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PubMed2002

Relationship between coffee and green tea consumption and all-cause mortality in a cohort of a rural Japanese population.

We conducted a cohort study to investigate the effects of coffee and green tea consumption on all-cause mortality in a rural Japanese population. Data were obtained from 2,855 men and women aged 40-79 years in 1989, and during the subsequent 9.9 years of follow-up. Using the Cox regression model to adjust for potential confounding factors, we calculated the multivariate hazard ratios of death from all causes separately for men and women. The multivariate hazard ratio of mortality for men who consumed two or more cups of coffee per day, compared with those who consumed less than half a cup per day, was 0.43 (95% confidence interval, 0.30-0.63), and the ratio for those who consumed half to one cup of coffee per day was 0.70 (95% confidence interval, 0.52-0.94). Exclusion of subjects with less than 5 years of follow-up did not substantially change the findings. No other statistically significant associations were identified between consumption of the two beverages and all-cause mortality. For men, multivariate hazard ratios of death from apoplexy showed a significant inverse association with increasing coffee consumption. The effects of habitual coffee consumption and its related factors on health in Japan need to be studied in greater detail.

Adult↗
PubMed1998

[Fluorescence microscopy for detection of frauds in ground coffee].

Currently, frauds in ground coffee are detected with traditional microscopy, which is a tedious and not very precise method. Therefore, a more efficient and rapid microscopical method based on fluorescence, was proposed. For the microscopy analysis, pure coffee was compared to coffee samples adulterated with rye, barley, corn and wheat at 2.5, 5.0, and 10.0% levels. Starch granules were detected and identified immediately with fluorescence microscopy, in the adulterated coffee mixtures, quite different from optical microscopy where no frauds were detected with certainty. The suggested fluorescence method for the detection of cereal frauds in coffee was found to be more efficient and precise than the current official one.

Coffee↗
PubMed2002

[Bacterial present in the xylem of coffee (Rubiaceae: coffea arabica) with "Crespera" disease].

"Crespera" is an infectious disease of coffee plants that affects both the coffee production and the economy of the coffee producer countries. This disease affects morphologically the plant: long and narrow leaves with wavy borders and marginal necrosis; strong chlorosis results in drying of the leave, and leads to bad conditions of the plant. The internodes are short, producing the appearance of multiple sprouts in the axial sprout, the flowers can turn greenish, and the plant can present branches with severe symptoms, and branches without apparent symptoms at the same time. As a result, the coffee bean production decreases strikingly. The aim of this work was to determine the occurrence of the possible causative agent in the coffee plants using transmission electron microscopy. Normal and infected plants were compared looking at the leaves, central vein, lateral veins and petiole. It was determined that xylematic vessels show the presence of gram negative bacilliform bacteria (of thick-wavy walls), with dimensions of 0.3-0.5 micron diameter and 1-4 microns, length. The control plants did not show bacteria in the xylem.

Coffee↗
PubMed1992

[Cardiovascular effects of everyday coffee consumption].

Whereas the earlier literature contains several studies on the acute cardiovascular effects of caffeine, systematic studies of the cardiovascular effects of regular daily coffee consumption have appeared only recently. Acute caffeine administration (total daily amount in one dose following caffeine abstinence) increases both systolic and diastolic blood pressures by 10-15 mm Hg and lowers the pulse by about 2-5 beats/min. Repeated caffeine administration leads to a rapid decline in the blood pressure response. Chronic switching between decaffeinated and caffeine-containing coffee showed no more than marginal changes in blood pressure. Plasma lipids are probably independent of caffeine consumption, but increase slightly with boiled (compared with filter) coffee. The question of the thermogenic effect of coffee consumption remains open. The prevalence of coronary disease appears to be epidemiologically independent of coffee consumption.

Blood Pressure↗
PubMed1992

[Effects of coffee on the respiratory system].

The consumption of coffee is a very old and popular habit. It is possible that it may have an effect on the respiratory system and on the regulation of respiration. Apart from the manifestations of hypersensitivity linked to the handling of green coffee, the consumption of coffee can have different effects. On the one hand it has a beneficial effect on bronchospasm. On the other hand its consumption has been suspected of contributing to the development of chronic airflow obstruction (COPD) and also in the genesis of bronchial cancer, without, however, its responsibility being proven in a clear fashion. In fact, in these two latter pathological circumstances, the causal relationship is probably indirectly linked to the fact that there is a strong positive correlation between the consumption of coffee and of tobacco. Finally the consumption of coffee increases ventilatory frequency in normal subjects and also in the course of COPD, and if taken in large quantities by pregnant women, there is an increased risk of neonatal apnoea in the newborn, by an abrupt cessation in the caffeine level.

Adult↗
PubMed2004

Effect of caffeine-containing versus decaffeinated coffee on serum clozapine concentrations in hospitalised patients.

Clozapine and caffeine are metabolised mainly by the cytochrome P4501A2 (CYP1A2) enzyme. Studies suggest that caffeine in coffee inhibits clozapine metabolism and increases serum clozapine concentrations. Our objective was to study whether coffee in the amounts usually consumed has an effect on steady-state serum clozapine concentrations. A randomised placebo-controlled cross-over design with two phases was used. Twelve hospitalised clozapine-using patients volunteered in the study where, after one-week run-in period, either caffeine-containing or decaffeinated instant coffee was available ad libitum for seven days. Serum concentrations of clozapine, N-desmethylclozapine, clozapine-N-oxide, caffeine, paraxanthine and C-reactive protein were measured after run-in period and on days 4 and 8 of the following study phases. Two patients were excluded from the statistical analysis because of non-compliance based on serum caffeine and paraxanthine determinations. In six fully compliant patients caffeine-containing coffee increased the mean serum trough concentration of clozapine by 26% (non-significant (NS), 95% CI -3% to +54%, P=0.07), N-desmethylclozapine by 6% (95% CI 1% to 12%, P=0.03), and clozapine-N-oxide by 7% (NS, 95% CI -6% to +20%, P=0.22). The ratio of N-desmethylclozapine/clozapine decreased by 13% (NS, 95% CI -1% to +27%, P=0.06) and that of clozapine-N-oxide/clozapine by 7% (NS, 95% CI -5% to +17%, P=0.19). In the analysis of combined data (including day 4 data of the four patients compliant up to that point) serum trough concentration of clozapine was 20% (95% CI 3% to 37% to P=0.03) higher, and that of N-desmethylclozapine 7% (95% CI 2% to 13%, P=0.02) higher during the caffeine phase than during the decaffeinated phase. We conclude that the effect of instant coffee drinking on serum clozapine concentrations is of minor clinical relevance in most of the patients, but some individuals may be more sensitive to this interaction due e.g. to genetic factors. The increase in serum clozapine concentration was most likely due to the inhibition of the CYP1A2 enzyme by caffeine.

Adult↗
PubMedDate not supplied

[Coffee tree cultivation and the social history of onchocerciasis in Soconusco, Chiapas state, Mexico].

Due to the social and ecological changes that have taken place in the region of Soconusco, Chiapas, Mexico, the coffee tree growth economy (established in the latter part of the last century) has been an important factor in the transmission of onchocerciasis. The optimum ecological conditions for the growth of the coffee tree coincide with those of the disease's growth rate vector; the mobilization of migrant workers for the cultivation and gathering of coffee beans, plus changes in the natural environment, are elements which explain the disease's distribution in the different regions. The origin of the disease in Chiapas may be due to the migration of coffee plantation workers from Guatemala in search of land in which to settle. Social changes occurring after the Agrarian Distribution (land distributions that occurred in 1918 and 1940) caused an intensification and modernization in the areas of cultivation which in turn caused a decline in the disease's growth rate vector. This, together with standard of living improvements and control measures against the disease, explain why the problem in these regions has decreased considerably. The use of ivermectin as a new therapy paves the way for better disease control in the future. Nevertheless, in the smaller locations occupied by middle and poor class farmers, where coffee bean cultivation is just commencing and still in a rudimentary form, onchocerciasis and other diseases continue to present serious health problems.

Agriculture↗
PubMed1989

Application of high performance liquid chromatography to the analysis of some non-volatile coffee components.

High performance liquid chromatography (HPLC) was applied to the analysis of caffeine, trigonelline, nicotinic acid and sucrose in Arabica and Robusta coffee. Green and roasted coffee samples were used in this study and the degradation of sucrose and trigonelline, with the formation of nicotinic acid, was followed during roasting. Caffeine did not undergo significant degradation with only 5.4% being lost under severe roasting. Sucrose was degraded rapidly during processing with light roasting producing a 97% loss and dark roasting degrading it completely. Loss of trigonelline was strongly dependent on the degree of roasting, being higher in the Robusta coffee. Trigonelline degradation was associated with nicotinic acid formation both in the Arabica and Robusta coffees as a consequence of the roasting process. Trigonelline and sucrose were determined simultaneously by partition chromatography and detection with the mass detector. Determination of caffeine was carried out using reversed phase chromatography and nicotinic acid by ion-pair reversed phase chromatography. Detection in both cases was achieved using an ultraviolet detector at 272 nm or 254 nm, respectively. HPLC showed adequate precision and accuracy for routine analyses. In addition, the methods used were more rapid and simple than traditional procedures. HPLC appears to be a suitable technique for quality control in the coffee industry, and for fundamental investigation on the mechanisms involved in the roasting process.

Alkaloids↗
PubMedDate not supplied

Caffeine as main interfering compound in radioimmunoassay of aflatoxin B1 in coffee samples.

The content of caffeine in coffee extracts prepared for radioimmunoassay of aflatoxin B1 was determined by gas chromatography. The extracts from coffee beans and decaffeinated coffee contained 1.76-4.60 and 0.71-0.85 g caffeine/kg, respectively. These concentrations of caffeine caused false results in radioimmunoassay of aflatoxin B1 in the range 1.0-2.8 micrograms/kg for coffee beans and 0.3-0.4 micrograms/kg for decaffeinated coffee.

Aflatoxin B1↗
PubMedDate not supplied

[Influence of coffee on plasma lipids].

The influence of coffee on plasma lipids has been largely investigated during the last twenty years, but still many doubts remain about this subject. For this reason the influence of the assumption of coffee on plasma lipids, in healthy people, during six weeks has been studied. The coffee was prepared with an Italian coffee-machine (moka). No relationship was found between coffee assumption and increase of hematic cholesterol.

Adult↗
PubMed1989

Coffee and alcohol use and the risk of ulcerative colitis.

We performed a population-based, case-control study of the risk of ulcerative colitis associated with coffee and alcohol use among the 304,000 members of a prepaid health plan. We compared coffee and alcohol use histories before ulcerative colitis onset in 209 cases and an equal number of age- and sex-matched controls selected from the enrollment file of the prepaid health plan. Neither coffee use, amount of coffee consumed daily, or cumulative coffee consumption before disease onset altered the risk of developing ulcerative colitis. A decreased risk of ulcerative colitis was associated with alcohol consumption before disease onset among never-smokers only. This risk declined as daily alcohol consumption increased. These results suggest that alcohol consumption may lower ulcerative colitis incidence.

Coffee↗
PubMed1989

[Specific bronchial reactivity in unripe coffee processing workers].

Ventilatory capacity was studied in nine coffee workers who complained of job-related respiratory symptoms. Bronchoprovocation testing with green coffee allergen provoked immediate asthmatic reactions with acute reductions of ventilatory capacity in four workers. The relative fall was greater in FEF25-75 ranging from 28% to 66% than in FEV1 where it ranged from 18% to 62% of the control values. Eight workers out of nine had increased total IgE serum levels and six showed a positive reaction to prick testing with green coffee allergen. According to our data bronhchoprovocation with green coffee allergen along with skin tests and immunoglobulin levels can serve as indicator of the sensitivity of the respiratory system to green coffee dust.

Adult↗
PubMed1989

Coffee consumption and digestive tract cancers.

The relationship between coffee drinking and the risk of digestive tract neoplasms was analyzed in a case-control study of 50 cases of cancer of the mouth or pharynx, 209 of the esophagus, 397 of the stomach, 455 of the colon, 295 of the rectum, 151 of the liver, 214 of the pancreas, and 1944 control subjects admitted for acute, non-digestive tract disorders. There was no significant or consistent association between coffee and cancers of the mouth or pharynx, esophagus, stomach, liver, or pancreas. In particular, for pancreatic cancer, the multivariate relative risks for the intermediate and upper tertiles were 1.05 and 1.01, respectively. There were significant inverse trends in risk with measures of coffee consumption for colon and rectal cancers, the multivariate relative risks according to tertiles of coffee consumption being 0.86 and 0.64 for colon and 0.97 and 0.66 for rectum. This apparent protection is in agreement with some (but not all) previous epidemiological evidence and finds a possible biological interpretation in terms of interference on bile secretion, causing reduced bile acid and neutral sterol concentrations in the bowel. In conclusion, the results of this study, the major interest of which lies in the opportunity of drawing up an overall pattern of risk for various digestive neoplasms, offer further reassurance as regards the effects of coffee on digestive tract carcinogenesis.

Adult↗
PubMed1987

Coffee extracts inhibit platelet aggregation in vivo and in vitro.

The effect of aqueous coffee extracts on platelet aggregation in humans (in vitro) and rabbits (both in vitro and in vivo) was investigated. Coffee extracts were found to have anti-aggregatory effects on in vitro platelet aggregation induced by ADP or arachidonate but not by collagen. Coffee extracts were also effective after intravenous administration in rabbits. The compound(s) responsible for these effects are water-soluble, heat-resistant, appeared to be different from salicylates, and might also be due to unidentified compounds besides nicotinic acid or known xanthines. Coffee extract and selected fractions decreased the conversion of [14C]-arachidonic acid to thromboxane B2 by the platelets. These studies show that coffee extracts contain compounds which are active in inhibiting platelet aggregation, a critical step involved in thrombosis and other vascular disorders.

Adenosine Diphosphate↗
PubMed1988

[Effects of the treatment of coffee pulp, fresh or ensilaged, with calcium hydroxide, on its nutritive value].

This study was carried out to determine the effects of the addition of calcium hydroxide on the chemical composition and nutritive value of fresh or ensilaged coffee pulp. Fresh or ensilaged pulp were mixed with 1, 2 and 3% of calcium hydroxide. The process was carried out during 0 and 16 hr, after which time the treated pulp was sun-dried for 36 hr until moisture content reached 12%. These samples were then analyzed for their proximate chemical composition and for some minerals (Ca, P, Na, K), as well as for caffeine, tannins and chlorogenic and caffeic acids content. Diets were then prepared from these materials, containing 15% protein and 15 or 30% fresh or ensilaged coffee pulp, and offered to weanling rats during six weeks. Information required on weight gain, food conversion, apparent digestibility and toxicity of the diets was recorded. Results of the chemical analysis revealed that the main changes found in both types of pulp as a result of the calcium hydroxide treatment were the following: a decrease in ether extract (from 4.0 to 2.5 g/100 g), crude fiber (from 18.3 to 11.9 g/100 g) and protein content (from 12.3 to 8.6 g/100 g) in an inverse relation to the amount of calcium hydroxide used. The amount of ash increased, fluctuated between 5.5 and 15.4%, depending on the amount of calcium hydroxide used. The latter affected the Ca:P ratio in the diets, where an average ratio of 7.2:1 was found in the control pulp (0% calcium hydroxide) and 59.0:1 in those treated with the highest amount of calcium hydroxide (3%). Regarding the caffeine, tannins and chlorogenic and caffeic acids contents, calcium hydroxide was effective in decreasing only tannins, more so in the fresh than in the ensilaged pulp; the decrease was in direct proportion to the amount of calcium hydroxide added and to the length of the Ca(OH)2 treatment. The results of the biological assays showed that the addition of Ca(OH)2 in either of the two time periods used and at either of the concentrations studied, did not improve the nutritive value of coffee pulp. There was always a better performance in the animals that consumed ensilaged pulp than in those fed fresh pulp. The animals fed 15% coffee pulp either fresh or ensilaged performed better than those consuming 30% coffee pulp.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1985

[Effect of polyphenols of coffee pulp on iron absorption].

The effect of the polyphenols of coffee pulp on iron absorption was studied using the method of ligated segments in rats. Optimal conditions to measure iron absorption, were determined using as criteria the concentration of Fe59 and the time that produced the highest value of blood radioactivity. A concentration of 0.4 uCi/dose of Fe59 and a 3-hr period were chosen to measure iron absorption. Experimental groups were formed assigning six rats randomly to each group. Each group was injected with a solution of 59Fe and either with the standard polyphenol solution or with the coffee pulp extract, except the control group which was injected with the Fe59 solution only. The effect of two polyphenol concentrations was also studied. Iron uptake from the duodenum was found to be the best indicator of iron absorption when compared to the sum of iron uptake by the tissues (blood, liver, spleen, kidneys, heart and carcass). Therefore, this indicator was used to interpret the results obtained. Catechin, tannic acid and the coffee pulp extract decreased significantly iron absorption when compared with the control group. The level of polyphenols used in these experiments is similar to the amounts consumed by animals fed coffee pulp at a 10% level. Therefore, we can conclude that the antinutritional effect of coffee pulp polyphenols may be partially due to their capacity to bind iron.

Animals↗
PubMed1982

Coffee drinking and cancer of the lower urinary tract.

The relation of coffee drinking to the incidence rate of cancer of the lower urinary tract ("bladder cancer") was evaluated. Broadly based series of cases and series of controls drawn from the general population of each area were assembled and interviewed in Boston, Massachusetts (587 cases, 528 controls), Manchester, England (541 cases, 725 controls), and Nagoya, Japan (289 cases, 586 controls). Compared to drinkers of an average of less than 1 cup of coffee per day, those who drank more had a relative risk of bladder cancer estimated as 1.0 (0.8-1.2, 95% confidence interval). With adjustment for cigarette smoking habits, only small and irregular changes in risk were seen with increasing frequency of coffee consumption. Duration of coffee drinking showed little relation to risk of bladder cancer may be due to incomplete control of the effect of cigarette smoking. If there is a true association of coffee drinking and bladder cancer it is likely to be weak.

Age Factors↗
PubMed1980

Effect of feeding coffee and its lipids on regenerating and intact liver.

Liver regeneration was stimulated in partially hepatectomized rats fed diets supplemental with up to 7.0% by weight of ground green and roasted Brazilian or Hawaiian (Kona) coffee in a basal powdered ration but was little influenced by decaffeinated or African Robusta coffee diets over a period of 10 days. The causative agent occurred in the total lipids from the active ground coffee batches and could be concentrated in the unsaponifiable portion as was also noted with the product from Robusta coffee. The lipids were inactive by the sc route. Pressed Brazilian green coffee oil elicited a lower regenerative response and other caffeine sources such as ground kola nuts and Paraquay tea at levels of 7.0% as demonstrated earlier for black tea, were nonstimulatory. Caffeine tended to depress liver regeneration, a level of 0.40% being quite inhibitory. As based on the composition of the unsaponifiable material, the activity might reside in the diterpene alcohol fraction containing cafestol and kahweol and some fractionation of the mixture was attempted currently. The agents which were active in the operated series generally elicited wet and dry liver enlargement in intact rats over the same period.

Animals↗