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PubMed1999

Effect of processed and non-processed coffee samples on gastric potential difference. Study with healthy male Helicobacter pylori-positive and Helicobacter pylori-negative volunteers.

In an open trial with 18 healthy male volunteers (21-45 years old) the effect of processed (test) and non-processed (reference) coffee samples of same origin on the gastric potential difference (GPD) was studied. Test coffee samples were processed with the patented "Darboven improvement procedure" before roasting. All treatment groups were subdivided according to the Helicobacter pylori status of the volunteers. The evaluation of the target parameters Reizindex (RI), area under the baseline (AUB), maximum potential difference (Pdmax) and total time (ttot) revealed a significant lower RI (p = 0.0282) and AUB (p = 0.0136), and a significant shorter ttot (p = 0.0286) for the processed coffee. Total cholesterol, high-density lipoprotein (HDL) cholesterol, and pancreatic peptides showed a comparable marked increase of the arithmetic mean with both coffee samples, however, being more intense in the Helicobacter pylori-positive subgroup than in the Helicobacter pylori-negative subgroup. No negative findings concerning tolerability and safety could be seen. In conclusion, the test coffee samples processed with a new method to improve the stomach mucosal irritation-potential of coffee charges revealed a remarkably lower stomach mucosal irritation.

Adult↗
PubMed2006

Effects of coffee consumption on glucose tolerance, serum glucose and insulin levels--a cross-sectional analysis.

OBJECTIVE: Coffee has several metabolic effects that could reduce the risk of type 2 diabetes. Our objective was to examine the effects of coffee consumption on glucose tolerance, glucose and insulin levels. RESEARCH DESIGN AND METHODS: A subsample of subjects aged 45 to 64 years in 1987 and in 1992 from the population-based FINRISK study (12,287 individuals) was invited to receive the standard oral glucose tolerance test at baseline. Plasma samples were taken after an overnight fast, and a two-hour oral glucose tolerance test was administered. Fasting and two-hour plasma glucose and insulin were measured in 2434 subjects with data on coffee use and potential confounders. RESULTS: After adjustment for potential confounding factors (age, body mass index, systolic blood pressure, occupational, commuting and leisure time physical activity, alcohol and tea drinking, smoking), coffee consumption was significantly and inversely associated with fasting glucose, two-hour plasma glucose, and fasting insulin in both men and women. Coffee consumption was significantly and inversely associated with impaired fasting glucose, impaired glucose regulation, and hyperinsulinemia among both men and women and with isolated impaired glucose tolerance among women. CONCLUSIONS: In this cross-sectional analysis, coffee showed positive effects on several glycemia markers.

Age Factors↗
PubMed1980

Pathogenesis of coffee-induced gastrointestinal symptoms.

Heartburn was the major gastrointestinal symptom associated with drinking coffee in 31 subjects. These symptomatic subjects had a diminished basal lower-esophageal-sphincter (LES) pressure, 8.3 +/- 1.1 mm Hg, as compared with the pressure in asymptomatic subjects, 19.4 +/- 1.3 mm Hg (P less than 0.01), in response to four separate doses of coffee. LES pressure increased in normal subjects but changed only minimally in the symptomatic group (P less than 0.01). Basal acid output was similar in both groups, but the maximal acid response to coffee was paradoxically greater in normal subjects, 20.9 +/- 3.6 meq per hour, than in the symptomatic group, 9.4 +/- 1.5 meq per hour (P less than 0.01). During coffee instillation into the stomach, 26 of 31 symptomatic subjects (83 per cent) had heartburn at the highest dosage. Cimetidine, but not placebo, reduced acid secretion and heartburn in response to coffee, suggesting that acid was required for the development of symptoms. These studies suggest that LES dysfunction and gastroesophageal reflux, rather than gastric hypersection, are responsible for the heartburn caused by coffee in certain susceptible persons.

Adult↗
PubMed2005

Is coffee a functional food?

Definitions of functional food vary but are essentially based on foods' ability to enhance the quality of life, or physical and mental performance, of regular consumers. The worldwide use of coffee for social engagement, leisure, enhancement of work performance and well-being is widely recognised. Depending on the quantities consumed, it can affect the intake of some minerals (K, Mg, Mn, Cr), niacin and antioxidant substances. Epidemiological and experimental studies have shown positive effects of regular coffee-drinking on various aspects of health, such as psychoactive responses (alertness, mood change), neurological (infant hyperactivity, Alzheimer's and Parkinson's diseases) and metabolic disorders (diabetes, gallstones, liver cirrhosis), and gonad and liver function. Despite this, most reviews do not mention coffee as fulfilling the criteria for a functional food. Unlike other functional foods that act on a defined population with a special effect, the wide use of coffee-drinking impacts a broad demographic (from children to the elderly), with a wide spectrum of health benefits. The present paper discusses coffee-drinking and health benefits that support the concept of coffee as a functional food.

Anti-Bacterial Agents↗
PubMed1996

Reasons for changing caffeinated coffee consumption: the Rancho Bernardo Study.

OBJECTIVE: To determine patterns of lifetime caffeinated and decaffeinated coffee use, focusing on frequency and determinants for curtailing caffeinated coffee. METHODS: Residents of Rancho Bernardo, a white, upper-middle class Southern California community, were surveyed about their lifetime coffee-drinking behavior; completed questionnaires were received from 69% (n = 2955; mean age was 64 years, age range: 30-105 years). Chi-square tests of differences between proportions in categorical data and t-tests for continuous data were used. Due to the large number of comparisons, statistical significance was defined as p or=5 cups/day only in those who curtailed caffeinated coffee on advice of a physician or for heart/circulatory problems. CONCLUSIONS: Curtailing of caffeinated coffee in this adult cohort was primarily due to health concerns, but few of those who curtailed caffeinated coffee attribute the change to the advice of a physician.

Adult↗
PubMed2006

Adsorption of divalent copper, zinc, cadmium and lead ions from aqueous solution by waste tea and coffee adsorbents.

The adsorption of the divalent cations of Cu, Zn, Cd and Pb by tea leaves and coffee grounds from aqueous solutions is described. Both adsorbents exhibited strong affinity for these ions which could be described by a simple single-site equilibrium model. For coffee, the order of increasing adsorption equilibrium constant K was Cu < Pb < Zn < Cd, while for tea the opposite order was observed indicating that the adsorption sites on each adsorbent have a different chemical nature. Adsorption decreased at low pH < 4 through competition with H+ for adsorption sites, and for all metals except Cu, at high pH > 10, probably because of anion formation in the case of Zn2+ and also increased leaching of metal-binding soluble materials. The effect of metal ion concentration on the adsorptive equilibria indicated a threshold concentration above which overall adsorption became limited by saturation of the adsorption sites. Competition between two metal ions for the same sites was not observed with Cu(II) and Pb(II), however Zn(II) reacted competitively with Cd(II) binding sites on both tea and coffee. If fresh coffee or tea adsorbents were used, the fraction of metal ion taken up by the adsorbent was diminished by the competitive effects of soluble metal-binding ligands released by the tea or coffee. Experiments with coffee showed that roasting temperature controls the formation of metal ion adsorption sites for this adsorbent.

Adsorption↗
PubMed1987

Studies on the estrogenic activity of a coffee extract.

Ethyl ether extracts derived from coffee were tested for in vitro estrogenic and in vivo uterotropic activities. Coffee extracts, unlike tea and cocoa, were found to actively compete with 17 beta-estradiol for uterine cytosol binding sites. The biologically active fractions possessed an unique ultraviolet absorbance spectrum that excluded them from containing flavonoid, coumestan, or resorcyclic acid lactone constituents. Coffee extracts administered to immature female mice for 3 d in feeding studies displayed significant (p less than 0.05) uterotropic responses, which were similar to results obtained in mice treated with a standard 17 beta-estradiol dose. Additional studies in mice disclosed that coffee extracts did not reduce the uterotropic effect normally induced by 17 beta-estradiol when administered simultaneously with estradiol. The complete estrogenic effects of coffee constituents, coupled with their failure to inhibit a biological response evoked by estradiol, strongly suggest that coffee contains constituent(s) that are weakly estrogenic.

Animals↗
PubMed1980

Caffeine and coffee: their influence on metabolic rate and substrate utilization in normal weight and obese individuals.

A series of four trials was carried out to investigate the effects of caffeine and coffee on the metabolic rate and substrate utilization in normal weight and obese individuals. In the first trial 8 mg/kg caffeine was compared with a placebo in normal weight subjects. Metabolic rate increased significantly during the 3 hr after caffeine ingestion. While plasma glucose, insulin, and carbohydrate oxidation did not change significantly, plasma free fatty acid levels rose from 432 +/- 31 to 848 +/- 135 muEq/liter and were accompanied by significant increases in fat oxidation during the last hour of the test. In the second and third trials the effects of coffee providing 4 mg/kg caffeine were studied in control and obese subjects. Metabolic rate increased significantly in both groups; however, significant increases in fat oxidation were only observed in the control group. Plasma free fatty acids did not change in the obese. In the fourth trial, coffee was taken with a 3080 kJ meal. The thermic effect of the meal was significantly greater after coffee than after decaffeinated coffee and again fat oxidation was significantly greater after coffee. In conclusion caffeine/coffee stimulates the metabolic rate in both control and obese individuals; however, this is accompanied by greater oxidation of fat in normal weight subjects.

Adult↗
PubMed1983

Tea and coffee as sources of some minerals in the New Zealand diet.

Daily intakes of tea and coffee of a representative sample of adult New Zealanders (865 men and 1100 women) were calculated from 24-h dietary recalls. The mineral concentrations in tea and coffee samples were determined by atomic absorption spectrometry and used to estimate daily mineral intakes from these beverages. More than 80% consumed tea and about 60% consumed coffee on the day of the recall. The men drank significantly more tea than the women (p less than 0.001), but coffee intakes were similar. The results indicate that for New Zealand adults tea is a very good source of manganese and it also contains appreciable amounts of potassium. Coffee is a better source of potassium than tea, has appreciable amounts of magnesium, and may contribute significantly to manganese intakes in some instances. The amounts of copper, zinc, sodium, calcium, and iron extracted from tea leaves and coffee beans in the brewing processes are too low to be of any nutritional significance but minerals in the water used in their preparation may make a significant contribution to dietary intakes.

Adult↗
PubMed1988

Coffee consumption as a factor in iron deficiency anemia among pregnant women and their infants in Costa Rica.

The influence of coffee consumption on hematological and trace element status was studied in two groups of pregnant, low-income Costa Rican women: coffee drinkers (greater than or equal to 450 mL/d, n = 22) and coffee nondrinkers (0 mL/d, n = 26). Groups had similar income, education, prenatal care, age, parity, weight, height, pregnancy weight gain, prenatal iron supplementation, energy, protein, Fe, and vitamin C intake and infant sex and gestational age. Maternal hemoglobin (Hb) and hematocrit (Hct) at 8 mo gestation, cord blood Hb and Hct, infant birth weight and Hb and Hct at 1 mo of age, and breast-milk Fe concentration were significantly lower in the coffee group than in the noncoffee group. The association of coffee with infant Hb and Hct was independent of maternal Fe status and birth weight. These results are consistent with our previously reported data in rats and indicate that maternal coffee intake may contribute to maternal and infant anemia.

Adult↗
PubMed1995

Effects of cafestol and kahweol from coffee grounds on serum lipids and serum liver enzymes in humans.

The diterpenes cafestol and kahweol are present in unfiltered coffee in oil droplets and floating fines. They elevate serum cholesterol and alanine aminotransferase (ALT). We measured fines in coffee brews, and examined diterpene availability from spent grounds in healthy volunteers. Turkish or Scandinavian boiled coffee contained 2-5 g fines/L and French press coffee contained 1.5 g fines/L. An intake of 8 g fine grounds/d for 3 wk increased cholesterol by 0.65 mmol/L (95% CI 0.41-0.89 mmol/L) and ALT by 18 U/L (95% CI 4-32 U/L) relative to control subjects (n = 7/group). In a crossover study (n = 15), mean serum cholesterol was 4.9 mmol/L after consumption of both fine and coarse grounds for 10 d (P = 0.43). Serum ALT activities were 29 U/L on fine and 21 U/L on coarse grounds (P = 0.02). Floating fines could contribute substantially to the hyperlipidemic and ALT-elevating effect of unfiltered coffee. Diterpene measurements in coffee brews should include the contribution of fines.

Adult↗
PubMed2005

Chronic coffee consumption has a detrimental effect on aortic stiffness and wave reflections.

BACKGROUND: The effect of coffee consumption on the cardiovascular system is still an unresolved issue. Aortic stiffness and wave reflections are important prognosticators of cardiovascular disease risk. We have shown that caffeine acutely increases aortic stiffness and wave reflections. OBJECTIVE: The objective was to investigate the effect of chronic coffee consumption on aortic stiffness and wave reflections. DESIGN: This was a cross-sectional study of 228 healthy subjects: 141 men (x +/- SD: 41 +/- 8 y old) and 87 women (41 +/- 9 y old). Aortic stiffness was evaluated with carotid-femoral pulse wave velocity (PWV). Wave reflections were evaluated with augmentation index (AIx) and augmented pressure (AP) of the aortic pressure waveform with the use of high-fidelity pulse wave analysis. Coffee consumption was ascertained over 1 y with a food-frequency questionnaire. RESULTS: A linear relation between coffee consumption and PWV, AIx, and AP was observed (P for trend < 0.05). Compared with the nonconsumption group, PWV was on average 13% higher, AIx was 2-fold higher, and AP was 2.4-fold higher (P < 0.01 for all) in the high-consumption group (>450 mL/d). The findings remained significant after control for confounders such as age, sex, smoking habits, body mass index, total and LDL cholesterol, triacylglycerols, blood glucose, mean blood pressure, and heart rate. The linear relation (P for trend < 0.05) observed between coffee consumption and arterial pressures was largely explained when the covariates were entered in the model. CONCLUSIONS: Chronic coffee consumption exerts a detrimental effect on aortic stiffness and wave reflections, which may increase the risk of cardiovascular disease.

Adult↗
PubMed2000

Association of coffee consumption with gallbladder disease.

Coffee consumption was recently shown to protect against symptomatic gallbladder disease in men. The authors examined the relation of ultrasound-documented gallbladder disease with coffee drinking in 13,938 adult participants in the Third National Health and Nutrition Examination Survey, 1988-1994. The prevalence of total gallbladder disease was unrelated to coffee consumption in either men or women. However, among women a decreased prevalence of previously diagnosed gallbladder disease was found with increasing coffee drinking (p = 0.027). These findings do not support a protective effect of coffee consumption on total gallbladder disease, although coffee may decrease the risk of symptomatic gallstones in women.

Adult↗
PubMed2001

Coffee consumption and serum lipids: a meta-analysis of randomized controlled clinical trials.

Coffee drinking has been associated with increased serum cholesterol levels in some, but not all, studies. A Medline search of the English-language literature published prior to December 1998, a bibliography review, and consultations with experts were performed to identify 14 published trials of coffee consumption. Information was abstracted independently by two reviewers using a standardized protocol. With a random-effects model, treatment effects were estimated by pooling results from individual trials after weighting the results by the inverse of total variance. A dose-response relation between coffee consumption and both total cholesterol and LDL cholesterol was identified (p < 0.01). Increases in serum lipids were greater in studies of patients with hyperlipidemia and in trials of caffeinated or boiled coffee. Trials using filtered coffee demonstrated very little increase in serum cholesterol. Consumption of unfiltered, but not filtered, coffee increases serum levels of total and LDL cholesterol.

Adult↗
PubMed2006

Coffee consumption and incidence of colorectal cancer in two prospective cohort studies of Swedish women and men.

Investigators have reported an inverse association between coffee consumption and risk of colorectal cancer in several case-control studies, but prospective studies, most of them involving small numbers of cases, have not supported such a relation. In this analysis, the authors prospectively examined the association of coffee consumption with colorectal cancer risk among participants from two population-based cohort studies: 61,433 women in the Swedish Mammography Cohort and 45,306 men in the Cohort of Swedish Men. Information about coffee consumption was obtained from food frequency questionnaires in 1987-1990 and 1997 for women and in 1997 for men. The authors used Cox proportional hazards modeling for cohort-specific multivariate analyses, and results were pooled using random-effects models. During 1,240,597 person-years of follow-up, 1,279 incident cases of colorectal cancer were diagnosed. Coffee consumption was not associated with risk of colorectal cancer, colon cancer, or rectal cancer in either women or men. For both cohorts combined, the multivariate rate ratio for colorectal cancer for each additional cup of coffee per day was 1.00 (95% confidence interval: 0.97, 1.04). The associations were not modified by colorectal cancer risk factors. The findings from these two large prospective cohort studies do not support the hypothesis that coffee consumption lowers the risk of colorectal cancer.

Adult↗
PubMed2006

Coffee consumption and risk of myocardial infarction among older Swedish women.

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.

Adult↗
PubMed1988

Coffee consumption and serum cholesterol: an epidemiological study in Belgium.

In a Belgian population group of 15,954 male and 2116 female soldiers and their spouses the relationship between coffee drinking and serum cholesterol has been studied. A moderate but highly significant monotonic positive relationship between coffee drinking and both serum total and non-high density lipoprotein (HDL)-cholesterol was observed in men (p less than 0.001) even when adjusted for the confounding effects of age, body mass index, smoking, alcohol, and dietary fat and cholesterol intake. Men drinking at least three cups of coffee daily had a mean level of serum total cholesterol about 4 mg/dl and of non-HDL-cholesterol about 3 mg/dl higher than those who did not drink coffee. No significant effect of coffee drinking on HDL-cholesterol was observed in men. In women coffee-drinking did not influence any of the measured serum lipids.

Adolescent↗
PubMed1993

Bladder cancer and coffee consumption in smokers and non-smokers in Spain.

The association between coffee consumption and bladder cancer was investigated in a multi-centre case-control study conducted in Spain from 1983 to 1986. A total of 497 cases (438 male and 59 female) with histopathologically confirmed bladder cancer were used in the analysis along with 566 hospital controls and 547 population controls. Odds ratios (OR), adjusted for age, province of residence, occupations at risk, consumption of artificial sweeteners and cigarette smoking, did not show any association between coffee consumption and bladder cancer for either sex. However, in non-smokers and mainly in males, for current coffee drinkers the OR was 2.78 (95% [Cl]: 0.78-9.87), while for drinkers of 2-7, 8-14 and > or = 15 cups/week the respective OR were 2.22, 3.11 and 1.87 with a dose-response relationship for lifelong consumption and years of exposure to regular coffee consumption. The OR in male non-smokers and current coffee drinkers were 2.36 (95% Cl: 0.62-9.05) with population controls only and 1.94, 2.58 and 1.48 for the corresponding levels of intensity of consumption (cups/week). The associations observed in non-smokers suggest the existence of a possible association between coffee consumption and bladder cancer, but are based on small numbers and need to be confirmed in larger studies.

Case-Control Studies↗