AGRONOMY

Botanical and geographical characterization of green coffee (Coffea arabica and Coffea canephora): chemometric evaluation of phenolic and methylxanthine contents

Alonso Salces, R. M.; Serra, F.; Reniero, F.; Heberger, K.

The botanical and geographical origin of green coffee beans of Arabica (Coffea Arabica) and Robusta (Coffea canephora) varieties were determined using liquid chromatography coupled with UV spectrophotometry to measure the chlorogenic acids, cinnamoyl amides, cinnamoyl glycosides, free phenolic acids and methylxanthines contents. Unequivocal botanical characterisation of green coffee beans was achieved by the measurement of 14 compounds including caffeine and some of these were suitable for use in determining geographical origin. Ugandan Robusta green coffee beans can be characterised by measurement of p-coumaroyl-N-tyrosine, caffeoyl-N-phenylalanine, caffeoyl-N-tyrosine, 3-dimethoxycinnamoyl-5-feruloylquinic acid and dimethoxycinnamic acid and multivariate data analysis of phenolic and methylxanthine profiles demonstrated the potential of these as markers of geographical origin. Linear discriminant analysis (LDA) and partial least-squares discriminant analysis (PLS-DA) were used to successfully identify Robusta green coffee beans from Vietnam, Cameroon and Indonesia, and PLS-DA was used to develop models for Robusta and Arabica samples

Source: Journal of Agricultural and Food Chemistry, (May 27), 57 (10): 4224-4235

CHEMISTRY / SENSORICS

Methodological considerations for the quantification of self-reported caffeine use

Addicott, M. A.; Yang, L. L.; Peiffer, A. M.; Laurienti, P. J.

The field of research regarding the effects of habitual caffeine use is immense and frequently utilizes self-report measures of caffeine use. However, various self-report measures have different methodologies, and the accuracy of these different methods has not been compared. MATERIALS AND METHODS: Self-reported caffeine use was estimated from two methods (a retrospective interview of weekly caffeine use and a 7-day prospective diary; n = 79). These estimates were then tested against salivary caffeine concentrations in a subset of participants (n = 55). RESULTS: The estimates of caffeine use (mg/day) from the interview-and diary-based methods correlated with one another (r = 0.77) and with salivary caffeine concentrations (r = 0.61 and 0.68, respectively). However, almost half of the subjects who reported more than 600 mg/day in the interview reported significantly less caffeine use in the diary. CONCLUSIONS: Self-report measures of caffeine use are a valid method of predicting actual caffeine levels. Estimates of high caffeine use levels may need to be corroborated by more than one method

Source: Psychopharmacology.203(3):571-8, 2009

Role of roasting conditions in the level of chlorogenic acid content in coffee beans: correlation with coffee acidity

Moon, J. K.; Yoo, H. S.; Shibamoto, T

Total chlorogenic acids of nine isomers from seven commercial green and roasted coffee beans ranged from 34.43 +/-1.50 to 41.64 +/-3.28 mg/g and from 2.05 +/-0.07 to 7.07 +/-0.16 mg/g, respectively. Methanol/water (7:3) extracts from four commercial green coffee beans roasted at different conditions (230 degrees C, 12 min; 24 degrees C, 14 min; 250 degrees C, 17 min; and 250 degrees C, 21 min) were also analyzed for chlorogenic acids. The total chlorogenic acid found in green coffee beans ranged from 86.42 +/-2.04 to 61.15 +/-1.40 mg/g. Total chlorogenic acids present were reduced in accordance with the intensity of roasting conditions. When green beans were roasted at 230 degrees C for 12 min and at 250 degrees C for 21 min, total chlorogenic acid content was reduced to nearly 50% and to almost trace levels, respectively. The results indicate that roasting conditions play an important role in chlorogenic acid content in roasted coffee beans. A general correlation between total caffeoylquinic acids and pH was observed

Source: Journal of Agricultural & Food Chemistry.57(12):5365-9, 2009 Jun 24

CHEMISTRY

Metabolite profiling of hydroxycinnamate derivatives in plasma and urine after the ingestion of coffee by humans: identification of biomarkers of coffee consumption

Stalmach, A.; Mullen, W.; Barron, D.; Uchida, K.; Yokota, T.; Cavin, C.; Steiling, H.; Williamson, G.; Crozier,
A.

Human subjects drank coffee containing 412 mumol of chlorogenic acids, and plasma and urine were collected 0 to 24 h after ingestion and were analyzed by high-performance liquid chromatography-mass spectrometry. Within 1 h, some of the components in the coffee reached nanomole peak plasma concentrations (C(max)), whereas chlorogenic acid metabolites, including caffeic acid-3-O-sulfate and ferulic acid-4-O-sulfate and sulfates of 3-and 4-caffeoylquinic acid lactones, had higher C(max) values. The short time to reach C(max) (T(max)) indicates absorption of these compounds in the small intestine. In contrast, dihydroferulic acid, its 4-O-sulfate, and dihydrocaffeic acid-3-O-sulfate exhibited much higher C(max) values (145-385 nM) with T(max) values in excess of 4 h, indicating absorption in the large intestine and the probable involvement of catabolism by colonic bacteria. These three compounds, along with ferulic acid-4-O-sulfate and dihydroferulic acid-4-O-glucuronide, were also major components to be excreted in urine (8.4-37.1 mumol) after coffee intake. Feruloylglycine, which is not detected in plasma, was also a major urinary component (20.7 mumol excreted). Other compounds, not accumulating in plasma but excreted in smaller quantities, included the 3-O-sulfate and 3-O-glucuronide of isoferulic acid, dihydro(iso)ferulic acid-3-O-glucuronide, and dihydrocaffeic acid-3-O-glucuronide. Overall, the 119.9 mumol excretion of the chlorogenic acid metabolites corresponded to 29.1% of intake, indicating that as well as being subject to extensive metabolism, chlorogenic acids in coffee are well absorbed. Pathways for the formation of the various metabolites within the body are proposed. Urinary dihydrocaffeic acid-3-O¬sulfate and feruloylglycine are potentially very sensitive biomarkers for the consumption of relatively small amounts of coffee

Source: Drug Metabolism & Disposition.37(8):1749-58, 2009 Aug.

COFFEE & HEALTH

Species, roasting degree and decaffeination influence the antibacterial activity of coffee against Streptococcus mutans

Antonio, A. G.; Moraes, R. S.; Perrone, D.; Maia, L. C.; Santos, K. R. N.; Iorio, N. L. P.; Farah, A.

Coffee beverage has been associated with antibacterial activity against Streptococcus mutans, a cariogenic bacterium. This study aimed at identifying natural compounds in coffee that contribute to such activity and investigate the influence of species, roasting and decaffeination on it. Coffee chemical compounds and aqueous extracts of green and roasted regular and decaffeinated Coffea arabica and Coffea canephora beans were tested. MIC, biofilm inhibition and biofilm reduction results were correlated with the concentration of coffee compounds in the extracts. 5-Caffeoylquinic acid, trigonelline and caffeic acid solutions showed bacteriostatic activity (MIC=0.8mg/mL). Lighter and regular extracts showed higher inhibitory activity than darker and decaffeinated extracts, with an inverse correlation between bacterial colony-forming units and roasting degree. Only regular C. canephora extracts showed biofilm formation inhibition. The joint effect of chlorogenic acids, trigonelline and caffeine or other compounds removed by decaffeination seems to be one of the causes for coffee antibacterial activity against S. mutans.

Source: Food Chemistry.118, (3):782-788, 2010

Coffee consumption and risk of heart failure in men: an analysis from the Cohort of Swedish Men

Ahmed, H. N.; Levitan, E. B.; Wolk, A.; Mittleman, M. A.

A previous study found that consuming 5 or more cups of coffee per day was associated with increased incidence of heart failure (HF). We sought to evaluate this association in a larger population. METHODS: We measured coffee consumption using food frequency questionnaires among 37,315 men without history of myocardial infarction, diabetes, or HF. They were observed for HF hospitalization or mortality from January 1, 1998, until December 31, 2006, using record linkage to the Swedish inpatient and cause of death registries. Cox proportional hazards models adjusted for age, dietary, and demographic factors were used to calculate incidence rate ratios (RR) and 95% confidence
intervals (CIs). RESULTS: For 9 years of follow-up, 784 men experienced an HF event. Compared to men who drank <or=1 cup of coffee per day (unadjusted rate 29.9 HF events/10,000 person-years), RR were
0.87 (95% CI 0.69-1.11, unadjusted rate 29.2/10,000 person-years) for 2 cups/d, 0.89 (95% CI 0.70-1.14, unadjusted rate 25.1/10,000 person-years) for 3 cups/d, 0.89 (95% CI 0.69-1.15, unadjusted rate 25.0/10,000 person-years) for 4 cups/d, and 0.89 (95% CI 0.69-1.15, unadjusted rate 18.1/10,000 person-years) for >or=5 cups/d (P for trend in RR = .61). CONCLUSIONS: This study did not support the hypothesis that high coffee consumption is associated with increased rates of HF hospitalization or mortality

Source: American Heart Journal.158(4):667-72, 2009 Oct

Caffeine effects on resting-state arousal in children

Barry, R. J.; Clarke, A. R.; Johnstone, S. J.; Brown, C. R.; Bruggemann, J. M.; van, Rijbroek, I

From previous work in our laboratory, increases in skin conductance level (SCL), together with global (across-scalp) decreases in electroencephalogram (EEG) alpha power and increases in alpha frequency, are useful indices of arousal increase, and here we sought to identify changes in these indices with caffeine ingestion in children. We explored the effects of a single oral dose of caffeine (80 mg) in a randomised double-blind placebo-controlled repeated-measures cross-over study. Thirty healthy children aged between 8 and 13 years (mean age 10.5 years; 11 females) participated in two sessions, 1 week apart. EEG and SCL from a 3 min eyes-closed epoch, commencing approximately 30 min after ingestion of caffeine or placebo, were examined. Caffeine was associated with increased SCL, and a global reduction in EEG power in the theta and alpha bands, as well as topographically-focused reductions in delta and beta power, and a focal increase in alpha frequency. Only global alpha level demonstrated the expected inverse relationship with SCL in both placebo and caffeine conditions. These results are generally consistent with recent electrodermal and EEG studies of arousal. Together with our previous adult data, they indicate that caffeine can be used to increase arousal in both adults and children, without the potential confounds associated with varying task demands. Caffeine appears useful as a simple tool for manipulating arousal in studies exploring its role in physiological and behavioural functioning. This may be helpful in determining the role of hypothetical arousal anomalies in syndromes such as attention¬deficit/hyperactivity disorder

Source: International Journal of Psychophysiology.73(3):355-61, 2009 Sep

Trigonelline is a novel phytoestrogen in coffee beans

Allred, K. F.; Yackley, K. M.; Vanamala, J.; Allred, C. D.

Drinking coffee has been associated with the development of several endocrine-related cancers. The interpretation of these data has often been limited to the role that caffeine plays. Trigonelline (Trig), a niacin-related compound, is a natural constituent of coffee accounting for approx. 1% dry matter in roasted beans. Studies exploring the effects of this bioactive compound on mammalian cells are limited. The initial purpose of our studies was to determine whether Trig alters the actions of estradiol (E2), using proliferation of estrogen-dependent human breast cancer (MCF-7) cells as a model system. When cells were cotreated with suboptimal doses of E2 (10 pmol/L) and Trig (100 pmol/L), an additive enhancement of MCF-7 growth was observed. In the absence of E2, Trig stimulated MCF-7 cell proliferation in a dose¬responsive manner and significantly enhanced cell growth at concentrations as low as 100 pmol/L. Cotreatment of MCF-7 cells with Trig and ICI 182,780, an estrogen receptor (ER) antagonist, inhibited Trig-induced cell proliferation. Trig treatment also induced activation of estrogen response element reporter assays in MCF-7 cells and increased expression of ER target genes (pS2, progesterone receptor, and cyclin D1) similar to E2. While our data demonstrate that Trig activates the ER, competitive binding assays showed that Trig does not compete E2 off of the ER at any concentration. This suggests that Trig is activating the ER through a separate mechanism. Collectively, these data demonstrate that Trig even at low concentrations stimulates MCF-7 cell growth and that this effect is mediated through ER, clearly identifying Trig as a novel phytoestrogen. (c)American Society for Nutrition.

Source: Journal of Nutrition.139, (10):1833-1838, 2009

Caffeine\'s effects on true and false memory

Capek, S.; Guenther, R. K.

Caffeine's effects on recall of word lists were investigated using the Deese-Roediger-McDermott (DRM) paradigm. College students were administered either 200 mg of caffeine or a 250-mg lactose placebo; after 30 min., they were tested on recall using six word lists. Words of each list were semantically related to a single word (a "critical lure") that was not presented in the list. Participants administered caffeine recalled more list words and more critical lures than participants administered lactose. Recall of list words was negatively correlated with recall of critical lures. Caffeine appears to intensify the strength of connections among list words and critical lures, thereby enhancing both true and false memory

 Source: Psychological Report 104(3) 787-95

Caffeinated and alcoholic beverage intake in relation to ovulatory disorder infertility

Chavarro, J. E.; Rich-Edwards, J. W.; Rosner, B. A.; Willett, W. C.

Many studies have examined whether caffeine, alcohol, or specific beverages containing these substances affect fertility in women. However, most of these studies have retrospectively collected information on alcohol and caffeine intake, making the results susceptible to biases. METHODS: We
followed 18,555 married women without a history of infertility for 8 years as they attempted to become (or became) pregnant. Diet was measured twice during this period and prospectively related to the incidence of ovulatory disorder infertility. RESULTS: There were 438 incident report of ovulatory disorder infertility during follow-up. Intakes of alcohol and caffeine were unrelated to the risk of ovulatory disorder infertility. Comparing the highest to lowest categories of intake, the multivariate-adjusted relative risk, was 1.11 (95% confidence interval = 0.76-1.64; P for trend 0.78) for alcohol and 0.86 (0.61-1.20; 0.44) for total caffeine. However, intake of caffeinated soft drinks was positively related to ovulatory disorder infertility. Comparing the highest to lowest categories of caffeinated soft drink consumption, the RR was 1.47 (1.09¬1.98; 0.01). Similar associations were observed for noncaffeinated, sugared, diet, and total soft drinks. CONCLUSIONS: Our findings do not support the hypothesis that alcohol and caffeine impair ovulation to the point of decreasing fertility. The association between soft drinks and ovulatory disorder infertility seems not to be attributable to their caffeine or sugar content, and deserves further investigation

Source: Epidemiology.20(3):374-81, 2009 May

Caffeine consumption attenuates neurochemical modifications in the hippocampus of streptozotocin¬induced diabetic rats

Duarte, J. M.; Carvalho, R. A.; Cunha, R. A.; Gruetter, R.

Type 1 diabetes can affect hippocampal function triggering cognitive impairment through unknown mechanisms. Caffeine consumption prevents hippocampal degeneration and memory dysfunction upon different insults and is also known to affect peripheral glucose metabolism. Thus we now characterized glucose transport and the neurochemical profile in the hippocampus of streptozotocin-induced diabetic rats using in vivo(1)H NMR spectroscopy and tested the effect of caffeine consumption thereupon. We found that hippocampal glucose content and transport were unaltered in diabetic rats, irrespective of caffeine consumption. However diabetic rats displayed alterations in their hippocampal neurochemical profile, which were normalized upon restoration of normoglycaemia, with the exception of myo-inositol that remained increased (36 +/-5%, p < 0.01 compared to controls) likely reflecting osmolarity deregulation. Compared to controls, caffeine-consuming diabetic rats displayed increased hippocampal levels of myo-inositol (15 +/-5%, p < 0.05) and taurine (23 +/-4%, p < 0.01), supporting the ability of caffeine to control osmoregulation. Compared to controls, the hippocampus of diabetic rats displayed a reduced density of synaptic proteins syntaxin, synaptophysin and synaptosome-associated protein of 25 kDa (in average 18 +/-1%, p < 0.05) as well increased glial fibrillary acidic protein (20 +/-5%, p < 0.05), suggesting synaptic degeneration and astrogliosis, which were prevented by caffeine consumption. In conclusion, neurochemical alterations in the hippocampus of diabetic rats are not related to defects of glucose transport but likely reflect osmoregulatory adaptations caused by hyperglycemia. Furthermore, caffeine consumption affected this neurochemical adaptation to high glucose levels, which may contribute to its potential neuroprotective effects, namely preventing synaptic degeneration and astrogliosis

Source: Journal of Neurochemistry.111(2):368-79, 2009 Oct

Coffee drinking and risk of endometrial cancer--a population-based cohort study

Friberg, E.; Orsini, N.; Mantzoros, C. S.; Wolk, A.

Coffee drinking has been reported to have beneficial effects on insulin resistance, which has been directly associated with endometrial cancer. Although a relationship between coffee consumption and endometrial cancer risk is biologically plausible, this hypothesis has been previously explored in only 2 prospective studies, with a small number of cases. We used data from the Swedish Mammography Cohort, a population-based prospective cohort study of 60,634 women. During 17.6 years of follow-up, 677 participants were diagnosed with incident endometrial cancer (adenocarcinoma). We examined the association between self-reported coffee consumption (at baseline 1987-90 and in 1997) and endometrial cancer risk using Cox proportional hazards models. Each additional cup (200 g) of coffee per day was associated with a rate ratio (RR) of 0.90 [95% confidence interval (CI), 0.83-0.97]. In women drinking 4 or more cups of coffee a day, the RR for the risk reduction of endometrial cancer was 0.75 (95% CI, 0.58¬0.97) when compared with those who drank 1 cup or less. The association seemed largely confined to overweight and obese women, who showed a respective risk reduction of 12% (95% CI, 0-23%) and 20% (95% CI, 7-31%) for every cup of coffee, but was not observed among normal-weight women. There was a statistically significant interaction between coffee consumption and body mass index (p(interaction) < 0.001). These data indicate that coffee consumption may be associated with decreased risk of endometrial cancer, especially among women with excessive body weight. If confirmed by other prospective studies, these results are of major public health significance

Source: International Journal of Cancer.125(10):2413-7, 2009 Nov 15

Coffee intake and risk of incident diabetes in Puerto Rican men: results from the Puerto Rico Heart Health Program

Fuhrman, B. J.; Smit, E.; Crespo, C. J.; Garcia-Palmieri, M. R.

A prospective study was conducted on the association of coffee intake with incident diabetes in the Puerto Rico Heart Health Program cohort, comprising 9824 middle-aged men (aged 35-79 yrs). Of 9824 men, 3869 did not provide a fasting blood sample at baseline, 1095 had prevalent diabetes and 131 were not given fasting glucose tests at any subsequent study visit. Thus, the present analysis includes 4685 participants. Diabetes was ascertained at baseline and at 2 study visits between 1968 and 1975 using fasting glucose tests and self-reports of physician-diagnosed diabetes or use of insulin or hypoglycaemic medication. Logistic regression analysis was used to assess the association of coffee intake with risk of
incident diabetes while adjusting for covariates (age, BMI, physical activity, smoking, education, alcohol intake, family history of diabetes, intakes of milk and sugar). 519 participants met the criteria for incident diabetes. Compared with those reporting intake of 1-2 servings of coffee/day, coffee abstainers were at reduced risk (OR = 0.64; 95% CI 0.43, 0.94). Among coffee drinkers, there was a significant trend of decreasing risk by intake (P = 0.02); intake of >=4 servings/day was associated with an odds ratio of 0.75 (95% CI 0.58, 0.97). Hence, results suggest a protective effect of coffee intake against diabetes risk, while also indicating that abstainers may be at reduced risk

Source: Public Health Nutrition.12, (6):842-848, 2009

Caffeine and a selective adenosine A2A receptor antagonist induce reward and sensitization behavior associated with increased phospho-Thr75-DARPP-32 in mice

Hsu, C. W.; Chen, C. Y.; Wang, C. S.; Chiu, T. H.

Caffeine, an antagonist of adenosine A(1) and A(2A) receptor, is the most widely used psychoactive substance in the world. Evidence indicates that caffeine interacts with the neuronal systems involved in drug reinforcing. Although adenosine A(1) and/or A(2A) receptor have been found to play important roles in the locomotor stimulation and probably reinforcing effect of caffeine, the relative contribution of the A(1) and/or A(2A) receptors to the acute and chronic motor activation and reinforcing effects of caffeine has not been completely investigated. OBJECTIVE: The roles of adenosine A(1) and/or A(2A) receptor and the association of phospho-Thr75-dopamine-and cAMP-regulated phosphoprotein of molecular weight 32 kDa (DARPP-32) in the motor activation and reinforcing effects of caffeine, 8¬cyclopentyl-1,3-dipropylxanthine (DPCPX), a selective A(1) antagonist, and 5-amino-7-(beta-phenylethyl)¬2-(8-furyl) pyrazolol [4,3-e]-1,2,4-triazolol [1,5-c] pyrimidine (SCH58261), a selective A(2A) receptor antagonist were examined. METHODS: Locomotor stimulation and behavioral sensitization of caffeine, DPCPX, and SCH58261 were studied in C57BL/6 male mice following acute and chronic administration. Conditioned place preference (CPP) paradigm was used to evaluate the drug-seeking potential of these compounds. Furthermore, the expression of phospho-Thr75-DARPP-32 in striatal membrane from behaviorally sensitized mice was analyzed by Western blot. RESULTS: Caffeine and SCH58261 but not DPCPX induced CPP and locomotor sensitization in C57BL/6 mice. The locomotor sensitization after chronic treatment was associated with increased DARPP-32 phosphorylation at Thr75 in the striatum. CONCLUSION: Caffeine-induced reinforcing effect and behavioral sensitization are mediated by antagonism at adenosine A(2A) receptor. These effects are associated with phosphorylation of DARPP¬32 at Thr75 in the striatum

Source: Psychopharmacology.204(2):313-25, 2009 Jun

Japan Public Health Center-Based Prospective Study Group Effect of coffee and green tea consumption on the risk of liver cancer: cohort analysis by hepatitis virus infection status

Inoue, M.; Kurahashi, N.; Iwasaki, M.; Shimazu, T.; Tanaka, Y.; Mizokami, M.; Tsugane, S

In spite of their anticarcinogenic potential, the effect of coffee and green tea consumption on the risk of liver cancer has not been clarified prospectively in consideration of hepatitis C (HCV) and B virus (HBV) infection. We examined whether coffee and green tea consumption was associated with a reduced risk of liver cancer by hepatitis virus infection status in the Japan Public Health Center-Based Prospective Study Cohort II. A total of 18,815 subjects ages 40 to 69 years participating in a questionnaire and health checkup survey in 1993 to 1994 were followed for the incidence of liver cancer through 2006. A total of 110 cases of liver cancer were newly documented. Hazard ratios for coffee and green tea consumption categories were calculated with a Cox proportional hazards model. Compared with almost never drinkers, increased coffee consumption was associated with a reduced risk of liver cancer in all subjects (hazard
ratio for <1, 1-2, and >or=3 cups/d; P(trend) = 0.67, 0.49, 0.54, and 0.025). A similar risk tendency was observed in those with either or both HCV and HBV infection. In contrast, no association was observed between green tea consumption and the risk of liver cancer in all subjects. Our results suggest that coffee consumption may reduce the risk of liver cancer regardless of HCV and HBV infection status, whereas green tea may not reduce this risk

Source: Cancer Epidemiology, Biomarkers & Prevention.18(6):1746-53, 2009 Jun

JPHC Study Group Psychological factors, coffee and risk of diabetes mellitus among middle-aged Japanese: a population¬based prospective study in the JPHC study cohort

Kato, M.; Noda, M.; Inoue, M.; Kadowaki, T.; Tsugane, S

An association between psychological factors and diabetes has been suspected for a long time. However, epidemiological data on this association is limited. We investigated the association between psychological factors (perceived mental stress and type A behavior) and the onset of diabetes in a community-based, prospective cohort study in a large number of middle-aged Japanese adults. A total of 55,826 subjects (24,826 men and 31,000 women) aged 40-69 years were followed for 10 years. A self-administered questionnaire on medical conditions including diabetes and other lifestyle factors was performed at baseline and 5 and 10 years later. Psychological factors and diabetes were assessed based on the questionnaire results. During the 10-year follow-up period, we documented 1,601 incident cases (6.4%) of diabetes among men and 1,093 cases (3.5%) among women. The risk of diabetes increased with an increasing stress level, especially among men. Multivariate adjusted odds ratios for high stress compared with low stress were 1.36 (1.13 to 1.63) among men and 1.22 (0.98 to 1.51) among women. The risk of diabetes increased with an increasing level of type A behavior only among women. Multivariate adjusted odds ratios for high levels of type A behavior compared with low levels of type A behavior were 1.09 (0.94 to 1.27) among men and 1.22 (1.01 to 1.47) among women. We found an association between perceived mental stress and the incidence of diabetes, especially among men. We also found an association between type A behavior and the incidence of diabetes among women. In addition, inverse association between coffee consumption and the incidence of diabetes which was consistent with other studies was observed

Source: : Endocrine Journal.56(3):459-68, 2009 Jun Full text

Panic disorder and social anxiety disorder subtypes in a caffeine challenge test

Nardi, A. E.; Lopes, F. L.; Freire, R. C.; Veras, A. B.; Nascimento, I.; Valenca, A. M.; Melo-Neto, V. L.; Soares-Filho, G. L.; King, A. L.; Araujo, D. M.; Mezzasalma, M. A.; Rassi, A.; Zin, W. A.

Studies have demonstrated the vulnerability of anxiety disorder patients to challenge tests. Our aim was to observe if panic disorder (PD) patients and generalized social anxiety disorder (GSAD) and performance social anxiety disorder (PSAD) patients respond in a similar way to the induction of anxiety symptoms and panic attacks by an oral caffeine challenge test. We compared 28 PD patients, 25 GSAD patients, 19 PSAD, and 26 control subjects after a 480-mg caffeine test. The patients had not received psychotropic drugs for at least a 4-week period. In a randomized double-blind experiment performed in two occasions 7 days apart, 480 mg of caffeine and a caffeine-free solution were administered and anxiety scales were administered before and after each test. A panic attack was induced in 17 (60.7%) PD patients, 4 (16.0%) GSAD patients, and 10 (52.6%) PSAD patients, during the caffeine test. None of the control subjects had a panic attack after the caffeine intake. Neither patients nor any control subject had a panic attack after drinking the caffeine-free solution. Our data suggest that there is an association between PD and PSAD hyperreactivity to an oral caffeine challenge test. The PD and PSAD patients had a higher number of induced panic attacks, some specific anxiety symptoms, and a more severe anxiety response than GSAD patients and normal volunteers

Source: Psychiatry Research.169(2):149-53, 2009 Sep 30

Does postprandial coffee intake enhance gastric emptying?: a crossover study using continuous real time 13C breath test (BreathID system)

Akimoto, K.; Inamori, M.; Iida, H.; Endo, H.; Akiyama, T.; Ikeda, T.; Fujita, K.; Takahashi, H.; Yoneda, M.; Goto, A.; Abe, Y.; Kobayashi, N.; Kirikoshi, H.; Kubota, K.; Saito, S.; Nakajima, A.

Coffee is one of the most popular beverages worldwide, however, few studies have examined the effects of coffee on the gastrointestinal system. The aim of this study was to determine whether there was a correlation between coffee intake and gastric emptying using a novel non-invasive technique for measuring gastric emptying with a continuous real time 13C breath test (BreathID system: Oridion, Israel). METHODOLOGY: Six healthy male volunteers participated in this randomized, two-way crossover study. The subjects were randomly assigned to receive a test meal (200 kcal per 200 mL) plus postprandial 190 mL black coffee or the test meal alone after fasting overnight. A 13C-acetic acid breath test was continuously performed using the BreathID system, which monitors gastric emptying, for 4 hours after the administration of the test meal. Using Oridion Research Software (beta version), the time for emptying of 50% of the labeled meals (T 1/2) and the analog to the scintigraphy lag time for 10% emptying of the labeled meal (T lag) were calculated. The parameters between two occasions were compared using the Wilcoxon signed-rank test. RESULTS: After coffee intake the T 1/2 and T lag constant were significantly decreased. CONCLUSIONS: The decrease in the T 1/2 and T lag suggests the acceleration of gastric emptying. This study showed that postprandial coffee intake enhances gastric emptying, suggesting the potential use of coffee in clinical settings for patients with functional gastrointestinal disorders

Source: Hepato-Gastroenterology 56(91-92)918-20, 2009

Relationship of blood pressure, behavioral mood state, and physical activity following caffeine ingestion in younger and older women

Arciero, P. J.; Ormsbee, M. J.

The purpose of this study was to examine the age-related differences in blood pressure, heart rate, and behavioral mood state after caffeine ingestion in younger and older women. Using a placebo-controlled, double-blind design, 10 younger (Y; 18-22 years) and 10 older (O; 50-67 years) healthy women who were moderate consumers of caffeine (self-reported mean intake: Y, 139 +/-152 mg.day-1; O, 204 +/-101 mg.day-1) were investigated. All volunteers were characterized for fasting plasma glucose, insulin, free¬fatty acids and caffeine levels, body composition, cardiovascular fitness, physical activity, and energy intake. Before and after placebo and caffeine ingestion (5 mg.kg-1 fat-free mass; approximately 208-270 mg) test days, the following variables were measured in all subjects: plasma caffeine levels, heart rate, blood pressure, and behavioral mood state. Results showed that, following caffeine ingestion: (i) both systolic and diastolic blood pressure (SBP and DBP, respectively) increased significantly (p < 0.05) in the older women (SBP, 128.4 +/-14.2 vs. 132.1 +/-13.0 mm Hg (3%); DBP, 80.2 +/-6.9 vs. 83.4 +/-7.5 mm Hg (4%), whereas only DBP increased in the younger women (67.1 +/-4.7 vs. 69.9 +/-5.4 mm Hg (4.2%); p < 0.05); (ii) heart rate decreased significantly (Y, 59.2 +/-8.7 to 53.9 +/-10.6 beats.min-1 (p < 0.05); O,
61.9 +/-9.2 to 59.2 +/-8.4 beats.min-1 (p < 0.05)) in both groups; and (iii) self-reported feelings of tension and vigor increased and feelings of fatigue decreased (p < 0.05) in younger women, whereas depression decreased (p < or = 0.05) in older women. Self-reported level of physical activity was inversely related to change in DBP following caffeine ingestion in younger women. In conclusion, blood pressure response is augmented and subjective feelings of behavioral mood state are attenuated to a greater degree in older than in younger women following acute caffeine ingestion. Less physically active younger women are more vulnerable to the pressor response to caffeine than more active younger women. It should be noted that these findings are limited to moderate consumers of caffeine who abstained for 48 h prior to testing, and who ingested caffeine in pill form (approximately 240 mg)

Source: Applied Physiology, Nutrition, & Metabolism = Physiologie Appliquee, Nutrition et Metabolisme.34(4):754-62, 2009 Aug

Early long-term exposure with caffeine induces cross-sensitization to methylphenidate with involvement of DARPP-32 in adulthood of rats

Boeck, C. R.; Marques, V. B.; Valvassori, S. S.; Constantino, L. C.; Rosa, D. V.; Lima, F. F.; Romano-Silva,
M. A.; Quevedo

Chronic ingestion of caffeine causes dependence and sleep disturbance in children and adolescents. In rodents, the administration of caffeine may produce behavioral cross-sensitization to some psychostimulants, such as dopaminergic psychoactive drugs. Methylphenidate (MPH; Ritalin) is a psychostimulant used in pediatric-and adult human populations to manage the symptoms associated with attention-deficit hyperactivity disorder (ADHD). Previous studies have suggested that dopamine-and cAMP-regulated phosphoproteins of 32 kDa (DARPP-32) participate in the manifestation of behavioral activity following ingestion of caffeine or MPH. The aim of the present study was to evaluate whether long¬term administration of low doses of caffeine in rodents during their adolescence induces cross-sensitization to MPH challenge in their adulthood and investigate the involvement of DARPP-32 in this model. Young rats (P25) consumed water or caffeine (0.3 g/L; mean consumption was 7.5 mg/day/kg) for 28 days. The caffeine consumption was then suspended for 14 days (washout period) when the animals received saline solution or MPH (1, 2, or 10 mg/kg) (P67) intraperitoneally. The locomotor activity of these rats was assessed using the open-field test, following which the immunocontent of DARPP-32 was evaluated in samples of their prefrontal cortex, striatum, or hippocampus. Rats chronically exposed to caffeine in their adolescent period and to inactive doses of MPH (1mg/kg) in adulthood showed augmented locomotor activity. The behavioral effect observed was accompanied by increased levels of
DARPP-32 in the striatum and prefrontal cortex compared to control groups (saline or caffeine). However, no alteration caused by these treatments was noted in the hippocampus. In conclusion, chronic caffeine exposure induces likely long-term cross-sensitization to MPH in a DARPP-32-dependent pathway

Source: Neurochemistry International 55(5)318-22, 2009

A preliminary investigation into the effect of coffee on hypolagesia associated with transcutaneous electrical nerve stimulation

Dickie, A.; Tabasam, G.; Tashani, O.; Marchant, P.; Johnson, M. I

Transcutaneous electrical nerve stimulation (TENS) is a non-invasive, inexpensive analgesic technique used to relieve pain. It has been suggested that caffeine, an adenosine antagonist, may interfere with TENS action. This double-blind controlled pilot study investigated the effect of coffee on response to TENS in healthy human participants experiencing experimentally induced pain. Twelve participants (7 female, age range = 20-41 years) took part in two experiments separated by 24 h. Each experiment lasted 80 min and consisted of 3 x 15 min cycles: pre-TENS, during TENS predrink and during TENS postdrink [coffee (100 mg caffeine) or decaffeinated coffee randomized across experiments]. During each cycle, thresholds for electrical (EPT), mechanical (MPT) and cold pressor (CPT) pain were recorded. The statistical analysis modelled the responses for the coffee and decaffeinated coffee conditions during TENS (i.e. as a standard crossover) and detected no statistically significant effects between coffee and decaffeinated drinks for the natural logarithm (ln) transformed values of electrical pain threshold [ln EPT Coffee-ln EPT Decaffeinated coffee mean (standard error) = 0.0147 (0.2159)], mechanical pain threshold [ln MPT Coffee-ln MPT Decaffeinated coffee mean (standard error) = 0.1296 (0.0816)] and cold pain threshold [ln CPT Coffee-ln CPT Decaffeinated coffee mean (standard error) = 0.0793 (0.1139)]. We conclude that a single cup of coffee (100 mg caffeine) had no detectable effect on TENS outcome. Reasons why coffee did not produce a detectable effect on pain threshold are discussed

Source: Clinical Physiology & Functional Imaging.29(4):293-9, 2009 Jul

Coffee consumption is not related to the metabolic syndrome at the age of 36 years: the Amsterdam Growth and Health Longitudinal Study

Driessen, M. T.; Koppes, L. L. J.; Veldhuis, L.; Samoocha, D.; Twisk, J. W. R.

Coffee consumption is suggested to reduce the risk of diabetes mellitus type-2, and this study investigated the relationship of long-term coffee consumption with the prevalence of metabolic syndrome (MS). Data on coffee consumption and MS components were obtained from healthy men and women, and data analysis was performed using generalised estimating equations and regression analysis. The growth of coffee consumption between subjects with or without MS or its components is discussed

Source: : European Journal of Clinical Nutrition (EJCN), (April), 63 (4): 536-542

Anti-cariogenic effects of polyphenols from plant stimulant beverages (cocoa, coffee, tea)

Ferrazzano, G. F.; Amato, I.; Ingenito, A.; De Natale, A.; Pollio, A.

Polyphenols occurring in cocoa, coffee and tea can have a role in the prevention of cariogenic processes, due to their antibacterial action. Cocoa polyphenol pentamers significantly reduce biofilm formation and acid production by Streptococcus mutans and S. sanguinis. In the same way, trigonelline, caffeine and chlorogenic acid occurring in green and roasted coffee interfere with S. mutans adsorption to saliva¬coated hydroxyapatite beads. Studies carried out on green, oolong and black tea indicate that tea polyphenols exert an anti-caries effect via an anti-microbial mode-of-action, and galloyl esters of (-)¬epicatechin, (-)-epigallocatechin and (-)-gallocatechin show increasing antibacterial activities. The anti¬cariogenic effects against alpha-haemolytic streptococci showed by polyphenols from cocoa, coffee, and tea suggest further studies to a possible application of these beverages in the prevention of pathogenesis of dental caries.

 Source: Fitoterapia 80(5)255-62

A scientific update on coffee\'s liver benefits

Gressner, O. A.

Scientists at the National Institutes of Health have reported that increased coffee consumption is associated with a slower progression of fibrogenesis in patients with chronic and particularly alcoholic liver disease and a reduced incidence of heptocellular carcinoma. However, a causal mechanistic explanation was pending. New results indicate that the methylxanthine caffeine--a major component of coffee and the most widely consumed pharmacologically active substance in the world--might be responsible for this phenomenon, because it inhibits the synthesis of connective tissue growth factor (CTGF/CCN2) in liver parenchymal and nonparenchymal cells, primarily by inducing degradation of Smad2 (and to a much lesser extent Smad3) and thus impairment of transforming growth factor beta (TGF-beta) signaling. CTGF and TGF-beta play crucial roles in the fibrotic remodeling of various organs, and, ultimately, carcinogenesis. This article summarizes the clinical-epidemiological observations as well as the pathophysiological background and provides suggestions for the therapeutic use of (methyl)xanthine derivatives in the management of fibro-/carcinogenic (liver) diseases.

Source: Hepatology.50(3):970-8, 2009 Sep

Sugar in coffee or tea and risk of obesity: a neglected issue

Gyntelberg, F.; Hein, H. O.; Suadicani, P

In the Copenhagen Male Study, sugar intake in coffee or tea is inversely associated with obesity. This study analysed the association of sugar intake with obesity among men with and without lifestyle factors indicating health awareness. A cross-sectional study was conducted of 3290 men aged 53-75 yrs, including information about smoking, alcohol, physical activity, tea and coffee use, avoidance of fatty foods, social class, self-assessed health and family obesity. Overall, 291 men (8.8%) were obese, with body mass index >=30. Among men using sugar in coffee or tea (36%), the prevalence was 6.2%, whereas among others it was 10.3% (odds ratio (95% confidence interval) =0.6 (0.4-0.8)). An inverse association between use of sugar in hot beverages and prevalence of obesity was consistent in subgroups, and most pronounced among the least health-conscious (odds ratio (95% confidence interval) = 0.4 (0.2-0.8)). Results indicate the occurrence of a wt.-controlling or reducing effect of small amounts of sucrose ingested several times per day

Source: International Journal of Food Sciences & Nutrition.60, (3):56-64, 2009

Regulation of cerebrospinal fluid production by caffeine consumption

Han, M. E.; Kim, H. J.; Lee, Y. S.; Kim, D. H.; Choi, J. T.; Pan, C. S.; Yoon, S.; Baek, S. Y.; Kim, B. S.; Kim,
J. B.; Oh, S. O.

Caffeine is the most commonly consumed psycho-stimulant in the world. The effects of caffeine on the body have been extensively studied; however, its effect on the structure of the brain has not been investigated to date. RESULTS: In the present study we found that the long-term consumption of caffeine can induce ventriculomegaly; this was observed in 40% of the study rats. In the caffeine-treated rats with ventriculomegaly, there was increased production of CSF, associated with the increased expression of Na(+), K(+)-ATPase and increased cerebral blood flow (CBF). In contrast to the chronic effects, acute treatment with caffeine decreased the production of CSF, suggesting 'effect inversion' associated with caffeine, which was mediated by increased expression of the A1 adenosine receptor, in the choroid plexus of rats chronically treated with caffeine. The involvement of the A1 adenosine receptor in the effect inversion of caffeine was further supported by the induction of ventriculomegaly and Na+, K+-ATPase, in A1 agonist-treated rats. CONCLUSION: The results of this study show that long-term consumption of caffeine can induce ventriculomegaly, which is mediated in part by increased production of CSF. Moreover, we also showed that adenosine receptor signaling can regulate the production of CSF by controlling the expression of Na(+), K(+)-ATPase and CBF

Source: BMC Neuroscience.10:110, 2009

Impact of serum caffeine monitoring on adverse effects and chemotherapeutic responses to caffeine-potentiated chemotherapy for osteosarcoma

Hayashi, K.; Tsuchiya, H.; Yamamoto, N.; Shirai, T.; Yamauchi, K.; Takeuchi, A.; Kawahara, M.; Miyamoto, K.; Tomita, K.

Caffeine can safely enhance the cytocidal effects of anticancer drugs through its DNA repair-inhibiting effect. We have demonstrated in several studies that caffeine-potentiated chemotherapy induces a high complete response rate in patients with osteosarcoma. The present study focused on monitoring and adjusting serum caffeine levels during caffeine-potentiated chemotherapy to reduce adverse effects. METHODS: We utilized a method for rapidly determining caffeine concentration by high¬performance liquid chromatography. The maximum caffeine concentration was predicted from the measured concentrations at 24 and 48 h after the beginning of caffeine administration. The caffeine infusion rate was then modified accordingly to prevent the expected final concentration from exceeding 80 microg/ml. The study involved 22 American Joint Committee on Cancer (AJCC) stage IIB high-grade osteosarcoma patients treated with caffeine-potentiated chemotherapy. Nine patients underwent monitoring of their serum caffeine levels (monitoring group), and the remaining 13 patients were not monitored (nonmonitoring group). Toxicities were graded according to the Japan Clinical Oncology Group Toxicity Criteria. RESULTS: Hematological toxic events were well tolerated in both groups. Grade 4 leukocyte toxicity events occurred in both groups. In the nonmonitoring group grade 2 or higher toxicities included 5 elevated aspartate aminotransferase/alanine aminotransferase level events and 17 hyponatremia events versus 1 hyponatremia event in the monitoring group. Histological examination of excised tumor samples after preoperative chemotherapy revealed that chemotherapeutic efficacy in the monitoring group was as good as in the nonmonitoring group. The median follow-up period in all patients was 72 months. Event-free survival was 76%, and overall survival was 100%. CONCLUSIONS: Monitoring and adjusting caffeine levels were achieved without apparent loss of chemotherapeutic efficacy

Source: Journal of Orthopaedic Science.14(3):253-8, 2009

Caffeine expectancy: instrument development in the Rasch measurement framework

Heinz, A. J.; Kassel, J. D.; Smith, E. V.

Although caffeine is the most widely consumed psychoactive drug in the world, the mechanisms associated with consumption are not well understood. Nonetheless, outcome expectancies for caffeine use are thought to underlie caffeine's reinforcing properties. To date, however, there is no available, sufficient measure by which to assess caffeine expectancy. Therefore, the current study sought to develop such a measure employing Rasch measurement models. Unlike traditional measurement development techniques, Rasch analyses afford dynamic and interactive control of the analysis process and generate helpful information to guide instrument construction. A 5-stage developmental process is described, ultimately yielding a 37-item Caffeine Expectancy Questionnaire (CEQ) comprised of 4 factors representing "withdrawal symptoms," "positive effects," "acute negative effects," and "mood effects." Initial evaluation of the CEQ yielded sufficient evidence for various aspects of validity. Although additional research with more heterogeneous samples is required to further assess the measure's reliability and validity, the CEQ demonstrates potential with regard to its utility in experimental laboratory research and clinical application.

Source: : Psychology of Addictive Behaviors.23(3):500-11, 2009 Sep

Caffeine and taurine enhance endurance performance

Imagawa, T. F.; Hirano, I.; Utsuki, K.; Horie, M.; Naka, A.; Matsumoto, K.; Imagawa, S

Caffeine enhances endurance performance; however, its effect on accumulated lactate remains unclear. Conversely, taurine, which also enhances endurance performance, decreases accumulated lactate. In this study, the effect of combination of caffeine and taurine on endurance performance was assessed. Mice ran on a treadmill, and the accumulated lactate was measured. In addition, muscle fibers from the gastrocnemius muscle of the mice were stained with ATPase and analyzed. The use of caffeine and taurine over a 2 week period enhanced endurance performance. Moreover, taurine significantly decreased the accumulated concentration of lactate over long running distances. However, the diameter of the cross-sections and ratios of Types I, IIA, and IIB muscle fibers were not affected

Source: International Journal of Sports Medicine.30(7):485-8, 2009 Jul

Coffee drinking in middle age is not associated with cognitive performance in old age

Laitala, V. S.; Kaprio, J.; Koskenvuo, M.; Raiha, I.; Rinne, J. O

The lack of effective disease-modifying treatments highlights the need for research on the prevention of dementia. It has been suggested that coffee has a protective effect on cognitive performance in old age, but only some of the previous studies have shown this association. OBJECTIVE: The aim of our study was to analyze the potential association between coffee drinking in middle age and cognitive performance in old age in a large sample of Finnish twins. DESIGN: Coffee consumption and other baseline variables of 2606 middle-aged Finnish twins were assessed in 1975 and 1981 by postal questionnaires. After the median follow-up of 28 y, their cognitive status was measured by using a validated telephone interview questionnaire. RESULTS: Coffee consumption was high and associated with educational level and several other baseline variables. After adjustment for these variables, linear regression analysis showed that coffee consumption was not an independent predictor of cognitive performance in old age ( beta = -0.12 test score units per coffee cup; 95% CI: -0.27, 0.04). No consistent differences in coffee consumption and cognitive score were observed within discordant twin pairs. Also, coffee drinking did not affect the risk of mild cognitive impairment or dementia. CONCLUSIONS: Coffee drinking is associated with many sociodemographic and health variables, but our results do not support an independent role of coffee in the pathogenesis of cognitive decline and dementia. (c)American Society for Nutrition.

Source: American Journal of Clinical Nutrition.90, (3):640-646, 2009

Mountain Dew or mountain don\'t?: a pilot investigation of caffeine use parameters and relations to depression and anxiety symptoms in 5th-and 10th-grade students

Luebbe, A. M.; Bell, D. J

Caffeine, the only licit psychoactive drug available to minors, may have a harmful impact on students' health and adjustment, yet little is known about its use or effects on students, especially from a developmental perspective. Caffeine use in 5th-and 10th-grade students was examined in a cross-sectional design, and relations and potential mediators of caffeine use to depression and anxiety symptoms were investigated. METHODS: Children (n = 135) and adolescents (n = 79) completed a measure of naturalistic use of caffeinated and noncaffeinated beverages. Furthermore, daily availability, perceived benefits, and stimulating, psychological, and withdrawal effects of caffeinated and noncaffeinated beverages were assessed. Measures of depression and anxiety were also administered. RESULTS: Fifth and 10th graders used caffeine frequently. Depression was positively related to caffeine use for both cohorts, though mediated by caffeine withdrawal effects. Surprisingly, anxiety was unrelated to use. Fifth graders reported less daily access to caffeine, but more psychological and stimulating effects of caffeine than 10th graders. CONCLUSIONS: Although both children and adolescents experience negative caffeine-related outcomes, intake is seemingly not greatly limited in either cohort. In particular, youth appear vulnerable to increased depressive symptoms with increasing caffeine consumption. Implications for school policy regarding students' caffeine use are discussed

Source: Journal of School Health.79(8):380-7, 2009 Aug.

Sensitivity to change in cognitive performance and mood measures of energy and fatigue in response to differing doses of caffeine or breakfast

Maridakis, V.; Herring, M. P.; O'Connor, P. J

This double-blind, placebo-controlled, within-subjects (N = 18) experiment compared the sensitivity to change of cognitive performance and mood measures of mental energy following consumption of either 100 or 200-mg caffeine or a 440-calorie breakfast. Breakfast and 200-mg caffeine improved mood and cognitive performance. The sensitivity to change of the measures did not differ in response to any treatment (all p values > .05). The mood and cognitive measures of mental energy used here have similar sensitivity to detecting change in response to a moderate dose of caffeine and breakfast consumption

Source: International Journal of Neuroscience.119(7):975-94, 2009

M. CYP1A2 genotype modifies the association between coffee intake and the risk of hypertension

Palatini, P.; Ceolotto, G.; Ragazzo, F.; Dorigatti, F.; Saladini, F.; Papparella, I.; Mos, L.; Zanata, G.; Santonastaso, M

The longitudinal relationship between coffee use and hypertension is still controversial. Cytochrome P450 1A2 (CYP1A2) is the main responsible enzyme for the metabolism of caffeine. The aim of the present study was to investigate the effect of coffee intake on the risk of developing hypertension needing antihypertensive treatment in individuals stratified by CYP1A2 genotype. DESIGN: We assessed prospectively 553 young White individuals screened for stage 1 hypertension. Coffee intake was ascertained from regularly administered questionnaires. Incident physician-diagnosed hypertension was the outcome measure. Genotyping of CYP1A2 SNP was performed by real time PCR. RESULTS: During a median follow-up of 8.2 years, 323 individuals developed hypertension. For carriers of the slow *1F allele (59%), hazard ratios of hypertension from multivariable Cox analysis were 1.00 in abstainers (reference), 1.72 (95%CI, 1.21-2.44) in moderate coffee drinkers (P = 0.03), and 3.00 (1.53-5.90) in heavy drinkers (P = 0.001). In contrast, hazard ratios for coffee drinkers with the rapid *1A/*1A genotype were 0.80 (0.52-1.23, P = 0.29) for moderate drinkers and 0.36 (0.14-0.89, P = 0.026) for heavy drinkers. In a two-way ANCOVA, a gene x coffee interactive effect was found on follow-up changes in systolic (P = 0.000) and diastolic (P = 0.007) blood pressure. Urinary epinephrine was higher in coffee drinkers than abstainers but only among individuals with slow *1F allele (P = 0.001). CONCLUSION: These data show that the risk of hypertension associated with coffee intake varies according to CYP1A2 genotype. Carriers of slow *1F allele are at increased risk and should thus abstain from coffee, whereas individuals with *1A/*1A genotype can safely drink coffee

Source: Journal of Hypertension.27(8):1594-601, 2009 Aug

Effects on sleep stages and microarchitecture of caffeine and its combination with zolpidem or trazodone in healthy volunteers

Paterson, L. M.; Nutt, D. J.; Ivarsson, M.; Hutson, P. H.; Wilson, S. J

Caffeine is the world's most popular stimulant and is known to disrupt sleep. Administration of caffeine
can therefore be used in healthy volunteers to mimic the effects of insomnia and thus to test the hypnotic effects of medication. This study assessed the effects of caffeine on sleep architecture and electroencephalography (EEG) spectrum alone and in combination with two different sleep-promoting medications. Home polysomnography was performed in 12 healthy male volunteers in a double-blind study whereby subjects received placebo, caffeine (150 mg), caffeine plus zolpidem (10 mg) and caffeine plus trazodone (100 mg) at bedtime in a randomised crossover design. In addition to delaying sleep onset, caffeine decreased total sleep time (TST), sleep efficiency (SE) and stage 2 sleep without significantly altering wake after sleep onset or the number of awakenings. Zolpidem attenuated the caffeine-induced decrease in SE and increased spindle density in the caffeine plus zolpidem combination compared with placebo. Trazodone attenuated the decrease in SE and TST, and it also increased stage 3 sleep, decreased the number of awakenings and decreased the spindle density. No significant changes in rapid eye movement (REM) sleep were observed, neither was any significant alteration in slow wave activity nor other EEG spectral measures, although the direction of change was similar to that previously reported for caffeine and appeared to 'normalise' after trazodone. These data suggest that caffeine mimics some, but not all of the sleep disruption seen in insomnia and that its disruptive effects are differentially attenuated by the actions of sleep-promoting compounds with distinct mechanisms of action

Source: Journal of Psychopharmacology.23(5):487-94, 2009 Jul

Characterisation of the effects of caffeine on sleep in the rat: a potential model of sleep disruption

Paterson, L. M.; Wilson, S. J.; Nutt, D. J.; Hutson, P. H.; Ivarsson, M

Caffeine is known to disrupt sleep and its administration to human subjects has been used to model sleep disruption. We previously showed that its effects on sleep onset latency are comparable between rats and humans. This study evaluated the potential use of caffeine as a model of sleep disruption in the rat, by assessing its effects on sleep architecture and electroencephalogram (EEG) frequency spectrum, and using sleep-promoting drugs to reverse these effects. Rats were implanted with radiotelemetry devices for body temperature, EEG, electromyogram and locomotor activity. Following recovery, animals were dosed with caffeine (10 mg/kg) alone or in combination with zolpidem (10 mg/kg) or trazodone (20 mg/kg). Sleep was scored for the subsequent 12 h using automated analysis software. Caffeine dose-dependently disrupted sleep: it increased WAKE time, decreased NREM (non-REM) sleep time and NREM bout duration (but not bout number), and decreased delta activity in NREM sleep. It also dose-dependently increased locomotor activity and body temperature. When given alone, zolpidem suppressed REM whilst trazodone increased NREM sleep time at the expense of WAKE, increased NREM bout duration, increased delta activity in NREM sleep and reduced body temperature. In combination, zolpidem attenuated caffeine's effects on WAKE, whilst trazodone attenuated its effects on NREM sleep, NREM bout duration, delta activity, body temperature and locomotor activity. Caffeine administration produced many of the signs of insomnia that were improved by two of its most successful current treatments. This model may therefore be useful in the study of new drugs for the treatment of sleep disturbance

Source: Journal of Psychopharmacology.23(5):475-86, 2009 Jul

Caffeine reduces resting-state BOLD functional connectivity in the motor cortex

Rack-Gomer, A. L.; Liau, J.; Liu, T. T.

In resting-state functional magnetic resonance imaging (fMRI), correlations between spontaneous low¬frequency fluctuations in the blood oxygenation level dependent (BOLD) signal are used to assess functional connectivity between different brain regions. Changes in resting-state BOLD connectivity measures are typically interpreted as changes in coherent neural activity across spatially distinct brain regions. However, this interpretation can be complicated by the complex dependence of the BOLD signal on both neural and vascular factors. For example, prior studies have shown that vasoactive agents that alter baseline cerebral blood flow, such as caffeine and carbon dioxide, can significantly alter the amplitude and dynamics of the task-related BOLD response. In this study, we examined the effect of caffeine (200 mg dose) on resting-state BOLD connectivity in the motor cortex across a sample of healthy
young subjects (N=9). We found that caffeine significantly (p<0.05) reduced measures of resting-state BOLD connectivity in the motor cortex. Baseline cerebral blood flow and spectral energy in the low-frequency BOLD fluctuations were also significantly decreased by caffeine. These results suggest that caffeine usage should be carefully considered in the design and interpretation of resting-state BOLD fMRI studies

Source: Neuroimage.46(1):56-63, 2009 May 15.

The efficacy of acetaminophen-caffeine compared to Ibuprofen in the control of postoperative pain after periodontal surgery: a crossover pilot study

Rashwan, W. A.

Previous studies showed that non-steroidal anti-inflammatory drugs (NSAIDs) have significant benefits in the control of pain after periodontal surgery. Acetaminophen (centrally acting NSAID) is believed to provide less analgesic efficacy than ibuprofen (centrally and peripherally acting NSAID). This study compared an alternative combination of acetaminophen, 500 mg, with caffeine, 30 mg, to ibuprofen, 400 mg, in pain management after periodontal surgeries. METHODS: A prospective, randomized, double-masked crossover clinical trial was conducted on 15 patients. Open flap debridement was performed on two quadrants with a 3-week interval in between. Each quadrant was randomly assigned to acetaminophen, 500 mg, with caffeine, 30 mg, or ibuprofen, 400 mg, immediately after surgery and 8 hours after the first dose. Postoperative pain was assessed during the first 8 hours and on the following day using the 101-point numeric rate scale (NRS-101) and the four-point verbal rating scale (VRS-4). RESULTS: Using the NRS-101, the acetaminophen-caffeine group showed statistically significantly lower mean pain scores than the ibuprofen group at 1 and 2 hours (P = 0.002), whereas at 6, 7, and 8 hours, the ibuprofen group showed statistically significantly lower mean pain scores (P <0.001). Using the VRS-4, there was no statistically significant difference between the two groups at all periods (P >0.05). CONCLUSION: Acetaminophen, 500 mg, with caffeine, 30 mg, can be used efficiently in controlling postoperative pain after open flap debridement, especially in patients with gastric ulcers or bleeding tendency because acetaminophen is less hazardous than ibuprofen

Source: Journal of Periodontology.80(6):945-52, 2009 Jun.

Acute caffeine ingestion and glucose tolerance in women with or without gestational diabetes mellitus

Robinson, L. E.; Spafford, C.; Graham, T. E.; Smith, G. N

Recent work showing that caffeine impairs glucose tolerance may be of particular concern in pregnancy because of a possible negative effect on fetal outcome. The current study sought to assess the effect of acute caffeine ingestion on glucose tolerance in women with or without gestational diabetes mellitus (GDM). METHODS: Nineteen women whose routine GDM test was negative (control) and eight women with an initial positive GDM screen completed two trials one week apart in a double-blind randomized crossover study. Following an overnight fast, subjects ingested caffeine (3 mg/kg pre¬pregnancy body weight) or an identical-appearing placebo (gelatin) capsule and one hour later began a 75 g 2-hour oral glucose tolerance test. RESULTS: In the control group, caffeine did not significantly affect blood glucose, insulin, or C-peptide. In the GDM group, glucose area under the curve (AUC) was greater (P < 0.01), C-peptide AUC was greater (P < 0.05), and insulin sensitivity index was lower (18%, P < 0.05) after caffeine than after placebo. CONCLUSION: Caffeine impaired insulin sensitivity in women with GDM. Additional research regarding more specific dietary caffeine recommendations for women with GDM is warranted

Source:  Journal of Obstetrics & Gynaecology Canada: JOGC.31(4):304-12, 2009 Apr  Full paper

The effect of a carbohydrate-caffeine sports drink on simulated golf performance

Stevenson, E. J.; Hayes, P. R.; Allison, S. J

A round of golf lasts approximately 4 h, during which time homeostasis could be challenged through either hypoglycemia or hypohydration. This might result in impaired motor skill or cognitive performance. Given the high cognitive demand of putting and the potential fatiguing effects from prolonged walking, the combination of a caffeine and carbohydrate drink could be beneficial in offsetting hypoglycemia and hypohydration. This study used a laboratory-simulated round of golf to examine the effect of an isotonic carbohydrate and caffeine sports drink on putting performance during a round of golf. After institutional ethics approval, 20 male golfers (mean +/-standard deviation: age 23 +/-4 years, stature 176.4 +/-5.6 cm, mass 72.8 +/-17.4 kg, handicap 15 +/-4, daily caffeine consumption 157.3 +/-47.2 mg) consumed either an isotonic sports drink containing caffeine (6.4 g carbohydrate and 16 mg caffeine per 100 mL) or a no-energy, flavour-matched placebo drink in a double-blind, randomized, counter-balanced crossover design . Drinks were consumed preround (5 mL.kg-1 body mass (BM)) and at holes 6 and 12 (2.5 mL.kg¬1 BM). Participants therefore consumed 1.6 mg.kg-1 BM of caffeine and 0.64 g.kg-1 BM of carbohydrate throughout the trial. Five and 2 m putting performance were assessed at each hole. Self-rated mood assessments were carried out every third hole. Putting performance over 5 m and 2 m and self-rated scores for alertness and relaxation showed a main effect for drink (p < 0.05). Ratings of mental fatigue and tiredness significantly increased during the round (p < 0.001). In experienced golfers, the consumption of an isotonic carbohydrate sports drink containing caffeine prior to and during a round of golf improved putting performance and increased feelings of alertness

Source: Applied Physiology, Nutrition, & Metabolism = Physiologie Appliquee, Nutrition et Metabolisme.34(4):681-8, 2009 Aug.

Dissociations between motor timing, motor coordination, and time perception after the administration of alcohol or caffeine

Terry, P.; Doumas, M.; Desai, R. I.; Wing, A. M

The impacts of psychoactive drugs on timing have usefully informed theories of timing and its substrates. OBJECTIVES: The objectives of the study are to test the effects of alcohol and caffeine on the explicit timing involved in tapping with the implicit timing observed in the coordinated picking up of an object, and with the temporal discrimination. MATERIALS AND METHODS: Participants in the "alcohol" experiment (N = 16) received placebo, "low" (0.12 g/kg or 0.14 g/kg for women/men, respectively) or "high" (0.37 g/kg or 0.42 g/kg, respectively) doses of alcohol, and those in the "caffeine" experiment (N = 16) received placebo, 200 or 400 mg caffeine. Time production variability was measured by repetitive tapping of specified intervals, and sources of variance attributable to central timer processes and peripheral motor implementation were dissociated. The explicit timing in tapping was compared with the implicit timing in the coordinated picking up of an object. Time perception was measured as discrimination thresholds for intervals of similar duration. Drug effects on reaction time were also measured. RESULTS: For tapping, alcohol significantly increased timer variability, but not motor variability; it did not affect coordination timing in the grip-lift task. Conversely, for time perception, the low dose of alcohol improved temporal discrimination. Caffeine produced no effects on any of the timing tasks, despite significantly reducing reaction times. CONCLUSIONS: The effects of alcohol argue against a common clock process underlying time interval perception and production in the range below 1 s. In contrast to reaction time measures, time perception and time production appear relatively insensitive to caffeine

Source: Psychopharmacology.202(4):719-29, 2009 Mar.

Effect of caffeine as an ergogenic aid during anaerobic exercise performance in caffeine naive collegiate football players

Woolf, K.; Bidwell, W. K.; Carlson, A. G

Research suggests that caffeine may improve performance in aerobic exercise; the evidence for anaerobic performance is mixed. This study examined the effect of caffeine (5 mg/kg body weight [BW]) vs. placebo on performance-based anaerobic exercise tests used during the National Football League (NFL) Combine. Collegiate football athletes (n = 17; 20 +/-2 yr; body mass index 29.4 +/-3.6 kg/m) completed 2 study visits, 1 week apart. Participants were low caffeine users with a reported average intake of 16 +/-20 mg/day. On the day of testing, participants ingested a caffeinated (5 mg/kg BW caffeine + 0.125 g/kg BW carbohydrate) or placebo (0.125 g/kg BW carbohydrate) beverage, ate a light meal, and completed 3 exercise tests (40-yard dash, 20-yard shuttle, and a bench press) 60 minutes later. Borg's rating of perceived exertion (RPE) was recorded after each exercise test. Heart rate (HR) and blood pressure (BP) were monitored (pre-exercise and postexercise). Data were analyzed using paired t-tests, Wilcoxon signed rank test, and repeated measures analysis of variance. No significant differences were found between treatments for the exercise tests (40-yard dash: 5.01 +/-0.25 vs. 5.03 +/-0.26 s, p = 0.43; 20-yard shuttle: 4.64 +/-0.19 vs. 4.66 +/-0.24 s, p = 0.51; bench press: 17 +/-8 vs. 17 +/-8 reps, p = 0.51; caffeine vs. placebo, respectively). However, 59% of the participants improved in performance with the caffeine during the bench press and the 40-yard dash. No differences were found between treatments for RPE, HR, and BP. Caffeine did not improve performance for anaerobic exercise tests used at the NFL Combine in caffeine naive male football athletes

Source: Journal of Strength & Conditioning Research.23(5):1363-9, 2009 Aug.

Uncovering multiple molecular targets for caffeine using a drug target validation strategy combining A 2A receptor knockout mice with microarray profiling

Yu, L.; Coelho, J. E.; Zhang, X.; Fu, Y.; Tillman, A.; Karaoz, U.; Fredholm, B. B.; Weng, Z.; Chen, J. F

Caffeine is the most widely consumed psychoactive substance and has complex pharmacological actions in brain. In this study, we employed a novel drug target validation strategy to uncover the multiple molecular targets of caffeine using combined A(2A) receptor (A(2A)R) knockouts (KO) and microarray profiling. Caffeine (10 mg/kg) elicited a distinct profile of striatal gene expression in WT mice compared with that by A(2A)R gene deletion or by administering caffeine into A(2A)R KO mice. Thus, A(2A)Rs are required but not sufficient to elicit the striatal gene expression by caffeine (10 mg/kg). Caffeine (50 mg/kg)
induced complex expression patterns with three distinct sets of striatal genes: 1) one subset overlapped with those elicited by genetic deletion of A(2A)Rs; 2) the second subset elicited by caffeine in WT as well as A(2A)R KO mice; and 3) the third subset elicited by caffeine only in A(2A)R KO mice. Furthermore, striatal gene sets elicited by the phosphodiesterase (PDE) inhibitor rolipram and the GABA(A) receptor antagonist bicucullin, overlapped with the distinct subsets of striatal genes elicited by caffeine (50 mg/kg) administered to A(2A)R KO mice. Finally, Gene Set Enrichment Analysis reveals that adipocyte differentiation/insulin signaling is highly enriched in the striatal gene sets elicited by both low and high doses of caffeine. The identification of these distinct striatal gene populations and their corresponding multiple molecular targets, including A(2A)R, non-A(2A)R (possibly A(1)Rs and pathways associated with PDE and GABA(A)R) and their interactions, and the cellular pathways affected by low and high doses of caffeine, provides molecular insights into the acute pharmacological effects of caffeine in the brain

Source: Physiological Genomics.37(3):199-210, 2009 May 13.

Alcohol and coffee drinking and smoking habit among subjects with HCV infection

Zani, C.; Donato, F.; Chiesa, M.; Baiguera, C.; Gelatti, U.; Covolo, L.; Antonini, M. G.; Nasta, P.; Gatti, F.; Orizio, G.; Puoti, M.

The aims were to estimate among patients with hepatitis C virus (HCV) infection the prevalence of alcohol and coffee intake and smoking habit, the reliability of these self-reported data and the possible change of patients' habit after their first contact with a Viral Hepatitis Service. METHODS: 229 patients were initially interviewed personally at the Viral Hepatitis Service and after 6 months they were re-interviewed by phone in regard to their alcohol, coffee drinking and smoking habits. RESULTS: Alcohol drinkers were 55.5% of males and 35.3% of females. Most subjects drank coffee daily, both men (90.0%) and women (84.9%). The proportion of current smokers was higher in males (43.6%) than females (26.9%). We found a fair to good reliability of self-reported data regarding patients' habits, alcohol and coffee intake, and number of cigarettes smoked daily. We observed a statistically significant decrease in alcohol and coffee intake and cigarettes smoked between baseline and follow-up interviews. CONCLUSION: We found a fairly high proportion of HCV-infected patients who regularly drink alcohol and coffee beverages and smoke cigarettes, especially among males. The reliability of self¬reported data on these habits seems satisfactory. More decisive action to modify these habits, especially alcohol intake, is required in these patients

Source: Digestive & Liver Disease.41(8):599-604, 2009 Aug