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PubMed1986

Coffee intake during pregnancy and lactation in rats: maternal and pup hematological parameters and liver iron, zinc and copper concentration.

To study the effects of maternal coffee intake on trace element status of the fetus and newborn, Sprague-Dawley female rats were fed a control purified diet and were provided ad libitum a freeze-dried coffee solution (1.5% wt/vol) (C) or distilled water (W) as their sole source of liquids from d 0 of gestation. On d 21 of gestation, a subsample of dams from each group was killed and litters were removed for examination. At birth, a subsample of litters from each group was cross-fostered to differentiate between pre- and postnatal exposure to coffee (water prenatally, coffee postnatally = WC; coffee prenatally, water postnatally = CW). Food and fluid intake during gestation, maternal weight gain and litter size were similar in the coffee and control groups, but pup birth weight was lower in the coffee group than in the control group (5.82 vs. 6.45 g, P less than 0.05). Compared with that of control pups, hemoglobin (Hb) was significantly lower in C and WC pups, but not in CW pups, at 3 and 14 d of age. Hematological values were not significantly different between C and W dams or C and W fetuses. Livers of C and WC pups had higher concentrations and total content of Fe, Zn and Cu at 3 d of age compared with controls, but the differences were reduced by 14 d of age. The results suggest that maternal coffee intake may impair mobilization of trace elements from liver reserves in early life and that this may result in reduced hemoglobin synthesis.

Animals↗
PubMed2006

Consumption of coffee, but not black tea, is associated with decreased risk of premenopausal breast cancer.

Caffeine has been suggested as a possible risk factor for breast cancer, potentially through its effect of facilitating the development of benign breast disease. However, coffee and tea also contain polyphenols, which exhibit anticarcinogenic properties. A hospital-based, case-control study was conducted to evaluate the role of coffee, decaffeinated coffee, and black tea in breast cancer etiology. Study participants included 1932 cases with primary, incident breast cancer and 1895 hospital controls with nonneoplastic conditions. All participants completed a comprehensive epidemiological questionnaire. Among premenopausal women, consumption of regular coffee was associated with linear declines in breast cancer risk (P for trend = 0.03); consumers of >or=4 cups/d experienced a 40% risk reduction (odds ratio = 0.62, 95% CI 0.39-0.98). No clear associations between intake of black tea or decaffeinated coffee and breast cancer risk were noted among premenopausal women, although black tea was associated with a protective effect unique to a subsample of cases with lobular histology. Among postmenopausal women, breast cancer risk was not associated with consumption of coffee, tea, or decaffeinated coffee. Results among postmenopausal women did not differ by histologic subtype. Our findings support a protective effect of coffee intake on premenopausal, but not postmenopausal breast cancer risk. Further studies are warranted to confirm these findings.

Adult↗
PubMed2005

Influence of coffee drinking on subsequent risk of hepatocellular carcinoma: a prospective study in Japan.

BACKGROUND: An association between coffee drinking and reduced risk of liver cancer has been suggested by animal studies, but epidemiologic evidence of such an association in a high-risk population is lacking. We conducted a large-scale population-based cohort study of the association between coffee drinking and hepatocellular carcinoma (HCC) in a Japanese population. METHODS: Newly diagnosed case patients (250 men and 84 women) with HCC were identified from a 10-year follow-up of the Japan Public Health Center-based Prospective Study, which consists of 90,452 middle-aged and elderly Japanese subjects (43,109 men and 47,343 women). Case patients were grouped according to coffee intake and were stratified by hepatitis virus infection, sex, age, diet, lifestyle factors, and previous history of liver disease. Multivariable-adjusted hazard ratios (HR) and 95% confidence intervals (CIs) for HCC were calculated with Cox proportional-hazards modeling. All statistical tests were two-sided. RESULTS: Subjects (men and women combined) who consumed coffee on a daily or almost daily basis had a lower HCC risk than those who almost never drank coffee (HR = 0.49 [95% CI = 0.36 to 0.66]); risk decreased with the amount of coffee consumed (compared with nondrinkers, the HR for 1-2 cups per day = 0.52 [95% CI = 0.38 to 0.73]; for 3-4 cups per day = 0.48 [95% CI = 0.28 to 0.83]; for > or =5 cups per day = 0.24 [95% CI = 0.08 to 0.77], P(trend) < .001). The risk of liver cancer in almost never drinkers in this population was 547.2 cases per 100,000 people over 10 years, but it was 214.6 cases per 100 000 people with drinking coffee on a daily basis. The inverse association persisted when the participants were stratified by lifestyle factors. Similar associations were observed when the analysis was restricted to hepatitis C virus-positive patients (all daily drinkers compared with nondrinkers: HR =0.57 [95% CI = 0.37 to 0.86]), to hepatitis B virus-positive patients (HR = 0.60 [95% CI = 0.31 to 1.18]) and to subjects with no past history of chronic liver disease (HR = 0.45 [95% CI = 0.30 to 0.67]). CONCLUSIONS: In the Japanese population, habitual coffee drinking may be associated with reduced risk of HCC.

Adult↗
PubMed1989

Cytogenetic response to coffee in Chinese hamster ovary AUXB1 cells and human peripheral lymphocytes.

We have investigated the genotoxic effects of three different brands and three types of coffee (freshly brewed regular, instant regular and freshly brewed decaffeinated) in two mammalian systems: the Chinese hamster ovary (CHO) AUXB1 cell line and human peripheral lymphocytes. Sister-chromatid exchanges (SCEs) and endoreduplicated cells (ERCs) were used as the endpoints. Coffee was prepared according to the manufacturer's suggestions, and after cooling, administered to cultured cells at dilutions ranging up to 11% that of full-strength coffee. Each brand and type of coffee induced significant levels of SCEs and ERCs in AUXB1 cells. SCEs, but not ERCs, were induced in human peripheral lymphocytes. Bisulfite, which complexes with carbonyls and reduces their genotoxicity, significantly diminished the number of SCEs and ERCs found after administration of coffee. Catalase and peroxidase, enzymes that destroy hydrogen peroxide activity, had no significant effect upon the SCE and ERC frequencies in AUXB1 cultures treated with freshly brewed regular coffee. These experiments indicate that different brands and types of coffee have sufficient genotoxic activity to increase SCEs and ERCs at levels only a fraction of those normally consumed. 1,2-Dicarbonyls alone and peroxides alone do not appear to be responsible for the majority of SCEs and ERCs that were observed to be induced by dilute coffee.

Aldehydes↗
PubMed1989

Coffee, dietary habits, and serum cholesterol among men and women 35-49 years of age.

The relations between coffee and dietary habits and between coffee, dietary habits, and serum cholesterol were examined in 11,912 men and 12.328 women aged 35-49 years in the Cardiovascular Disease Risk Factor Study in Oppland, southern Norway, 1976-1978. Dietary data are based on results from a self-administered questionnaire. In both sexes, the dietary pattern of persons with a high coffee consumption differed from that of persons with a low coffee consumption: Heavy coffee drinkers had a higher consumption of bread, potatoes, and butter or margarine per slice of bread and more frequent use of hard margarine; men had a higher consumption of eggs and a lower consumption of skim milk. These results suggest a higher total food and fat consumption and a lower ratio of polyunsaturated to saturated fatty acids among heavy coffee drinkers. However, only 20% of the variation in coffee consumption was explained by dietary and lifestyle variables. The study confirmed a positive relation between serum cholesterol and use of butter or hard margarine (p less than 0.001) and between serum cholesterol and coffee consumption (p less than 0.001). Bread consumption and milk consumption were negatively correlated to serum cholesterol. The negative association with skim milk was significant only in women (p less than 0.01).

Adult↗
PubMed1983

Blood pressure, coffee, tea and tobacco consumption: an epidemiological study in Algiers.

The connections and possible interactions between coffee consumption, tobacco consumption, blood pressure (BP), age, and body mass index (BMI) were analysed in a cross-sectional epidemiologic study of 1098 men and 393 women of the Algiers district. Systolic blood pressure (SBP) was negatively and significatively correlated with cigarette smoking. Diastolic blood pressure (DBP) was positively and significantly associated with coffee consumption (P less than 0.001) and negatively and significantly with cigarette consumption (P less than 0.001). These associations remained significant after multivariate analysis including sex, age, BMI, physical exertion at work, athletic activity, rural versus urban residency, tobacco, tea and coffee consumption. Coffee consumption and cigarette smoking were positively associated (P less than 0.001). In the subgroup of men, the association between coffee consumption and DBP was significant only after adjustment for cigarette smoking. In the subgroup of women, containing a low percentage of smokers, this association was significant without such adjustment. This finding suggests that cigarette consumption might partly mask the association between coffee consumption and BP. The contradictory interactions observed between BP, cigarette consumption and coffee consumption might help to explain the conflicting reports concerning the association between coffee consumption and ischemic heart disease.

Adolescent↗
PubMed1995

Coffee and cancer of the pancreas: an Italian multicenter study.

While cigarette smoking is a well-established risk factor for pancreatic cancer, the role of alcohol, coffee and tea consumption remains controversial. In view of this, and because of the limited information on possible environmental risk factors of pancreatic cancer in Italy, we carried out this study. Five hundred seventy patients with newly diagnosed pancreatic cancer and 570 controls from 14 Italian centers were studied. Using a standardized questionnaire, all were interviewed personally about their smoking habits, as well as habitual alcohol, coffee, and tea consumption throughout their lives prior to clinical onset of the disease. Details were also obtained on exposure to potential occupational carcinogens. A moderate association, statistically significant only in women (odds ratio, 2.18; 95% confidence interval, 1.30-3.68), was found between pancreatic cancer and cigarette smoking, but none was observed with alcohol or tea consumption or with any particular occupational exposure. Consumption of 1 or 2 cups of coffee per day was not associated with increased risk; 3 coffees per day increased the risk, but not significantly (odds ratio, 1.49; 95% confidence interval, 0.97-2.30); with consumption of more than 3 coffees per day the increase in risk was highly significant (odds ratio, 2.53; 95% confidence interval, 1.53-4.18). A statistically significant dose-response relationship (p < 0.001) was observed in each sex. The association between coffee use and pancreatic cancer still held after controlling for potential confounding factors such as cigarette smoking or alcohol use, and when the analysis was restricted to nonsmoking coffee drinkers. The results of this study, one of the largest of its type so far published, suggest that a causal relationship may exist between coffee consumption and pancreatic cancer.

Adult↗
PubMed2002

Coffee and tea consumption and cancers of the bladder, colon and rectum.

Coffee has been observed to be associated weakly or not at all with bladder cancer risk, inversely with colon cancer risk, and inconsistently with rectal cancer risk. The association between these cancers and consumption of coffee and tea was examined in a single case-control study conducted in Ontario, Canada from 1992 to 1994. A questionnaire was filled out by 927 bladder cancer cases, 991 colon cancer cases, 875 rectal cancer cases, and 2118 population controls. Although bladder cancer risk was not associated with coffee or tea, risk estimates associated with coffee among subjects who had never smoked were non-significantly increased. Colon cancer risk was inversely associated with coffee. Relative to those drinking less than 1 cup of coffee per day, the odds ratios (OR) for those drinking 1-2 cups was 0.9 (95% CI 0.8-1.1), for those drinking 3-4 cups was 0.8 (95% CI 0.7-1.0), and for those drinking 5 or more cups was 0.7 (95% CI 0.5-0.9); these ORs decreased linearly (P = 0.008). The reduced risk estimates were more pronounced with cancer of the proximal colon than the distal colon. Rectal cancer risk was not associated with either coffee or tea. Coffee consumption was observed to have a different relationship for each of the cancer sites and tea consumption was not related to any cancer site.

Case-Control Studies↗
PubMed2006

Transient exposure to coffee as a trigger of a first nonfatal myocardial infarction.

BACKGROUND: The effects of coffee on myocardial infarction are uncertain. We hypothesize that coffee in the presence of predisposing factors can induce a cascade of events that, through sympathetic nervous activation, can induce the onset of myocardial infarction. METHODS: We recruited 503 incident cases of nonfatal myocardial infarction between 1994 and 1998 in Costa Rica. We used a case-crossover design to calculate relative risks (RRs) and 95% confidence intervals (95% CIs). RESULTS: The RR of myocardial infarction in the hour after coffee intake was 1.49 (95% CI = 1.17-1.89). Occasional coffee drinkers (< or =1 cup/day, n = 103) had a RR of myocardial infarction of 4.14 (2.03-8.42), moderate coffee drinkers (2-3 cups/day, n = 280) had a RR of 1.60 (1.16-2.21), and heavy coffee drinkers (> or =4 cups/d, n = 120) had a RR of 1.06 (0.69-1.63; P = 0.006, test of homogeneity). Patients with 3 or more risk factors (n = 101) had a RR of myocardial infarction of 2.10 (1.30-3.39), whereas patients with fewer than 3 risk factors (n = 396) had a RR of 1.39 (1.04-1.82; P = 0.15, test of homogeneity); and RR was 1.72 (1.30-2.30) among sedentary patients compared with 1.07 (0.66-1.72) among nonsedentary (P = 0.10, test of homogeneity). CONCLUSIONS: The findings indicate that coffee intake may trigger myocardial infarction. The association is particularly strong among people with light/occasional intake of coffee (< or =1 cup/day), with sedentary lifestyle, or with 3 or more risk factors for coronary heart disease.

Acute Disease↗
PubMed1989

Coffee and tea consumption, dietary fat intake and serum cholesterol concentration of Finnish men and women.

The association between the consumption of coffee and tea and serum cholesterol concentration was studied in a population sample of 653 men and 695 women from east and south-west Finland. Cholesterol and high density lipoprotein (HDL) cholesterol were determined from fresh serum samples. Smoking and the intake of coffee, tea and alcohol were assessed by a questionnaire, and nutrient intake was determined from 3-day food records. Serum cholesterol and non-HDL cholesterol showed a positive and linear association with coffee consumption in men. In women, no such significant linear association was evident, although the highest mean serum cholesterol levels were found in subjects consuming seven to nine cups of coffee daily. Both in men and in women coffee consumption was positively associated with smoking and the intake of saturated and monounsaturated fatty acids and cholesterol. Serum cholesterol values, adjusted for age, body mass index, smoking, dietary cholesterol, fatty acids, alcohol and physical activity, showed a significant linear association with coffee consumption in men but not in women. Although coffee consumption and high intake of saturated fatty acids and cholesterol were related both in men and in women, adjustment for dietary and other confounding factors did not remove the association between coffee consumption and serum cholesterol concentration in men.

Adult↗
PubMed2004

Coffee consumption, type 2 diabetes and impaired glucose tolerance in Swedish men and women.

OBJECTIVES: The association between coffee consumption, type 2 diabetes and impaired glucose tolerance was examined. In addition, indicators of insulin sensitivity and beta-cell function according to homeostasis model assessment were studied in relation to coffee consumption. DESIGN: Population-based cross-sectional study. SETTING AND SUBJECTS: The study comprised 7949 healthy Swedish subjects aged 35-56 years residing within five municipalities of Stockholm. An oral glucose tolerance test identified 55 men and 52 women with previously undiagnosed type 2 diabetes and 172 men and 167 women with impaired glucose tolerance. Information about coffee consumption and other factors was obtained by questionnaire. RESULTS: The relative risks (adjusted for potential confounders) of type 2 diabetes and impaired glucose tolerance when drinking >/=5 cups of coffee per day compared with </=2 cups per day in men were 0.45 [95% confidence intervals (CI) 0.22-0.92] and 0.63 (CI: 0.41-0.97), respectively, and in women 0.27 (CI: 0.11-0.66) and 0.47 (CI: 0.29-0.76) respectively. In subjects with type 2 diabetes and impaired glucose tolerance, high coffee consumption (>/=5 cups day(-1)) was inversely associated with insulin resistance. In addition, in those with type 2 diabetes and in women (not in men) with impaired glucose tolerance high coffee consumption was inversely associated with low beta-cell function. In women, but not obviously in men, with normal glucose tolerance, coffee consumption was associated with a reduced risk of insulin resistance. CONCLUSIONS: The results of this study indicated that high consumers of coffee have a reduced risk of type 2 diabetes and impaired glucose tolerance. The beneficial effects may involve both improved insulin sensitivity and enhanced insulin response.

Adult↗
PubMed1997

The propensity of different brands of tea and coffee to cause staining associated with chlorhexidine.

Dental staining is a well known and probably the most problematic side effect of using chlorhexidine oral products. Whatever mechanisms are involved, there is no doubt that cationic antiseptics, such as chlorhexidine, can precipitate or bind to surfaces anionic chromogens contained in foods and beverages. The aim of this study in vitro was to determine whether, under controlled conditions, different brands of tea or coffee varied in their propensity to cause staining associated with chlorhexidine. Optically clear acrylic specimens were cycled through saliva, chlorhexidine and different tea and coffee solutions. Staining was measured using a spectrophotometer. After 15 cycles, it was apparent that staining varied at the extreme, both within and between the tea and coffee groups. All coffee brands produced less staining than the tea brands. The least staining coffee and least staining tea brands were approximately 3x less chromogenic than the most staining equivalent beverage. Previous randomised controlled clinical trials have indicated that tea and coffee contribute to dental and tongue staining associated with chlorhexidine mouthrinses. Additionally, abstinence from tea and coffee significantly reduces staining. The results of this study in vitro suggest that when abstinence is difficult, tea and coffee brands of low chromogenicity may be recommended. Clearly these data in vitro require validation in vivo.

Analysis of Variance↗
PubMed1987

Coffee consumption is correlated with serum cholesterol in middle-aged Finnish men and women.

The association between coffee consumption and serum cholesterol was studied in a cross-sectional epidemiological study in Finland where the annual per capita consumption of coffee (13.0 kg) is the highest in the world. Coffee consumption was assessed by a questionnaire in a representative population sample of 4744 men and 4495 women aged 25 to 64 years. Serum total cholesterol and HDL-cholesterol concentrations were determined in fresh sera by the enzymatic method. Data on a large number of potential confounding variables were also collected. In the age group 25 to 44 years, the level of serum total cholesterol increased linearly with increasing coffee consumption in both sexes, but in people aged 45 to 64 the peak level of serum cholesterol was found in those who consumed 4 to 6 cups of coffee per day. In the analysis of covariance controlling for age, body mass index, intake of fat, sugar, and alcohol, smoking, physical activity, and fasting time, the mean level of serum cholesterol of men was lower (p less than 0.001) in those who drank no coffee (5.9 mmol/l) than in those who drank 1 to 3 cups (6.1 mmol/l) or 4 or more cups (6.2 mmol/l) per day. In women, the corresponding mean serum cholesterol values were 5.8 mmol/l, 6.1 mmol/l, and 6.1 mmol/l (p less than 0.05). Serum HDL-cholesterol levels did not vary significantly with coffee consumption. There was a slight inverse association between tea drinking and serum total cholesterol in men (p less than 0.05) but not in women. Although our results suggest a positive association, the impact of coffee drinking on serum cholesterol seems to be minimal. The results also indicate that the possible mechanisms do not include caffeine.

Adult↗
PubMed1993

Coffee and tea consumption and the prevalence of coronary heart disease in men and women: results from the Scottish Heart Health Study.

STUDY OBJECTIVES: The aim was to determine if there was a relationship between coffee or tea consumption and the prevalence of coronary heart disease in Scotland. DESIGN: The relationship between self reported coffee and tea consumption and the prevalence of coronary heart disease (history, symptoms, or electrocardiographic evidence) was investigated using multiple logistic regression analysis in the Scottish Heart Health Study (SHHS), a cross sectional study. SETTING: Twenty two Scottish districts were surveyed for the SHHS between 1984 and 1986. SUBJECTS: A total of 10,359 men and women aged 40-59 years were studied. MEASUREMENTS AND MAIN RESULTS: Of the 9740 subjects who were assigned a category, 21.8% (2122) were classified as having indications of coronary heart disease. Men and women were combined in the odds ratio analysis because they showed almost identical patterns in the prevalence of coronary heart disease across the coffee and tea quarters (grouped according to consumption). Those who did not drink coffee had a significantly higher (p < 0.05) prevalence of coronary heart disease than the three groups for coffee drinkers. Adjustments for risk factors including cigarette smoking, total blood cholesterol, and diastolic blood pressure did not remove the significance of the odds ratios. There was a positive dose-response effect between tea consumption and coronary heart disease which was removed after adjustment for various risk factors. CONCLUSIONS: These findings do not support a positive relationship between coffee or tea consumption and coronary heart disease in this British study where most coffee consumed is instant coffee.

Adult↗
PubMed1999

Coffee and tea consumption in the Scottish Heart Health Study follow up: conflicting relations with coronary risk factors, coronary disease, and all cause mortality.

STUDY OBJECTIVE: To relate habitual (cups per day) tea and coffee consumption to conventional coronary risk factors and subsequent risk of coronary heart disease and death. DESIGN: Cohort study. SETTING: Nationwide random population study. PARTICIPANTS: Over 11,000 men and women aged 40-59 who took part in the Scottish Heart Health Study lifestyle and risk factor survey in 1984-87. Participants were followed up to the end of 1993, an average of 7.7 years, for all cause mortality, coronary death, or any major coronary event (death, non-fatal infarction or coronary artery surgery). Cox's proportional hazards regression model was used to estimate the hazard in consumers of tea and coffee relative to the zero consumption group, both before and after correction for other factors. MAIN RESULTS: Coffee and tea consumption showed a strong inverse relation. For many conventional risk factors, coffee showed a weak, but beneficial, gradient with increasing consumption, whereas increasing tea consumption showed the reverse. Increasing coffee consumption was associated with beneficial effects for mortality and coronary morbidity, whereas tea showed the opposite. Adjusting for age and social class had some effect in reducing associations. Multiple adjustment for other risk factors removed the associations for tea and most of those for coffee although there was a residual benefit of coffee consumption in avoiding heart disease among men. CONCLUSIONS: The epidemiological differences shown in this study occurred despite the pharmacological similarities between tea and coffee. Either they differ more than is realised, or they identify contrasting associated lifestyle and health risks, for which this multiple adjustment was inadequate.

Adult↗
PubMed1979

The combined effect of smoking and coffee drinking on LDL and HDL cholesterol.

Conflicting reports on the effect of smoking and coffee drinking on lipoproteins prompted us to study the combined effect of these two associated, widely prevalent habits in 361 persons randomly sampled from the Evans County cohort. Low-density lipoprotein (LDL) cholesterol levels were significantly higher among persons who smoked cigarettes and consumed five or more cups of coffee per day than among nonsmokers who abstained from coffee. Conversely, high-density lipoprotein (HDL) cholesterol was higher in persons who did not smoke or drink coffee than in coffee-consuming smokers. However, this trend was not statistically significant. Triglycerides and very low-density lipoprotein (VLDL) cholesterol were highest among smokers who drank five or more cups of coffee per day, but these differences did not reach statistical significance. Lipoprotein cholesterol levels were adjusted for age, sex and body mass. Smoking and coffee drinking interact in affecting LDL and total cholesterol, but coffee drinking alone did not appear to affect blood lipids.

Age Factors↗
PubMed1989

Effect of decaffeinated versus regular coffee on blood pressure. A 12-week, double-blind trial.

The effect of decaffeinated versus regular coffee on blood pressure and heart rate was investigated. In a randomized double-blind, crossover trial, 45 healthy volunteers (23 women and 22 men, 25-45 years old) with a habitual intake of 4-6 cups coffee/day received 5 cups of regular coffee each day for a period of 6 weeks, and 5 cups of decaffeinated coffee for the next 6 weeks or vice versa. The background diet was kept constant. The total amount of caffeine ingested was 40 mg during the decaffeinated coffee period and 445 mg during the regular coffee period. Use of decaffeinated coffee led to a significant but small decrease in systolic (mean +/- SEM, -1.5 +/- 0.4 mm Hg; p = 0.002) and diastolic (-1.0 +/- 0.4 mm Hg; p = 0.017) ambulant blood pressure and to a small increase in ambulant heart rate (+1.3 +/- 0.6 beats/min; p = 0.031). Individual differences in rate of caffeine metabolism did not explain differences in long-term response of blood pressure to caffeine. We conclude that in normotensive adults replacement of regular by decaffeinated coffee leads to a real but small fall in blood pressure. However, it remains to be established whether a mass switch from regular to decaffeinated coffee would significantly reduce the total incidence of hypertension-related disorders.

Adolescent↗
PubMed2005

Effect of coffee intake on blood pressure in male habitual alcohol drinkers.

Many cross-sectional epidemiological studies have revealed that alcohol consumption is closely related to an increase in blood pressure, which is known to be associated with an elevated serum gamma-glutamyltransferase (GGT) level, rather than to the volume of alcohol consumed. Since recent studies showed that coffee intake is inversely related to serum GGT, we investigated the effect of coffee on blood pressure in habitual alcohol drinkers. A total of 42 male hypertensive or prehypertensive volunteers who consumed alcohol and coffee daily completed this randomized controlled crossover trial. After a 2-week baseline period, these participants were randomly assigned to either a coffee-drinking group or a non-coffee-drinking group for the first 4 weeks. The situation was then reversed for the next 4 weeks. All participants continued their usual alcohol consumption. Blood pressure was measured once a week and compared between the two groups. After 1 week of coffee intake of more than 3 cups per day, the systolic and diastolic blood pressure began to fall slowly, and cessation of coffee intake raised the blood pressure. Systolic blood pressure was lowered by 7-10 mmHg, and diastolic pressure by 3-7 mmHg in 4 weeks. Alcohol consumption of more than 60 ml per day was maintained and there were no lifestyle changes in the participants of either group throughout the study period. Analyses of urine electrolytes and urea nitrogen indicated that there were no significant dietary changes. In conclusion, coffee intake of more than 3 cups per day in hypertensive and prehypertensive men who regularly consume alcohol lowers blood pressure.

Adult↗