochrome P450 enzymes. Caffeine therefore enjoys interactive relationships with a wide range of bioactive medicinal and dietary compounds, potentially broadening, increasing, decreasing, or modulating the time course of their functional effects, or vice versa. This narrative review explores the mechanisms of action and efficacy of caffeine and the potential for combinations of caffeine and other dietary compounds to exert psychological effects in excess of those expected following caffeine alone. The review focusses on, and indeed restricted its untargeted search to, the most commonly consumed sources of caffeine: products derived from caffeine-synthesising plants that give us tea (Camellia sinensis), coffee (Coffea genus), cocoa (Theabroma cacao) and guaraná (Paullinia cupana), plus multi-component energy drinks and shots. This literature suggests relevant benefits to mental performance that exceed those associated with caffeine for multi-ingredient energy drinks/shots and several low-caffeine extracts, including high-flavanol cocoa and guarana. However, there is a general lack of research conducted in such a way as to disentangle the relative contributions of the component parts of these products.

Caffeine Induces Autophagy and Apoptosis in Auditory Hair Cells via the SGK1/HIF-1α Pathway

Caffeine is being increasingly used in daily life, such as in drinks, cosmetics, and medicine. Caffeine is known as a mild stimulant of the central nervous system, which is also closely related to neurologic disease. However, it is unknown whether caffeine causes hearing loss, and there is great interest in determining the effect of caffeine in cochlear hair cells. First, we explored the difference in auditory brainstem response (ABR), organ of Corti, stria vascularis, and spiral ganglion neurons between the control and caffeine-treated groups of C57BL/6 mice. RNA sequencing was conducted to profile mRNA expression differences in the cochlea of control and caffeine-treated mice. A CCK-8 assay was used to evaluate the approximate concentration of caffeine. Flow cytometry, TUNEL assay, immunocytochemistry, qRT-PCR, and Western blotting were performed to detect the effects of SGK1 in HEI-OC1 cells and basilar membranes. In vivo research showed that 120 mg/ kg caffeine injection caused hearing loss by damaging the organ of Corti, stria vascularis, and spiral ganglion neurons. RNA-seq results suggested that SGK1 might play a vital role in ototoxicity. To confirm our observations in vitro, we used the HEI-OC1 cell line, a cochlear hair cell-like cell line, to investigate the role of caffeine in hearing loss. The results of flow cytometry, TUNEL assay, immunocytochemistry, qRT-PCR, and Western blotting showed that caffeine caused autophagy and apoptosis via SGK1 pathway. We verified the interaction between SGK1 and HIF-1α by co-IP. To confirm the role of SGK1 and HIF-1α, GSK650394 was used as an inhibitor of SGK1 and CoCl₂ was used as an inducer of HIF-1α. Western blot analysis suggested that GSK650394 and CoCl₂ relieved the caffeine-induced apoptosis and autophagy. Together, these results indicated that caffeine induces autophagy and apoptosis in auditory hair cells via the SGK1/HIF-1α pathway, suggesting that caffeine may cause hearing loss. Additionally, our findings provided new insights into ototoxic drugs, demonstrating that SGK1 and its downstream pathways may be potential therapeutic targets for hearing research at the molecular level.

NMR, RP-HPLC-PDA-ESI-MSn, and RP-HPLC-FD Characterization of Green and Oolong Teas (Camellia sinensis L.)

Untargeted (NMR) and targeted (RP-HPLC-PDA-ESI-MSⁿ, RP-HPLC-FD) analytical methodologies were used to determine the bioactive components of 19 tea samples, characterized by different production processes (common tea and GABA tea), degrees of fermentation (green and oolong teas), and harvesting season (autumn and spring). The combination of NMR data and a multivariate statistical approach led to a statistical model able to discriminate between GABA and non-GABA teas and green and oolong teas. Targeted analyses showed that green and GABA green teas had similar polyphenol and caffeine contents, but the GABA level was higher in GABA green teas than in regular green tea samples. GABA oolong teas showed lower contents of polyphenols, caffeine, and amino acids, and a higher content of GABA, in comparison with non-GABA oolong teas. In conclusion, the results of this study suggest that the healthy properties of teas, especially GABA teas, have to be evaluated via comprehensive metabolic profiling rather than only the GABA content.

Impacts of caffeine on resistant chicken's performance and cardiovascular gene expression

We previously reported a study on 288 broiler (Gallus gallus) chicks who received caffeine in water between days 3 and 42, at levels of 0, 6.25, 12.5, 25, 50 and 100 mg/kg body weight (BW)/day. In the previous report, we found that caffeine caused pulmonary hypertension (PH)-associated mortality in a significant minority (20%-30%) of birds, including right ventricular hypertrophy and ascites. We have also shown a significant upregulation of the serotonin transporter (SERT), troponin T2, adenosine A₁ receptor (ADORA1) and phosphodiesterase 5A (PDE5) in chicken suffering from PH. Here, we examine the resistant (survived) chicks from the first study that had not died due to acute heart failure and did not have clinical signs of pulmonary hypertension. Our goal was to determine whether birds who lacked overt signs of disease had subclinical manifestations, including similar changes in gene expression, growth rates and altered systemic haemodynamics. We found that growth was significantly increased by caffeine consumption (p < 0.01) at low doses; however, dosage over 50 mg/BW/d had remarkable adverse effects on growth (p < 0.01). Blood pressure, troponin T2 and PDE5 gene expression were not significantly altered by caffeine administration (p > 0.05). However, SERT gene expression linearly increased with increasing caffeine dosage (p < 0.01). The impact of caffeine on ADORA1 gene expression was dose dependent and nonlinear. In conclusion, despite the significant effects of caffeine on birds' growth, no significant negative effects of caffeine were observed on the cardiovascular function of resistant chickens. This work provides valuable information for further study on different dosage of caffeine in an animal model.

Coffee Consumption and Cardiovascular Diseases: A Mendelian Randomization Study

Coffee consumption has been linked to a lower risk of cardiovascular disease in observational studies, but whether the associations are causal is not known. We conducted a Mendelian randomization investigation to assess the potential causal role of coffee consumption in cardiovascular disease. Twelve independent genetic variants were used to proxy coffee consumption. Summary-level data for the relations between the 12 genetic variants and cardiovascular diseases were taken from the UK Biobank with up to 35,979 cases and the FinnGen consortium with up to 17,325 cases. Genetic predisposition to higher coffee consumption was not associated with any of the 15 studied cardiovascular outcomes in univariable MR analysis. The odds ratio per 50% increase in genetically predicted coffee consumption ranged from 0.97 (95% confidence interval (CI), 0.63, 1.50) for intracerebral hemorrhage to 1.26 (95% CI, 1.00, 1.58) for deep vein thrombosis in the UK Biobank and from 0.86 (95% CI, 0.50, 1.49) for subarachnoid hemorrhage to 1.34 (95% CI, 0.81, 2.22) for intracerebral hemorrhage in FinnGen. The null findings remained in multivariable Mendelian randomization analyses adjusted for genetically predicted body mass index and smoking initiation, except for a suggestive positive association for intracerebral hemorrhage (odds ratio 1.91; 95% CI, 1.03, 3.54) in FinnGen. This Mendelian randomization study showed limited evidence that coffee consumption affects the risk of developing cardiovascular disease, suggesting that previous observational studies may have been confounded.

Targeting Melanoma-Initiating Cells by Caffeine: In Silico and In Vitro Approaches

The beneficial effects of coffee on human diseases are well documented, but the molecular mechanisms of its bioactive compounds on cancer are not completely elucidated. This is likely due to the large heterogeneity of coffee preparations and different coffee-based beverages, but also to the choice of experimental models where proliferation, differentiation and immune responses are differently affected. The aim of the present study was to investigate the effects of one of the most interesting bioactive compounds in coffee, i.e., caffeine, using a cellular model of melanoma at a defined differentiation level. A preliminary in silico analysis carried out on public gene-expression databases identified genes potentially involved in caffeine’s effects and suggested some specific molecular targets, including tyrosinase. Proliferation was investigated in vitro on human melanoma initiating cells (MICs) and cytokine expression was measured in conditioned media. Tyrosinase was revealed as a key player in caffeine’s mechanisms of action, suggesting a crucial role in immunomodulation through the reduction in IL-1β, IP-10, MIP-1α, MIP-1β and RANTES secretion onto MICs conditioned media. The potent antiproliferative effects of caffeine on MICs are likely to occur by promoting melanin production and reducing inflammatory signals’ secretion. These data suggest tyrosinase as a key player mediating the effects of caffeine on melanoma.

Retinoic Acid Signaling Plays a Crucial Role in Excessive Caffeine Intake-Disturbed Apoptosis and Differentiation of Myogenic Progenitors

Whether or not the process of somitogenesis and myogenesis is affected by excessive caffeine intake still remains ambiguous. In this study, we first showed that caffeine treatment results in chest wall deformities and simultaneously reduced mRNA expressions of genes involved in myogenesis in the developing chicken embryos. We then used embryo cultures to assess in further detail how caffeine exposure affects the earliest steps of myogenesis, and we demonstrated that the caffeine treatment suppressed somitogenesis of chicken embryos by interfering with the expressions of crucial genes modulating apoptosis, proliferation, and differentiation of myogenic progenitors in differentiating somites. These phenotypes were abrogated by a retinoic acid (RA) antagonist in embryo cultures, even at low caffeine doses in C2C12 cells, implying that excess RA levels are responsible for these phenotypes in cells and possibly in vivo. These findings highlight that excessive caffeine exposure is negatively involved in regulating the development of myogenic progenitors through interfering with RA signaling. The RA somitogenesis/myogenesis pathway might be directly impacted by caffeine signaling rather than reflecting an indirect effect of the toxicity of excess caffeine dosage.

Caffeine and high energy drink use and knowledge by nurses in three countries

AIM

The purpose of this study was to examine nurses' use and knowledge of caffeine and high energy drinks (HED) in three countries.

METHODS

Nurses in each country completed a survey on caffeine and HED use and knowledge.

RESULTS

In a sample of 182 nurses, caffeine use was high with 92% of nurses in Korea, 90.8% in Italy and 88.1% in the United States (US) having at least one cup of coffee a day while 64% of Koreans and 11.9% of those in the US had at least one HED per day. In Korea 68% of nurses (Italy 63.1% and 35.8% US) had at least one cup of caffeinated tea per day. Most agreed there is a need to educate nurses about HED, which contain high amounts of caffeine. Over half of nurses in Korea (58%) and the US (56.7%) said their colleagues consume HED at work.

CONCLUSION

Findings of this study indicate many nurses are consuming caffeine at work and there is a need for education. It is unclear how caffeine affects nurses' clinical performance, which raises the issue of patient safety. Further research is needed regarding safe amounts of caffeine while nurses are on the job as well as an understanding of how HED additives may affect the well-being and clinical care of nurses.

Daily Coffee Drinking Is Associated with Lower Risks of Cardiovascular and Total Mortality in a General Italian Population: Results from the Moli-sani Study

BACKGROUND

An inverse relationship between coffee intake and mortality has been observed in several population cohorts, but rarely within Mediterranean countries. Moreover, the biological pathways mediating such an association remain unclear.

OBJECTIVES

We assessed the associations between coffee consumption and total and cause-specific mortality and examined the mediating roles of N-terminal pro B-type natriuretic peptide (NTproBNP), high-sensitivity Troponin I, blood glucose, lipid metabolism, and selected biomarkers of inflammation and renal function.

METHODS

We longitudinally analyzed data on 20,487 men and women (35-94 years old at baseline) in the Moli-sani Study, a prospective cohort established in 2005-2010. Individuals were free from cardiovascular disease (CVD) and cancer and were followed-up for a median of 8.3 years. Dietary data were collected by a 188-item semi-quantitative FFQ. Coffee intake was standardized to a 30-mL Italian espresso cup size. HRs with 95% CIs were calculated by multivariable Cox regression.

RESULTS

In comparison with no/rare coffee consumption (up to 1 cup/d), HRs for all-cause mortality across categories of coffee consumption (>1 to ≤2, >2 to ≤3, >3 to ≤4 and >4 cups/d) were 0.79 (95% CI, 0.65-0.95), 0.84 (95% CI, 0.69-1.03), 0.72 (95% CI, 0.57-0.92), and 0.85 (95% CI, 0.62-1.12), respectively. For CVD mortality, a nonlinear (P for non-linearity = 0.021) J-shaped association was found (magnitude of the relative reduction = 37%; nadir at 3-4 cups/d). Circulating levels of NTproBNP explained up to 26.4% of the association between coffee and all-cause mortality, while systolic blood pressure was likely to be on the pathway between coffee and CVD mortality, although to a lesser extent.

CONCLUSIONS

In this large cohort of Italian adults, moderate consumption (3-4 cups/d) of Italian-style coffee was associated with lower risks of all-cause and, specifically, of CVD mortality. Among the known biomarkers investigated here, NTproBNP likely mediates the relationship between coffee intake and all-cause mortality.

Caffeine ingestion alters central hemodynamics following aerobic exercise in middle-aged men

PURPOSE

To examine the acute influence of caffeine on post-exercise central blood pressures, arterial stiffness, and wave reflection properties.

METHODS

In a double-blind randomized placebo-controlled crossover study design, ten middle-aged males (55 ± 5 year) completed two exercise trials after ingestion of caffeine (400 mg) or placebo. Measurements were taken before and 30 min post-ingestion via cuff-based pulse wave analysis (PWA) and carotid-femoral pulse wave velocity (PWV). Participants performed a 40-min cycling bout at 70% HRmax with matched workloads between trials. PWA and PWV were reassessed 30 min post-exercise.

RESULTS

Prior to exercise, compared to placebo, caffeine increased brachial systolic blood pressure (bSBP) (+ 12.3 ± 2.4 mmHg; p = 0.004), brachial diastolic blood pressure (bDBP) (+ 7.7 ± 0.9 mmHg; p = 0.011), central systolic blood pressure (cSBP) (+ 11.1 ± 2.1 mmHg; p = 0.005) and central diastolic blood pressure (cDBP) (+ 7.6 ± 1.0 mmHg; p = 0.012). PWV was higher 30 min after pill ingestion (p = 0.021 for time) with a trend for a greater increase in caffeine (p = 0.074 for interaction). bSBP (p = 0.036) and cSBP (p = 0.007) were lower after exercise but remained higher (both p < 0.001) in caffeine compared to placebo. PWV remained higher (p = 0.023) after exercise in caffeine compared to placebo but was not influenced by exercise. At rest, augmentation pressure (AP) and index (AIx) were not influenced by caffeine ingestion. Conversely, AIx was lower (p = 0.009) after exercise in placebo only.

CONCLUSION

In healthy and active middle-aged men, pre-exercise caffeine ingestion led to higher central and peripheral systolic blood pressures, PWV and AIx at 30 min post-exercise, indicating an increased left ventricular workload which may have implications for cardiovascular event risk.

Decaffeinated coffee and its benefits on health: focus on systemic disorders

The current literature has mainly focused on benefits and risks deriving from the consumption of caffeinated coffee and its implications for inflammation, cardiovascular diseases, neurodegenerative disorders, and cancer. Today, data about the role of caffeine in many disorders are controversial and the attention has increasingly focused on decaffeinated coffee and its non-caffeine compounds, which could have mainly beneficial effects. In fact, coffee phenolic compounds not only exhibit well-known antioxidant properties, but they can also antagonize some negative effects of caffeine, for example in inflammatory pathway and in glucose metabolism and homeostasis. In this review, we consider the literature of the last two decades and critically discuss the effects of decaffeinated coffee compounds on systemic disorders, mainly inflammation, cardiovascular diseases, hepatic dysfunctions, and cancer.

Cardiovascular and Autonomic Responses to Energy Drinks-Clinical Implications

There is an increasing consumption of energy drinks both in the United States and worldwide. The components of these beverages are sometimes unclear but commonly include caffeine, sugars, taurine, and B-vitamins. Young people, particularly those engaged in sports, studying, and in the military are especially likely to be consumers of energy drinks. While limited data are available regarding their autonomic and hemodynamic effects, current literature suggests that energy drink consumption is accompanied by increases in blood pressure, sympathetic drive, and also in QT prolongation. There are no systematic long term studies identifying consequences of frequent energy drink consumption. However, multiple anecdotal reports implicate energy drinks in adverse cardiovascular events including atrial fibrillation, ventricular arrhythmia, myocardial infarction, and sudden death. Events such as atrial fibrillation may even occur in otherwise healthy subjects with structurally normal hearts. It is likely that these cardiovascular outcomes are triggered by the hemodynamic, autonomic, and electrocardiographic responses to energy drink consumption. What remains unclear is how concomitant use of other stimulants such as amphetamines and nicotine may interact to potentiate neural and circulatory responses and cardiovascular consequences when combined with energy drinks.

The association between lifestyle factors and Parkinson's disease progression and mortality

BACKGROUND

Lifestyle factors may contribute to the development of Parkinson's disease, but little is known about factors that influence progression. The objective of the current study was to examine whether caffeine or alcohol consumption, physical activity, or cigarette smoking is associated with progression and survival among PD patients.

METHODS

We assessed lifelong coffee, tea, and alcohol consumption, smoking, and physical activity in a prospective community-based cohort (n = 360). All patients were passively followed for mortality (2001-2016); 244 were actively followed on average ± SD 5.3 ± 2.1 years (2007-2014). Movement disorder specialists repeatedly assessed motor function (Hoehn & Yahr) and cognition (Mini-Mental State Exam). We used Cox proportional hazards models and inverse probability weights to account for censoring.

RESULTS

Coffee, caffeinated tea, moderate alcohol consumption, and physical activity were protective against at least 1 outcome. Smoking and heavy alcohol consumption were associated with increased risks. Coffee was protective against time to Hoehn & Yahr stage 3 (hazard ratio, 0.52; 95% confidence interval, 0.28-1.01), cognitive decline (hazard ratio, 0.23; 95% confidence interval, 0.11, 0.48), and mortality (hazard ratio, 0.47; 95% confidence interval, 0.32-0.69). Relative to moderate drinkers, those who never drank liquor and those who drank more heavily were at an increased risk of Hoehn & Yahr 3 (hazard ratio, 3.48; 95% confidence interval, 1.90-6.38; and hazard ratio, 2.16; 95% confidence interval, 1.03, 4.54, respectively). A history of competitive sports was protective against cognitive decline (hazard ratio, 0.46; 95% confidence interval, 0.22-0.96) and Hoehn & Yahr 3 (hazard ratio, 0.42; 95% confidence interval, 0.23-0.79), as was physical activity measured by metabolic-equivalent hours. Current cigarette smoking was associated with faster cognitive decline (hazard ratio, 3.20; 95% confidence interval, 1.02-10.01).

CONCLUSIONS

This population-based study suggests that lifestyle factors influence PD progression and mortality. © 2019 International Parkinson and Movement Disorder Society.

Mental energy: plausible neurological mechanisms and emerging research on the effects of natural dietary compounds

Objective: Lack of mental energy is one of the leading reasons adults turn to dietary supplements, with three out of ten supplement users hoping to improve their energy level; even more consume caffeine-containing products for the same reason. Despite this interest from consumers, there is no consensus scientific definition of mental energy or sole validated instrument for measuring it. We performed this review to summarize main findings from research regarding the influence of natural dietary compounds on three aspects of mental energy: cognition (vigilance), motivation (to do mental work), and mood (feelings of energy and/or absence of feelings of fatigue).Methods: A narrative review of key papers.Results: In addition to caffeine, a number of other compounds, including the polyphenols, which are found in all plant-derived products, and the phytochemicals in culinary herbs and herbal products such as Panax ginseng and Ginkgo biloba, have been shown in animal models to modulate neurotransmitter activity potentially relevant to mental energy. Inadequate intake of B vitamins could also potentially have a negative effect on mental energy due to their role in overall energy production, as precursors of key cofactors in the citric acid cycle, as well as their role in brain function and neurotransmitter synthesis. Consumption of some of these products may have direct or indirect effects on one or more elements of mental energy.Conclusion: Large, prospective clinical trials of these products using appropriate, validated instruments designed to measure mental energy may be worthwhile if sufficient evidence exists to justify such trials.

Estrogenic Activity of Coffee Constituents

Here, the constituents of coffee with estrogenic activity are summarized by a comprehensive literature search, and their mechanisms of action for their physiological effects are discussed at the molecular and cellular levels. The estrogenic activity of coffee constituents, such as acids, caramelized products, carbohydrates, lignin, minerals, nitrogenous compounds, oil (lipids), and others, such as volatile compounds, was first evaluated by activity assays, such as animal tests, cell assay, ligand-binding assay, protein assay, reporter-gene assay, transcription assay, and yeast two-hybrid assay. Second, the health benefits associated with the estrogenic coffee constituents, such as bone protection, cancer treatment/prevention, cardioprotection, neuroprotection, and the improvement of menopausal syndromes, were summarized, including their potential therapeutic/clinical applications. Inconsistent results regarding mixed estrogenic/anti-estrogenic/non-estrogenic or biphasic activity, and unbeneficial effects associated with the constituents, such as endocrine disruption, increase the complexity of the effects of estrogenic coffee constituents. However, as the increase of the knowledge about estrogenic cell signaling, such as the types of specific signaling pathways, selective modulations of cell signaling, signal crosstalk, and intercellular/intracellular networks, pathway-based assessment will become a more realistic means in the future to more reliably evaluate the beneficial applications of estrogenic coffee constituents.

How to recognize caffeine overdose

Caffeine is the most widely consumed stimulant in the world and can offer a variety of benefits when consumed in moderation. But consuming caffeine in extremely high amounts can lead to an overdose. This article examines how nurses can recognize the signs and symptoms of caffeine overdose and educate patients on how to prevent this common problem.

In vivo protein expression changes in mouse livers treated with dialyzed coffee extract as determined by IP-HPLC

Background

Coffee extract has been investigated by many authors, and many minor components of coffee are known, such as polyphenols, diterpenes (kahweol and cafestol), melanoidins, and trigonelline, to have anti-inflammatory, anti-oxidant, anti-angiogenic, anticancer, chemoprotective, and hepatoprotective effects. Therefore, it is necessary to know its pharmacological effect on hepatocytes which show the most active cellular regeneration in body.

Methods

In order to determine whether coffee extract has a beneficial effect on the liver, 20 C57BL/6J mice were intraperitoneally injected once with dialyzed coffee extract (DCE)-2.5 (equivalent to 2.5 cups of coffee a day in man), DCE-5, or DCE-10, or normal saline (control), and then followed by histological observation and IP-HPLC (immunoprecipitation high performance liquid chromatography) over 24 h.

Results

Mice treated with DCE-2.5 or DCE-5 showed markedly hypertrophic hepatocytes with eosinophilic cytoplasms, while those treated with DCE-10 showed slightly hypertrophic hepatocytes, which were well aligned in hepatic cords with increased sinusoidal spaces. DCE induced the upregulations of cellular proliferation, growth factor/RAS signaling, cellular protection, p53-mediated apoptosis, angiogenesis, and antioxidant and protection-related proteins, and the downregulations of NFkB signaling proteins, inflammatory proteins, and oncogenic proteins in mouse livers. These protein expression changes induced by DCE were usually limited to the range ± 10%, suggesting murine hepatocytes were safely reactive to DCE within the threshold of physiological homeostasis. DCE-2.5 and DCE-5 induced relatively mild dose-dependent changes in protein expressions for cellular regeneration and de novo angiogenesis as compared with non-treated controls, whereas DCE-10 induced fluctuations in protein expressions.

Conclusion

These observations suggested that DCE-2.5 and DCE-5 were safer and more beneficial to murine hepatocytes than DCE-10. It was also found that murine hepatocytes treated with DCE showed mild p53-mediated apoptosis, followed by cellular proliferation and growth devoid of fibrosis signaling (as determined by IP-HPLC), and subsequently progressed to rapid cellular regeneration and wound healing in the absence of any inflammatory reaction based on histologic observations.

Electronic supplementary material

The online version of this article (10.1186/s40902-018-0183-z) contains supplementary material, which is available to authorized users.

Berberine protects myocardial cells against anoxia-reoxygenation injury via p38 MAPK-mediated NF-κB signaling pathways

Ischemic heart disease is a leading cause of mortality and occurs due to coronary arterial atherosclerosis, vascular cavity stenosis and occlusion. It has previously been demonstrated that berberine treatment may ameliorate and help to prevent cardiovascular diseases due to its anti-inflammatory and anti-apoptotic effects in myocardial cells. However, the potential signaling mechanisms mediated by berberine in the progression of myocardial injury remain to be elucidated. The aim of the present study was to investigate the therapeutic effects of berberine and its potential mechanism in a mouse model of myocardial cell injury. The results revealed that berberine treatment downregulated the serum expression of inflammatory factors, including interleukin (IL)-6, tumor necrosis factor-α, IL-10 and IL-17A in mice with anoxia-reoxygenation injury. Berberine treatment also decreased myocardial cell apoptosis following anoxia-reoxygenation injury via regulating the expression of apoptosis-associated genes. Histological analysis revealed that the area, circumference fragmentation and segmentation of myocardial cells were significantly decreased by berberine treatment compared with the control group. The body weight, blood lipid levels, blood pressure and heart rate were markedly improved in mice with anoxia-reoxygenation injury following berberine treatment compared with untreated mice. The expression of p38 mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-κB expression was downregulated in myocardial cells from in mice with anoxia-reoxygenation injury following berberine treatment compared with untreated mice. However, p38 MAPK overexpression ameliorated the berberine-induced decrease in NF-κB activity and expression, as well as the berberine-induced inhibition of myocardial apoptosis in myocardial cells isolated from experimental mice. In conclusion, the results of the present study indicate that berberine is able to decrease the expression of inflammatory cytokines expression and inhibit myocardial cell apoptosis via downregulating the p38 MAPK-mediated NF-κB signaling pathway. These results suggest that berberine may be an effective treatment for anoxia-reoxygenation injury.

The clinical toxicology of caffeine: A review and case study

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

Coffee consumption and total mortality in a Mediterranean prospective cohort

Background

The relation of coffee consumption with total mortality is controversial, because the available evidence is still inconsistent.

Objective

This study aimed to assess this association in a highly educated, middle-aged Mediterranean cohort.

Design

We analyzed data from 201,055 person-years of follow-up arising from 19,888 participants. Coffee consumption was obtained at baseline with the use of a previously validated semiquantitative food-frequency questionnaire. Information on mortality was ascertained by permanent contact with the "Seguimiento Universidad de Navarra" (SUN) participants and their families, postal authorities, and consultation of the National Death Index. We used Cox regression models to estimate HRs and 95% CIs for mortality according to baseline total coffee consumption adjusted for potential confounders. Sex, age, and baseline adherence to the Mediterranean diet were considered as potential effect modifiers.

Results

Among the 19,888 participants, 337 died. Overall, in the multivariable adjusted analysis, we found a 22% lower risk of all-cause mortality for each 2 additional cups of total coffee per day (HR: 0.78; 95% CI: 0.66, 0.93). This association was stronger for participants aged ≥55 y (HR: 0.67; 95% CI: 0.52, 0.86) than for younger participants, who showed no significant association (P-interaction = 0.002).

Conclusion

In a Mediterranean cohort, we found an inverse linear association between total coffee consumption and the risk of all-cause mortality that was strongest among participants older than 54 y.

The Acute Effects of Caffeinated Black Coffee on Cognition and Mood in Healthy Young and Older Adults

Cognitive and mood benefits of coffee are often attributed to caffeine. However, emerging evidence indicates behavioural effects of non-caffeine components within coffee, suggesting the potential for direct or synergistic effects of these compounds when consumed with caffeine in regular brewed coffee. The current randomised, placebo-controlled, double-blind, counterbalanced-crossover study compared the effects of regular coffee, decaffeinated coffee, and placebo on measures of cognition and mood. Age and sex effects were explored by comparing responses of older (61–80 years, N = 30) and young (20–34 years, N = 29) males and females. Computerised measures of episodic memory, working memory, attention, and subjective state were completed at baseline and 30 min post-drink. Regular coffee produced the expected effects of decreased reaction time and increased alertness when compared to placebo. When compared to decaffeinated coffee, increased digit vigilance accuracy and decreased tiredness and headache ratings were observed. Decaffeinated coffee also increased alertness when compared to placebo. Higher jittery ratings following regular coffee in young females and older males represented the only interaction of sex and age with treatment. These findings suggest behavioural activity of coffee beyond its caffeine content, raising issues with the use of decaffeinated coffee as a placebo and highlighting the need for further research into its psychoactive effects.

In vitro protein expression changes in RAW 264.7 cells and HUVECs treated with dialyzed coffee extract by immunoprecipitation high performance liquid chromatography

RAW 264.7 cells and HUVECs were compared to evaluate the effects of dialyzed coffee extract (DCE) and artificial coffee (AC). Immunoprecipitation high performance liquid chromatography (IP-HPLC) showed DCE-2.5- (equivalent to 2.5 cups of coffee a day) and DCE-5-induced protein expression that was beneficial to human health, i.e., they led to significant increases in proliferation-, immunity-, cellular protection-, antioxidant signaling-, and osteogenesis-related proteins but decreases in inflammation-, NFkB signaling-, cellular apoptosis-, and oncogenic signaling-related proteins in RAW 264.7 cells, and slight decreases in angiogenesis-related proteins in HUVECs. These protein expression changes were less frequently observed for DCE-10 treatment, while AC treatment induced very different changes in protein expression. We suggest that the favorable cellular effects of DCE were derived from minor coffee elements that were absent in AC, and that the reduced effects of DCE-10 compared with those of DCE-2.5 or DCE-5 might have been caused by greater adverse reactions to caffeine and chlorogenic acid in DCE-10 than DCE-2.5 or DCE-5. IP-HPLC results suggested that minor coffee elements in DCE might play beneficial roles in the global protein expression of proliferation-, immunity-, anti-inflammation-, cell protection-, antioxidant-, anti-apoptosis-, anti-oncogenesis-, and osteogenesis-related proteins in RAW 264.7 cells and enhance anti-angiogenic signaling in HUVECs.

Coffee Drinking and Associated Factors in an Elderly Population in Spain

Coffee consumption is highly prevalent worldwide, and many studies have reported positive and inverse associations of coffee with many diseases. However, factors associated with coffee consumption remain poorly characterized in some populations, such as the elderly. This study aimed to assess the factors associated with total, caffeinated and decaffeinated coffee consumption in an elderly population in Spain. Data were analyzed from 903 participants, aged 65 years and above, from two population-based studies carried out in the Valencia region in Spain (Valencia Nutritional Survey (VNS) and European Eye Study (EUREYE-Study). Total, caffeinated and decaffeinated coffee consumption was assessed through two specific questions using a validated food frequency questionnaire. Information on personal characteristics, anthropometry and lifestyles was collected in personal interviews. Multinomial logistic regression analysis was used to estimate the adjusted relative risk ratios (RRR) and confidence intervals (95% CI). The prevalence of total, caffeinated and decaffeinated coffee consumption was 70%, 38% and 32%, respectively. The consumption of caffeinated coffee was positively associated with: Educational level, RRR = 1.63 (1.09–2.44); body mass index (≥30), RRR = 2.03 (1.05–3.95); tobacco smoking, RRR = 1.96 (1.13–3.39); alcohol intake [≥12 g/day category intake vs. no-alcohol intake, RRR = 6.25 (3.56–10.95)]; and energy intake (p < 0.05). Consumption of caffeinated coffee was negatively associated with: Age (≥75 years), RRR = 0.64 (0.43–0.94); and pre-existing hypertension, RRR = 0.67 (0.45–0.98). The consumption of decaffeinated coffee was positively associated with: Alcohol intake, RRR = 2.63 (1.19–4.64); pre-existing diabetes, RRR = 1.67 (1.06–2.62); and energy intake (p < 0.01). The consumption of coffee is high among elderly people in Spain. It is a novelty in this study with elderly population that tobacco smoking and alcohol drinking were the two main factors associated with higher coffee consumption. Self-reported hypertension was associated with a lower consumption of caffeinated coffee, and pre-existing diabetes was associated with a higher consumption of decaffeinated coffee. These associations should be taken into account when the health effects of coffee consumption are investigated.

Caffeine effects on VO2max test outcomes investigated by a placebo perceived-as-caffeine design

BACKGROUND

Ergogenic effects of caffeine (CAF) ingestion have been observed in different cycling exercise modes, and have been associated with alterations in ratings of perceived exertion (RPE). However, there has been little investigation of maximal oxygen uptake (VO_2MAX) test outcomes.

AIM

This study aimed to verify whether CAF may reduce RPE, thereby improving maximal incremental test (MIT) outcomes such as VO_2MAX, time to exhaustion and peak power output (W_PEAK).

METHODS

Nine healthy individuals performed three MITs (25 W/min until exhaustion) in a random, counterbalanced fashion after ingestion of CAF, placebo perceived as caffeine (PLA), and no supplementation (baseline control). VO₂ was measured throughout the test, while RPE was rated according to overall and leg effort sensations. The power output corresponding to submaximal (RPE = 14 according to the 6-20 Borg scale) and maximal RPE was recorded for both overall (O-RPE₁₄ and O-RPE_MAX) and leg RPE (L-RPE₁₄ and L-RPE_MAX).

RESULTS

VO_2MAX did not change significantly between MITs; however, CAF and PLA increased time to exhaustion (↑ ∼18.7% and ∼17.1%, respectively; p < .05) and W_PEAK (↑ ∼13.0% and ∼11.8%, respectively; p < .05) when compared with control. When compared with control, CAF ingestion reduced submaximal and maximal overall and leg RPEs, the effect being greater in maximal (likely beneficial in O-RPE_MAX and L-RPE_MAX) than submaximal RPE (possibly beneficial in O-RPE₁₄ and L-RPE₁₄). Similar results were found when participants ingested PLA.

CONCLUSIONS

Compared with control, CAF and PLA improved MIT performance outcomes such as time to exhaustion and W_PEAK, without altering VO_2MAX values. CAF effects were attributed to placebo.

Caffeine in Kidney Stone Disease: Risk or Benefit?

Kidney stone disease is a global health care problem, with a high recurrence rate after stone removal. It is thus crucial to develop effective strategies to prevent the formation of new or recurrent stones. Caffeine is one of the main components in caffeinated beverages worldwide (i.e., coffee, tea, soft drinks, and energy drinks). Previous retrospective and prospective studies have reported contradictory effects of caffeine on kidney stone risk. Although it has a diuretic effect on enhancing urinary output, it may slightly increase the stone risk index. However, 3 large cohorts have suggested a preventive role of caffeine in kidney stone disease. In addition, a recent in vitro study has addressed relevant mechanisms underlying the preventive role of caffeine against stone pathogenesis. This review summarizes the relevant data from previous evidence and discusses the association between caffeine consumption and kidney stone risk reduction.

Coffee Consumption and Cardiovascular Disease: A Condensed Review of Epidemiological Evidence and Mechanisms

Coffee is one of the most widely consumed beverages, and some studies have suggested it may be related to cardiovascular disease (CVD), the leading cause of poor health in the world. This review evaluates the evidence on the effect of habitual coffee consumption on CVD incidence and mortality. The review is based mostly on observational studies and meta-analyses of the literature. In healthy people, in comparison to not consuming coffee, habitual consumption of 3-5 cups of coffee per day is associated with a 15% reduction in the risk of CVD, and higher consumption has not been linked to elevated CVD risk. Moreover, in comparison to no coffee intake, usual consumption of 1-5 cups/day is associated with a lower risk of death. In people who have already suffered a CVD event, habitual consumption does not increase the risk of a recurrent CVD or death. However, hypertensive patients with uncontrolled blood pressure should avoid consuming large doses of caffeine. In persons with well-controlled blood pressure, coffee consumption is probably safe, but this hypothesis should be confirmed by further investigations.

Determination of the mutational landscape in Taiwanese patients with papillary thyroid cancer by whole-exome sequencing

Among women in Taiwan, thyroid cancer is the fifth most common malignant neoplasia. However, genomic profiling of papillary thyroid cancer (PTC) cases from Taiwan has not been attempted previously. We used whole-exome sequencing to identify mutations in a cohort of 19 PTC patients. Sequencing was performed using the Illumina system; Sanger sequencing was used to validate all identified mutations. We identified new somatic mutations in APC, DICER1, LRRC8D and NDRG1. We also found somatic mutations in ARID5A, CREB3L2, MDM4, PPP2R5A and TFPT; mutations in these genes had been found previously in other tumors, but had not been described previously in PTC. We also investigated the pathway deregulation in BRAF-mutated PTC compared with wild-type BRAF PTC. In checking our gene mutations against The Cancer Genome Atlas (TCGA) database, we identified aberrations in one pathway that are specific to BRAF-mutated PTC: maturity-onset diabetes of the young. In addition, the caffeine metabolism pathway showed aberrations that are specific to wild-type BRAF PTC. For this study, we performed a comprehensive exome-wide analysis of the mutational spectra of Taiwanese patients with PTC. We identified novel genes that are potentially associated with PTC tumorigenesis, as well as aberrations in pathways that led to the distinct pathogeneses of BRAF-mutated PTC and wild-type BRAF PTC, which may provide a new target for PTC therapy.

Bare carbon electrodes as simple and efficient sensors for the quantification of caffeine in commercial beverages

Food quality control is a mandatory task in the food industry and relies on the availability of simple, cost-effective and stable sensing platforms. In the present work, the applicability of bare glassy carbon electrodes for routine analysis of food samples was evaluated as a valid alternative to chromatographic techniques, using caffeine as test analyte. A number of experimental parameters were optimized and a differential pulse voltammetry was applied for quantification experiments. The detection limit was found to be 2 × 10^-5 M (3σ criterion) and repeatability was evaluated by the relative standard deviation of 4.5%. The influence of sugars, and compounds structurally related to caffeine on the current response of caffeine was evaluated and found to have no significant influence on the electrode performance. The suitability of bare carbon electrodes for routine analysis was successfully demonstrated by quantifying caffeine content in seven commercially available drinks and the results were validated using a standard ultra-high performance liquid chromatography method. This work demonstrates that bare glassy carbon electrodes are a simple, reliable and cost-effective platform for rapid analysis of targets such as caffeine in commercial products and they represent therefore a competitive alternative to the existing analytical methodologies for routine food analysis.

Metabolic profiling of four South African herbal teas using high resolution liquid chromatography-mass spectrometry and nuclear magnetic resonance

Increased preference to herbal drinks has led to global interest in the use and production of different plant species for the preparation of various drink formulations. Medicinal properties derived from bioactive compounds remain the main driver of choice for herbal teas. This study determined the chemical variation in honeybush, rooibos, special and bush tea, profiled compounds responsible for such differences and compared their peak areas. Nuclear magnetic resonance and high resolution liquid chromatography-mass spectrometry were used to determine compound variation and profiling. Principal component analysis and partial-least square multivariate statistical analysis showed distinct differences (P < 0.05) between the different types of herbal teas. Detected compounds included flavonoids, phenolics, lignans, megastigmane glycoside, most of which possess health benefits. The findings showed that South African herbal teas could play a vital role as health promoting drinks, and that bush tea and special tea are phytochemically comparable with other commercialized herbal teas.

Tea, cocoa, coffee, and affective disorders: vicious or virtuous cycle?

BACKGROUND

The prevalence of psychiatric disorders is increasing worldwide, which underscores the importance of increasing research in this field, in terms of better detection, prevention based on improvement of lifestyle and diet, and effectiveness of treatment. Increasing evidence suggest that diet and exercise can affect proper neuronal development and physiology and protect the brain from neurological illnesses or injuries. Of note, cocoa, tea, and coffee are being actively investigated because they are rich in (poly)phenolic compounds that can modulate mental health, namely brain plasticity, behavior, mood, depression, and cognition.

METHODS

We here systematically review human studies conducted on tea, cocoa, and coffee as related to affective disorders such as depression and anxiety. We carried out a systematic literature search in April 2016, using MEDLINE, on data from the last 10 years. After screening 955 articles, we selected 17 articles that met the criteria of being human studies and that used whole foods or their components.

RESULTS

The results of our systematic review indicate that consumption of tea, cocoa, or coffee might have protective effects against depression.

CONCLUSIONS

Even though this is encouraging, it should be underscored that the near totality of the current evidence comes from observational studies. Ad-hoc human trials and mechanistic, basic science studies are needed before we can provide sound advice to the public.

Effects of energy drinks on the cardiovascular system

Throughout the last decade, the use of energy drinks has been increasingly looked upon with caution as potentially dangerous due to their perceived strong concentration of caffeine aside from other substances such as taurine, guarana, and L-carnitine that are largely unknown to the general public. In addition, a large number of energy drink intoxications have been reported all over the world including cases of seizures and arrhythmias. In this paper, we focus on the effect of energy drinks on the cardiovascular system and whether the current ongoing call for the products’ sales and regulation of their contents should continue.

Coffee, Caffeine, and Health Outcomes: An Umbrella Review

To evaluate the associations between coffee and caffeine consumption and various health outcomes, we performed an umbrella review of the evidence from meta-analyses of observational studies and randomized controlled trials (RCTs). Of the 59 unique outcomes examined in the selected 112 meta-analyses of observational studies, coffee was associated with a probable decreased risk of breast, colorectal, colon, endometrial, and prostate cancers; cardiovascular disease and mortality; Parkinson's disease; and type-2 diabetes. Of the 14 unique outcomes examined in the 20 selected meta-analyses of observational studies, caffeine was associated with a probable decreased risk of Parkinson's disease and type-2 diabetes and an increased risk of pregnancy loss. Of the 12 unique acute outcomes examined in the selected 9 meta-analyses of RCTs, coffee was associated with a rise in serum lipids, but this result was affected by significant heterogeneity, and caffeine was associated with a rise in blood pressure. Given the spectrum of conditions studied and the robustness of many of the results, these findings indicate that coffee can be part of a healthful diet.

J-shaped relationship between habitual coffee consumption and 10-year (2002-2012) cardiovascular disease incidence: the ATTICA study

PURPOSE

The purpose of this work was to evaluate the association between coffee consumption and 10-year cardiovascular disease (CVD) incidence in the ATTICA study, and whether this is modified by the presence or absence of metabolic syndrome (MetS) at baseline.

METHODS

During 2001-2002, 3042 healthy adults (1514 men and 1528 women) living in the greater area of Athens were voluntarily recruited to the ATTICA study. In 2011-2012, the 10-year follow-up was performed in 2583 participants (15% of the participants were lost to follow-up). Coffee consumption was assessed by a validated food-frequency questionnaire at baseline (abstention, low, moderate, heavy). Incidence of fatal or non-fatal CVD event was recorded using WHO-ICD-10 criteria and MetS was defined by the National Cholesterol Education Program Adult Treatment panel III (revised) criteria.

RESULTS

Overall, after controlling for potential CVD risk factors, the multivariate analysis revealed a J-shaped association between daily coffee drinking and the risk for a first CVD event in a 10-year period. Particularly, the odds ratio for low (<150 ml/day), moderate (150-250 ml/day) and heavy coffee consumption (>250 ml/day), compared to abstention, were 0.44 (95% CI 0.29-0.68), 0.49 (95% CI 0.27-0.92) and 2.48 (95% CI 1.56-1.93), respectively. This inverse association was also verified among participants without MetS at baseline, but not among participants with the MetS.

CONCLUSIONS

These data support the protective effect of drinking moderate quantities of coffee (equivalent to approximately 1-2 cups daily) against CVD incidents. This protective effect was only significant for participants without MetS at baseline.