Palacios-Cabrera, H. A.; Menezes, H. C.; Iamanaka, B. T.; Canepa, F.; Teixeira, A. A.; Carvalhaes, N.; Santi, D.; Leme, P. T.; Yotsuyanagi, K.; Taniwaki, M. H.
Changes in temperature, relative humidity, and moisture content of green coffee beans were monitored during transportation of coffee from Brazil to Italy. Six containers (three conventional and three prototype) were stowed in three different places (hold, first floor, and deck) on the ship. Each prototype was located next to a conventional container. The moisture content of the coffee in the container located on the first floor was less affected by environmental variations (0.7%) than that in the hold and on the deck. Coffee located in the hold showed the highest variation in moisture content (3%); in addition, the container showed visible condensation. Coffee transported on the deck showed an intermediary variation in moisture (2%), and there was no visible condensation. The variation in coffee moisture content of the prototype containers was similar to that of the conventional ones, especially in the top layers of coffee bags (2 to 3%), while the increase in water activity was 0.70. This suggests that diffusion of moisture occurs very slowly inside the cargo and that there are thus sufficient time and conditions for fungal growth. The regions of the container near the wall and ceiling are susceptible to condensation since they are close to the headspace with its high relative humidity. Ochratoxin A production occurred in coffee located at the top of the container on the deck and in the wet bags from the hold (those found to be wet on opening the containers at the final destination).
Azevedo-Pereira, R.; Nogueira-Batista, J. A.; da Silva, M. C.; Brilhante-de-Oliveira-Neto, O.; Zangrando-Figueira, E. L.; Valencia-Jimenez, A.; Grossi-de-Sa, M. F.
Plant alpha-amylase inhibitors are proteins found in several plants, and play a key role in natural defenses. In this study, a gene encoding an alpha-amylase inhibitor, named alphaAI-Pc1, was isolated from cotyledons of Phaseolus coccineus. This inhibitor has an enhanced primary structure to P. vulgaris alpha-amylase inhibitors (alpha-AI1 and alpha-AI2). The alphaAI-Pc1 gene, constructed with the PHA-L phytohemaglutinin promoter, was introduced into tobacco plants, with its expression in regenerated (T0) and progeny (T1) transformant plants monitored by PCR amplification, enzyme-linked immunosorbent assay (ELISA) and immunoblot analysis, respectively. Seed protein extracts from selected transformants reacted positively with a polyclonal antibody raised against alphaAI-1, while no reaction was observed with untransformed tobacco plants. Immunological assays showed that the alphaAI-Pc1 gene product represented up to 0.05% of total soluble proteins in T0 plants seeds. Furthermore, recombinant alphaAIPc1 expressed in tobacco plants was able to inhibit 65% of digestive H. hampei alpha-amylases. The data herein suggest that the protein encoded by the alphaAI-Pc1 gene has potential to be introduced into coffee plants in order to increase their resistance to the coffee berry borer.
Chen, Z.; Liang, J.; Zhang, C.; Rodrigues, C.-J. Jr
Colletotrichum kahawae is the causal agent of coffee berry disease. Appressorial melanization is essential for the fungal penetration of plant cuticle. Epicatechin is abundant in green coffee berry pericarp. Inoculation of C. kahawae conidial suspension containing 1.2 mg epicatechin or catechin/ml did not affect conidial germination or appressorial formation but appressorial melanization was completely inhibited and infection by the treated conidia was less than 30% of the untreated control. Epicatechin and catechin may, therefore, prevent coffee berry disease by inhibition of the appressorial melanization of C. kahawae.
Lopes, S. A.; Torres, S. C.
Buffered charcoal-yeast extract medium (BCYE) has been used for isolation of Xylella fastidiosa from citrus (Citrus sinensis) and coffee (Coffea arabica) plants affected by citrus variegated chlorosis (CVC) and coffee leaf scorch (CLS). BCYE is composed of ACES (2-[2-amino-2oxoethyl) amino]-ethanesulfonic acid) buffer, activated charcoal, yeast extract, L-cysteine, ferric pyrophosphate, and agar. ACES buffer is costly and not always commercially available in Brazil, and the L-cysteine and ferric pyrophosphate need to be filter sterilized in 0.22-mum pore membranes before inclusion in the medium. Omission of Lcysteine, addition of magnesium sulfate, and replacements of ACES and ferric pyrophosphate for potassium phosphate and ferrous sulfate resulted in an effective, less expensive, and entirely autoclavable medium, named phosphate buffered charcoal-yeast extract medium (PCYE). The final cost of PCYE was approximately one tenth that of BCYE. Its effectiveness was tested for the isolation of X. fastidiosa from symptomatic leaves collected from 52 citrus plants affected by CVC and 43 coffee plants affected by CLS. PCYE was as effective as BCYE and has been used routinely in our and other laboratories for isolation, growth, and quantification of X. fastidiosa from plant tissues.
Sibanda, L.
Control of mycotoxin formation, especially ochratoxin A, in green coffee beans is discussed with respect to: causes of contamination of beans during harvesting; primary coffee cherry processing in the country of origin using either the wet or dry method and the development of ochratoxin A contamination; mould growth and development of mycotoxins during storage; European ochratoxin A regulations for coffee; and the need for importers to screen green coffee for ochratoxin A before mixing batches of beans and roasting.
Source : Tea and Coffee Trade Journal 2006 vol.178 (1), pp 3
Samson, N.; Bausher, M. G.; Lee, S. B.; Jansen, R. K.; Daniell, H.
The chloroplast genome sequence of Coffea arabica L., the first sequenced member of the fourth largest family of angiosperms, Rubiaceae, is reported. The genome is 155 189 bp in length, including a pair of inverted repeats of 25,943 bp. Of the 130 genes present, 112 are distinct and 18 are duplicated in the inverted repeat. The coding region comprises 79 protein genes, 29 transfer RNA genes, four ribosomal RNA genes and 18 genes containing introns (three with three exons). Repeat analysis revealed five direct and three inverted repeats of 30 bp or longer with a sequence identity of 90% or more. Comparisons of the coffee chloroplast genome with sequenced genomes of the closely related family Solanaceae indicated that coffee has a portion of rps19 duplicated in the inverted repeat and an intact copy of infA. Furthermore, whole-genome comparisons identified large indels (> 500 bp) in several intergenic spacer regions and introns in the Solanaceae, including trnE (UUC)-trnT (GGU) spacer, ycf4-cemA spacer, trnI (GAU) intron and rrn5-trnR (ACG) spacer. Phylogenetic analyses based on the DNA sequences of 61 protein-coding genes for 35 taxa, performed using both maximum parsimony and maximum likelihood methods, strongly supported the monophyly of several major clades of angiosperms, including monocots, eudicots, rosids, asterids, eurosids II, and euasterids I and II. Coffea (Rubiaceae, Gentianales) is only the second order sampled from the euasterid I clade. The availability of the complete chloroplast genome of coffee provides regulatory and intergenic spacer sequences for utilization in chloroplast genetic engineering to improve this important crop.
Almeida, A. A. P.; Farah, A.; Silva, D. A. M.; Nunan, E. A.; Gloria, M. B. A.
Antimicrobial activity has been attributed to coffee and, in this study, the antibacterial activity of coffee extracts and chemical compounds on microorganisms relevant to human health was examined. The coffee extracts and compounds examined showed antimicrobial activity for the enterobacteria investigated. Results indicated that caffeine, chlorogenic acid and protocatechuic acid had a strong effect against Serratia marcescens and Enterobacter cloacae. The authors conclude that trigonelline, caffeine and protocatechuic acids are potential natural antimicrobials against Salmonella enterica.
Gomes-Junior, R. A.; Moldes, C. A.; Delite, F. S.; Pompeu, G. B.; Gratao, P. L.; Mazzafera, P.; Lea, P. J.; Azevedo, R. A.
The antioxidant responses of coffee (Coffea arabica L.) cell suspension cultures to cadmium (Cd) were investigated. Cd accumulated very rapidly in the cells and this accumulation was directly correlated with an increase in applied CdCl(2) concentration in the external medium. At 0.05mM CdCl(2), growth was stimulated, but at 0.5mM CdCl(2), the growth rate was reduced. An alteration in activated oxygen metabolism was detected by visual analysis as well as by an increase in lipid peroxidation at the higher CdCl(2) concentration. Catalase (CAT; EC 1.11.1.6), glutathione reductase (GR; EC 1.6.4.2) and superoxide dismutase (SOD; EC 1.15.1.1) activity increased, particularly at the higher concentration of CdCl(2). Ascorbate peroxidase (APX; EC 1.11.1.11) activity was increased at the lower CdCl(2) concentration used, but could not be detected in cells growing in the higher CdCl(2) concentration after 24h of growth, whilst guaiacol peroxidase (GOPX; EC 1.11.1.7) did not show a clear response to Cd treatment. An analysis by non-denaturing PAGE followed by staining for enzyme activity, revealed one CAT isoenzyme, nine SOD isoenzymes and four GR isoenzymes. The SOD isoenzymes were differently affected by CdCl(2) treatment and one GR isoenzyme was shown to specifically respond to CdCl(2). The results suggest that the higher concentrations of CdCl(2) may lead to oxidative stress. The main response appears to be via the induction of SOD and CAT activities for the removal of reactive oxygen species (ROS), and by the induction of GR to ensure the availability of reduced glutathione for the synthesis of Cd-binding peptides, which may also be related to the inhibition of APX activity probably due to glutathione and ascorbate depletion.
Osses, L. R.; Godoy, C. A.
Early intercellular signaling in Coffea arabica L.-Hemileia vastatrix host-pathogen interaction was studied, using inside-out plasma membrane from two varieties of coffee leaf and a fungal fraction to determine the plant's biochemical responses. Microsomal pellets (100,000 x g) from the susceptible (Caturra) and resistant (Colombia) coffee leaf varieties were purified by partitioning in two-polymer DEX (6.3% w/w) and PEG (6.3% w/w) system aqueous phase. Fungal material was obtained from orange rust Hemileia vastatrix Berk and Br. race II urediospore germ tubes. Plasma membrane vesicles were preferentially localized to PEG phase, as indicated by its enzyme marker distribution. Both H(+)-ATPase activities displayed similar kinetic and biochemical characteristics, comparable to those described for P-type ATPases. Several enzymes may play pivotal roles in plants regarding early interaction with fungal elicitors. Studies of fungal fractions' effects on H(+)-ATPase and both varieties' proton pumping activities were thus carried out. Concentration as low as 0.1 Gluc eq. ml(-1) fungal fraction induced specific inhibition of H(+)-ATPase and the resistant variety's proton pumping activities. The present work describes characterizing the H(+)-ATPase plasma membrane from two Coffea arabica L. varieties (Caturra and Colombia) for the first time and the race specific inhibitory effect of a crude fungal fraction on both H(+)-ATPase and the resistant variety's proton pumping activities.
Source : Plant Physiol Biochem 2006 vol.44 (4), pp 226 - 235
Wu, F.; Mueller, L. A.; Crouzillat, D.; Petiard, V.; Tanksley, S. D.
We report herein the application of a set of algorithms to identify a large number (2869) of single-copy orthologs (COSII), which are shared by most, if not all, euasterid plant species as well as the model species Arabidopsis. Alignments of the orthologous sequences across multiple species enabled the design of "universal PCR primers," which can be used to amplify the corresponding orthologs from a broad range of taxa, including those lacking any sequence databases. Functional annotation revealed that these conserved, single-copy orthologs encode a higher-than-expected frequency of proteins transported and utilized in organelles and a paucity of proteins associated with cell walls, protein kinases, transcription factors, and signal transduction. The enabling power of this new ortholog resource was demonstrated in phylogenetic studies, as well as in comparative mapping across the plant families tomato (family Solanaceae) and coffee (family Rubiaceae). The combined results of these studies provide compelling evidence that (1) the ancestral species that gave rise to the core euasterid families Solanaceae and Rubiaceae had a basic chromosome number of x=11 or 12.2) No whole-genome duplication event (i.e., polyploidization) occurred immediately prior to or after the radiation of either Solanaceae or Rubiaceae as has been recently suggested.
Zhenjia, Chen; Franco, C. F.; Baptista, R. P.; Cabral, J.-M. S.; Coelho, A. V.; Rodrigues, C. J., Jr.; Melo, E. P.
Colletotrichum kahawae is the causal agent of coffee berry disease, infecting leaves and coffee berries at any stage of their development. C. gloeosporioides is the causal agent of brown blight, infecting ripe berries only. Both fungi secrete the same pattern of carboxylesterases to the fermentation broth when cutin is used as a C source. Using 2 different strategies composed of 2 precipitation steps (ammonium sulfate and acetic acid precipitation) and 2 chromatographic steps, 2 proteins displaying carboxylesterase activity were purified to electrophoretic homogeneity. One, with a mol. wt. of 21 kDa, had a blocked N terminus and was identified as cutinase by peptide mass fingerprint and MS-MS data acquired after peptide derivatization with 4-sulfophenyl isothiocyanate. The second, with a mol. wt. of 40 kDa, displayed significant carboxylesterase activity on tributyrin but low activity on p-nitrophenyl butyrate. N-terminal sequencing for this protein did not reveal any homology to other carboxylesterases. The 2 enzymes, which were secreted by both fungi, appear to be homologous.
Source : Appl Microbiol Biotechnol 2006 vol.73 (6), pp 1306 - 1313
Boeneke, C. A.; McGregor, J. U.; Aryana, K. J.
The objective of this study was to evaluate the effects of coffee bean roast on the acceptability of a dairy-based espresso drink. Espresso coffee was made from freshly ground coffee beans with lightmedium roast, intermediate roast (between medium and dark) and dark French roast in order to evaluate the influence of roasting on flavour. Samples were prepared by blending skim milk, soft-serve ice cream mix, ice and fresh espresso extracts. No significant differences (P < 0.05) were detected in TS and fat contents among treatments. Viscosity for the light-medium roasted beverage was significantly (P < 0.05) higher than that of the others. Beverage pH increased with increased darkening of roast. Beverage made with the light-medium roasted coffee had significantly (P < 0.05) higher preference scores for coffee flavour and overall flavour than beverages made with the intermediate and French roasts. The intermediate and French roasted treatments were shown to generate a more intense coffee flavour. However, consumers in this study preferred a less intense coffee flavour.
de Ferran, F.; Grunert, K. G.
The growth in fair trade products has been linked with consumers' interest in ethical trading and sustainability. This survey (using a means-end chain analysis approach) of 54 French consumers examined the motives and values that drive them to purchase fair trade coffee. Consumer attributes to fair trade coffee, the principal means-end chains and hierarchical value maps are presented. Purchase motivation was affected by the type of store in which consumers shopped. For example, supermarket shoppers were motivated by a desire to protect the environment and participate in alternative economy. Knowledge of the factors that influence purchasing decisions could be used to develop marketing strategies for fair trade products.
Source : Food Qual Pref 2007 vol. 18 (2), pp 218-229
Pittia, P.; Nicoli, M. C.; Sacchetti, G.
Effect of moisture and aw on the texture of raw and roasted (light, medium and dark) coffee beans was investigated. Water-coffee interactions were described by the sorption isotherm, and the mechanical properties of the samples equilibrated in the 0-0.95 aw range were studied by uniaxial compression. Roasted beans presented a lower strength and toughness than raw ones and, independently from roasting, resulting textural properties were highly dependent on aw. At increasing hydration degree, an increase in strength and toughness was observed until a critical aw value, different for raw (0.75) and roasted (approx. 0.86) beans which was related to water content, was reached. This was a plasticization effect. Above these critical aw values, a progressive softening of the bean matrix occured. In roasted coffee beans, this plasticization determined the loss of the characteristic brittleness. The critical aw value, above which plasticization occurred, was determined by modelling the compressive modulus using the Fermi's distribution function.
Nebesny, E.; Budryn, G.
Robusta coffee beans with varying initial moisture contents (5, 7.5 and 10%) were convectively roasted at 230°C, microwaved at 700 W, and roasted by the coupled convective-microwave method. Sensory attributes of brews prepared from these coffee samples were evaluated. Final temp. of microwaved coffee beans was lower than that of the beans processed by the 2 other methods, which resulted in a higher content of volatile aroma compounds and a lesser degree of charring of their surface. Lower initial humidity of coffee beans shortened the time of roasting. However, the aroma developed upon roasting of the moistest beans was the most intense and pleasant. Modification of roasting conditions increased shifting of the overall acceptability of coffee infusions by 2 points in a 10-point hedonic scale, which implies that, if roasting conditions are adequate to the type of coffee, its sensory properties can be improved. Thus, results suggest that optimization of roasting parameters can increase the share of robusta in well-accepted commercial coffee blends, a convenient fact because of the significant difference in price between the latter and arabica coffee.
Source : Eur Food Res Technol 2006 vol.224 (2), pp 159 - 165
Ross, C. F.; Pecka, K.; Weller, K.
This study sought to determine how long ground coffee beans could be stored at room and freezing temp. before sensory changes could be detected, and to identify specific attribute changes associated with this storage. Ground beans were stored for 0 (fresh), 1, 2 and 3 wk at room and freezing temp. Coffee was prepared from each of these treatments and difference testing was performed. Paired comparison tests were conducted on the fresh, 1- and 2-wk-stored coffee grounds to examine coffee aroma, flavour, bitterness and overall preference. At room temp. storage, results indicated significant (P < 0.05) differences in the coffee prepared from fresh vs. the 2-wk-stored ground beans. Coffee made from freshly ground beans had a stronger coffee aroma, was less bitter and was more preferred compared with the beans stored for 1 or 2 wk (P < 0.05). At freezer storage, differences were detected between coffee prepared from coffee grounds stored for 1 or 2 wk. Coffee prepared from grounds stored for 2 wk had a stronger coffee aroma and was more bitter compared with the other storage times (P < 0.05) .
Rovira, D. de
The development of flavour in coffee is discussed with special reference to flavours developed during roasting. Aspects considered include: effect of soil type and climate on flavour development; flavours developed naturally by chemical reactions involving carbohydrates and fats in the coffee bean; flavour development during the bean ripening process; and flavour development during the endothermic and exothermic phases of roasting
Source : Tea and Coffee Trade Journal 2006 vol.178 (7), pp 3
Bekedam, E. K.; De Laat, M. P.; Schols, H. A.; Van Boekel, M. A.; Smit, G.
The charge properties of melanoidins in high molecular weight (HMw) coffee brew fractions, isolated by diafiltration and membrane dialysis, were studied. Ion exchange chromatography experiments with the HMw fractions showed that coffee brew melanoidins were negatively charged whereas these molecules did not expose any positive charge at the pH of coffee brew. Fractions with different ionic charges were isolated and subsequently characterized by means of the specific extinction coefficient (K(mix 405nm)), sugar composition, phenolic group content, nitrogen content, and the arabinogalactan protein (AGP) specific Yariv gel-diffusion assay. The isolated fractions were different in composition and AGP was found to be present in one of the HMw fractions. The AGP accounted for 6% of the coffee brew dry matter and had a moderate negative charge, probably caused by the presence of uronic acids. As the fraction that precipitated with Yariv was brown (K(mix 405nm) = 1.2), compared to a white color in the green bean, it was concluded that these AGPs had undergone Maillard reaction resulting in an AGP-melanoidin complex. The presence of mannose (presumably from galactomannan) indicates the incorporation of galactomannans in the AGP-melanoidin complex. As the uronic acid content in the more negatively charged melanoidin-rich, AGP-poor HMw fractions decreased, it was hypothesized that acidic groups are formed or incorporated during melanoidin formation.
Parras, P.; Martinez-Tome, M.; Jimenez, A. M.; Murcia, M. A.
The antioxidant capacity of coffees (Arabica and Robusta) from 12 different points of origin (Uganda, Papua, Jamaica, Ethiopia, Kenya, Puerto Rico, 'Caracolillo' Puerto Rico, Nicaragua, Colombia, Vietnam, Brazil and Guatemala) and two decaffeinated coffees from Colombia and Brazil prepared by three commonly used procedures (espresso, filter and Italian) were evaluated and compared with antioxidant standards and other phenolic compounds which have been described in coffee. All the coffees studied were very effective as scavengers of lipoperoxyl and OH. radicals. The results also showed that there are no significant differences (P < 0.05) between the three ways of brewing (espresso, filter and Italian). The H2O2 scavenging capacity was analysed in freshly made coffee and 6 h later, the antioxidant activity slightly increasing with time. The filtered coffee showed a greater capacity to react with H2O2 (P < 0.05) than the Italian and espresso coffees. All the coffee samples improved the oxidative stability of butter (Rancimat test), espresso and Italian coffee providing greater protection (P < 0.05) than the filtered beverages. The coffee beverages from different origins did not show significant differences during 28 days of storage as regards the autoxidation of linoleic acid. However, filter brews produced stronger antioxidant activity (P < 0.05) during storage than espresso and Italian brewing techniques. The TEAC value provided a ranking in decreasing order of antioxidant capacity for samples at 6 min: Vietnam, Uganda, Nicaragua, Colombia, Brazil, 'Caracolillo', Puerto Rico, Guatemala, Kenya, Papua, decaffeinated Colombia, Ethiopia, Jamaica, and decaffeinated Brazil. In general, decaffeinated coffees (Colombia and Brazil) showed lower TEAC values than coffees with caffeine. Filter and Italian coffee analysed after 6 min exhibited higher TEAC value than espresso coffees. All the coffees studied are good antioxidants regardless of their cost, origin and way in which they are brewed (espresso, filter or Italian), which is a point worth considering. All rights reserved, Elsevier.
Anon.
Minutes of the 38th session of the Codex Committee on Food Additives and Contaminants, held in The Hague, Netherlands, on 24-28 April 2006, are reported. Agenda items considered include: endorsement and/or revision of max. levels for food additives, processing aids and contaminants in Codex standards; the Codex General Standard for Food Additives; an updated inventory of processing aids; the international numbering system for food additives; specifications for identity and purity of food additives; a discussion paper on development of guidelines for flavouring agents; the Codex General Standard for Contaminants and Toxins in Foods, including a report by the ad hoc Working Group on Contaminants and Toxins in Foods; mycotoxins in food and feed (draft proposed regulations and discussion papers on aflatoxins in raw and processed nuts, ochratoxin in wine, coffee and cocoa, and deoxynivalenol); various contaminants in foods (MRL for Pb in fish, MRL for Cd, proposed draft MRL for 3-MCPD in liquid condiments and Sn, proposed codes of practice for reducing dioxin and PCB contamination in foods and formation of chloropropanols in hydrolysed vegetable protein, proposed draft revised levels for radionuclides and discussion papers on PAH and acrylamide); and the priority list of food additives and contaminants proposed by the Joint Expert Committee for Food Additives (JECFA). 33 appendices are included containing a list or participants and the proposed documents discussed.
This report is available, in En, Fr and Es, from the Codex Alimentarius website.
Nebesny, E.; Budryn, G.
Effects of roasting method (convective heating at 230°C or microwaving at 700 W) and moisture content before roasting (5.0, 7.5 or 10.0%) on lipid content of coffee beans, lipid degradation (changes in iodine, peroxide and saponification values) and deterioration of lipid quality during storage of ground vacuum packaged coffee samples for up to 6 months were investigated. Lipid content decreased during roasting, the decrease being greatest for the samples with low initial moisture content. Lipid quality deteriorated during roasting and aldehydes formed by autoxidation of fatty acids appeared. Lipid degradation was greater for convective roasting and low initial moisture content. Microwave roasting of the relatively high-moisture coffee beans gave the least decrease in lipid content and quality. Storage of the ground vacuum packaged coffee resulted in further deterioration of lipid quality .
Source : Deutsche Lebensmittel Rundschau 2006 vol.102(12), pp 547 - 554 (not available on line)
Nebesny, E.; Budryn, G.
Coffee beans were analysed for free radicals using ESR spectroscopy. Effects of roasting method (convective roasting or microwaving) and initial moisture content of the coffee beans (5-10%) on free radical generation and changes in free radical contents during storage of roasted ground coffee In vacuum packs for 6 months were investigated. Concn. of free radicals increased considerably during roasting. Roasting method had little effect on free radical formation. Free radical formation was greater in coffee beans with low initial moisture content; free radical content remained higher during storage in coffee samples prepared from beans with a low initial moisture content.
Source : Deutsche Lebensmittel Rundschau 2006 vol.102 (11), pp 526 - 530 (not available on line)
Baker, J. A.; Boakye, K.; McCann, S. E.; Beehler, G. P.; Rodabaugh, K. J.; Villella, J. A.; Moysich, K. B.
The goal of this study was to investigate the associations between ovarian cancer risk and usual consumption of black tea, regular coffee, or decaffeinated coffee. Using a hospital-based case-control design, participants included 414 women with primary epithelial ovarian, fallopian, or peritoneal cancer and 868 age- and region-matched women with nonneoplastic conditions. All participants completed a comprehensive epidemiologic questionnaire. Black tea consumption was associated with a linear decline in ovarian cancer risk (P for trend 0.03), with individuals consuming two or more cups daily experiencing a 30% decline in risk (adjusted OR 0.70, 95% CI 0.51-0.97). Similar declines were noted among individuals consuming two or more cups of decaffeinated coffee daily (adjusted OR 0.71, 95% CI 0.51-0.99; P for trend 0.002). However, no association was noted between any level of regular coffee consumption and risk of ovarian cancer. The chemoprotective effects of phytochemicals in black tea and decaffeinated coffee may be important, although the effects of phytochemicals in regular coffee may be counteracted by the elevated risk associated with its higher caffeine content.
Cheng, H. Y.
Introduction : Pereira and colleagues found that coffee consumption, especially decaffeinated, was independently associated with lower risk of type 2 diabetes mellitus after adjusting many confounders in postmenopausal women. In Table 3 of their article, there were 104 cases of type 2 diabetes mellitus among heavy coffee drinkers (ie, total coffee 6 cups per day). The number of cases declined further when decaffeinated coffee was analyzed separately. Considering the large number of study participants (n = 28 812) during the 11 years of follow-up,1 the absolute contribution of coffee intake to the risk of type 2 diabetes mellitus could be minimum. Therefore, at this point, encouraging coffee intake might not become a very popular recommendation. However, their study is a big step in exploring the potential benefit of coffee consumption in reducing the risk of type 2 diabetes mellitus, an epidemic disease.
Clemens, R.; Coughlin, J.
Health benefits that may be associated with coffee consumption are discussed, including reduced risk of type 2 diabetes, cancer, liver disease, Parkinson's disease and cardiovascular disease.
Cureton, K. J.; Warren, G. L.; Millard-Stafford, M. L.; Wingo, J. E.; Trilk, J.; Buyckx, M.
This double-blind experiment examined the effects of a caffeinated sports drink during prolonged cycling in a warm environment. 16 highly trained cyclists completed 3 trials: placebo, carbohydrate electrolyte sports drink (CES), and caffeinated sports drink (CES+CAF). Subjects cycled for 135 min, alternating between 60% and 75% VO2max every 15 min for the 1st 120 min, followed by a 15-min performance ride. Max. voluntary (MVC) and electrically evoked contractile properties of the knee extensors were measured before and after cycling. Work completed during the performance ride was 15-23% greater for CES+CAF than for the other beverages. Ratings of perceived exertion were lower with CES+CAF than with placebo and CES. After cycling, the MVC strength loss was two-thirds less for CES+CAF than for the other beverages (5 vs. 15%). Data from the interpolated-twitch technique indicated that attenuated strength loss with CES+CAF was explained by reduced intrinsic muscle fatigue.
Dall'Igna, O. P.; Fett, P.; Gomes, M. W.; Souza, D. O.; Cunha, R. A.; Lara, D. R.
Consumption of caffeine, an adenosine receptor antagonist, was found to be inversely associated with the incidence of Alzheimer's disease. Moreover, caffeine protects cultured neurons against beta-amyloidinduced toxicity, an effect mimicked by adenosine A(2A) but not A(1) receptor antagonists. We now tested if caffeine administration would prevent beta-amyloid-induced cognitive impairment in mice and if this was mimicked by A(2A) receptor blockade. One week after icv administration of the 25-35 fragment of betaamyloid (Abeta, 3 nmol), mice displayed impaired performance in both inhibitory avoidance and spontaneous alternation tests. Prolonged treatment with caffeine (1 mg/ml) had no effect alone but prevented the Abeta-induced cognitive impairment in both tasks when associated with acute caffeine (30 mg/kg) 30 min treatment before Abeta administration. The same protective effect was observed after subchronic (4 days) treatment with daily injections of either caffeine (30 mg/kg) or the selective adenosine A(2A) receptor antagonist SCH58261 (0.5 mg/kg). This provides the first direct in vivo evidence that caffeine and A(2A) receptor antagonists afford a protection against Abeta-induced amnesia, which prompts their interest for managing Alzheimer's disease.
Hirose, K.; Niwa, Y.; Wakai, K.; Matsuo, K.; Nakanishi, T.; Tajima, K.
Coffee has become a popular beverage worldwide. Caffeine, a major ingredient of coffee, has been proposed to have a favorable affect on the modulation of circulating estrogen levels and therefore may be of importance in developments on hormone-related cancers. However, epidemiological evidence is limited and inconsistent. We examined the relationship between intake of coffee and hormone-related cancer risk among Japanese women using data from the hospital-based epidemiological research program at Aichi Cancer Center (HERPACC). In total, 2122 breast, 229 endometrial and 166 ovarian cancer cases were included, and 12 425 women, confirmed as free of cancer, were recruited as the control group. Odds ratios (OR) and 95% confidence intervals (95% CI) were determined by multiple logistic regression analysis. A statistically significant inverse association between risk of endometrial cancer and coffee consumption was noted in Japanese women, with no clear association evident for breast and ovarian cancer risk. Compared to non-drinker, the OR of daily drinking of 1-2 cups and 3 or more cups per day for endometrial cancer were 0.64 (95% CI: 0.43-0.94) and 0.41 (95% CI: 0.19-0.87), respectively, and the linear trend was also statistically significant (P < 0.01). However, there was no statistically significant association between caffeine intake and endometrial cancer. In summary, the results of the present study suggest that coffee consumption reduces the risk of endometrial cancer in Japanese subjects. Given the scarcity of studies of coffee intake and endometrial cancer and other hormone-dependent cancer risk, additional investigations are warranted.
Source : Cancer Sci vol.98 (3), pp 411 - 415
Mascitelli, L.; Pezzetta, F.; Sullivan, J. L.
Introduction : Pereira and colleagues found an inverse association between coffee consumption and the risk of type 2 diabetes mellitus. Because this relation was stronger for decaffeinated coffee intake, it is likely that constituents other than caffeine are involved in this beneficial association. We suggest that some of the involved mechanisms might be related to inhibition of iron absorption by polyphenol compounds present in coffee, be it regular coffee or decaffeinated coffee. The main phenolic compound in coffee, chlorogenic acid, is a potent inhibitor of nonheme iron absorption. Hurrell et al. report that the polyphenolic content typical in a cup of instant coffee reduces iron absorption from a test meal by 60% to 90%. Among elderly participants in the Framingham Heart Study, each 236 mL/wk (1 cup per week) of coffee consumed was associated with 1% lower serum ferritin concentration.
Montella, M.; Polesel, J.; La Vecchia, C.; Maso, L. D.; Crispo, A.; Crovatto, M.; Casarin, P.; Izzo, F.; Tommasi, L. G.; Talamini, R.; Franceschi, S.
The role of coffee in the aetiology of hepatocellular carcinoma has raised great interest. In Italy, coffee consumption is high, thus allowing the investigation of the topic over a broad range of consumption. A hospital-based case-control study was conducted in Italy in 1999-2002, including 185 incidents, histologically confirmed cases of hepatocellular carcinoma aged 43-84 years. Controls were 412 subjects admitted to the same hospitals' networks for acute, non-neoplastic diseases unrelated to diet. Coffee and tea consumption were assessed using a validated food-frequency questionnaire. Odds ratios (ORs) and corresponding the 95% confidence intervals (CI) were computed using unconditional multiple logistic regression, adjusting for hepatitis viruses seropositivity, alcohol intake, smoking habits and other potential confounding factors. Compared to people who drunk <14 cups/week of coffee, the risk of hepatocellular carcinoma decreased for increasing levels of consumption (OR = 0.4, 95% CI: 0.2-1.1 for >/=28 cups/week, p for trend = 0.02). In the present study, inverse relations were observed across strata of hepatitis C and, B virus infections and alcohol drinking. No significant association emerged with consumption of decaffeinated coffee (OR = 0.7, 95% CI = 0.2-2.5) or tea (OR = 1.4, 95% CI = 0.8-2.7). The present study supports the hypothesis of a favourable effect of coffee, though not decaffeinated coffee and tea, on the risk on hepatocellular carcinoma. (c) 2006 Wiley-Liss, Inc.
Naganuma, T.; Kuriyama, S.; Akhter, M.; Kakizaki, M.; Nakaya, N.; Matsuda-Ohmori, K.; Shimazu, T.; Fukao, A.; Tsuji, I.
An inverse association between coffee consumption and the risk of colorectal cancer has been reported in several case-control studies, but results from prospective cohort studies have been inconclusive. We conducted a prospective cohort study among a Japanese population to clarify the association between coffee consumption and the risk of colorectal cancer incidence. We used data from the Miyagi Cohort Study for this analysis. Usable self-administered questionnaires about coffee consumption were returned from 22,836 men and 24,769 women, aged 40-64 years, with no previous history of cancer. We used the Cox proportional-hazard regression model to estimate hazard ratios and 95% confidence intervals. During 11.6 years of follow-up (425,303 person-years), we identified 457 cases of colorectal cancer. Coffee consumption was not associated with the incidence of colorectal, colon or rectal cancer. The multivariate adjusted hazard ratio (95% confidence interval) of colorectal cancer incidence for 3 or more cups of coffee per day as compared with no consumption was 0.95 (0.65-1.39) for men and women (p for trend = 0.55), 0.91 (0.56-1.46) for men (p for trend = 0.53) and 1.16 (0.60-2.23) for women (p for trend = 0.996). Coffee consumption was also not associated with incidence of either proximal or distal colon cancer. We conclude that coffee consumption is not associated with the incidence risk of colorectal cancer in the general population in Japan. (c) 2006 Wiley-Liss, Inc.
Peyrin-Biroulet, L.; Gueant, J. L.; Roblin, X.
Introduction : We read with great interest the article by Pereira et al1 showing an inverse association of coffee intake with risk of type 2 diabetes mellitus in a large prospective study of postmenopausal women. The protective effect of coffee against diabetes could not be attributed to caffeine because the inverse associations of coffee consumption with diabetes risk were stronger for decaffeinated coffee than for regular (caffeinated) coffee.1 The authors concluded that other components of coffee such as antioxidants could reduce the risk of diabetes, but the question remains of why regular coffee consumption might not decrease the risk of diabetes. In this setting, it would have been interesting to investigate the contribution of the homocysteine-raising effect of caffeine to the risk of diabetes.
Rosner, S. A.; Akesson, A.; Stampfer, M. J.; Wolk, A.
Numerous studies have examined the association between coffee consumption and risk of myocardial infarction (MI), but results have been inconsistent. Case-control studies generally suggest a harmful effect of coffee drinking, whereas cohort studies have mostly shown no association. Recent studies found that coffee may lower the risk of diabetes, a major coronary risk factor. The authors prospectively examined the effect of coffee consumption on MI risk in 32,650 older Swedish women, aged 40-74 years, participating in the Swedish Mammography Cohort; 459 cases of MI developed during 165,896 person years of follow-up from 1997 to 2002. After adjustment for age, coronary heart disease risk factors, and dietary variables, the relative risk of MI associated with drinking >/=5 cups/week versus 0-4 cups/week was 0.68 (95% confidence interval (CI): 0.43, 1.07). The authors observed a nonsignificant trend toward lower risk with higher consumption levels. Compared with that for 0-4 cups/week, the relative risks of MI were 0.84 (95% CI: 0.51, 1.38) for 5-7 cups/week, 0.65 (95% CI: 0.41, 1.03) for 2-3 cups/day, 0.64 (95% CI: 0.39, 1.04) for 4-5 cups/day, and 0.65 (95% CI: 0.37, 1.12) for >/=6 cups/day (p-trend = 0.07). Contrary to previous case-control studies, the authors concluded that coffee consumption does not increase MI risk. Coffee consumption of >/=5 cups/week was nonsignificantly inversely associated with MI risk among older Swedish women.
Rufian-Henares, J. A.; Morales, F. J.
Melanoidins formed at the last stage of the Maillard reaction have been pointed out to possess certain functional properties. Potential antihypertensive activity of food melanoidins (coffee, beer, and sweetwine) has been evaluated according to in-vitro ACE-inhibitory activity. Precision of the assay (3.2% of coefficient of variation, n = 10) for melanoidins is similar to those reported of well-known antihypertensive peptides. Assay was applied on food melanoidins obtained from coffee (three roasting degrees), beer, and sweet-wine. All samples showed in-vitro ACE-inhibitory activity. The activity in coffee melanoidins was significantly higher at more severe heating conditions. These experiments demonstrate that food melanoidins could inhibit ACE activity. In-vitro ACE-inhibitory activity of coffee melanoidins is likely located within the melanoidin structure. But ACE-inhibitory activity is also partly due to the low-molecular weight compound nonchemically bound to the melanoidin structure, then melanoidins can act as carrier protecting agents. These compounds could be naturally phenolic compounds present in the green beans or intermediary Maillard reaction products with antihypertensive activity. Keywords: Melanoidin; antihypertensive activity; coffee brew; roasting degree; Maillard reaction.
Tanaka, K.; Hara, M.; Sakamoto, T.; Higaki, Y.; Mizuta, T.; Eguchi, Y.; Yasutake, T.; Ozaki, I.; Yamamoto, K.; Onohara, S.; Kawazoe, S.; Shigematsu, H.; Koizumi, S.
Coffee use has consistently been associated with lower serum liver enzyme levels and a reduced risk of liver cirrhosis. A limited number of cohort and case-control studies also suggest a decreased risk of hepatocellular carcinoma (HCC) among coffee drinkers, but mostly without consideration of hepatitis virus infection. In the present case-control study, we recruited 209 incident HCC cases and three different controls (1308 community controls, 275 hospital controls, and 381 patients with chronic liver disease [CLD] without HCC), all of whom were aged 40-79 years and residents of Saga Prefecture, Japan. A questionnaire survey elicited information on coffee use during the last 1-2 years and 10 years before, and plasma hepatitis B surface antigen and antibodies to hepatitis C virus were tested for all but community controls. After adjustment for sex, age, heavy alcohol use, smoking status and hepatitis virus markers (except for community controls), coffee use during the last 1-2 years was associated with a decreased risk against any control group. For coffee use 10 years before, comparison between HCC cases and either community controls or CLD patients revealed a decreased risk; adjusted odds ratios for occasional use, 1-2 cups/day and > or =3 cups/day compared with no use were 0.33, 0.27 and 0.22 (P trend <0.001), respectively, against community controls, and 0.86, 0.62 and 0.53 (P trend = 0.05), respectively, against CLD patients. These results suggest that coffee may protect against the development of HCC, yet further elaborate studies (hopefully, intervention studies) are warranted to corroborate these findings.
van Gelder, B. M.; Buijsse, B.; Tijhuis, M.; Kalmijn, S.; Giampaoli, S.; Nissinen, A.; Kromhout, D.
To investigate whether coffee consumption is associated with 10-year cognitive decline in elderly men, as results of previous studies obtained hitherto have been controversial and prospective information on this association has been lacking. DESIGN, SUBJECTS AND SETTING: Six hundred and seventy six healthy men born between 1900 and 1920 from Finland, Italy and the Netherlands participated in a 10-year prospective cohort study. Cognitive functioning was assessed using the Mini-Mental State Examination (0-30 points, with a higher score indicating better cognitive performance). Coffee consumption was estimated in cups per day. A mixed longitudinal model was used to investigate the association between baseline coffee consumption and 10-year cognitive decline. Multiple adjustments were made. RESULTS: Men who consumed coffee had a 10-year cognitive decline of 1.2 points (4%). Non-consumers had an additional decline of 1.4 points (P<0.001). An inverse and J-shaped association was observed between the number of cups of coffee consumed and cognitive decline, with the least cognitive decline for three cups of coffee per day (0.6 points). This decline was 4.3 times smaller than the decline of non-consumers (P<0.001).
CONCLUSIONS: Findings suggest that consuming coffee reduces cognitive decline in elderly men. An inverse and J-shaped association may exist between the number of cups of coffee consumed and cognitive decline, with the least cognitive decline for men consuming three cups of coffee per day.
Beedie, C. J.; Stuart, E. M.; Coleman, D. A.; Foad, A. J.
The placebo effect-a change attributable only to an individual's belief in the efficacy of a treatment-might provide a worthwhile improvement in physical performance. Although sports scientists account for placebo effects by blinding subjects to treatments, little research has sought to quantify and explain the effect itself. The present study explored the placebo effect in laboratory cycling performance using quantitative and qualitative methods. METHOD: Six well-trained male cyclists undertook two baseline and three experimental 10-km time trials. Subjects were informed that in the experimental trials they would each receive a placebo, 4.5 mg.kg caffeine, and 9.0 mg.kg caffeine, randomly assigned. However, placebos were administered in all experimental conditions. Semistructured interviews were also conducted to explore subjects' experience of the effects of the capsules before and after revealing the deception. RESULTS: A likely trivial increase in mean power of 1.0% over baseline was associated with experimental trials (95% confidence limits, -1.4 to 3.6%), rising to a likely beneficial 2.2% increase in power associated with experimental trials in which subjects believed they had ingested caffeine (-0.8 to 5.4%). A dose-response relationship was evident in experimental trials, with subjects producing 1.4% less power than at baseline when they believed they had ingested a placebo (-4.6 to 1.9%), 1.3% more power than at baseline when they believed they had ingested 4.5 mg.kg caffeine (-1.4 to 4.1%), and 3.1% more power than at baseline when they believed they had ingested 9.0 mg.kg caffeine (-0.4 to 6.7%). All subjects reported caffeine-related symptoms.
CONCLUSIONS: Quantitative and qualitative data suggest that placebo effects are associated with the administration of caffeine and that these effects may directly or indirectly enhance performance in well-trained cyclists.
Source : Med Sci Sports Exerc 2006 vol. 38 (12), pp 2159 - 2164
Greenberg, J. A.; Boozer, C. N.; Geliebter, A.; Lopez, Garcia E.; van Dam, R. M.; Qi, L.; Hu, F. B.
Studies have shown that ingestion of caffeinated and decaffeinated coffee can reduce the risk of diabetes. The first of these papers reviews epidemiologic and laboratory studies on the effects of coffee and its constituents, with emphasis on diabetes risk. The role of weight loss in these effects is discussed. Results have indicated that decaffeinated coffee or non-caffeine constituents in coffee might be better suited for enhancing glucose tolerance and insulin sensitivity than caffeinated coffee. The second paper describes a study that assessed the relationship between long-term caffeinated and decaffeinated filtered coffee consumption and markers of inflammation and endothelial dysfunction - risk factors for cardiovascular disease. Caffeinated and decaffeinated coffee did not have a detrimental effect on endothelial function in healthy and diabetic women, and results indicated that coffee consumption was inversely associated with markers of inflammation and endothelial dysfunction.
Source : Amer J Clin Nutr 2006 vol. 84 (4), pp 682-693 & 888-893
Kalda, A.; Yu, L.; Oztas, E.; Chen, J. F.
The adenosine A(2A) receptor has recently emerged as a leading non-dopaminergic therapeutic target for Parkinson's disease, largely due to the restricted distribution of the receptor in the striatum and the profound interaction between adenosine and dopamine receptors in brain. Two lines of research in particular have demonstrated the promise of the A(2A) receptor antagonists as novel anti-parkinsonian drugs. First, building on extensive preclinical animal studies, the A(2A) receptor antagonist KW6002 has demonstrated its potential to increase motor activity in PD patients of the advanced stage in a recent clinical phase IIB trial. Second, recently two prospective epidemiological studies of large cohorts have firmly established the inverse relationship between the consumption of caffeine (a non-specific adenosine antagonist) and the risk of developing PD. The potential neuroprotective effect of caffeine and A(2A) receptor antagonists in PD is further substantiated by the demonstration that pharmacological blockade (by caffeine or specific A(2A) antagonists) or genetic depletion of the A(2A) receptor attenuated dopaminergic neurotoxicity and neurodegeneration in animal models of PD. Moreover, A(2A) receptor antagonism-mediated neuroprotection goes beyond PD models and can be extended to a variety of other brain injuries induced by stroke, excitotoxicity and mitochondrial toxins. Intensive investigations are under way to dissect out common cellular mechanisms (such as A(2A) receptor modulation of neuroinflammation) which may underlie the broad spectrum of neuroprotection by A(2A) receptor inactivation in brain.
Kim, H. G.; Kim, J. Y.; Hwang, Y. P.; Lee, K. J.; Lee, K. Y.; Kim, D. H.; Kim, D. H.; Jeong, H. G.
Endothelial cells produce adhesion molecules after being stimulated with various inflammatory cytokines. These adhesion molecules play an important role in the development of atherogenesis. Recent studies have highlighted the chemoprotective and anti-inflammatory effects of kahweol, a coffee-specific diterpene. This study examined the effects of kahweol on the cytokine-induced monocyte/human endothelial cell interaction, which is a crucial early event in atherogenesis. Kahweol inhibited the adhesion of TNFalpha-induced monocytes to endothelial cells and suppressed the TNFalpha-induced protein and mRNA expression of the cell adhesion molecules, VCAM-1 and ICAM-1. Furthermore, kahweol inhibited the TNFalpha-induced JAK2-PI3K/Akt-NF-kappaB activation pathway in these cells. Overall, kahweol has anti-inflammatory and anti-atherosclerotic activities, which occurs partly by down-regulating the pathway that affects the expression and interaction of the cell adhesion molecules on endothelial cells.
Source : Toxicol Appl Pharmacol 2006 vol.217 (3), pp 332 - 341
Klug, T. L.; Bageman, E.; Ingvar, C.; Rose, C.; Jernstrom, H.
Most, but not all, studies have found that women with a high urinary 2-hydroxyestrogen (2OHE) to 16alpha-hydroxyestrone (16alphaOHE1) ratio are at reduced risk for breast cancer and have a better prognosis. The aim was to identify factors associated with the pre-operative 2OHE to 16alphaOHE1 ratio and factors that predicted the change in the ratio between the pre-operative visit and first follow-up visit three to six months post-operatively among 59 women with primary ER positive breast cancer tumors. Body measurements, questionnaires and blood samples for measurements of the 2OHE and 16alphaOHE1 plasma levels and CYP1A2 *1F genotyping were collected at both visits. Post-operatively, 15 women received tamoxifen, 30 women tamoxifen and radiotherapy concomitantly, and 14 women radiotherapy. The pre-operative ratio was not correlated with tumor characteristics, but was significantly higher in women who consumed three or more cups of coffee daily (p = 0.009). The number of CYP1A2 *1F C-alleles was correlated with a lower ratio at both visits (p = 0.13 and p = 0.02, respectively). The ratio increased between the two visits in 69.5% of the women. The factors associated with a significant increase in the ratio were concomitant tamoxifen and radiotherapy (p = 0.006), increasing alcohol consumption (p = 0.006), and a high coffee consumption (p = 0.03), but not age or CYP1A2 *1F genotype. In this pilot study, breast cancer patients who started tamoxifen during radiotherapy and who had a moderate coffee and alcohol consumption demonstrated a significant improvement in their estrogen metabolite profile between the pre- and post-operative visits.
Oba, S.; Shimizu, N.; Nagata, C.; Shimizu, H.; Kametani, M.; Takeyama, N.; Ohnuma, T.; Matsushita, S.
The risk of the development of colon cancer in relation to a western diet was studied in a communitybased cohort in Japan. From 1992 to 2000, 13,894 men and 16,327 women were followed. In men, high consumption of processed meat increased the risk in comparison with low consumption (adjusted RR=1.98, 95% CI: 1.24-3.16). In women, daily coffee drinkers had a reduced risk in comparison with individuals who never or rarely drank coffee (adjusted RR=0.43, 95% CI: 0.22-0.85). The findings suggest the possible linkage between a western diet and risk of colon cancer.
Taylor, L.; Antonio, J.
This chapter discusses the role of coffee as a functional food, and presents information under the following section headings: introduction to coffee and caffeine; doses of caffeine; coffee and caffeine in weight loss and energy expenditure; effects of coffee (caffeine) in the brain and body; exercise performance with coffee and caffeine consumption; health related issues in coffee consumption; and conclusion and closing remarks.
Source : Handbook of nutraceuticals and functional foods, Ed. R.E.C. Wildman, CRC Press, 2006
Dall'igna, O. P.; Fett, P.; Gomes, M. W.; Souza, D. O.; Cunha, R. A.; Lara, D. R.
Consumption of caffeine, an adenosine receptor antagonist, was found to be inversely associated with the incidence of Alzheimer's disease. Moreover, caffeine protects cultured neurons against beta-amyloidinduced toxicity, an effect mimicked by adenosine A(2A) but not A(1) receptor antagonists. We now tested if caffeine administration would prevent beta-amyloid-induced cognitive impairment in mice and if this was mimicked by A(2A) receptor blockade. One week after icv administration of the 25-35 fragment of betaamyloid (Abeta, 3 nmol), mice displayed impaired performance in both inhibitory avoidance and spontaneous alternation tests. Prolonged treatment with caffeine (1 mg/ml) had no effect alone but prevented the Abeta-induced cognitive impairment in both tasks when associated with acute caffeine (30 mg/kg) 30 min treatment before Abeta administration. The same protective effect was observed after subchronic (4 days) treatment with daily injections of either caffeine (30 mg/kg) or the selective adenosine A(2A) receptor antagonist SCH58261 (0.5 mg/kg). This provides the first direct in vivo evidence that caffeine and A(2A) receptor antagonists afford a protection against Abeta-induced amnesia, which prompts their interest for managing Alzheimer's disease.
Back, S. A.; Craig, A.; Ling-Luo, N.; Ren, J.; Akundi, R. S.; Ribeiro, I.; Rivkees, S. A.
Periventricular white matter injury (PWMI) is the major cause of cerebral palsy and cognitive impairment in prematurely born infants. PWMI is characterized by reductions in cerebral myelination and cerebrocortical volumes and is associated with secondary ventriculomegaly. In neonatal rodents, these features of PWMI can be induced by rearing in chronic hypoxia or by activation of A1 adenosine receptors. We determined: (1) whether altered maturation or development of one or more oligodendrocyte (OL) lineage stages plays a role in the pathogenesis of the myelination disturbances associated with exposure to chronic hypoxia, and (2) whether blockade of A1 adenosine receptor action with the adenosine antagonist caffeine can prevent hypoxia-induced white matter injury. METHODS: Ventriculomegaly and reduced cerebral myelination were generated in mice reared in hypoxia (10% oxygen) from postnatal days 3 (P3) through 12. RESULTS: Hypomyelination was related to abnormal OL lineage progression and a reduction in the OL progenitor pool. Myelination was enhanced and ventriculomegaly reduced in hypoxia-exposed neonatal pups treated with caffeine from P3 to P12. INTERPRETATION: These observations support that hypoxia inhibits OL maturation and that caffeine administration during early postnatal development may have utility in the prevention of PWMI. Ann Neurol 2006.
Lopez, J. R.; Dominguez-Ramirez, A. M.; Cook, H. J.; Bravo, G.; Diaz-Reval, M. I.; Deciga-Campos, M.; Lopez-Munoz, F. J.
It has been observed that caffeine improves antinociceptive efficacy of some non-steroidal antiinflammatory drugs (NSAIDs) in several experimental models, however, these effects have been questioned in humans. Controversy in clinical studies may be due to the use of different protocols as well as to high interindividual variability in patient response. In addition, the antinociceptive interaction of ibuprofen+caffeine has not been studied. To assess a possible synergistic antinociceptive interaction, the antinociceptive effects of ibuprofen, and caffeine administered either separately or in combinations were determined in a model of arthritic pain: "Pain-induced functional impairment in the rat (PIFIR model). The antinociceptive efficacies were evaluated using several dose-response curves and time courses. The antinociceptive effects from the combination that produced the greater effect were compared with the maximal antinociceptive effect of either morphine or acetylsalicylic acid alone. The animals were administered with 0.05 ml intra-articular (i.a.) of uric acid to induce nociception. Groups of six rats received either acetylsalicylic acid, morphine, ibuprofen or caffeine, or a combination ibuprofen+caffeine (18 combinations). We report here that caffeine (17.8 and 31.6 mg/kg) is able to potentiate the antinociceptive effect of ibuprofen. This investigation showed that six combinations presented effects of potentiation and twelve combinations only showed antinociceptive effects not different from that of ibuprofen alone. The maximum antinociceptive effect was 270.7+/-12.7 area units (au), produced by ibuprofen 100 mg/kg+caffeine 17.8 mg/kg; this effect was greater than the maximum produced by morphine 17.8 mg/kg (244.7+/-22.9 au) in these experimental conditions. The maximum potentiation was 197 % produced with the combination of ibuprofen 17.8 mg/kg+caffeine 17.8 mg/kg. These results suggest that the antinociceptive effect of ibuprofen was significantly potentiated by doses of caffeine that by themselves are ineffective in this model.
Schneider, R.; Gruner, M.; Heiland, A.; Keller, M.; Kujanova, Z.; Peper, M.; Riegl, M.; Schmidt, S.; Volz, P.; Walach, H.
The objective of this study is to determine the impact of expectation associated with placebo and caffeine ingestion. We used a three-armed, randomized, double-blind design. Two three-armed experiments varying instruction (true, false, control) investigated the role of expectations of changes in arousal (blood pressure, heart rate), subjective well-being, and reaction time (RT). In Experiment 1 (N = 45), decaffeinated coffee was administered, and expectations were produced in one group by making them believe they had ingested caffeinated coffee. In Experiment 2 (N = 45), caffeinated orange juice was given in both experimental groups, but only one was informed about the true content. In Experiment 1, a significant effect for subjective alertness was found in the placebo treatment compared to the control group. However, for RT and well-being no significant effects were found. In Experiment 2, no significant expectancy effects were found. Caffeine produced large effects for blood pressure in both treatments compared to the control group, but the effects were larger for the false information group. For subjective well-being (alertness, calmness), considerable but nonsignificant changes were found for correctly informed participants, indicating possible additivity of pharmacologic effect and expectations. The results tentatively indicate that placebo and expectancy effects primarily show through introspection.
Tieges, Z.; Snel, J.; Kok, A.; Wijnen, J. G.; Lorist, M. M.; Richard-Ridderinkhof, K.
We studied the effects of moderate amounts of caffeine on task switching and task maintenance using mixed-task (AABB) blocks, in which participants alternated predictably between two tasks, and single-task (AAAA, BBBB) blocks. Switch costs refer to longer reaction times (RT) on task switch trials (e.g. AB) compared to task-repeat trials (e.g. BB); mixing costs refer to longer RTs in task-repeat trials compared to single-task trials. In a double-blind, within-subjects experiment, two caffeine doses (3 and 5mg/kg body weight) and a placebo were administered to 18 coffee drinkers. Both caffeine doses reduced switch costs compared to placebo. Event-related brain potentials revealed a negative deflection developing within the preparatory interval, which was larger for switch than for repeat trials. Caffeine increased this switchrelated difference. These results suggest that coffee consumption improves task-switching performance by enhancing anticipatory processing such as task set updating, presumably through the neurochemical effects of caffeine on the dopamine system.