Coffee and health: a review of recent human research

High Blood caffeine levels in MCI linked to lack of progression to dementia

Although both human epidemiologic and animal model studies have suggested that caffeine/coffee protects against Alzheimer's disease, direct human evidence for this premise has been lacking. In the present case-control study, two separate cohorts consisting of 124 total individuals (65-88 years old) were cognitively assessed and a blood sample taken for caffeine/biomarker analysis. Subjects were then monitored for cognitive status over the ensuing 2-4 year period to determine the extent to which initial plasma caffeine/biomarkers levels would be predictive of changes in cognitive status. Plasma caffeine levels at study onset were substantially lower (-51%) in mild cognitive impairment (MCI) subjects who later progressed to dementia (MCI→DEM) compared to levels in stable MCI subjects (MCI→MCI). Moreover, none of the MCI→DEM subjects had initial blood caffeine levels that were above a critical level of 1200 ng/ml, while half of stable MCI→MCI subjects had blood caffeine levels higher than that critical level. Thus, plasma caffeine levels greater than 1200 ng/ml (≈6 μM) in MCI subjects were associated with no conversion to dementia during the ensuing 2-4 year follow-up period. Among the 11 cytokines measured in plasma, three of them (GCSF, IL-10, and IL-6) were decreased in MCI→DEM subjects, but not in stable MCI→MCI subjects with high plasma caffeine levels. Coffee would appear to be the major or perhaps only source of caffeine for such stable MCI patients. This case-control study provides the first direct evidence that caffeine/coffee intake is associated with a reduced risk of dementia or delayed onset, particularly for those who already have MCI.

Lifestyle factors and site-specific risk of hip fracture in community dwelling older women--a 13-year prospective population-based cohort study

BACKGROUND

Several risk factors are associated to hip fractures. It seems that different hip fracture types have different etiologies. In this study, we evaluated the lifestyle-related risk factors for cervical and trochanteric hip fractures in older women over a 13-year follow-up period.

METHODS

The study design was a prospective, population-based study consisting of 1681 women (mean age 72 years). Seventy-three percent (n = 1222) participated in the baseline measurements, including medical history, leisure-time physical activity, smoking, and nutrition, along with body anthropometrics and functional mobility. Cox regression was used to identify the independent predictors of cervical and trochanteric hip fractures.

RESULTS

During the follow-up, 49 cervical and 31 trochanteric fractures were recorded. The women with hip fractures were older, taller, and thinner than the women with no fractures (p < 0.05). Low functional mobility was an independent predictor of both cervical and trochanteric fractures (HR = 3.4, 95% CI 1.8-6.6, and HR = 5.3, 95% CI 2.5-11.4, respectively). Low baseline physical activity was associated with an increased risk of hip fracture, especially in the cervical region (HR = 2.5, 95% CI 1.3-4.9). A decrease in cervical fracture risk (p = 0.002) was observed with physically active individuals compared to their less active peers (categories: very low or low, moderate, and high). Moderate coffee consumption and hypertension decreased the risk of cervical fractures (HR = 0.4, 95% CI 0.2-0.8, for both), while smoking was a predisposing factor for trochanteric fractures (HR = 3.2, 95% CI 1.1-9.3).

CONCLUSIONS

Impaired functional mobility, physical inactivity, and low body mass may increase the risk for hip fractures with different effects at the cervical and trochanteric levels.

Caffeine use among active duty US Army soldiers

Eighty-percent of the US adult population regularly consumes caffeine, but limited information is available on the extent and patterns of use. Caffeine use is a public health issue and its risks and benefits are regularly considered in scientific literature and the lay media. Recently, new caffeine-containing products have been introduced and are widely available on Army bases and are added to rations to maintain cognitive performance. This study surveyed caffeine consumption and demographic characteristics in 990 US Army soldiers. Data were weighted by age, sex, rank, and Special Forces status. Total caffeine intake and intake from specific products were estimated. Logistic regression was used to examine relationships between caffeine use and soldier demographic and lifestyle characteristics. Eighty-two percent of soldiers consumed caffeine at least once a week. Mean daily caffeine consumption was 285 mg/day (347 mg/day among regular caffeine consumers). Male soldiers consumed, on average, 303 mg/day and females 163 mg/day (regular consumers: 365 mg/day for male soldiers, 216 mg/day for female soldiers). Coffee was the main source of caffeine intake. Among young males, energy drinks were the largest source of caffeine intake, but their intake was not greater than older males. Regression analysis indicated an association of higher caffeine intake with male sex, white race, and tobacco use (P<0.01). Most soldiers consume caffeine in levels accepted as safe, but some consume greater quantities than recommended, although definitive information on safe upper limits of caffeine intake is not available. Labels of caffeine-containing products should provide caffeine content so individuals can make informed decisions.

Tea and coffee consumption in relation to vitamin D and calcium levels in Saudi adolescents

BACKGROUND

Coffee and tea consumption was hypothesized to interact with variants of vitamin D-receptor polymorphisms, but limited evidence exists. Here we determine for the first time whether increased coffee and tea consumption affects circulating levels of 25-hydroxyvitamin D in a cohort of Saudi adolescents.

METHODS

A total of 330 randomly selected Saudi adolescents were included. Anthropometrics were recorded and fasting blood samples were analyzed for routine analysis of fasting glucose, lipid levels, calcium, albumin and phosphorous. Frequency of coffee and tea intake was noted. 25-hydroxyvitamin D levels were measured using enzyme-linked immunosorbent assays.

RESULTS

Improved lipid profiles were observed in both boys and girls, as demonstrated by increased levels of HDL-cholesterol, even after controlling for age and BMI, among those consuming 9-12 cups of coffee/week. Vitamin D levels were significantly highest among those consuming 9-12 cups of tea/week in all subjects (p-value 0.009) independent of age, gender, BMI, physical activity and sun exposure.

CONCLUSION

This study suggests a link between tea consumption and vitamin D levels in a cohort of Saudi adolescents, independent of age, BMI, gender, physical activity and sun exposure. These findings should be confirmed prospectively.

Coffee attenuates fibrosis by decreasing the expression of TGF-β and CTGF in a murine model of liver damage

This study was performed to evaluate the antifibrotic properties of coffee in a model of liver damage induced by repeated administration of thioacetamide (TAA) in male Wistar rats. In this study, cirrhosis was induced by chronic TAA administration and the effects of co-administration of conventional caffeinated coffee or decaffeinated coffee (CC, DC, respectively) for 8 weeks were evaluated. TAA administration elevated serum alkaline phosphatase (AP), γ-glutamyl transpeptidase (γ-GTP) and alanine aminotransferase (ALAT), liver lipid peroxidation, collagen content, depleted liver glycogen and glutathione peroxidase (GPx) activity. Additionally increased levels of a number of proteins were detected including transforming growth factor-beta (TGF-β), connective tissue growth factor (CTGF) and alpha-smooth muscle actin (α-SMA), and matrix metalloproteinase (MMP)-2, 9 and 13. Coffee suppressed most of the changes produced by TAA. Histopathological analysis was in agreement with biochemical and molecular findings. These results indicate that coffee attenuates experimental cirrhosis; the action mechanisms are probably associated with its antioxidant properties and mainly by its ability to block the elevation of the profibrogenic cytokine TGF-β and its downstream effector CTGF. Various components of coffee that have been related to such a favorable effect include caffeine, coffee oils kahweol, cafestol and antioxidant substances; however, no definite evidence for the role of these components has been established. These results support earlier findings suggesting a beneficial effect of coffee on the liver. However, more basic clinical studies must be performed to confirm this hypothesis.

The coffee constituent chlorogenic acid induces cellular DNA damage and formation of topoisomerase I- and II-DNA complexes in cells

Chlorogenic acid (CGA) is a plant polyphenol with known antioxidant properties. Although some studies suggest that CGA has anticancer properties, others indicate that this dietary constituent may cause DNA damage and induce carcinogenic effects. Because CGA is widely consumed in the form of coffee, it is important to further evaluate the putative DNA-damaging activity of CGA. Here we have employed two standard techniques commonly used for DNA damage detection (the comet assay and the γ- H2AX focus assay) and observed that CGA (0.5-5 mM) induces DNA damage in normal and cancer cells. We report for the first time that CGA induces high levels of topoisomerase I- and topoisomerase II-DNA complexes in cells (TARDIS assay). Catalase pretreatment abolished the formation of these topoisomerase-DNA complexes and reduced the cytotoxic activity of CGA, therefore indicating that hydrogen peroxide plays an important role in these activities. Lung cancer cells (A549) were more sensitive than normal lung fibroblasts (MRC5) to the cytotoxic activity of CGA, supporting previous findings that CGA may induce selective killing of cancer cells. Taking into consideration our results and the pharmacokinetic profile of CGA, the possible cancer preventive, carcinogenic and therapeutic potential of this dietary agent are discussed.

Assessing caffeine intake in the United Kingdom diet

Caffeine occurs naturally in the leaves and seeds of many plants and is artificially added to some beverages. Consumption of caffeine has been linked to both positive and adverse health outcomes. We incorporated estimates of caffeine content (mg/100g or ml) of foods and drinks, taken from the published literature, to provide a preliminary estimate of caffeine intake for the UK population, based on data collected in the National Diet and Nutrition Survey 2008-10. Among consumers mean total caffeine intakes of adult men 19+ y were significantly greater than intakes by boys 4-10y and 11-18y (p<0.05), with the same age-related differences seen for females. 4.1% of men 19+ y and 3.8% of women 19+ y had caffeine intakes in excess of 300mg/d. The addition of caffeine to UK food composition databases will allow more detailed study of the health effects of caffeine consumption.

A genome-wide association study of caffeine-related sleep disturbance: confirmation of a role for a common variant in the adenosine receptor

OBJECTIVES

To identify common genetic variants that predispose to caffeine-induced insomnia and to test whether genes whose expression changes in the presence of caffeine are enriched for association with caffeine-induced insomnia.

DESIGN

A hypothesis-free, genome-wide association study.

SETTING

Community-based sample of Australian twins from the Australian Twin Registry.

PARTICIPANTS

After removal of individuals who said that they do not drink coffee, a total of 2,402 individuals from 1,470 families in the Australian Twin Registry provided both phenotype and genotype information.

MEASUREMENTS AND RESULTS

A dichotomized scale based on whether participants reported ever or never experiencing caffeine-induced insomnia. A factor score based on responses to a number of questions regarding normal sleep habits was included as a covariate in the analysis. More than 2 million common single nucleotide polymorphisms (SNPs) were tested for association with caffeine-induced insomnia. No SNPs reached the genome-wide significance threshold. In the analysis that did not include the insomnia factor score as a covariate, the most significant SNP identified was an intronic SNP in the PRIMA1 gene (P = 1.4 × 10⁻⁶, odds ratio = 0.68 [0.53 - 0.89]). An intergenic SNP near the GBP4 gene on chromosome 1 was the most significant upon inclusion of the insomnia factor score into the model (P = 1.9 × 10⁻⁶, odds ratio = 0.70 [0.62 - 0.78]). A previously identified association with a polymorphism in the ADORA2A gene was replicated.

CONCLUSIONS

Several genes have been identified in the study as potentially influencing caffeine-induced insomnia. They will require replication in another sample. The results may have implications for understanding the biologic mechanisms underlying insomnia.

Coffee induces breast cancer resistance protein expression in Caco-2 cells

Coffee is a beverage that is consumed world-wide on a daily basis and is known to induce a series of metabolic and pharmacological effects, especially in the digestive tract. However, little is known concerning the effects of coffee on transporters in the gastrointestinal tract. To elucidate the effect of coffee on intestinal transporters, we investigated its effect on expression of the breast cancer resistance protein (BCRP/ABCG2) in a human colorectal cancer cell line, Caco-2. Coffee induced BCRP gene expression in Caco-2 cells in a coffee-dose dependent manner. Coffee treatment of Caco-2 cells also increased the level of BCRP protein, which corresponded to induction of gene expression, and also increased cellular efflux activity, as judged by Hoechst33342 accumulation. None of the major constituents of coffee tested could induce BCRP gene expression. The constituent of coffee that mediated this induction was extractable with ethyl acetate and was produced during the roasting process. Dehydromethylepoxyquinomicin (DHMEQ), an inhibitor of nuclear factor (NF)-κB, inhibited coffee-mediated induction of BCRP gene expression, suggesting involvement of NF-κB in this induction. Our data suggest that daily consumption of coffee might induce BCRP expression in the gastrointestinal tract and may affect the bioavailability of BCRP substrates.

Effects of Alcohol, Coffee, and Tobacco, Alone or in Combination, on Physiological Parameters and Anxiety in a Young Population

OBJECTIVE

The objective was to evaluate the effects of a single dose of alcohol, caffeine, and nicotine, alone or in combination, on physiological parameters (systolic and diastolic blood pressure [SBP and DBP] and heart rate [HR]) and state-trait anxiety in healthy young volunteers.

METHOD

The procedure reproduces the conditions under which the subjects (n=76) usually ingest alcohol (through an alcoholic beverage), caffeine (through a cup of coffee), and nicotine (by smoking a cigarette), separately or in combination, according to their consumption habits of each individual. SBP and DBP, HR, and state anxiety (SA) were registered before (phase 1) and after (phase 2) treatment.

RESULTS

Intake of alcohol or alcohol-nicotine reduced DBP. Comparisons between control and combined treatment (coffee-alcohol-nicotine) groups revealed a decrease in HR in the former group but not in the latter. The coffee consumers alone exhibited a tendency toward an increase in SA, while the control group showed a tendency toward a decrease in this measure. When Phase 1 and Phase 2 were compared, a decrease was observed in SBP (alcohol and coffee-alcohol groups), DBP (alcohol and alcohol-nicotine groups), HR (all groups, except coffee-alcohol and coffee-alcohol-nicotine groups), and SA (coffee-alcohol-nicotine group).

CONCLUSIONS

(i) A low dose of alcohol, either alone or in combination with a cigarette, decreases DBP but not SBP; (ii) the polyconsumption of coffee, alcohol, and nicotine blocks the adaptation response (the reduction in HR in control subjects in the second phase); (iii) an increase of SA is observed after consuming coffee, while the opposite occurs in control subjects (a decrease of SA).

Chlorogenic acid ameliorates brain damage and edema by inhibiting matrix metalloproteinase-2 and 9 in a rat model of focal cerebral ischemia

Chlorogenic acid (CGA) has been reported to have various beneficial effects on the cardiovascular and central nervous systems. The purpose of the current study was to investigate whether CGA has protective effects against cerebral ischemia and whether these effects are due to modification of brain edema-related vascular factors. In a rat model of transient middle cerebral artery occlusion (MCAo, 2h of occlusion followed by 22 h of reperfusion), we measured infarct volume and performed behavioral test to evaluate the effects of CGA on brain damage and sensory-motor functional deficits. Brain water content and Evans blue extravasation were measured to evaluate brain edema and blood brain barrier (BBB) damage. Lipid peroxidation (LPO) and the expressions and activities of matrix metalloproteinase (MMP)-2 and MMP-9 were measured to investigate the mechanisms of action. Intraperitoneal injection of CGA (3, 10, and 30 mg/kg) at 0 h and 2h after MCAo dose-dependently reduced infarct volume and sensory-motor functional deficits. It also reduced brain water content and Evans blue extravasation. Mechanistically, CGA reduced LPO and MMPs expressions and activities. These results suggest that CGA reduces brain damage, BBB damage and brain edema by radical scavenging activity and the inhibitory effects on MMP-2 and MMP-9.

Coffee, colon function and colorectal cancer

For several years the physiological effects of coffee have been focused on its caffeine content, disregarding the hundreds of bioactive coffee components, such as polyphenols, melanoidins, carbohydrates, diterpenes, etc. These compounds may exert their protection against colorectal cancer (CRC), the third most common cancer worldwide. However, the amount and type of compounds ingested with the beverage may be highly different depending on the variety of coffee used, the roasting degree, the type of brewing method as well as the serving size. In this frame, this paper reviews the mechanisms by which coffee may influence the risk of CRC development focusing on espresso and filtered coffee, as well as on the components that totally or partially reach the colon i.e. polyphenols and dietary fiber, including melanoidins. In particular the effects of coffee on some colon conditions whose deregulation may lead to cancer, namely microbiota composition and lumen reducing environment, were considered. Taken together the discussed studies indicated that, due to their in vivo metabolism and composition, both coffee chlorogenic acids and dietary fiber, including melanoidins, may reduce CRC risk, increasing colon motility and antioxidant status. Further studies should finally assess whether the coffee benefits for colon are driven through a prebiotic effect.

Coffee consumption and risk of chronic disease in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Germany study

BACKGROUND

Early studies suggested that coffee consumption may increase the risk of chronic disease.

OBJECTIVE

We investigated prospectively the association between coffee consumption and the risk of chronic diseases, including type 2 diabetes (T2D), myocardial infarction (MI), stroke, and cancer.

DESIGN

We used data from 42,659 participants in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Germany study. Coffee consumption was assessed by self-administered food-frequency questionnaire at baseline, and data on medically verified incident chronic diseases were collected by active and passive follow-up procedures. HRs and 95% CIs were calculated with multivariate Cox regression models and compared by competing risk analysis.

RESULTS

During 8.9 y of follow-up, we observed 1432 cases of T2D, 394 of MI, 310 of stroke, and 1801 of cancer as first qualifying events. Caffeinated (HR: 0.94; 95% CI: 0.84, 1.05) or decaffeinated (HR: 1.05; 95% CI: 0.84, 1.31) coffee consumption (≥4 cups/d compared with <1 cup/d; 1 cup was defined as 150 mL) was not associated with the overall risk of chronic disease. A lower risk of T2D was associated with caffeinated (HR: 0.77; 95% CI: 0.63, 0.94; P-trend 0.009) and decaffeinated (HR: 0.70; 95% CI: 0.46, 1.06; P-trend: 0.043) coffee consumption (≥4 cups/d compared with <1 cup/d), but cardiovascular disease and cancer risk were not. The competing risk analysis showed no significant differences between the risk associations of individual diseases.

CONCLUSION

Our findings suggest that coffee consumption does not increase the risk of chronic disease, but it may be linked to a lower risk of T2D.

Relationship between coffee consumption and prevalence of metabolic syndrome among Japanese civil servants

Background

Metabolic syndrome has become a major worldwide public health problem. We examined the relationship between coffee consumption and the prevalence of metabolic syndrome among Japanese civil servants.

Methods

The study participants were 3284 employees (2335 men and 948 women) aged 20 to 65 years. Using data from their 2008 health checkup records, we analyzed the relationship between coffee consumption and the prevalence of metabolic syndrome. Metabolic syndrome was defined according to the Japanese criteria.

Results

Metabolic syndrome was diagnosed in 374 of the 2335 men (16.0%) and 32 of the 948 women (3.4%). In univariate and multiple logistic regression analyses, the odds ratios (ORs) among men for the presence of metabolic syndrome were 0.79 (95% CI: 0.56–1.03) and 0.61 (0.39–0.95), respectively, among moderate (≥4 cups of coffee per day) coffee drinkers as compared with non-coffee drinkers. Among all components of metabolic syndrome, high blood pressure and high triglyceride level were inversely associated with moderate coffee consumption in men, after adjusting for age, body mass index, smoking status, drinking status, and exercise. However, in women, moderate coffee consumption was not significantly associated with the prevalence of metabolic syndrome or its components.

Conclusions

Moderate coffee consumption was significantly associated with lower prevalence of metabolic syndrome in Japanese male civil servants.

Caffeinated coffee, decaffeinated coffee, and the phenolic phytochemical chlorogenic acid up-regulate NQO1 expression and prevent H₂O₂-induced apoptosis in primary cortical neurons

Neurodegenerative disorders are strongly associated with oxidative stress, which is induced by reactive oxygen species including hydrogen peroxide (H₂O₂). Epidemiological studies have suggested that coffee may be neuroprotective, but the molecular mechanisms underlying this effect have not been clarified. In this study, we investigated the protective effects of caffeinated coffee, decaffeinated coffee, and the phenolic phytochemical chlorogenic acid (5-O-caffeoylquinic acid), which is present in both caffeinated and decaffeinated coffee, against oxidative neuronal death. H₂O₂-induced apoptotic nuclear condensation in neuronal cells was strongly inhibited by pretreatment with caffeinated coffee, decaffeinated coffee, or chlorogenic acid. Pretreatment with caffeinated coffee, decaffeinated coffee, or chlorogenic acid inhibited the H₂O₂-induced down-regulation of anti-apoptotic proteins Bcl-2 and Bcl-X(L) while blocking H₂O₂-induced pro-apoptotic cleavage of caspase-3 and pro-poly(ADP-ribose) polymerase. We also found that caffeinated coffee, decaffeinated coffee, and chlorogenic acid induced the expression of NADPH:quinine oxidoreductase 1 (NQO1) in neuronal cells, suggesting that these substances protect neurons from H₂O₂-induced apoptosis by up-regulation of this antioxidant enzyme. The neuroprotective efficacy of caffeinated coffee was similar to that of decaffeinated coffee, indicating that active compounds present in both caffeinated and decaffeinated coffee, such as chlorogenic acid, may drive the effects.

Caffeine challenge test and panic disorder: a systematic literature review

This systematic review aimed to examine the results of studies that have investigated the induction of panic attacks and/or the anxiogenic effect of the caffeine challenge test in patients with panic disorder. The literature search was performed in PubMed, Biblioteca Virtual em Saúde and the ISI Web of Knowledge. The words used for the search were caffeine, caffeine challenge test, panic disorder, panic attacks and anxiety disorder. In total, we selected eight randomized, double-blind studies where caffeine was administered orally, and none of them controlled for confounding factors in the analysis. The percentage of loss during follow-up ranged between 14.3% and 73.1%. The eight studies all showed a positive association between caffeine and anxiogenic effects and/or panic disorder.

Development of an innovative nutraceutical fermented beverage from herbal mate (Ilex paraguariensis A.St.-Hil.) extract

Herbal mate (Ilex paraguariensis A.St.-Hil.) leaves are traditionally used for their stimulant, antioxidant, antimicrobial, and diuretic activity, presenting as principal components polyphenolic compounds. The aim of this work was to develop an innovative, non-dairy, functional, probiotic, fermented beverage using herbal mate extract as a natural ingredient which would also be hypocholesterolemic and hepatoprotective. Among different strains used, Lactobacillus acidophilus was selected as the best for fermentation. The addition of honey positively affected the development of L. acidophilus and the formulated beverage maintained microbial stability during shelf life. Key ingredients in the extract included xanthines, polyphenols and other antioxidants with potential health benefits for the consumer. Caffeine levels and antioxidant activity were also studied. Acceptable levels of caffeine and large antioxidant capacity were observed for the formulation when compared to other antioxidant beverages. An advantage of this product is the compliance to organic claims, while providing caffeine, other phyto-stimulants and antioxidant compounds without the addition of synthetic components or preservatives in the formulation. Sensorial analysis demonstrated that the beverage had good consumer acceptance in comparison to two other similar commercial beverages. Therefore, this beverage could be used as a new, non-dairy vehicle for probiotic consumption, especially by vegetarians and lactose intolerant consumers. It is expected that such a product will have good market potential in an era of functional foods.

Nutritional and hormonal modulation of adiponectin and its receptors adipoR1 and adipoR2

Adiponectin is the most abundant plasma protein synthesized mostly by adipose tissue and is an insulin-sensitive hormone, playing a central role in glucose and lipid metabolism. Adiponectin effects are mediated via two receptors, adipoR1 and adipoR2. Several hormones and diet components that are involved in insulin resistance may impair insulin sensitivity at least in part by decreasing adiponectin and adiponectin receptors. Adiponectin expression and serum levels are associated with the amount and type of fatty acids and carbohydrate consumed. Other food items, such as vitamins, alcohol, sodium, green tea, and coffee, have been reported to modify adiponectin levels. Several hormones, including testosterone, estrogen, prolactin, glucocorticoids, catecholamines, and growth hormone, have been shown to inhibit adiponectin production, but the studies are still controversial. Even so, adiponectin is a potential therapeutic target in the treatment of diabetes mellitus and other diseases associated with hypoadiponectinemia.

Caffeine alters cytokine secretion by PBMC induced by colon cancer cells

BACKGROUND

Studies have shown that caffeine might be capable to prevent colon cancer development. This activity is linked in part to its anti-inflammatory properties mediated through modulation of immune responses. It was the aim of the study to evaluate the role of caffeine in the immune balance between peripheral blood mononuclear cells (PBMC) and those of HT-29 and RKO human colon cancer lines.

METHODS

Cytokine production was evaluated following incubation of the two types of cancer cells without and with three concentrations of caffeine.

RESULTS

A concentration-dependent inhibition of TNFα and IFNγ secretion by PBMC was observed only after their stimulation by cancer cells. Reduction of the anti-inflammatory IL-1ra and IL-10 production was observed using higher caffeine concentrations only.

CONCLUSION

We presume that by changing the equilibrium between pro- and anti-inflammatory cytokines in favor of anti-inflammation, caffeine may reduce the inflammatory process with a consequent suppression of colorectal cancer progress.

Maternal caffeine intake and its effect on pregnancy outcomes

OBJECTIVE

Estimation of the maternal caffeine intake during pregnancy and its influence on pregnancy duration, birthweight and Apgar score of the newborn.

STUDY DESIGN

The research was conducted on pregnant women who gave birth at the Clinic of Obstetrics, Gynaecology and Oncology, 2nd Faculty of Medicine, Medical University of Warsaw. It covered unifetal pregnancies without diseases (N=509). Research data were collected by direct questionnaire supplemented with data from patients' records. Statistical analysis employed a multivariate logistic regression model and a non-parametric Spearman's rank correlation coefficient.

RESULTS

98.4% of pregnant women consume no more than 300 mg of caffeine per day. Pregnant women who smoke and older women consume more caffeine than non-smokers and younger women [β 1.95 (95% CI: 1.02-2.88)] and [β 0.68 (95% CI: 0.05-1.3)] respectively. There is no association between maternal caffeine intake during pregnancy and the risk of premature birth, the birthweight or the Apgar score of newborns.

CONCLUSION

Caffeine intake of no more than 300 mg per day during pregnancy does not affect pregnancy duration and the condition of the newborn.

Top Three Pharmacogenomics and Personalized Medicine Applications at the Nexus of Renal Pathophysiology and Cardiovascular Medicine

Pharmacogenomics is a field with origins in the study of monogenic variations in drug metabolism in the 1950s. Perhaps because of these historical underpinnings, there has been an intensive investigation of 'hepatic pharmacogenes' such as CYP450s and liver drug metabolism using pharmacogenomics approaches over the past five decades. Surprisingly, kidney pathophysiology, attendant diseases and treatment outcomes have been vastly under-studied and under-theorized despite their central importance in maintenance of health, susceptibility to disease and rational personalized therapeutics. Indeed, chronic kidney disease (CKD) represents an increasing public health burden worldwide, both in developed and developing countries. Patients with CKD suffer from high cardiovascular morbidity and mortality, which is mainly attributable to cardiovascular events before reaching end-stage renal disease. In this paper, we focus our analyses on renal function before end-stage renal disease, as seen through the lens of pharmacogenomics and human genomic variation. We herein synthesize the recent evidence linking selected Very Important Pharmacogenes (VIP) to renal function, blood pressure and salt-sensitivity in humans, and ways in which these insights might inform rational personalized therapeutics. Notably, we highlight and present the rationale for three applications that we consider as important and actionable therapeutic and preventive focus areas in renal pharmacogenomics: 1) ACE inhibitors, as a confirmed application, 2) VDR agonists, as a promising application, and 3) moderate dietary salt intake, as a suggested novel application. Additionally, we emphasize the putative contributions of gene-environment interactions, discuss the implications of these findings to treat and prevent hypertension and CKD. Finally, we conclude with a strategic agenda and vision required to accelerate advances in this under-studied field of renal pharmacogenomics with vast significance for global public health.

Evaluating Dependence Criteria for Caffeine

Background: Although caffeine is the most widely used mood-altering drug in the world, few studies have operationalized and characterized Diagnostic and Statistical Manual IV (DSM-IV) substance dependence criteria applied to caffeine. Methods: As a part of a nosological study of substance use disorders funded by the National Institute on Drug Abuse, we assessed caffeine use and dependence symptoms among high school and college students, drug treatment patients, and pain clinic patients who reported caffeine use in the last 7 days and also reported use of alcohol, nicotine, or illicit drugs within the past year (n=167). Results: Thirty-five percent met the criteria for dependence when all seven of the adopted DSM dependence criteria were used. Rates of endorsement of several of the most applicable diagnostic criteria were as follows: 26% withdrawal, 23% desire to cut down or control use, and 44% continued use despite harm. In addition, 34% endorsed craving, 26% said they needed caffeine to function, and 10% indicated that they talked to a physician or counselor about problems experienced with caffeine. There was a trend towards increased caffeine dependence among those dependent on nicotine or alcohol. Within a subgroup that had used caffeine, alcohol, and nicotine in the past year, 28% fulfilled criteria for caffeine dependence compared to 50% for alcohol and 80% for nicotine. Conclusion: The present study adds to a growing literature suggesting the reliability, validity, and clinical utility of the caffeine dependence diagnosis. Recognition of caffeine dependence in the DSM-V may be clinically useful.

High molecular weight coffee melanoidins are inhibitors for matrix metalloproteases

High molecular (above 10 kDa) melanoidins isolated from coffee beans of varying roasting degree were found to be efficient inhibitors for the zinc-containing matrix metalloproteases MMP-1, MMP-2, and MMP-9 with IC(50) values ranging between 0.2 and 1.1 mg/mL in vitro. The inhibitory potential increased with roasting degree. No or only slight inhibition of other zinc-containing peptidases closely related to MMPs, namely, Clostridium histolyticum collagenase and angiotensin converting enzyme, was found, indicating specific structural features of melanoidins to be responsible for the interaction with MMPs. A continuous increase on the apparent molecular weight of melanoidins as well as incorporation of phenolic substances into the melanoidin structure with progress of roasting was observed, concomitant with a significant increase in the carbon/nitrogen of the melanoidins. This suggests that the melanoidins are mainly formed by incorporation of carbohydrates and phenolic compounds onto a proteinaceous backbone. As MMP-1, MMP-2, and MMP-9 play a pivotal role in pathogenesis of colorectal cancer, studies on possible physiological effects of melanoidins are mandatory.

Chlorogenic acid differentially affects postprandial glucose and glucose-dependent insulinotropic polypeptide response in rats

Regular coffee consumption significantly lowers the risk of type 2 diabetes (T2D). Coffee contains thousands of compounds; however, the specific component(s) responsible for this reduced risk is unknown. Chlorogenic acids (CGA) found in brewed coffee inhibit intestinal glucose uptake in vitro. The objective of this study was to elucidate the mechanisms by which CGA acts to mediate blood glucose response in vivo. Conscious, unrestrained, male Sprague-Dawley rats were chronically catheterized and gavage-fed a standardized meal (59% carbohydrate, 25% fat, 12% protein), administered with or without CGA (120 mg·kg(-1)), in a randomized crossover design separated by a 3-day washout period. Acetaminophen was co-administered to assess the effects of CGA on gastric emptying. The incretins glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) were measured. GLP-1 response in the presence of glucose and CGA was further examined, using the human colon cell line NCI-H716. Total area under the curve (AUC) for blood glucose was significantly attenuated in rats fed CGA (p < 0.05). Despite this, no differences in plasma insulin or nonesterified fatty acids were observed, and gastric emptying was not altered. Plasma GIP response was blunted in rats fed CGA, with a lower peak concentration and AUC up to 180 min postprandially (p < 0.05). There were no changes in GLP-1 secretion in either the in vivo or in vitro study. In conclusion, CGA treatment resulted in beneficial effects on blood glucose response, with alterations seen in GIP concentrations. Given the widespread consumption and availability of coffee, CGA may be a viable prevention tool for T2D.

Adenosine receptors and fibrosis: a translational review

Adenosine—a purine nucleoside generated extracellularly from adenine nucleotides released by cells as a result of direct stimulation, hypoxia, trauma, or metabolic stress—is a well-known physiologic and pharmacologic agent. Recent studies demonstrate that adenosine, acting at its receptors, promotes wound healing by stimulating both angiogenesis and matrix production. Subsequently, adenosine and its receptors have also been found to promote fibrosis (excess matrix production) in the skin, lungs, and liver, but to diminish cardiac fibrosis. A commonly ingested adenosine receptor antagonist, caffeine, blocks the development of hepatic fibrosis, an effect that likely explains the epidemiologic finding that coffee drinking, in a dose-dependent fashion, reduces the likelihood of death from liver disease. Accordingly, adenosine may be a good target for therapies that prevent fibrosis of the lungs, liver, and skin.

Coffee polyphenols modulate whole-body substrate oxidation and suppress postprandial hyperglycaemia, hyperinsulinaemia and hyperlipidaemia

Postprandial energy metabolism, including postprandial hyperglycaemia, hyperinsulinaemia and hyperlipidaemia, is related to the risk for developing obesity and CVD. In the present study, we examined the effects of polyphenols purified from coffee (coffee polyphenols (CPP)) on postprandial carbohydrate and lipid metabolism, and whole-body substrate oxidation in C57BL/6J mice. In mice that co-ingested CPP with a lipid-carbohydrate (sucrose or starch)-mixed emulsion, the respiratory quotient determined by indirect calorimetry was significantly lower than that in control mice, whereas there was no difference in VO2 (energy expenditure), indicating that CPP modulates postprandial energy partitioning. CPP also suppressed postprandial increases in plasma glucose, insulin, glucose-dependent insulinotropic polypeptide and TAG levels. Inhibition experiments on digestive enzymes revealed that CPP inhibits maltase and sucrase, and, to a lesser extent, pancreatic lipase in a concentration-dependent manner. Among the nine kinds of polyphenols (caffeoyl quinic acids (CQA), di-CQA, feruloyl quinic acids (FQA)) contained in CPP, di-CQA showed more potent inhibitory activity than CQA or FQA on these digestive enzymes, suggesting a predominant role of di-CQA in the regulation of postprandial energy metabolism. These results suggest that CPP modulates whole-body substrate oxidation by suppressing postprandial hyperglycaemia and hyperinsulinaemia, and these effects are mediated by inhibiting digestive enzymes.

Profile of nucleotide catabolism and ectonucleotidase expression from the hippocampi of neonatal rats after caffeine exposure

Nucleotides and nucleosides play an important role in neurodevelopment acting through specific receptors. Ectonucleotidases are the major enzymes involved in controlling the availability of purinergic receptors ligands. ATP is co-released with several neurotransmitters and is the most important source of extracellular adenosine by catabolism exerted by ectonucleotidases. The main ectonucleotidases are named NTPDases (1-8) and 5'-nucleotidase. Adenosine is a powerful modulator of neurotransmitter release. Caffeine blocks adenosine receptor activity as well as adenosine-mediated neuromodulation. Considering the susceptibility of the immature brain to caffeine and the need for correct purinergic signaling during fetal development, we have analyzed the effects of caffeine exposure during gestational and lactational periods on nucleotide degradation and ectonucleotidase expression from the hippocampi of 7-, 14- and 21-days-old rats. Nucleotides hydrolysis was assessed by colorimetric determination of inorganic phosphate released. Ectonucleotidases expression was performed by RT-PCR. ATP and ADP hydrolysis displayed parallel age-dependent decreases in both control and caffeine-treated groups. AMP hydrolysis increased with caffeine treatment in 7-days-old rats (75%); although there was no significant difference in AMP hydrolysis between control (non caffeine-treated) rats and 14- or 21-days caffeine-treated rats. ADP hydrolysis was not affected by caffeine treatment. Caffeine treatment in 7- and 14-days-old rats decreased ATP hydrolysis when compared to the control group (19% and 60% decrease, respectively), but 21-days-treated rats showed an increase in ATP hydrolysis (39%). Expression levels of NTPDase 1 and 5 decreased in hippocampi of caffeine-treated rats. The expression of 5'-nucleotidase was not affected after caffeine exposure. The changes observed in nucleotide hydrolysis and ectonucleotidases expression could promote subtle effects on normal neural development considering the neuromodulatory role of adenosine.

Producing low-caffeine tea through post-transcriptional silencing of caffeine synthase mRNA

In this study, attempt has been made to produce a selected cultivar of tea with low-caffeine content using RNAi technology. The caffeine biosynthetic pathway in tea has been proposed to involve three N-methyltransferases such as xanthosine methyltransferase, 7-N-methylxanthine methyltransferase and 3, 7-dimethylxanthine methyltransferase. Last two steps of caffeine biosynthesis in tea have been known to be catalyzed by a bifunctional enzyme known as caffeine synthase. To suppress the caffeine synthesis in the selected tea [Camellia sinensis (L.) O. Kuntze] cv. Kangra jat, we isolated a partial fragment of caffeine synthase (CS) from the same cultivar and used to design RNAi construct (pFGC1008-CS). Somatic embryos were transformed with the developed construct using biolistic method. Transformed somatic embryos showed reduction in the levels of CS transcript expression as well as in caffeine content. Plants were regenerated from the transformed somatic embryos. Transgenic plants showed a significant suppression of CS transcript expression and also showed a reduction of 44-61% in caffeine and 46-67% in theobromine contents as compared to the controls. These results suggest that the RNAi construct developed here using a single partial fragment of CS gene reduced the expression of the targeted endogenous gene significantly. However, the reduction in theobromine content in addition to caffeine documented the involvement of this single CS in the catalysis of last two methyl transfer steps in caffeine biosynthesis of tea.

Oral diuretic activity of hot water infusion of Sri Lankan black tea (Camellia sinensis L.) in rats

Background:

Black tea [Camellia sinensis (L.) O. Kuntze (family: Theaceae)] has been used by Sri Lankan traditional practitioners to promote diuresis. However, the type and grade of tea is not specified.

Materials and Methods:

This study investigates the diuretic activity of black tea infusion (BTI) in rats using Broken Orange Pekoe Fannings (BOPF) grade from major agroclimatic elevations: high-, mid-, and low-grown. Different concentrations of BTI, furosemide (positive control), and water (vehicle) were orally administered to starved (18 h) male rats (n = 9/group), then hydrated. Acute and chronic (28 days) diuretic activities were assessed by measuring cumulative urine output at hourly intervals for 6 h. Electrolyte levels (Na⁺, K⁺, Ca²⁺, H⁺, Cl⁻, HCO₃⁻), pH, osmolarity of urine, and glomerular filtration rate (GFR) of treated rats were determined.

Results:

Administration of BTI induced a significant (P < 0.05) and dose-dependent diuretic activity, which varied with the tea produced in different agroclimatic elevations. Diuretic activity had a rapid onset (1^st h), peaked at 2^nd h and maintained up to 4^th h (except the low dose). Furthermore, there was a dose-dependent increase in micturition frequency, which peaked at 2^nd h. A close association between the caffeine content of tea and diuretic activity was evident. BTI-induced diuresis was accompanied with an increased urine Na⁺ level and GFR. The diuretic activity of BTI was mediated via multiple mechanisms: inhibition of both aldosterone secretion (with increased Na⁺/K⁺ ratio) and carbonic anhydrase [with decreased Cl⁻/(Na⁺ + K⁺) ratio] and via thiazide type of diuretic action (evaluated with increased Na⁺/Cl⁻ ratio).

Conclusion:

The Sri Lankan BOPF grade black tea possesses mild oral diuretic activity whose efficacy differs with the agroclimatic elevation of production. Furthermore, it supports the traditional claim that the black tea acts as a diuretic.

Coffee consumption and the risk of venous thromboembolism: the Tromsø study

BACKGROUND

Several studies have investigated the association between coffee consumption and cardiovascular disease, but little is known about coffee intake and the risk of venous thromboembolism (VTE).

OBJECTIVE

The aim of this prospective cohort study was to investigate the association between coffee consumption and the risk of incident VTE in a general population.

METHODS

Information about coffee consumption habits was obtained with a self-administered questionnaire in 26, 755 subjects, aged 25-97 years, who participated in the fourth survey of the Tromsø study (1994-1995). Incident VTE events were registered until the end of follow-up, 1 September 2007.

RESULTS

There were 462 incident VTE events (1.60 per 1000 person-years, 95% confidence interval [CI] 1.46-1.75) during a median of 12.5 years of follow-up. A daily consumption of three to four cups was borderline associated (hazard ratio [HR] 0.70; 95% CI 0.48-1.02) and a daily consumption of five to six cups (HR 0.67; 95% CI 0.45-0.97) was significantly associated with reduced risk of VTE as compared with coffee abstainers in multivariable analysis adjusted for age, sex, body mass index (BMI), smoking status, physical activity, diabetes, history of cardiovascular disease and cancer. Similar risk estimates were found for provoked and unprovoked VTE, and in sex-stratified analyses.

CONCLUSION

Our findings suggest a possible U-shaped relationship between coffee consumption and VTE, and that moderate coffee consumption may be associated with a reduced risk of VTE. However, more studies are needed to establish whether moderate coffee consumption is inversely associated with the risk of VTE.

Combined effects of coffee consumption and serum γ-glutamyltransferase on serum C-reactive protein in middle-aged and elderly Japanese men and women

BACKGROUND

The association between coffee intake and circulating levels of C-reactive protein (CRP) may be modified by oxidative stress. The authors examined the relation of coffee consumption to serum CRP considering potential inter-actions of serum γ-glutamyltransferase (GGT) and bilirubin.

METHODS

The subjects included 4455 men and 5942 women aged 49-76 years who participated in the baseline survey of a cohort study on lifestyle-related diseases in Fukuoka, Japan. Geometric means of serum CRP and 95% confidence intervals across the category of coffee intake stratified by serum GGT and bilirubin were estimated using multiple linear regression.

RESULTS

Serum CRP concentrations were progressively lower with higher intake of coffee in men with high serum GGT (p for trend=0.009), but not in those with low serum GGT (p for trend=0.73) and GGT modified the association (p for interaction=0.03). Women showed no association between coffee intake and CRP whether serum GGT was low or high. There was no effect modification of serum bilirubin on the association between coffee intake and CRP in either men or women.

CONCLUSIONS

These results support a protective effect of coffee intake against systematic inflammation in middle-aged and elderly Japanese men and imply that such an effect may be stronger in elevated oxidative stress.

Organic and conventional Coffea arabica L.: a comparative study of the chemical composition and physiological, biochemical and toxicological effects in Wistar rats

Differentiation between organic and conventional coffee has increased due to the growing demand and high consumption of healthy foods that contain compounds with antioxidant potential, which have been associated with the reduction of chronic diseases. We used organic and conventional coffee in powder 4% (w/w) and infusions 5%, 10% and 20% (w/v) incorporated in a commercial diet to test in vivo. The levels of chlorogenic acid, caffeine and trigonelline were determined by high performance liquid chromatography. The body weight, weight gain, food consumption, aberrant foci crypt, mucin depleted foci, stress biomarkers protein carbonyl and malondialdehyde, biochemical parameters and behavior of the rats were compared between the experimental and control groups within a framework of colon carcinogenesis. The organic coffee showed higher levels of chlorogenic acid, caffeine and trigonelline than conventional, however, this difference did not significantly affect behavior. The infusions had an antioxidant effect, reducing the levels of malondialdehyde; however, the biochemical parameters of the serum were not altered, and there was neither induction nor prevention of preneoplasic lesions.

Instant coffee with high chlorogenic acid levels protects humans against oxidative damage of macromolecules

SCOPE

Coffee is among the most frequently consumed beverages. Its consumption is inversely associated to the incidence of diseases related to reactive oxygen species; the phenomenon may be due to its antioxidant properties. Our primary objective was to investigate the impact of consumption of a coffee containing high levels of chlorogenic acids on the oxidation of proteins, DNA and membrane lipids; additionally, other redox biomarkers were monitored in an intervention trial.

METHODS AND RESULTS

The treatment group (n=36) consumed instant coffee co-extracted from green and roasted beans, whereas the control consumed water (800 mL/P/day, 5 days). A global statistical analysis of four main biomarkers selected as primary outcomes showed that the overall changes are significant. 8-Isoprostaglandin F2α in urine declined by 15.3%, 3-nitrotyrosine was decreased by 16.1%, DNA migration due to oxidized purines and pyrimidines was (not significantly) reduced in lymphocytes by 12.5 and 14.1%. Other markers such as the total antioxidant capacity were moderately increased; e.g. LDL and malondialdehyde were shifted towards a non-significant reduction.

CONCLUSION

The oxidation of DNA, lipids and proteins associated with the incidence of various diseases and the protection against their oxidative damage may be indicative for beneficial health effects of coffee.

The antioxidant and chlorogenic acid profiles of whole coffee fruits are influenced by the extraction procedures

Commercial whole coffee fruit extracts and powder samples were analyzed for chlorogenic acids (CGA), caffeine and antioxidant activities. CGA and caffeine were characterized by LC-MS(n) and HPLC accordingly, and quantified by UV absorbance. ORAC, HORAC, NORAC, SORAC and SOAC (antioxidant capacities) were assessed. Three caffeoylquinic acids, three feruloylquinic acids, three dicaffeoylquinic acids, one p-coumaroylquinic acid, two caffeoylferuloylquinic acids and three putative chlorogenic lactones were quantified, along with a methyl ester of 5-caffeoylquinic acid (detected in one sample, the first such report in any coffee material). Multistep whole coffee fruit extracts displayed higher CGA content than single-step extracts, freeze-dried, or air-dried whole raw fruits. Caffeine in multistep extracts was lower than in the single-step extracts and powders. Antioxidant activity in whole coffee fruit extracts was up to 25-fold higher than in powders dependent upon the radical. Total antioxidant activity of samples displayed strong correlation to CGA content.