[Coffee and health: the place of coffee in dietetics].
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Asthenia↗
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[Coffee and the heart. Coffee, increase of blood lipid parameters and coronary diseases].
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Caffeine↗
[Mineral makeup of instant coffee drink substitutes for natural instant coffee].
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Beverages↗
[Detection of benzo(a)pyrene in coffee and coffee substitutes].
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Benzo(a)pyrene↗
Fate of ochratoxin A (OTA) during processing of coffee. Cooperative work by PEC (Physiological Effects of Coffee committee).
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Coffee↗
Lower esophageal sphincter pressure, acid secretion, and blood gastrin after coffee consumption.
This study tested the hypothesis that differences in the processing of raw coffee beans can account for some of the variability in gastric effects of coffee drinking. Coffees were selected to represent several ways that green coffee beans are treated, ie, processing variables. These included instant and ground coffee processing, decaffeination method (ethyl acetate or methylene chloride extraction), instant coffee processing temperature (112 degrees F or 300 degrees F), and steam treatment. Lower esophageal sphincter pressure, acid secretion, and blood gastrin was measured in eight human subjects after they consumed each of the different coffees. Consumption of coffee was followed by a sustained decrease in lower esophageal sphincter pressure (P less than 0.05) except for three of the four coffees treated with ethyl acetate regardless of whether or not they contained caffeine. Caffeinated ground coffee stimulated more acid secretion that did decaf ground coffees (P less than 0.05), but not more than a steam-treated caffeinated coffee. Instant coffees did not differ in acid-stimulating ability. Ground caffeinated coffee resulted in higher blood gastrin levels than other ground coffees (P less than 0.05). Freeze-dried instant coffee also tended toward higher gastrin stimulation. It is concluded that some of the observed variability in gastric response to coffee consumption can be traced to differences in how green coffee beans are processed.
Adult↗
Coffee and health in the elderly.
Coffee is a very attractive but not a unique drink. There are various types of coffee, e.g. Arabica, Canephora, and Robusta. In addition, various coffee blends containing several coffee types of different origin are offered in coffee-houses in Croatia and worldwide. These coffee blends can differ substantially according to their components, especially to the proportion of caffeine. Caffeine is the major coffee constituent which the coffee tolerance or intolerance depends on. In a healthy liver, the majority of caffeine is degraded by the hepatic microsomal enzymatic system. Caffeine is mostly degraded to paraxanthine substances, partially to theobromine and theophylline, and a small amount of unchanged caffeine is excreted by urine. Therefore, the metabolism of caffeine depends on the state of this enzymatic system of the liver. Elderly individuals with a depleted enzymatic system do not tolerate coffee with caffeine. They are recommended to take decaffeinated coffee, and this only if their stomach is healthy, because both decaffeinated coffee and coffee with caffeine cause heartburn. Moderate amounts of coffee (50-100 mg of caffeine or 5-10 g of coffee powder a day) are well tolerated by a majority of elderly people, who enjoy to meet and chat over a cup of coffee. Excessive amounts of coffee, however, can in many individuals cause very unpleasant, exceptionally even life-threatening side effects. Therefore, elderly persons are recommended to take moderate amounts of coffee which will not cause any health impairments.
Aged↗
Coffee acutely increases sympathetic nerve activity and blood pressure independently of caffeine content: role of habitual versus nonhabitual drinking.
BACKGROUND: Coffee is the most abundantly consumed stimulant worldwide. However, its cardiovascular safety remains controversial. Possible health hazards have been related to its main ingredient, caffeine. Activation of the sympathetic nervous system by coffee may enhance cardiovascular risk; however, it is unclear whether this effect of coffee is related to caffeine or other substance(s) also contained in decaffeinated coffee. METHODS AND RESULTS: In 15 healthy volunteers (6 habitual and 9 nonhabitual coffee drinkers) arterial blood pressure (BP), heart rate, and muscle sympathetic nervous activity (MSA) were continuously recorded before and after drinking a triple espresso or a decaffeinated triple espresso or after intravenous administration of caffeine (250 mg) or placebo (saline) in the same subjects. There was a significant time x condition interaction for the intravenous caffeine and placebo conditions for MSA, with caffeine showing a significant increase in MSA at 60 minutes (53.2+/-14.1% total activity) and the placebo group showing no effect. A similar significant time effect was found for coffee drinking (54.1+/-22.5% total activity). Habitual and nonhabitual coffee drinkers demonstrated similar changes in MSA and BP after intravenous caffeine, whereas coffee drinking increased BP in nonhabitual drinkers only, despite comparable increases of MSA and plasma caffeine levels. Nonhabitual coffee drinkers showed similar activation of MSA and BP after caffeine infusion, coffee, or decaffeinated coffee. CONCLUSIONS: Acutely, coffee and caffeine induced comparable increases in MSA and BP in nonhabitual coffee drinkers, whereas habitual coffee drinkers exhibited lack of BP increase despite MSA activation to coffee. Because decaffeinated coffee also increases BP and MSA in nonhabitual drinkers, ingredients other than caffeine must be responsible for cardiovascular activation.
Administration, Oral↗
Boiled coffee and blood pressure. A 14-week controlled trial.
The question of whether long-term elimination of coffee from the diet lowers blood pressure has not been settled. Consumption of Scandinavian-style "boiled coffee" is associated with coronary heart disease. However, little is known about the effect of brewing method on the blood pressure-raising potential of coffee. We have studied the effects on blood pressure and heart rate of total elimination of coffee and tea in comparison with drinking boiled coffee consumed as such, or boiled coffee consumed after filtration through paper filter. Thirty-one women and 33 men first consumed 6 cups/day of boiled and filtered coffee for 17 days. Then they were randomly divided into three groups, which for the next 79 days received either unfiltered boiled coffee (caffeine content 860 mg/l), boiled-and-filtered coffee (887 mg caffeine/l), or no coffee, the latter being replaced by fruit juice and mineral water. Total elimination of coffee did not significantly affect blood pressure or heart rate relative to boiled-and-filtered coffee. In subjects who drank boiled coffee, mean ambulant systolic blood pressure rose significantly relative to those who consumed boiled-and-filtered coffee (mean difference +/- SEM, 3.1 +/- 1.1 mm Hg, p = 0.006). This response showed a tendency to be stronger for women (4.5 +/- 1.8 mm Hg) than for men (1.7 +/- 1.2 mm Hg). We conclude that elimination of filtered coffee has no substantial long-term effect on blood pressure, but consumption of unfiltered boiled coffee may cause a slight but significant rise in systolic blood pressure.
Adult↗
Cholesterol-raising factor from boiled coffee does not pass a paper filter.
Previous studies have indicated that consumption of boiled coffee raises total and low density lipoprotein (LDL) cholesterol, whereas drip-filtered coffee does not. We have tested the effect on serum lipids of consumed coffee that was first boiled and then filtered through commercial paper coffee filters. Sixty-four healthy volunteers consumed six cups per day of this boiled and filtered coffee for 17 days. Then, they were randomly divided into three groups, which, for the next 79 days, received either unfiltered boiled coffee (lipid content, 1.0 g/l), boiled and filtered coffee (0.02 g lipid/l), or no coffee. Serum total cholesterol levels rose by 0.42 mmol/l (16 mg/dl; 95% confidence interval [CI], 0.14-0.71), LDL cholesterol levels by 0.41 mmol/l (16 mg/dl; 95% CI, 0.16-0.66), and apolipoprotein B levels by 8.6 mg/dl (95% CI, 3.8-13.4) in those who consumed boiled coffee relative to those who consumed boiled and filtered coffee. Responses of triglycerides, high density lipoprotein cholesterol, and apolipoprotein A-I did not differ significantly among these groups. No significant effects on serum lipid levels were found in the boiled and filtered coffee-consuming group compared with those who drank no coffee. In subjects who drank boiled coffee, serum campesterol level, an indicator of cholesterol absorption, remained constant. The serum lathosterol level, an indicator of cholesterol synthesis, increased by 11% (p less than 0.05), but the lathosterol to cholesterol ratio did not change. We propose that paper filters of the type used for drip-filtered coffee retain the lipid present in boiled coffee and in that way remove the hypercholesterolemic factor.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
The effect of coffee on blood lipids and blood pressure. Results from a Norwegian cross-sectional study, men and women, 40-42 years.
The association between boiled and filter coffee consumption and levels of cholesterol, triglycerides and blood pressure was studied, including 14168 men and 14859 women. A total of 94% drank coffee, 55% of the men and 48% of the women drank more than 4 cups per day. The type of coffee consumed varied between the counties, from 11 to 49% boiled and 49 to 87% filter coffee. Serum cholesterol increased linearly with increasing coffee consumption, and most strongly for boiled coffee. Controlling for other variables gave, for boiled coffee, an 8% increase for men and 10% for women. For filter coffee drinkers the coffee dose-cholesterol association remained significant only for women. Triglycerides showed a negative association with coffee, significant after adjustment for other variables. This effect was stronger for filter than for boiled coffee in both sexes. For men and women drinking 1 cup of coffee or more, a significant negative association between both systolic and diastolic blood pressure and number of cups of filter coffee was found. The influence of high consumption of different coffee-types on death rate from coronary heart disease is discussed.
Adult↗
Reproducibility and validity of coffee and tea consumption in Italy.
OBJECTIVE: The reproducibility and validity of coffee, decaffeinated coffee and tea intake has not been adequately studied, particularly in Italy, where coffee drinking is peculiar in terms of type and amount of coffee consumed. DESIGN: We compared coffee and tea consumption, measured by two interviewer-administered food frequency questionnaires (FFQ), with average intake derived from two 7-day dietary (DD) records (the reference method) on 395 volunteers. The Pearson correlation coefficients (r) were used to assess both reproducibility and validity of information on coffee intake. RESULTS: A satisfactory level of reproducibility and validity of the pattern consumption was observed for coffee, decaffeinated coffee and tea. The reproducibility for both sex combined showed r of 0.74-0.78 for coffee, 0.57-0.65 for decaffeinated coffee and 0.61-0.67 for tea. The validity was about 0.70 for coffee, around 0.58 for decaffeinated coffee and 0.56-0.60 for tea intake. CONCLUSIONS: The FFQ is a satisfactorily reliable and valid instrument for collecting information on coffee, decaffeinated coffee and tea intake.
Adult↗
Coffee and gastrointestinal function: facts and fiction. A review.
BACKGROUND: Effects of coffee on the gastrointestinal system have been suggested by patients and the lay press, while doctors tend to discourage its consumption in some diseases. METHODS: The literature on the effects of coffee and caffeine on the gastrointestinal system is reviewed with emphasis on gastrointestinal function. RESULTS: Although often mentioned as a cause of dyspeptic symptoms, no association between coffee and dyspepsia is found. Heartburn is the most frequently reported symptom after coffee drinking. It is demonstrated that coffee promotes gastro-oesophageal reflux. Coffee stimulates gastrin release and gastric acid secretion, but studies on the effect on lower oesophageal sphincter pressure yield conflicting results. Coffee also prolongs the adaptive relaxation of the proximal stomach, suggesting that it might slow gastric emptying. However, other studies indicate that coffee does not affect gastric emptying or small bowel transit. Coffee induces cholecystokinin release and gallbladder contraction, which may explain why patients with symptomatic gallstones often avoid drinking coffee. Coffee increases rectosigmoid motor activity within 4 min after ingestion in some people. Its effects on the colon are found to be comparable to those of a 1000 kCal meal. Since coffee contains no calories, and its effects on the gastrointestinal tract cannot be ascribed to its volume load, acidity or osmolality, it must have pharmacological effects. Caffeine cannot solely account for these gastrointestinal effects. CONCLUSIONS: Coffee promotes gastro-oesophageal reflux, but is not associated with dyspepsia. Coffee stimulates gallbladder contraction and colonic motor activity.
Caffeine↗
Human coffee drinking: manipulation of concentration and caffeine dose.
In a residential research ward coffee drinking was studied in 9 volunteer human subjects with histories of heavy coffee drinking. A series of five experiments was undertaken to characterize adlibitum coffee consumption and to investigate the effects of manipulating coffee concentration, caffeine dose per cup, and caffeine preloads prior to coffee drinking. Manipulations were double-blind and scheduled in randomized sequences across days. When cups of coffee were freely available, coffee drinking tended to be rather regularly spaced during the day with intercup intervals becoming progressively longer throughout the day; experimental manipulations showed that this lengthening of intercup intervals was not due to accumulating caffeine levels. Number of cups of coffee consumed was an inverted U-shaped function of both coffee concentration and caffeine dose per cup; however, coffee-concentration and dose-per-cup manipulations did not produce similar effects on other measures of coffee drinking (intercup interval, time to drink a cup, within-day distribution of cups). Caffeine preload produced dose-related decreases in number of cups consumed. As a whole, these experiments provide some limited evidence for both the suppressive and the reinforcing effects of caffeine on coffee consumption. Examination of total daily coffee and caffeine intake across experiments, however, provides no evidence for precise regulation (i.e., titration) of coffee or caffeine intake.
Caffeine↗
The hypercholesterolemic effect of cafestol in coffee oil in gerbils and rats.
Coffee beans contain the diterpene cafestol, which raises plasma cholesterol concentrations in humans. Daily consumption of 2 g coffee oil, which provides approximately 60 mg cafestol (equivalent to 5.7 mg cafestol/MJ), increases plasma cholesterol concentrations by 28%. We studied the effect of cafestol in coffee oil on gerbils and rats to determine whether the pathways that lead to cafestol-induced hypercholesterolemia in humans are also present in other species. We fed coffee oil from the same batch used in humans to female gerbils and rats. Gerbils were fed a semipurified diet containing 0.5% or 5% (w/w) coffee oil (equivalent to 8.7 and 86.8 mg cafestol/MJ, respectively) in the presence or absence of 0.05% (w/w) cholesterol for a period of 10 weeks. When compared with the gerbils fed no coffee oil, the addition of 0.5% coffee oil to the diets did not affect plasma cholesterol. Plasma cholesterol was significantly higher only when 5% coffee oil was fed, both in the absence (1.01 mmol/L, 33% higher) and presence (1.87 mmol/L, 70% higher) of dietary cholesterol. Liver weight was also significantly higher when 5% coffee oil was fed. Rats were also fed diets containing 0.5% or 5% coffee oil (equivalent to 8.7 and 86.8 mg cafestol/MJ) with and without 0.05% cholesterol for 8 weeks. Feeding 0.5% coffee oil compared with no coffee oil resulted in significantly higher plasma cholesterol levels throughout the study both in the absence (0.46 mmol/L, 27% higher) and presence (0.28 mmol/L, 15% higher) of dietary cholesterol. Diets containing 5% coffee oil appeared to be toxic. Thus, coffee oil diterpenes can result in higher plasma cholesterol in gerbils and rats. The failure to observe these effects in previous studies may be due to doses that were too low.
Journal Article↗
Variability in caffeine consumption from coffee and tea: possible significance for epidemiological studies.
Five surveys, using a previously developed high-performance liquid chromatography procedure to measure caffeine concentrations, indicated great variations in the concentrations of caffeine in tea and coffee. In the study of beverages prepared at home, data on caffeine concentrations in 58 samples of tea and coffee, volumes of cups, and numbers of cups consumed/day, indicated that the range of caffeine intakes for the women participating was 49-1022 mg/day. There were considerable day-to-day variations in caffeine contents in coffee samples from some commercial coffee shops. When 17 samples of five national brands of instant coffee were made into beverages in the laboratory, variations in caffeine concentrations between lots were small but between brands were significant. A considerable range of caffeine concentrations was also found when 12 samples of coffee prepared at work by different individuals using the same jar of instant coffee were analysed. Analysis of tea samples prepared in the laboratory indicated that steeping time had an important influence on resulting caffeine and theobromine concentrations. People preparing their own beverages were found to drink more liquid than the volume offered commerically. The mean caffeine 'contents' of home-made coffee and of coffee prepared by individuals at work were 79.4 and 81.7 mg/cup respectively, indicating a mean intake of approximately 80 mg caffeine/cup. When this amount (80 mg/cup) was used to estimate daily intakes of caffeine from coffee, on the basis of the number of reported cups/day, and the values obtained were compared with the amounts actually consumed by individuals, the potential for misrepresentation of individual consumption became obvious. For example, for subjects consuming three cups of coffee, only 25% would have been correctly categorized in the expected range for the daily intake of caffeine, 39% would have been overestimated and 36% underestimated for the amount of caffeine consumed. These variations in caffeine concentrations and in the volume of coffee consumed have frequently been ignored in examinations of the possible relationship between coffee consumption and various health problems, and this could perhaps partly explain some conflicting results seen in epidemiological studies.
Adult↗
Lipid content and composition of coffee brews prepared by different methods.
The lipid content and composition of boiled, filtered, dripped, Turkish and espresso coffees prepared from roasted beans of Coffea arabica and Coffea robusta, and of coffees prepared from different brands of instant coffee were examined. The lipid content varied with the method of preparation. While coffee brews filtered through filter paper contained less than 7 mg lipids, those prepared by boiling without filtering and espresso coffee reached 60-160 mg lipids/150-ml cup. Coffee brew filtered through a metal screener contained 50 mg lipids/150-ml cup. Although the lipid content varied, the method of preparation of the brew and filtration had no important influence on the lipid composition. During paper filtration lipids remained mainly in spent coffee grounds, and the brew and filter paper retained only 0.4 and 9.4%, respectively, of the total lipids recovered. However, the lipids in the brew, filter paper and spent coffee grounds had the same profile, indicating that there was no preferential retention of a particular lipid component in filter paper. Triglycerides and diterpene alcohol esters were the major lipid classes in coffee brewed from ground coffee beans, and ranged from 86.6 to 92.9 and 6.5 to 12.5% of total lipids, respectively. For coffee brews made from instant coffee, the levels of these two lipid classes were 96.4-98.5 and 1.6-3.6%, respectively. The lipid contents of both regular and decaffeinated instant coffees varied slightly from one brand to the other, and ranged from 1.8 to 6.6 mg/150-ml cup.
Chromatography, Thin Layer↗
The effect on serum cholesterol levels of coffee brewed by filtering or boiling.
Previous reports have indicated that coffee consumption may increase serum cholesterol levels. We studied the effects of coffee prepared by two common brewing methods (filtering and boiling) on serum lipid levels in a 12-week randomized trial involving 107 young adult subjects with normal serum cholesterol levels. After a three-week run-in period during which they all consumed filtered coffee, the participants were randomly assigned to one of three groups receiving four to six cups of boiled coffee a day, four to six cups of filtered coffee a day, or no coffee, for a period of nine weeks. As compared with the change from base line in the filtered-coffee group, the serum total cholesterol level increased after the consumption of boiled coffee by 0.48 mmol per liter (95 percent confidence limits, 0.13 and 0.83), and the low-density lipoprotein cholesterol level increased by 0.39 mmol per liter (95 percent confidence limits, -0.04 and 0.82). There was no significant difference in the change in serum total or low-density lipoprotein cholesterol levels between the filtered-coffee group and the group that drank no coffee. The levels of high-density lipoprotein cholesterol and apolipoproteins were not affected by boiled or filtered coffee. We conclude that drinking filtered coffee does not affect serum lipid levels. The consumption of boiled coffee, however, has an effect on serum cholesterol levels amounting to a mean net increase of 10 percent of the base-line level after nine weeks.
Adult↗