Coffee and tea: perks for health and longevity?

Bitter taste receptors: Key target to understand the effects of polyphenols on glucose and body weight homeostasis. Pathophysiological and pharmacological implications

Experimental and clinical research has reported beneficial effects of polyphenol intake on high prevalent diseases such as type 2 diabetes and obesity. These phytochemicals are ligands of taste 2 receptors (T2Rs) that have been recently located in a variety of organs and extra-oral tissues. Therefore, the interaction between polyphenol and T2Rs in brain structures can play a direct effect on appetite/satiety regulation and food intake. T2Rs are also expressed along the digestive tract, and their interaction with polyphenols can induce the release of gastrointestinal hormones (e.g., ghrelin, GLP-1, CCK) influencing appetite, gastrointestinal functionally, and glycemia control. Intestinal microbiota can also influence on network effects of polyphenols-T2Rs interaction and vice versa, impacting innate immune responses and consequently on gut functionally. Furthermore, polyphenols binding to T2Rs present important effects on adipose tissue metabolism. Interestingly, T2R polymorphism could, at least partially, explain the inter-individual variability of the effects of polyphenols on glucose and body weight homeostasis. Together, these factors can contribute to understand the beneficial effects of polyphenol-rich diets but also might aid in identifying new pharmacological pathway targets for the treatment of diabetes and obesity.

Tea and coffee consumption and risk of acute stroke: The INTERSTROKE Study

BACKGROUND

Stroke is a leading global cause of death and disability. Daily tea/coffee intake is consumed by > 50% of populations and may represent an important population-level exposure. Therefore, it is first essential that we better understand the associations between the tea/coffee intake and stroke.

AIMS

This research aims to generate hypotheses about the global associations between tea and coffee intake and stroke. These insights will identify interventions for stroke prevention that can be further explored using alternative study designs.

METHODS

INTERSTROKE is a large international matched case-control study of first stroke from 32 countries. Participants were asked "how many cups do you drink each day?" of coffee, green tea, black tea, and other tea. Multivariable conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for associations between intake and stroke.

RESULTS

We included 13,462 cases and 13,488 controls from INTERSTROKE; mean age was 61.7 (13.4) years and 59.6% (n = 16,010) were male. Overall, 19.4% (n = 5239) did not consume tea/coffee, 47.0% (n = 12,666) consumed tea only, 14.9% (n = 4024) consumed coffee alone, and 18.6% (n = 5021) consumed both, with significant regional variations. After multivariable adjustment, there was no association between low/moderate coffee intake and stroke, but high consumption (> 4/day) was associated with higher odds of all stroke (OR = 1.37 (95% CI = 1.06-1.77)) or ischemic stroke (OR = 1.32 (95% CI = 1.00-1.74)). Tea consumption was associated with lower odds of all (OR = 0.81 (95% CI = 0.69-0.94) for highest intake) or ischemic stroke (OR = 0.81 (95% CI = 0.68-0.98) for highest intake).

CONCLUSIONS

High coffee consumption was associated with higher odds of all or ischemic stroke; low-moderate coffee had no association with stroke. In contrast, tea consumption was associated with lower odds of stroke. These associations suggest that individuals consider avoiding high coffee consumption (⩾ five cups/day) to impact future stroke risk.

DATA ACCESS STATEMENT

The design and rationale of INTERSTROKE was published previously. Individual participant data, or other documents are not available.

Severe iron-deficiency anemia after short-term moderate consumption of green tea in woman: A rare case report

While the mechanisms by which tea consumption hinders iron absorption are well understood, tea-related anemia usually stems from prolonged and excessive intake, which obstructs iron absorption and depletes the body's iron reserves. Consequently, it is uncommon for hemoglobin levels to plummet by 6.9 g/dl solely due to moderate tea consumption over a span of three months. We present a case of severe iron-deficiency anemia in a woman following short-term, moderate green tea consumption. After modifying her tea intake regimen, there was no recurrence of anemia. Clinicians should be mindful that even moderate tea consumption can precipitate severe iron-deficiency anemia in individuals particularly vulnerable to its effects on iron absorption.

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.

A weighted quantile sum regression with penalized weights and two indices

Background

New statistical methodologies were developed in the last decade to face the challenges of estimating the effects of exposure to multiple chemicals. Weighted Quantile Sum (WQS) regression is a recent statistical method that allows estimating a mixture effect associated with a specific health effect and identifying the components that characterize the mixture effect.

Objectives

In this study, we propose an extension of WQS regression that estimates two mixture effects of chemicals on a health outcome in the same model through the inclusion of two indices, one in the positive direction and one in the negative direction, with the introduction of a penalization term.

Methods

To evaluate the performance of this new model we performed both a simulation study and a real case study where we assessed the effects of nutrients on obesity among adults using the National Health and Nutrition Examination Survey (NHANES) data.

Results

The method showed good performance in estimating both the regression parameter and the weights associated with the single elements when the penalized term was set equal to the magnitude of the Akaike information criterion of the unpenalized WQS regression. The two indices further helped to give a better estimate of the parameters [Positive direction Median Error (PME): 0.022; Negative direction Median Error (NME): -0.044] compared to the standard WQS without the penalization term (PME: -0.227; NME: 0.215). In the case study, WQS with two indices was able to find a significant effect of nutrients on obesity in both directions identifying sodium and magnesium as the main actors in the positive and negative association, respectively.

Discussion

Through this work, we introduced an extension of WQS regression that improved the accuracy of the parameter estimates when considering a mixture of elements that can have both a protective and a harmful effect on the outcome; and the advantage of adding a penalization term when estimating the weights.

Essential role of the mitochondrial Na+/Ca2+ exchanger NCLX in mediating PDE2-dependent neuronal survival and learning

Impaired phosphodiesterase (PDE) function and mitochondrial Ca2+ (i.e., [Ca2+]m) lead to multiple health syndromes by an unknown pathway. Here, we fluorescently monitor robust [Ca2+]m efflux mediated by the mitochondrial Na+/Ca2+ exchanger NCLX in hippocampal neurons sequentially evoked by caffeine and depolarization. Surprisingly, neuronal depolarization-induced Ca2+ transients alone fail to evoke strong [Ca2+]m efflux in wild-type (WT) neurons. However, pre-treatment with the selective PDE2 inhibitor Bay 60-7550 effectively rescues [Ca2+]m efflux similarly to caffeine. Moreover, PDE2 acts by diminishing mitochondrial cAMP, thus promoting NCLX phosphorylation at its PKA site. We find that the protection of neurons against excitotoxic insults, conferred by PDE2 inhibition in WT neurons, is NCLX dependent. Finally, the administration of Bay 60-7550 enhances new object recognition in WT, but not in NCLX knockout (KO), mice. Our results identify a link between PDE and [Ca2+]m signaling that may provide effective therapy for cognitive and ischemic syndromes.

Biological Role of Nutrients, Food and Dietary Patterns in the Prevention and Clinical Management of Major Depressive Disorder

Major Depressive Disorder (MDD) is a growing disabling condition affecting around 280 million people worldwide. This complex entity is the result of the interplay between biological, psychological, and sociocultural factors, and compelling evidence suggests that MDD can be considered a disease that occurs as a consequence of an evolutionary mismatch and unhealthy lifestyle habits. In this context, diet is one of the core pillars of health, influencing multiple biological processes in the brain and the entire body. It seems that there is a bidirectional relationship between MDD and malnutrition, and depressed individuals often lack certain critical nutrients along with an aberrant dietary pattern. Thus, dietary interventions are one of the most promising tools to explore in the field of MDD, as there are a specific group of nutrients (i.e., omega 3, vitamins, polyphenols, and caffeine), foods (fish, nuts, seeds fruits, vegetables, coffee/tea, and fermented products) or dietary supplements (such as S-adenosylmethionine, acetyl carnitine, creatine, amino acids, etc.), which are being currently studied. Likewise, the entire nutritional context and the dietary pattern seem to be another potential area of study, and some strategies such as the Mediterranean diet have demonstrated some relevant benefits in patients with MDD; although, further efforts are still needed. In the present work, we will explore the state-of-the-art diet in the prevention and clinical support of MDD, focusing on the biological properties of its main nutrients, foods, and dietary patterns and their possible implications for these patients.

Caffeine Consumption among Various University Students in the UAE, Exploring the Frequencies, Different Sources and Reporting Adverse Effects and Withdrawal Symptoms

Background

Caffeine is widely consumed among students due to its cognitive and physical enhancing effects. However, little is known about the consumption pattern of different caffeinated products among university students in the United Arab Emirates (UAE).

Aim

To investigate the frequency of caffeine consumption among the young population of students, assess types of caffeinated products consumed, and document adverse effects and withdrawal symptoms experienced by university students.

Methods

A cross-sectional study was conducted in the UAE from December 2019 to March 2020. A random sample of 500 university students from different universities in the UAE were approached and asked to complete a self-administered online-based questionnaire. Data were analyzed using the Statistical Package for Social Science (SPSS) version 26.

Results

Of (n = 500) surveyed students, (n = 467) completed the survey 93.4%. The average level of caffeine consumption was significantly higher in females compared to male students (p < 0.005). Coffee was the highest favored source of caffeine (67.7%) followed by tea (47.3%). The average daily intake of caffeine was found to be 264 mg/day. Surprisingly, almost a third of students reported a high level of daily consumption (>400 mg/day) and more than half of them consumed less than 199 mg/day. Large proportions of students 91.1% have their caffeinated beverage after or while eating meals and 42.8% considered that this habit helped in avoiding acid reflux. Interestingly, around one third of participants have poor knowledge of caffeine-containing medical products, which seemed to affect the level of consumption in the student population (p < 0.05). The highest reported reason for caffeine intake was for studying purposes (59.4%).

Conclusion

Caffeine consumption is highly prevalent among university students in the UAE. Yet, there is insufficiency in the current knowledge of safe caffeine consumption patterns reflecting the importance of health awareness programs and nutritional lectures to decrease the long-term health issues and unintentional overdose of caffeine.

The associations between sleep behaviors, lifestyle factors, genetic risk and mental disorders: A cohort study of 402 290 UK Biobank participants

BACKGROUND

Sleep behaviors were believed to be associated with mental disorders (MD). However, the underlying mechanism of such association relationship, especially the role of multiple lifestyle factors in it remains unclear.

METHODS

A total of 402,290 participants from UK Biobank who don't have MD at baseline were included. They were divided into poor, intermediate and healthy sleep patterns according to the sleep score, which was calculated based on the data collecting from five sleep behaviors. Cox proportional hazard model was used to estimate the associations between sleep behaviors and MD. The associations were further estimated when taking lifestyle factors such as physical activity, coffee intake, tea intake and genetic susceptibility into account.

RESULTS

Healthy sleep pattern was associated with lower risk of overall MD status (HR,0.41, 95%CI,0.39-0.43), depressive disorders (HR,0.34, 95%CI,0.31-0.37) and anxiety disorders (HR,0.46, 95%CI,0.41-0.79), compared with poor sleep pattern. And in each subgroup of physical activity, tea intake, coffee intake, age and genetic risk scores (GRS), healthy sleep pattern could partly offset the risk of diseases.

CONCLUSIONS

Our study suggested healthy sleep behaviors could diminish the negative effect from genetic predisposition and lifestyle factors on the risk of MD, highlighting the benefit of healthy sleep pattern.

Neuroprotective and anxiolytic potential of green rooibos (Aspalathus linearis) polyphenolic extract

South African rooibos (Aspalathus linearis) tea is globally consumed for its health benefits and caffeine free nature, but no information is available on the neuroprotective capacity of (unfermented) green rooibos. Our aim was to investigate the cytoprotective activity of green rooibos in neuronal cells, including probing antioxidant and enzyme inhibitory properties that could explain observed effects in these cells. We also investigated the anxiolytic potential of green rooibos using zebrafish larval models. Green rooibos extract (Green oxithin™) was assessed for its neuroprotective potential in Neuro-2a cells treated with different concentrations of the extract (12.5-25-50-100 μg mL^-1) and different concentrations of hydrogen peroxide (250 or 125 μM) as oxidizing agent. Cell viability (MTT) and redox status (intracellular ROS) were also quantified in these cells. Antioxidant properties of the extract were quantified using cell-free systems (DPPH, ORAC and xanthine/xanthine oxidase), and potential neuroprotection evaluated in terms of its potential to inhibit key enzymes of the CNS (monoamine oxidase A (MOA-A), acetylcholinesterase (AChE) and tyrosinase (TYR)). Results demonstrated that green rooibos extract exerted significant cytoprotective properties in Neuro-2a cells, particularly when exposed to lethal 250 μM hydrogen peroxide, increasing cell survival by more than 100%. This may be ascribed (at least partially) to its capacity to limit intracellular ROS accumulation in these cells. Data from cell-free systems confirmed that green rooibos was able to scavenge free radicals (synthetic and physiological) in a dose dependent manner with a similar profile activity to vitamins C and E. Green rooibos also acted as a moderate MAO-A inhibitor, but had no significant effect on AChE or TYR. Finally, zebrafish larvae treated with lower doses of green rooibos demonstrated a significant anxiolytic effect in the light-dark anxiety model. Using the PTZ excitotoxicity model, green rooibos was shown to rescue GABA receptor signalling, which together with its demonstrated inhibition of MAO-A, may account for the anxiolytic outcome. Current data confirms that green rooibos could be considered a "functional brain food" and may be a good option as starting ingredient in the development of new nutraceuticals.

Therapeutic effects of green tea on endometriosis

Endometriosis is a chronic disorder characterized by the presence of endometrial glands and stroma outside the uterine cavity. It affects 8%-10% of women in their reproductive years, and represents a major clinical problem with deleterious social, sexual and reproductive consequences. Current treatment options include pain relief, hormonal intervention and surgical removal. However, these treatments are deemed unsatisfactory owing to varying success, significant side effects and high recurrence rates. Green tea and its major bioactive component, (-)-epigallocatechin gallate (EGCG), possess diverse biological properties, particularly anti-angiogenic, anti-proliferation, anti-metastasis, and apoptosis induction. In recent years, preclinical studies have proposed the use of green tea to inhibit the growth of endometriosis. Herein, the aim of this review is to summarize the potential therapeutic effects of green tea on molecular and cellular mechanism through inflammation, oxidative stress, invasion and adhesion, apoptosis and angiogenesis in endometriosis.

Therapeutic potential of targeting intestinal bitter taste receptors in diabetes associated with dyslipidemia

Intestinal release of incretin hormones after food intake promotes glucose-dependent insulin secretion and regulates glucose homeostasis. The impaired incretin effects observed in the pathophysiologic abnormality of type 2 diabetes have triggered the pharmacological development of incretin-based therapy through the activation of glucagon-like peptide-1 (GLP-1) receptor, including GLP-1 receptor agonists (GLP-1 RAs) and dipeptidyl peptidase 4 (DPP4) inhibitors. In the light of the mechanisms involved in the stimulation of GLP-1 secretion, it is a fundamental question to explore whether glucose and lipid homeostasis can be manipulated by the digestive system in response to nutrient ingestion and taste perception along the gastrointestinal tract. While glucose is a potent stimulant of GLP-1 secretion, emerging evidence highlights the importance of bitter tastants in the enteroendocrine secretion of gut hormones through activation of bitter taste receptors. This review summarizes bitter chemosensation in the intestines for GLP-1 secretion and metabolic regulation based on recent advances in biological research of bitter taste receptors and preclinical and clinical investigation of bitter medicinal plants, including bitter melon, hops strobile, and berberine-containing herbs (e.g. coptis rhizome and barberry root). Multiple mechanisms of action of relevant bitter phytochemicals are discussed with the consideration of pharmacokinetic studies. Current evidence suggests that specific agonists targeting bitter taste receptors, such as human TAS2R1 and TAS2R38, may provide both metabolic benefits and anti-inflammatory effects with the modulation of the enteroendocrine hormone secretion and bile acid turnover in metabolic syndrome individuals or diabetic patients with dyslipidemia-related comorbidities.

The anti-obesity and health-promoting effects of tea and coffee

This paper reviews provenance, chemical composition and properties of tea (Camelia sinensis L.) and coffee (Coffee arabica, L. and Coffeacaniphora, L.), their general health effects, as well as the currently available knowledge concerning their action on fat storage, physiological mechanisms of their effects, as well as their safety and recommended dosage for treatment of obesity. Both tea and coffee possess the ability to promote health and to prevent, to mitigate and to treat numerous disorders. This ability can be partially due to presence of caffeine in both plants. Further physiological and medicinal effects could be explained by other molecules (theaflavins, catechins, their metabolites and polyphenols in tea and polyphenol chlorogenic acid in coffee). These plants and plant molecules can be efficient for prevention and treatment of numerous metabolic disorders including metabolic syndrome, cardiovascular diseases, type 2 diabetes and obesity. Both plants and their constituents can reduce fat storage through suppression of adipocyte functions, and support of gut microbiota. In addition, tea can prevent obesity via reduction of appetite, food consumption and food absorption in gastrointestinal system and through the changes in fat metabolism.

Assessment of beverage consumption by young adults in Saudi Arabia

Objective

The primary objective was to assess beverage consumption pattern and calorie intake among undergraduate students on weekly and daily basis. Secondary objectives were to determine the relationship between demographic variables and beverage intake, assess mean differences in calorie intake between students’ groups and, report the predictors of beverage consumption.

Methods

A cross-sectional study was conducted for 3 months (January–March 2019) among currently enrolled undergraduate students studying in 8 colleges of a public sector university in Dammam, Saudi Arabia. The study used the Arabic version of Beverage Frequency Questionnaire (BFQ) and collected data through purposive stratified sampling. Total intake in ml and calories in kcals were calculated. Data was analyzed through SPSS version 23 and the study was approved from ethics committee of the university (IRB‐2019‐05‐021).

Results

A total of 507 students responded to the survey. The average volume of sugar sweetened beverages (SSBs), caffeine containing beverage (CCBs) and carbonated beverages (CarBs) consumed was 4.2 L, 4 L and 1.5 L per week and 650.6 ml, 575.2 ml and 224.6 ml per day, respectively. Average daily calorie intake from SSBs, CCBs and CarBs was 187.6 kcals, 87.6 kcals and 52.5 kcals, respectively. Body mass index (BMI) was significantly related to CCB (ρ = 0.130) and CarBs (ρ = 0.100) intake (mL) (p < 0.05). Mean difference in calorie intake was mostly significant (p < 0.05) when accounted for students’ demographics, gender, BMI, residence, illness and, examination time, in case of SSBs, CCBs, CarBs and, all beverages. Averge % contribution towards total daily energy expenditure (TDEE) for SSBs, CCBs and CarBs were 10.2%, 6.3% and 2.8%, respectively. Year of study, BMI, residence and illness were predictors of SSBs consumption while BMI, residence and examination time were predictors of CCBs consumption. Gender and BMI were predictors of CarBs intake.

Conclusion

There was a high consumption of beverages in students that was related to their demographic characteristics. There is a need to create awareness among the students regarding the detrimental effects of chronic consumption of these beverages.

Habitual Coffee and Tea Consumption and Cardiometabolic Biomarkers in the UK Biobank: The Role of Beverage Types and Genetic Variation

BACKGROUND

Mechanisms linking habitual consumption of coffee and tea to the development of type 2 diabetes and cardiovascular diseases remain unclear.

OBJECTIVES

We leveraged dietary, genetic, and biomarker data collected from the UK Biobank to investigate the role of different varieties of coffee and tea in cardiometabolic health.

METHODS

We included data from ≤447,794 participants aged 37-73 y in 2006-2010 who provided a blood sample and completed questionnaires regarding sociodemographic factors, medical history, diet, and lifestyle. Multivariable linear regression was used to examine the association between coffee or tea consumption and blood concentrations of glycated hemoglobin, fasting glucose, total cholesterol, HDL cholesterol, LDL cholesterol, fasting triglycerides (TGs), apoA-1, apoB, lipoprotein-a, and C-reactive protein (CRP). Lifestyle and genetic factors affecting caffeine metabolism, responses, or intake were tested for interactions with beverage intake in relation to biomarker concentrations.

RESULTS

Compared with coffee nonconsumers, each additional cup of coffee was significantly associated with higher total cholesterol, HDL-cholesterol, and LDL-cholesterol concentrations and lower TG and CRP concentrations in both men and women (P-trend < 0.002). Higher consumption of espresso coffee (≥2 compared with 0 cups/d) was associated with higher LDL cholesterol in men (β: 0.110 mmol/L; 95% CI: 0.058, 0.163 mmol/L) and women (β: 0.161 mmol/L; 95% CI: 0.088, 0.234 mmol/L), whereas no substantial association was observed for instant coffee. Compared with tea nonconsumers, higher tea consumption was associated with lower total and LDL cholesterol and apoB and higher HDL cholesterol (P-trend < 0.002); these associations were similar for black and green tea. Associations were not modified by genetics.

CONCLUSIONS

In the UK Biobank, consumption of certain coffee brews such as espresso had unfavorable associations with blood lipids, whereas consumption of tea had favorable associations. Findings were not modified by genetic variants affecting caffeine metabolism, suggesting a role of noncaffeine constituents of these beverages in cardiometabolic health.

Dipeptidyl Peptidase-4 Is a Target Protein of Epigallocatechin-3-Gallate

Epigallocatechin-3-gallate (EGCG), a major active ingredient in green tea, has various health benefits. It affects glucose metabolism, but the mechanism is not well understood. This study aimed to identify targets of EGCG related to glucose metabolism. The core fragment of EGCG is a flavonoid. The flavonoid scaffold was used as a substructure to find proteins cocrystallized with flavonoids in the Protein Data Bank. The proteins identified were screened in PubMed for known relationships with diabetes. Dipeptidyl peptidase-4 (DPP4; PDB 5J3J) was identified following this approach. By molecular docking, the interactions of EGCG and DPP4 were assessed. To test the stability of the interactions between EGCG and DPP4, molecular dynamics simulation for 100 ns was performed using Desmond software. In vitro, the concentration of EGCG required to inhibit DPP4 activity by 50% (the IC50 value) was 28.42 μM. These data provide a theoretical basis for intervention in glucose metabolism with EGCG.

Low-dose caffeine administration increases fatty acid utilization and mitochondrial turnover in C2C12 skeletal myotubes

Caffeine has been shown to directly increase fatty acid oxidation, in part, by promoting mitochondrial biogenesis. Mitochondrial biogenesis is often coupled with mitophagy, the autophagy-lysosomal degradation of mitochondria. Increased mitochondrial biogenesis and mitophagy promote mitochondrial turnover, which can enhance aerobic metabolism. In addition, recent studies have revealed that cellular lipid droplets can be directly utilized in an autophagy-dependent manner, a process known as lipophagy. Although caffeine has been shown to promote autophagy and mitochondrial biogenesis in skeletal muscles, it remains unclear whether caffeine can increase lipophagy and mitochondrial turnover in skeletal muscle as well. The purpose of this study was to determine the possible contribution of lipophagy to caffeine-dependent lipid utilization. Furthermore, we sought to determine whether caffeine could increase mitochondrial turnover, which may also contribute to elevated fatty acid oxidation. Treating fully differentiated C2C12 skeletal myotubes with 0.5 mM oleic acid (OA) for 24 hr promoted an approximate 2.5-fold increase in cellular lipid storage. Treating skeletal myotubes with 0.5 mM OA plus 0.5 mM caffeine for an additional 24 hr effectively returned cellular lipid stores to control levels, and this was associated with an increase in markers of autophagosomes and autophagic flux, as well as elevated autophagosome density in TEM images. The addition of autophagy inhibitors 3-methyladenine (10 mM) or bafilomycin A1 (10 μM) reduced caffeine-dependent lipid utilization by approximately 30%. However, fluorescence and transmission electron microscopy analysis revealed no direct evidence of lipophagy in skeletal myotubes, and there was also no lipophagy-dependent increase in fatty acid oxidation. Finally, caffeine treatment promoted an 80% increase in mitochondrial turnover, which coincided with a 35% increase in mitochondrial fragmentation. Our results suggest that caffeine administration causes an autophagy-dependent decrease in lipid content by increasing mitochondrial turnover in mammalian skeletal myotubes.

Modelling the Effects of Beverage Substitution during Adolescence on Later Obesity Outcomes in Early Adulthood: Results from the Raine Study

High sugar-sweetened beverage (SSB) consumption has been linked with obesity. The present study examined the associations between adolescent SSB intake and body mass index (BMI), waist circumference (WC), and overweight status in early adulthood, and modelled the association of alternative beverage substitution with BMI and WC. Data of offspring from the Western Australian Pregnancy Cohort (Raine) Study at ages 14 and 22 years were used (n = 667). SSB intake at 14 years (100 g/day) was associated with higher BMI (β = 0.19 kg/m², 95% CI 0.04, 0.33), WC (β = 0.41cm, 95% CI 0.04, 0.78), and being overweight at 22 years (OR 1.10, 95% CI 1.02, 1.18). Every 100g modelled substitution of SSB with milk at age 14 years was associated with lower BMI (−0.19 kg/m²) and WC (−0.52 cm) at age 22 years. Replacement of SSB with diet drink was associated with higher BMI and WC. No association was found for substitutions of SSB with water, tea/coffee, or 100% fruit juice with BMI or WC. SSB intake during adolescence was associated with higher BMI, WC, and being overweight in early adulthood. Milk as an alternative to SSB was associated with less adiposity. Caution is necessary in recommending diet drinks as a SSB alternative.

Tea polyphenols: application in the control of oral microorganism infectious diseases

One of the most popular drinks worldwide, tea is rich in polyphenols and is beneficial to our health because it contributes to the prevention of many diseases. In the human oral cavity, there are more than 750 different species of bacteria living together within dental plaque. Some of the bacteria are pathogens that contribute to the development of oral diseases such as dental caries, periodontitis, pulpitis, mucosal disease, or halitosis through their virulence factors and their metabolites. Until now, many studies have reported that tea polyphenols (TPs) have evident inhibitory effects on some oral pathogenic microorganisms by suppressing pivotal steps of their pathogenic processes. The aim of this review is to summarize the effectiveness and mechanisms of TPs in inhibiting microorganisms, so as to provide new ideas for the prevention and treatment of oral diseases, and to contribute to the global dental public health.

Chemistry, pharmacology and new trends in traditional functional and medicinal beverages

Functional and medicinal beverages consumption plays an important role in human health, considering that metabolites, with a wide range of pharmacological effects, are inserted in the human diet. Nowadays, the most consumed beverages are obtained from Camellia sinensis leaves and coffee grain processing, and contain different classes of polyphenols and phenolic acids in their phytochemical composition. Besides C. sinensis and coffee, numerous plants have been receiving attention due to their phytochemical composition and pharmacological effects, such as yerba mate, hibiscus, chamomile, lemongrass, fennel and mentha. Furthermore, atomized or lyophilized medicinal plant extracts can be employed in many beverage formulations and the consumption of these products is an excellent delivery means for nutrients and bioactive compounds, such as: minerals, vitamins, terpenes, antioxidants, saponins, alkaloids and polysaccharides. Innovation in food processing in order to insert functional and medicinal beverages in the human diet poses a challenge for the coming years. The technological development of new processing forms and use of plants with bioactive metabolites could be an important tool in relation to this proposal. In this context, this review has aimed to summarize and analyze pharmacological, phytochemistry and technological aspects of species with classical ethnobotanical and traditional use.

Review of animal studies on the cardiovascular effects of caffeine

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

Management of hyperuricemia through dietary polyphenols as a natural medicament: A comprehensive review

Hyperuricemia, a condition due to high serum uric acid level and is notorious to health. It is considered to be a potent risk factor for gout and dramatically associated in the development of many chronic diseases such as malignant tumor, cardiovascular disorders and renal failure. Modern innovative medicinal and therapeutic interventions are underlying these days to combat hyperuricemia. Previously reported studies revealed the significant impact of dietary polyphenols (e.g. anthocyanins, phenolic acids, flavonoids etc.) against hyperurecemia disorder. Dietary plant polyphenols, unlike anti- hyperuricemic agents, are not reported to have any side effects in curing hyperuricemia. The current comprehensive review figure outs the use of dietary polyphenols as a natural remedy for the management of hyperuricemia. The sources, affiliated pathways, mode of actions and factors affecting their efficiency to prevent hyperuricemia are deeply discussed in this article. Additionally, limitations and suggestions regarding previously reported studies are also highlighted.

Caffeine at a Moderate Dose Did Not Affect the Skeletal System of Rats with Streptozotocin-Induced Diabetes

Diabetes may lead to the development of osteoporosis. Coffee drinking, apart from its health benefits, is taken into consideration as an osteoporosis risk factor. Data from human and animal studies on coffee and caffeine bone effects are inconsistent. The aim of the study was to investigate effects of caffeine at a moderate dose on the skeletal system of rats in two models of experimental diabetes induced by streptozotocin. Effects of caffeine administered orally (20 mg/kg aily for four weeks) were investigated in three-month-old female Wistar rats, which, two weeks before the start of caffeine administration, received streptozotocin (60 mg/kg, intraperitoneally) alone or streptozotocin after nicotinamide (230 mg/kg, intraperitoneally). Bone turnover markers, mass, mineral density, histomorphometric parameters, and mechanical properties were examined. Streptozotocin induced diabetes, with profound changes in the skeletal system due to increased bone resorption and decreased bone formation. Although streptozotocin administered after nicotinamide induced slight increases in glucose levels at the beginning of the experiment only, slight, but significant unfavorable changes in the skeletal system were demonstrated. Administration of caffeine did not affect the investigated skeletal parameters of rats with streptozotocin-induced disorders. In conclusion, caffeine at a moderate dose did not exert a damaging effect on the skeletal system of diabetic rats.

Association of sleep duration and incidence of diabetes modified by tea consumption: a report from the Shanghai men's health study

OBJECTIVES

To evaluate the association between sleep duration and the incidence of diabetes stratified by sleep-related factors among Chinese men.

METHODS

This study included 34,825 men who provided information on sleep-related questions in the Shanghai Men's Health Study, a population-based cohort study conducted in Shanghai, China from 2002 to 2011. Participants were excluded who had a history of diabetes or who were diagnosed with diabetes within 2 years of recruitment. Cox regression was employed to evaluate the influence of sleep duration and its interaction with sleep-related factors on diabetes risk.

RESULTS

A total of 1521 incident cases were documented during a median of 5.6 follow-up years. Adjusted hazard ratios and 95% confidence intervals were 1.0 (0.9-1.1) and 1.2 (1.0-1.3) for men who slept <7 and ≥8 h per day, respectively, compared with those who slept 7 h per day (p_trend = 0.01). Stratified analyses revealed that the association between sleep duration and risk of diabetes was only statistically significant among current smokers and regular drinkers, never tea drinkers, men with a high body mass index, hypertension or comorbidity, and men who did not work nightshift or who snored. A statistically significant interaction between tea drinking and sleep duration was observed (p_interaction = 0.01). The above association patterns remained when daytime nappers were excluded from the analyses.

CONCLUSIONS

The data suggested that longer sleep duration, particularly among individuals already exhibiting factors linked to poor quality of sleep, was associated with diabetes. The association between sleep duration and diabetes may be modified by tea drinking, especially in older men or men with more sleep-related factors.

Associations of Coffee, Diet Drinks, and Non-Nutritive Sweetener Use with Depression among Populations in Eastern Canada

Consumption of coffee and diet drinks and the use of non-nutritive sweeteners is commonplace worldwide. We conducted a cross-sectional analysis to investigate the associations between coffee consumption and non-nutritive sweetener use and depression among populations in Atlantic Canada. During 2009 to 2013, we recruited 18838 participants aged 35-69 years (5854 men and 12984 women) for the baseline survey of the Atlantic Partnership for Tomorrow's Health cohort study. Coffee consumption, sweetener use, and major depression were assessed using a set of standardized questionnaires. We utilized multiple logistic regression models to assess the associations of coffee drinking and non-nutritive sweetener use with major depression. Compared with non-coffee drinkers, female participants who drank coffee ≥4 cups/day had an odds ratio of 1.38 (95% confidence interval, 1.15-1.64) for major depression with adjustment for sociodemographic and behavioral factors, chronic disease status, and body mass index. We found a significant association between depression and consumption of sweeteners and diet drinks, which was more apparent among women than men. We conclude that heavy coffee drinking and non-nutritive sweetener use were associated with depression among populations in Atlantic Canada. Further studies are warranted to investigate the underlying biological mechanisms.

Inhibition of green tea polyphenol EGCG((-)-epigallocatechin-3-gallate) on the proliferation of gastric cancer cells by suppressing canonical wnt/β-catenin signalling pathway

(-)-Epigallocatechin-3-gallate (EGCG), the major polyphenol in green tea, could affect carcinogenesis and development of many cancers. However, the effects and underlying mechanisms of EGCG on gastric cancer remain unclear. We found that EGCG significantly inhibited proliferation and increased apoptosis of SGC-7901 cells in vitro. The decreased expressions of p-β-catenin(Ser552), p-GSK3β(S9) and β-catenin target genes were detected in SGC-7901 cells after treated by EGCG. XAV939 and β-catenin plasmid were further used to demonstrate the inhibition of EGCG on canonical Wnt/β-catenin signalling. Moreover, EGCG significantly inhibited gastric tumour growth in vivo by inhibiting Wnt/β-catenin signalling. Taken together, our findings establish that EGCG suppressed gastric cancer cell proliferation and demonstrate that this inhibitory effect is related to canonical Wnt/β-catenin signalling. This study raises a new insight into gastric cancer prevention and therapy, and provides evidence that green tea could be used as a nutraceutical beverage.

Impact of polyphenol-rich sources on acute postprandial glycaemia: a systematic review

Increasingly, evidence suggests a role for polyphenols in blood glucose control. The objective of this systematic review was to evaluate the effect of polyphenol-rich sources in combination with carbohydrate sources on resulting postprandial glycaemic and insulin responses. A literature search was conducted using Medline, CINHAL and Web of Science databases. Selected studies included randomised controlled trials in which the association of polyphenol-containing food or beverage consumption with a carbohydrate source and effect on acute postprandial glycaemia and/or insulin was reported. A total of thirteen full articles were included in the review. Polyphenol sources included coffee, black tea, fruit juice, plant extracts, berries and different rye breads, and carbohydrate sources included bread, pancakes and simple sugars such as sucrose, glucose and fructose. Although glycaemic and insulin responses differed depending on the polyphenol-carbohydrate combination, overall, polyphenol sources were shown to reduce the peak and early-phase glycaemic response and maintain the glycaemic response in the later stages of digestion. To a lesser extent, polyphenol sources were also shown to reduce peak insulin response and sustain the insulin response, especially when consumed with bread. This review supports epidemiological data suggesting that polyphenols in foods and beverages may have a beneficial effect on reducing the risk of type 2 diabetes. However, the extent of this effect is variable depending on the polyphenol and carbohydrate source.

Effect of Natural Polyphenols on CYP Metabolism: Implications for Diseases

Cytochromes P450 (CYPs) are a large group of hemeproteins located on mitochondrial membranes or the endoplasmic reticulum. They play a crucial role in the metabolism of endogenous and exogenous molecules. The activity of CYP is associated with a number of factors including redox potential, protein conformation, the accessibility of the active site by substrates, and others. This activity may be potentially modulated by a variety of small molecules. Extensive experimental data collected over the past decade point at the active role of natural polyphenols in modulating the catalytic activity of CYP. Polyphenols are widespread micronutrients present in human diets of plant origin and in medicinal herbs. These compounds may alter the activity of CYP either via direct interactions with the enzymes or by affecting CYP gene expression. The polyphenol-CYP interactions may significantly alter the pharmacokinetics of drugs and thus influence the effectiveness of chemical therapies used in the treatment of different types of cancers, diabetes, obesity, and cardiovascular diseases (CVD). CYPs are involved in the oxidation and activation of external carcinogenic agents, in which case the inhibition of the CYP activity is beneficial for health. CYPs also support detoxification processes. In this case, it is the upregulation of CYP genes that would be favorable for the organism. A CYP enzyme aromatase catalyzes the formation of estrone and estradiol from their precursors. CYPs also catalyze multiple reactions leading to the oxidation of estrogen. Estrogen signaling and oxidative metabolism of estrogen are associated with the development of cancer. Thus, polyphenol-mediated modulation of the CYP's activity also plays a vital role in estrogen carcinogenesis. The aim of the present review is to summarize the data collected over the last five to six years on the following topics: (1) the mechanisms of the interactions of CYP with food constituents that occur via the direct binding of polyphenols to the enzymes and (2) the mechanisms of the regulation of CYP gene expression mediated by polyphenols. The structure-activity relationship relevant to the ability of polyphenols to affect the activity of CYP is analyzed. The application of polyphenol-CYP interactions to diseases is discussed.

Food Inhibits the Oral Bioavailability of the Major Green Tea Antioxidant Epigallocatechin Gallate in Humans

The bioavailability of the most abundant and most active green tea antioxidant, epigallocatechin gallate (EGCG) remains uncertain. Therefore, the systemic absorption of EGCG was tested in healthy fasted humans. It was administered as capsules with water or with a light breakfast, or when incorporated within a strawberry sorbet. The results for plasma EGCG clearly revealed that taking EGCG capsules without food was better; the AUC was 2.7 and 3.9 times higher than when EGCG capsules were taken with a light breakfast (p = 0.044) or with EGCG imbedded in the strawberry sorbet (p = 0.019), respectively. This pattern was also observed for Cmax and Cav. Therefore, ingesting food at the same time as EGCG, whether it was imbedded or not in food, substantially inhibited the absorption of the catechin. As with some types of medications that are affected by food, it appears that EGCG should be taken without food in order to maximise its systemic absorption. Therefore, based on these findings, ingesting EGCG with water on an empty stomach is the most appropriate method for the oral delivery of EGCG in clinical trials where EGCG is to be investigated as a potential bioactive nutraceutical in humans.

Strategies of Functional Foods Promote Sleep in Human Being

Sleep is a vital segment of life, however, the mechanisms of diet promoting sleep are unclear and are the focus of research. Insomnia is a general sleep disorder and functional foods are known to play a key role in the prevention of insomnia. A number of studies have demonstrated that major insomnia risk factors in human being are less functional foods in dietary. There are higher functional components in functional foods promoting sleep, including tryptophan, GABA, calcium, potassium, melatonin, pyridoxine, L-ornithine and hexadecanoic acid; but wake-promoting neurochemical factors include serotonin, noradrenalin, acetylcholine, histamine, orexin and so on. The factors promoting sleep in human being are the functional foods include barley grass powder, whole grains, maca, panax, Lingzhi, asparagus powder, lettuce, cherry, kiwifruits, walnut, schisandra wine, and milk; Barley grass powder with higher GABA and calcium, as well as potassium is the most ideal functional food promoting sleep, however, the sleep duration for modern humans is associated with food structure of ancient humans. In this review, we put forward possible mechanisms of functional components in foods promoting sleep. Although there is clear relevance between sleep and diet, their molecular mechanisms need to be studied further.

Soft drink consumption and multimorbidity among adults

BACKGROUND AND AIMS

We aimed to examine the association between soft drink consumption and multimorbidity among adults in South Australia.

METHODS

Data were collected using a risk factor surveillance system between 2008 and 2013. Each month a representative random sample of South Australians are selected from the Electronic White Pages with interviews conducted using Computer Assisted Telephone Interviewing (CATI). We define multimorbidity as currently having two or more of nine chronic conditions: asthma, diabetes, hypertension, high cholesterol, cardiovascular disease (CVD), chronic obstructive pulmonary disease (COPD), mental health problems, osteoporosis, and arthritis.

RESULTS

Among 36,663 participants aged over 16 years old, 10.5% reported daily soft drink consumption of more than half a litre and 28.5% had multimorbidity. Soft drink consumption was positively associated with all nine chronic diseases except osteoporosis. High levels of soft drink consumption were positively associated with multimorbidity and increased with the number of chronic diseases. In the multivariable analysis, after adjusting for socio-demographic and lifestyle factors, comparing those who consumed more than half a litre of soft drink per day with those not consuming soft drink, the relative risk ratios (RRRs) for multimorbidity were 1.87 (95% CI 1.61-2.17) and higher for women 2.18 (95% CI 1.78-2.66). Multimorbidity prevalence increased with age but its association with soft drink consumption was stronger in those under 60 years old. In 2008, close to one out of three participants with multimorbidity had a high level of soft drink consumption. The prevalence of high levels of soft drink consumption decreased over the five years.

CONCLUSION

There is a positive association between consumption of soft drink and multimorbidity among adults in South Australia and this relationship is stronger in younger people. This has implications for population level strategies to reduce the risk of developing chronic diseases and multimorbidity.

Beverage habits and mortality in Chinese adults

BACKGROUND

There is limited research examining beverage habits, one of the most habitual dietary behaviors, with mortality risk.

OBJECTIVE

This study examined the association between coffee, black and green tea, sugar-sweetened beverages (soft drinks and juice), and alcohol and all-cause and cause-specific mortality.

METHODS

A prospective data analysis was conducted with the use of the Singapore Chinese Health Study, including 52,584 Chinese men and women (aged 45-74 y) free of diabetes, cardiovascular disease (CVD), and cancer at baseline (1993-1998) and followed through 2011 with 10,029 deaths. Beverages were examined with all-cause and cause-specific (cancer, CVD, and respiratory disease) mortality risk with the use of Cox proportional hazards regression.

RESULTS

The associations between coffee, black tea, and alcohol intake and all-cause mortality were modified by smoking status. Among never-smokers there was an inverse dose-response association between higher amounts of coffee and black tea intake and all-cause, respiratory-related, and CVD mortality (black tea only). The fully adjusted HRs for all-cause mortality for coffee for <1/d, 1/d, and ≥2/d relative to no coffee intake were 0.89, 0.86, and 0.83, respectively (P-trend = 0.0003). For the same black tea categories the HRs were 0.95, 0.90, and 0.72, respectively (P-trend = 0.0005). Among ever-smokers there was no association between coffee or black tea and the outcomes. Relative to no alcohol, light to moderate intake was inversely associated with all-cause mortality (HR: 0.87; 95% CI: 0.79, 0.96) in never-smokers with a similar magnitude of association in ever-smokers. There was no association between heavy alcohol intake and all-cause mortality in never-smokers and a strong positive association in ever-smokers (HR: 1.56; 95% CI: 1.40, 1.74). Green tea and sugar-sweetened beverages were not associated with all-cause or cause-specific mortality.

CONCLUSIONS

Higher coffee and black tea intake was inversely associated with mortality in never-smokers, light to moderate alcohol intake was inversely associated with mortality regardless of smoking status, heavy alcohol intake was positively associated with mortality in ever-smokers, and there was no association between sugar-sweetened beverages and green tea and mortality.

Levels of caffeine and its metabolites among U.S. smokers and nonsmokers

Data from National Health and Nutrition Examination Survey for the years 2009-2010 were used to estimate the levels of caffeine and 14 of its metabolite among U.S. smokers and nonsmokers after adjustments were made for other factors that affect observed caffeine levels. In this study, when adjusted for daily caffeine intake, adjusted levels (AGM) of caffeine and its metabolites were not found to be statistically significantly different between smokers and nonsmokers. AGMs for caffeine and all of its metabolites were found to be statistically significantly higher (p < 0.01) among females aged ≥ 12 years than males. For caffeine, 1,3-dimethylxanthine, and 1,7-dimethylxanthine, those aged ≥ 20 years had statistically significantly higher (p < 0.01) AGM than those aged 12-19 years but the reverse was true for 7-methylxanthine and 3,7-dimethylxanthine (p ≤ 0.02). The order of the AGMs by race/ethnicity was non-Hispanic whites > Hispanics > non-Hispanic blacks and most of the differences were statistically significant, at least between non-Hispanic whites and non-Hispanic blacks (p < 0.01). In general, there was a statistically significant positive association between the levels of caffeine and its metabolites and body mass index as well as daily caffeine intake. However, the levels of 7-methylxanthine were negatively associated with body mass index.

Impact of caffeine and coffee on our health

Coffee is the most frequently consumed caffeine-containing beverage. The caffeine in coffee is a bioactive compound with stimulatory effects on the central nervous system and a positive effect on long-term memory. Although coffee consumption has been historically linked to adverse health effects, new research indicates that coffee consumption may be beneficial. Here we discuss the impact of coffee and caffeine on health and bring attention to the changing caffeine landscape that includes new caffeine-containing energy drinks and supplements, often targeting children and adolescents.