Habitual coffee consumption and risk of hypertension: a systematic review and meta-analysis of prospective observational studies

Coffee consumption and risk of hypertension: a dose-response meta-analysis of prospective studies

PURPOSE

Recently, a large prospective study provided additional information concerning the debated possible association between habitual coffee consumption and risk of hypertension (HPT). Therefore, we updated the state of knowledge on this issue by carrying out a comprehensive new systematic review of the literature and a meta-analysis of the available relevant studies.

METHODS

We performed a systematic search for prospective studies on general population, published without language restrictions (1966-August 2017). A random-effects dose-response meta-analysis was conducted to combine study specific relative risks (RRs) and 95% confidence intervals. Potential non-linear relation was investigated using restricted cubic splines.

RESULTS

Four studies (196,256 participants, 41,184 diagnosis of HPT) met the inclusion criteria. Coffee intake was assessed by dietary questionnaire. Dose-response meta-analysis showed a non-linear relationship between coffee consumption and risk of HPT (p for non-linearity < 0.001). Whereas the habitual drinking of one or two cups of coffee per day, compared with non-drinking, was not associated with risk of HPT, a significantly protective effect of coffee consumption was found starting from the consumption of three cups of coffee per day (RR = 0.97, 95% CI = 0.94 to 0.99), and was confirmed for greater consumption.

CONCLUSIONS

The results of this analysis indicate that habitual moderate coffee intake is not associated with higher risk of HPT in the general population and that in fact a non-linear inverse dose-response relationship occurs between coffee consumption and risk of HPT.

Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes

Objectives To evaluate the existing evidence for associations between coffee consumption and multiple health outcomes.Design Umbrella review of the evidence across meta-analyses of observational and interventional studies of coffee consumption and any health outcome.Data sources PubMed, Embase, CINAHL, Cochrane Database of Systematic Reviews, and screening of references.Eligibility criteria for selecting studies Meta-analyses of both observational and interventional studies that examined the associations between coffee consumption and any health outcome in any adult population in all countries and all settings. Studies of genetic polymorphisms for coffee metabolism were excluded.Results The umbrella review identified 201 meta-analyses of observational research with 67 unique health outcomes and 17 meta-analyses of interventional research with nine unique outcomes. Coffee consumption was more often associated with benefit than harm for a range of health outcomes across exposures including high versus low, any versus none, and one extra cup a day. There was evidence of a non-linear association between consumption and some outcomes, with summary estimates indicating largest relative risk reduction at intakes of three to four cups a day versus none, including all cause mortality (relative risk 0.83 (95% confidence interval 0.79 to 0.88), cardiovascular mortality (0.81, 0.72 to 0.90), and cardiovascular disease (0.85, 0.80 to 0.90). High versus low consumption was associated with an 18% lower risk of incident cancer (0.82, 0.74 to 0.89). Consumption was also associated with a lower risk of several specific cancers and neurological, metabolic, and liver conditions. Harmful associations were largely nullified by adequate adjustment for smoking, except in pregnancy, where high versus low/no consumption was associated with low birth weight (odds ratio 1.31, 95% confidence interval 1.03 to 1.67), preterm birth in the first (1.22, 1.00 to 1.49) and second (1.12, 1.02 to 1.22) trimester, and pregnancy loss (1.46, 1.06 to 1.99). There was also an association between coffee drinking and risk of fracture in women but not in men.Conclusion Coffee consumption seems generally safe within usual levels of intake, with summary estimates indicating largest risk reduction for various health outcomes at three to four cups a day, and more likely to benefit health than harm. Robust randomised controlled trials are needed to understand whether the observed associations are causal. Importantly, outside of pregnancy, existing evidence suggests that coffee could be tested as an intervention without significant risk of causing harm. Women at increased risk of fracture should possibly be excluded.

Integrative Medicine for Cardiovascular Disease and Prevention

Cardiovascular disease (CVD) is traditionally treated through medications and lifestyle modifications, yet adherence to these treatments is often poor. The use of complementary therapies is increasing, and it is vital for physicians to be aware of the risks and benefits of these options. This article summarizes the current evidence base on integrative therapies for the prevention and treatment of CVD, including hypertension, hyperlipidemia, coronary artery disease, heart failure, and arrhythmias. Where applicable, recommendations are included for therapies that may be used as an adjunct to traditional medical care to improve cardiovascular health and quality of life.

How coffee affects metabolic syndrome and its components

Metabolic syndrome, with its increasing prevalence, is becoming a major public health problem throughout the world. Many risk factors including nutrition play a role in the emergence of metabolic syndrome. Of the most-consumed beverages in the world, coffee contains more than 1000 components such as caffeine, chlorogenic acid, diterpenes and trigonelline. It has been proven in many studies that coffee consumption has a positive effect on chronic diseases. In this review, starting from the beneficial effects of coffee on health, the relationship between coffee consumption and metabolic syndrome and its components has been investigated. There are few studies investigating the relationship between coffee and metabolic syndrome, and the existing ones put forward different findings. The factors leading to the differences are thought to stem from coffee variety, the physiological effects of coffee elements, and the nutritional ingredients (such as milk and sugar) added to coffee. It is reported that consumption of coffee in adults up to three cups a day reduces the risk of Type-2 diabetes and metabolic syndrome.

Long-Term Coffee Consumption Is Associated with Decreased Incidence of New-Onset Hypertension: A Dose-Response Meta-Analysis

Objective: To perform a dose–response meta-analysis of prospective cohort studies investigating the association between long-term coffee intake and risk of hypertension. Methods: An online systematic search of studies published up to November 2016 was performed. Linear and non-linear dose–response meta-analyses were conducted; potential evidence of heterogeneity, publication bias, and confounding effect of selected variables were investigated through sensitivity and meta-regression analyses. Results: Seven cohorts including 205,349 individuals and 44,120 cases of hypertension were included. In the non-linear analysis, there was a 9% significant decreased risk of hypertension per seven cups of coffee a day, while, in the linear dose–response association, there was a 1% decreased risk of hypertension for each additional cup of coffee per day. Among subgroups, there were significant inverse associations for females, caffeinated coffee, and studies conducted in the US with longer follow-up. Analysis of potential confounders revealed that smoking-related variables weakened the strength of association between coffee consumption and risk of hypertension. Conclusions: Increased coffee consumption is associated with a modest decrease in risk of hypertension in prospective cohort studies. Smoking status is a potential effect modifier on the association between coffee consumption and risk of hypertension.

Association between tea and coffee consumption and prevalence of metabolic syndrome in Poland - results from the WOBASZ II study (2013-2014)

The study aimed to assess a relationship between tea and coffee consumption and metabolic syndrome (MetS). Cross-sectional study of a random sample of total Polish population was done (The WOBASZ II Study), and the present analysis included 5146 participants at age 20 years and above. Tea and coffee consumption was assessed by 24-h recall method. MetS was defined according to IDF/NHLBI/AHA criteria. After adjustment for covariates, coffee consumption was related to blood pressure and HDL cholesterol, and moderate drinkers had 17% lower odds of MetS compared with non-drinkers (OR = 0.83, 95%CI = 0.72-0.97). Tea consumption was related to some components but not to MetS in general. Inverse association between coffee consumption and MetS may reflect the content of the antioxidants that offer cardiovascular protection. However, weak relation of tea with components of MetS points toward the potential importance of composition of polyphenols and the types of tea consumed.

The impact of coffee consumption on blood pressure, cardiovascular disease and diabetes mellitus

INTRODUCTION

Coffee is the most widely consumed beverage, next to water. However, there has been a long-standing controversy regarding its safety on blood pressure (BP) and cardiovascular disease (CVD) and intuitively, physicians dissuaded their patients from coffee drinking. Areas covered: This controversy was, primarily, based on older prospective studies or case reports, which showed a positive association of coffee drinking with the incidence of hypertension and CVD. In contrast to these reports, recent, well controlled, studies have demonstrated either a neutral or beneficial effect of moderate coffee consumption (3-4 cups/day), on BP, CVD, heart failure (HF), cardiac arrhythmias, or diabetes mellitus (DM). For the preparation of this special report, an English language focused search of the Medline database was conducted between 2010 and 2016 on studies with data on effect on the coffee consumption in patients with high BP, CVD, HF, cardiac arrhythmias or DM. Of the 94 abstracts reviewed, 34 pertinent papers were selected, and the findings from these papers together with collateral literature will be discussed in this special report. Expert commentary: Based on the evidence from these studies, coffee consumption in moderation, is safe and is beneficial in both healthy persons as well as patients with high BP, CVD, HF, cardiac arrhythmias or DM. Therefore, coffee restriction is not warranted for these patients, although some caution should be exercised.

Dairy Food Intake Is Inversely Associated with Risk of Hypertension: The Singapore Chinese Health Study

BACKGROUND

Epidemiological evidence from Western populations suggests that dairy food intake may reduce the risk of hypertension, probably through its calcium content. However, there are no epidemiological studies among Asian populations with generally lower dairy and calcium consumption.

OBJECTIVE

The relation between dairy or calcium intake and risk of hypertension was evaluated in a Chinese population in Singapore.

METHODS

The analysis included 37,124 Chinese men and women aged 45-74 y who participated in the Singapore Chinese Health Study in 1993-1998. The subjects included in the present study had no history of cancer, hypertension, or cardiovascular disease at baseline and completed ≥1 follow-up interview. Diet at baseline was assessed by using a validated 165-item semiquantitative food-frequency questionnaire. The occurrence of new, physician-diagnosed hypertension was ascertained through follow-up interviews during 1999-2004 and 2006-2010. The Cox proportional hazard regression method was used to compute HRs and 95% CIs with adjustment for potential confounders.

RESULTS

Dairy food intake was inversely associated with the risk of hypertension in a dose-dependent manner: HRs across quartiles were 1.00 (lowest quartile, reference), 0.97 (95% CI: 0.92, 1.02), 0.98 (95% CI: 0.92, 1.03), and 0.93 (95% CI: 0.88, 0.98) (P-trend = 0.01). Milk accounted for ∼80% of all dairy products consumed in this population. Daily milk drinkers had a lower risk of hypertension (HR: 0.94; 95% CI: 0.89, 0.99) than did nondrinkers. Nondairy calcium intake contributed 80% of total calcium intake. Although dairy calcium intake was associated with a lower risk of hypertension (HR comparing extreme quartiles: 0.88; 95% CI: 0.83, 0.94; P-trend < 0.001), there was no association for nondairy calcium intake (HR: 1.02; 95% CI: 0.94, 1.10; P-trend = 0.58).

CONCLUSIONS

Baseline dairy food intake, and specifically that of milk, may reduce the risk of developing hypertension in Chinese adults, and this may not be associated with the calcium component.

Association of coffee consumption and chronic kidney disease: A meta-analysis

BACKGROUND/OBJECTIVES

The risk of chronic kidney disease (CKD) in individuals who regularly drink coffee is controversial. The aim of this meta-analysis was to evaluate the association between coffee consumption and CKD.

METHODS

A literature search was performed using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from inception until April 2016. We included studies that reported odd ratios or hazard ratios comparing the risk of CKD in individuals consuming significant amount of coffee vs. those who did not consume coffee. Pooled risk ratios (RR) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method.

RESULTS

Four observational studies with 14 898 individuals were included in our analysis to assess the association between coffee consumption and CKD. Coffee consumption was defined as one cup of coffee per day or greater. The pooled RR of CKD in individuals consuming coffee was 0.71 (95% CI, 0.47-1.08). The subgroup analysis showed the pooled RRs of CKD of 1.10 (95% CI, 0.94-1.29) in males and 0.81 (95% CI, 0.58-1.13) in females, respectively.

CONCLUSIONS

Our study demonstrates no significant association between coffee consumption and CKD in males. However, future studies are required to assess a potential inverse association between coffee consumption and risk for developing CKD in females.

Study Frequency of Hypertension and Obesity and their Relationship with Lifestyle Factors (Nutritional Habits, Physical Activity, Cigarette Consumption) in Ardabil City Physicians, 2012-13

Background and Objective:

Few studies have been done on lifestyle of Iranian physicians. As physicians have important role in health promotion, the main goal of the study was to assess the lifestyle of this influential group.

Materials and Methods:

A cross-sectional descriptive study was conducted on lifestyle of all registered physicians of Ardabil hospitals, Iran, 2012–13. In this research, 225 physicians were selected, by using simple random sampling. Demographic and lifestyle data were obtained by self-report using standard questionnaires, physical activity by official Iranian short-version of the international physical activity questionnaire, and dietary intake by food frequency questionnaire. Weight and height was performed according to standard protocols by using standardized and zero calibrated instruments. Data were analyzed by inferential statistics using Statistical Package for the Social Sciences. 16 software.

Results:

Findings showed that 8% of participants were hypertensive, 21.3% smoker, 40%–47% inactive, 51.1% overweight, and 18.2% obese. There was a significant relationship between blood pressure and self-reported lifestyle habits (P < 0.05). And 70.7% of males and 74.1% of females had regular 10-min walking each day and moderate activity of males was significantly higher than females (P < 0.05). Food frequency weekly consumption of overweight and obese physicians were significantly higher than normal weight physicians (P < 0.05).

Conclusion:

Few doctors follow a healthy lifestyle; this may have a negative effect on society attitude about health.

Polyphenol-based nutraceuticals for the prevention and treatment of cardiovascular disease: Review of human evidence

BACKGROUND

In addition to prescription drugs, nutraceuticals/functional foods/medical foods are being increasingly added as adjunct treatment of cardiovascular disease (CVD), even though most of them have been exclusively studied in vitro.

HYPOTHESIS/PURPOSE

We review the available evidence (focusing on when the amount of polyphenols' intake was measured) coming from randomized controlled trials (RCTs) of (poly)phenol-based supplements.

CONCLUSION

We conclude that (poly)phenol-based nutraceuticals and functional foods might be indeed used as adjunct therapy of CVD, but additional long-term RCTs with adequate numerosity and with clinically relevant end points are needed to provide unequivocal evidence of their clinical usefulness.

Coffee and tea consumption in relation to estimated glomerular filtration rate: results from the population-based longitudinal Doetinchem Cohort Study

BACKGROUND

Although coffee consumption and tea consumption have been linked to diabetes, the relation with kidney function is less clear and is underresearched.

OBJECTIVE

We investigated the prospective associations of coffee and tea consumption with estimated glomerular filtration rate (eGFR).

DESIGN

We included 4722 participants aged 26-65 y from the Doetinchem Cohort Study who were examined every 5 y for 15 y. Coffee and tea consumption (in cups/d) were assessed at each round. eGFR was assessed by using the Chronic Kidney Disease Epidemiology Collaboration equation based on both plasma creatinine and cystatin C. We determined the association between categories of coffee and tea intake and 1) eGFR and 2) subsequent annual changes in eGFR by using generalized estimating equation analyses.

RESULTS

Baseline mean ± SD eGFR was 108.0 ± 14.7 mL · min(-1) · 1.73 m(-2) Tea consumption was not associated with eGFR. Those individuals who drank >6 cups coffee/d had a 1.33 (95% CI: 0.24, 2.43) mL · min(-1) · 1.73 m(-2) higher eGFR than those who drank <1 cup/d (P-trend = 0.02). This association was most apparent among those with a median age of ≥46 y at baseline, with eGFR being 2.47 (95% CI: 0.42, 4.51) mL · min(-1) · 1.73 m(-2) higher in participants drinking >6 cups/d compared with <1 cup/d (P-trend = 0.02). Adjustment for biological risk factors and coffee constituents did not attenuate the associations. Neither coffee nor tea consumption was associated with changes in eGFR.

CONCLUSIONS

Coffee consumption was associated with a slightly higher eGFR, particularly in those aged ≥46 y. The absence of an association with eGFR changes suggests that the higher eGFR among coffee consumers is unlikely to be a result of glomerular hyperfiltration. Therefore, low to moderate coffee consumption is not expected to be a concern for kidney health in the general population.

Acute effects of coffee consumption on self-reported gastrointestinal symptoms, blood pressure and stress indices in healthy individuals

Background

It has been suggested that coffee may affect the gut-brain axis with conflicting outcomes. Moreover, there is insufficient evidence to determine whether the type or temperature of coffee consumed will have a different impact on the gut-brain axis. The purpose of this study was to investigate the effects of acute coffee consumption on the following: 1. self-reported GI symptoms and salivary gastrin, 2. stress indices [salivary cortisol and alpha-amylase (sAA)] and psychometric measures, and 3. blood pressure (BP), in healthy, daily coffee consuming individuals in non-stressful conditions.

Methods

This was a randomized, double blind, crossover clinical trial, in which 40 healthy individuals (20 men, 20 women), 20–55 years of age, randomly consumed four 200 ml coffee beverages containing 160 mg caffeine (hot and cold instant coffee, cold espresso, hot filtered coffee), 1 week apart. Salivary samples and psychometric questionnaires were collected at baseline and post-coffee consumption at 15,30, and 60 min for salivary gastrin and sAA measurements and at 60,120, and 180 min for cortisol measurements. BP was measured at beginning and end of each intervention. ClinicalTrials.gov ID: NCT02253628

Results

Coffee consumption significantly increased sAA activity (P = 0.041), with significant differences only between cold instant and filter coffee at 15 and 30 min post-consumption (P < 0.05). Coffee temporarily increased salivary gastrin, without differences between coffee types. Coffee did not affect salivary cortisol or self-reported anxiety levels. Coffee consumption significantly increased BP, within the healthy physiological levels, in a gender specific manner at the end of the experimental periods, without differences between coffee types.

Conclusion

Acute coffee consumption in non-stressful conditions activated sAA and BP but not salivary cortisol, indicating activation of the sympathetic nervous system. Post-coffee sAA increase without a concomitant cortisol increase may also indicate that coffee may have some anti-stress properties.

Coffee Consumption Increases the Antioxidant Capacity of Plasma and Has No Effect on the Lipid Profile or Vascular Function in Healthy Adults in a Randomized Controlled Trial

BACKGROUND

Coffee, a source of antioxidants, has controversial effects on cardiovascular health.

OBJECTIVE

We evaluated the bioavailability of chlorogenic acids (CGAs) in 2 coffees and the effects of their consumption on the plasma antioxidant capacity (AC), the serum lipid profile, and the vascular function in healthy adults.

METHODS

Thirty-eight men and 37 women with a mean ± SD age of 38.5 ± 9 y and body mass index of 24.1 ± 2.6 kg/m(2) were randomly assigned to 3 groups: a control group that did not consume coffee or a placebo and 2 groups that consumed 400 mL coffee/d for 8 wk containing a medium (MCCGA; 420 mg) or high (HCCGA; 780 mg) CGA content. Both were low in diterpenes (0.83 mg/d) and caffeine (193 mg/d). Plasma caffeic and ferulic acid concentrations were measured by GC, and the plasma AC was evaluated with use of the ferric-reducing antioxidant power method. The serum lipid profile, nitric oxide (NO) plasma metabolites, vascular endothelial function (flow-mediated dilation; FMD), and blood pressure (BP) were evaluated.

RESULTS

After coffee consumption (1 h and 8 wk), caffeic and ferulic acid concentrations increased in the coffee-drinking groups, although the values of the 2 groups were significantly different (P < 0.001); caffeic and ferulic acid concentrations were undetectable in the control group. At 1 h after consumption, the plasma AC in the control group was significantly lower than the baseline value (-2%) and significantly increased in the MCCGA (6%) and HCCGA (5%) groups (P < 0.05). After 8 wk, no significant differences in the lipid, FMD, BP, or NO plasma metabolite values were observed between the groups.

CONCLUSIONS

Both coffees, which contained CGAs and were low in diterpenes and caffeine, provided bioavailable CGAs and had a positive acute effect on the plasma AC in healthy adults and no effect on blood lipids or vascular function. The group that did not drink coffee showed no improvement in serum lipid profile, FMD, BP, or NO plasma metabolites. This trial was registered at registroclinico.sld.cu as RPCEC00000168.

Coffee consumption and risk of hypertension in the Polish arm of the HAPIEE cohort study

BACKGROUND/OBJECTIVES

Coffee consumption has been hypothesized to be associated with blood pressure (BP), but previous findings are not homogeneous. The aim of this study was to evaluate the association between coffee consumption and the risk of developing hypertension.

SUBJECTS/METHODS

Data on coffee consumption, BP and use of anti-hypertensive medicament were derived from 2725 participants of the Polish arm of the HAPIEE project (Health, Alcohol and Psychosocial factors In Eastern Europe) who were free of hypertension at baseline and followed up for an average of 5 years. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by multivariate logistic regression analyses and stratified for potential confounding factors.

RESULTS

Coffee consumption was related to decreased age, smoking status and total energy intake. Compared with persons who drink <1 cup coffee per day, systolic BP was significantly associated with coffee consumption and the risk of hypertension was lower for individuals consuming 3-4 cups per day. Despite the analysis stratified by gender showed that the protective effect of coffee consumption on hypertension was significant only in women, the analysis after stratification by smoking status revealed a decreased risk of hypertension in non-smokers drinking 3-4 cups of coffee per day in both sexes (OR 0.41, 95% CI: 0.21, 0.79 for men and OR 0.54, 95% CI: 0.29, 0.99 for women). Upper category coffee consumption (>4 cups per day) was not related to significant increased risk of hypertension.

CONCLUSIONS

Relation between coffee consumption and incidence of hypertension was related to smoking status. Consumption of 3-4 cups of coffee per day decreased the risk of hypertension in non-smoking men and women only.

Coffee and caffeine consumption and the risk of hypertension in postmenopausal women

BACKGROUND

The associations of coffee and caffeine intakes with the risk of incident hypertension remain controversial.

OBJECTIVE

We sought to assess longitudinal relations of caffeinated coffee, decaffeinated coffee, and total caffeine intakes with mean blood pressure and incident hypertension in postmenopausal women in the Women's Health Initiative Observational Study.

DESIGN

In a large prospective study, type and amount of coffee and total caffeine intakes were assessed by using self-reported questionnaires. Hypertension status was ascertained by using measured blood pressure and self-reported drug-treated hypertension. The mean intakes of caffeinated coffee, decaffeinated coffee, and caffeine were 2-3 cups/d, 1 cup/d, and 196 mg/d, respectively. Using multivariable linear regression, we examined the associations of baseline intakes of caffeinated coffee, decaffeinated coffee, and caffeine with measured systolic and diastolic blood pressures at annual visit 3 in 29,985 postmenopausal women who were not hypertensive at baseline. We used Cox proportional hazards models to estimate HRs and their 95% CIs for time to incident hypertension.

RESULTS

During 112,935 person-years of follow-up, 5566 cases of incident hypertension were reported. Neither caffeinated coffee nor caffeine intake was associated with mean systolic or diastolic blood pressure, but decaffeinated coffee intake was associated with a small but clinically irrelevant decrease in mean diastolic blood pressure. Decaffeinated coffee intake was not associated with mean systolic blood pressure. Intakes of caffeinated coffee, decaffeinated coffee, and caffeine were not associated with the risk of incident hypertension (P-trend > 0.05 for all).

CONCLUSION

In summary, these findings suggest that caffeinated coffee, decaffeinated coffee, and caffeine are not risk factors for hypertension in postmenopausal women.

Coffee Consumption and Cardiovascular Health

Coffee is the most widely consumed beverage worldwide and is only second to water drinking and is consumed by 83% of adults in the United States. The long-held controversy regarding the association of coffee consumption with an increased incidence of cardiovascular diseases (CVDs) and hypertension has been reversed by several recent prospective cohort studies and meta-analyses, which have demonstrated that coffee consumption is not associated with increased incidence of CVDs and hypertension and instead it could have a beneficial effect. To get a better understanding of the effects of coffee consumption on cardiovascular health, a Medline search of the English language literature was conducted from 2010 to early 2015 and 25 pertinent reports with information on the effects of coffee drinking, the incidence of CVDs, and hypertension and its mechanism of action were selected for inclusion in this commentary. These studies have shown either a neutral or beneficial effect of coffee on cardiovascular health. In conclusion, coffee is safe to drink by both normal subjects and by those with preexisting CVDs and hypertension.

The role of coffee consumption on the 10-year (2004-2014) Acute Coronary Syndrome (ACS) incidence among cardiac patients: the GREECS observational study

The association between long-term coffee consumption and 10-year cardiovascular disease incidence among Acute Coronary Syndrome (ACS) patients was evaluated. From 2003 to 2004, 2172 ACS consecutive patients from six major Greek hospitals were enrolled. During 2013-2014, the 10-year follow-up was performed (88% participation rate) and recurrent fatal or non-fatal ACS was recorded. Baseline coffee consumption (cups/day) was assessed using a semi-quantitative Food Frequency Questionnaire. Multi adjusted analysis revealed that 1-2 cups of coffee/day versus no consumption had an adverse effect on the ACS incidence [odds ratio (OR) = 1.35, 95% confidence interval (CI) 1.01, 1.79]. In subgroup analysis, with hypertension as strata, only the normotensive reached significance. Odds ratios for 1-2 and ≥3 cups relative to no consumption were [OR = 1.66, 95% CI 1.07, 2.60] and [OR = 1.86, 95% CI 1.06, 3.27], respectively, after controlling for potential confounders. Thus, avoidance of coffee may be of high importance to ameliorate disease prognosis among cardiac patients.

Correlation between tea consumption and prevalence of hypertension among Singaporean Chinese residents aged ⩾40 years

By a cross-sectional epidemiology study, we attempted to correlate the consumption of tea and/or health supplements, living habits and socio-demographic factors to the prevalence of hypertension among Singaporean Chinese residents. Singaporean Chinese residents aged ⩾40 years were randomly selected and interviewed face-to-face by clinical research assistants. Hypertension was defined as measured systolic blood pressure at least 140 mm Hg and/or diastolic blood pressure at least 90  mmHg or self-reported history/treatment for hypertension. The prevalence of hypertension among the whole investigated population (N=1184, 58.27% females) was 49.73% and the prevalence increased to 66.47% in the sub-population aged ⩾60 years. High risk of hypertension was associated with age ⩾60 years (odds ratio (OR): 4.15-4.19, P<0.01), obesity (body mass index >25 kg m(-2), OR: 2.10-2.11, P<0.01), family history of hypertension (OR: 2.69-2.76, P<0.01), diabetes history (OR: 2.29-2.33, P<0.01), hyperlipidemia history (OR: 1.79-1.80, P<0.01), male (OR: 1.56-1.59, P<0.01) and coffee intake (OR: 1.44-1.46, P<0.05). In contrast, drinking green tea at least 150 ml per week was associated with lower hypertension risk (OR: 0.63, 95% confidence interval (CI): 0.43-0.91, P<0.05). Drinking combination of green tea and British tea was associated with higher reduction in the risk of hypertension (OR: 0.58, 95% CI: 0.39-0.85, P<0.05). This cross-sectional study suggests that consumption of tea, especially green tea and British tea, was associated with lowering the risk of hypertension. On the other hand, consumption of coffee could be a risk factor of hypertension. These findings may provide useful information for health promotion to reduce risk of hypertension and warrant further study to confirm and elucidate such association.

Caffeine Use Disorder: A Review of the Evidence and Future Implications

The latest edition of the Diagnostic and Statistical Manual (DSM-5) has introduced new provisions for caffeine-related disorders. Caffeine Withdrawal is now an officially recognized diagnosis, and criteria for caffeine use disorder have been proposed for additional study. caffeine use disorder is intended to be characterized by cognitive, behavioral, and physiological symptoms indicative of caffeine use despite significant caffeine-related problems, similar to other Substance Use Disorders. However, since nonproblematic caffeine use is so common and widespread, it may be difficult for some health professionals to accept that caffeine use can result in the same types of pathological behaviors caused by alcohol, cocaine, opiates, or other drugs of abuse. Yet there is evidence that some individuals are psychologically and physiologically dependent on caffeine, although the prevalence and severity of these problems is unknown. This article reviews the recent changes to the DSM, the concerns regarding these changes, and some potential impacts these changes could have on caffeine consumers.

Long-term coffee consumption and risk of cardiovascular disease: a systematic review and a dose-response meta-analysis of prospective cohort studies

BACKGROUND

Considerable controversy exists on the association between coffee consumption and cardiovascular disease (CVD) risk. A meta-analysis was performed to assess the dose-response relationship of long-term coffee consumption with CVD risk.

METHODS AND RESULTS

PubMed and EMBASE were searched for prospective cohort studies of the relationship between coffee consumption and CVD risk, which included coronary heart disease, stroke, heart failure, and CVD mortality. Thirty-six studies were included with 1 279 804 participants and 36 352 CVD cases. A nonlinear relationship of coffee consumption with CVD risk was identified (P for heterogeneity=0.09, P for trend <0.001, P for nonlinearity <0.001). Compared with the lowest category of coffee consumption (median, 0 cups per day), the relative risk of CVD was 0.95 (95% confidence interval, 0.87-1.03) for the highest category (median, 5 cups per day) category, 0.85 (95% confidence interval, 0.80-0.90) for the second highest category (median, 3.5 cups per day), and 0.89 (95% confidence interval, 0.84-0.94) for the third highest category (median, 1.5 cups per day). Looking at separate outcomes, coffee consumption was nonlinearly associated with both coronary heart disease (P for heterogeneity=0.001, P for trend <0.001, P for nonlinearity <0.001) and stroke (P for heterogeneity=0.07, P for trend <0.001, P for nonlinearity <0.001; P for trend differences >0.05) risks.

CONCLUSIONS

A nonlinear association between coffee consumption and CVD risk was observed in this meta-analysis. Moderate coffee consumption was inversely significantly associated with CVD risk, with the lowest CVD risk at 3 to 5 cups per day, and heavy coffee consumption was not associated with elevated CVD risk.

Cardiovascular disease in latin american patients with systemic lupus erythematosus: a cross-sectional study and a systematic review

Objective. This study was performed to determine the prevalence of and associated risk factors for cardiovascular disease (CVD) in Latin American (LA) patients with systemic lupus erythematosus (SLE). Methods. First, a cross-sectional analytical study was conducted in 310 Colombian patients with SLE in whom CVD was assessed. Associated factors were examined by multivariate regression analyses. Second, a systematic review of the literature on CVD in SLE in LA was performed. Results. There were 133 (36.5%) Colombian SLE patients with CVD. Dyslipidemia, smoking, coffee consumption, and pleural effusion were positively associated with CVD. An independent effect of coffee consumption and cigarette on CVD was found regardless of gender and duration of disease. In the systematic review, 60 articles fulfilling the eligibility criteria were included. A wide range of CVD prevalence was found (4%-79.5%). Several studies reported ancestry, genetic factors, and polyautoimmunity as novel risk factors for such a condition. Conclusions. A high rate of CVD is observed in LA patients with SLE. Awareness of the observed risk factors should encourage preventive population strategies for CVD in patients with SLE aimed at facilitating the suppression of cigarette smoking and coffee consumption as well as at the tight control of dyslipidemia and other modifiable risk factors.

A meta-analysis of prospective studies of coffee consumption and mortality for all causes, cancers and cardiovascular diseases

Several prospective studies considered the relation between coffee consumption and mortality. Most studies, however, were underpowered to detect an association, since they included relatively few deaths. To obtain quantitative overall estimates, we combined all published data from prospective studies on the relation of coffee with mortality for all causes, all cancers, cardiovascular disease (CVD), coronary/ischemic heart disease (CHD/IHD) and stroke. A bibliography search, updated to January 2013, was carried out in PubMed and Embase to identify prospective observational studies providing quantitative estimates on mortality from all causes, cancer, CVD, CHD/IHD or stroke in relation to coffee consumption. A systematic review and meta-analysis was conducted to estimate overall relative risks (RR) and 95 % confidence intervals (CI) using random-effects models. The pooled RRs of all cause mortality for the study-specific highest versus low (≤1 cup/day) coffee drinking categories were 0.88 (95 % CI 0.84-0.93) based on all the 23 studies, and 0.87 (95 % CI 0.82-0.93) for the 19 smoking adjusting studies. The combined RRs for CVD mortality were 0.89 (95 % CI 0.77-1.02, 17 smoking adjusting studies) for the highest versus low drinking and 0.98 (95 % CI 0.95-1.00, 16 studies) for the increment of 1 cup/day. Compared with low drinking, the RRs for the highest consumption of coffee were 0.95 (95 % CI 0.78-1.15, 12 smoking adjusting studies) for CHD/IHD, 0.95 (95 % CI 0.70-1.29, 6 studies) for stroke, and 1.03 (95 % CI 0.97-1.10, 10 studies) for all cancers. This meta-analysis provides quantitative evidence that coffee intake is inversely related to all cause and, probably, CVD mortality.

Effect of beetroot juice on lowering blood pressure in free-living, disease-free adults: a randomized, placebo-controlled trial

Background

The consumption of beetroot juice on a low nitrate diet may lower blood pressure (BP) and therefore reduce the risk of cardiovascular events. However, it is unknown if its inclusion as part of a normal diet has a similar effect on BP. The aim of the study was to conduct a randomized controlled trial with free-living adults to investigate if consuming beetroot juice in addition to a normal diet produces a measureable reduction in BP.

Method

Fifteen women and fifteen men participated in a double-blind, randomized, placebo-controlled, crossover study. Volunteers were randomized to receive 500 g of beetroot and apple juice (BJ) or a placebo juice (PL). Volunteers had BP measured at baseline and at least hourly for 24-h following juice consumption using an ambulatory blood pressure monitor (ABPM). Volunteers remained at the clinic for 1-h before resuming normal non-strenuous daily activities. The identical procedure was repeated 2-wk later with the drink (BJ or PL) not consumed on the first visit.

Results

Overall, there was a trend (P=0.064) to lower systolic blood pressure (SBP) at 6-h after drinking BJ relative to PL. Analysis in men only (n=13) after adjustment for baseline differences demonstrated a significant (P<0.05) reduction in SBP of 4 – 5 mmHg at 6-h after drinking BJ.

Conclusions

Beetroot juice will lower BP in men when consumed as part of a normal diet in free-living healthy adults.

Trial registration

anzctr.org.au ACTRN12612000445875

Coffee Consumption and Stroke Risk: A Meta-analysis of Epidemiologic Studies

Background

Coffee is one of the most widely consumed beverages in the world, and contains caffeine and phenolic compounds. Many studies on the association between coffee consumption and risk of stroke have been reported, however, more research is needed to further explore many studies' inconsistent results. Therefore, we conducted a meta-analysis to verify the relationship between coffee consumption and stroke.

Methods

We searched MEDLINE (PubMed), EMBASE, and the Cochrane Library, using the keywords "coffee" or "caffeine" for the exposure factors, and "transient ischemic attack" or "stroke" or "acute cerebral infarction" or "cardiovascular events" for the outcome factors. We included prospective cohort and case-control studies published between 2001 and July 2011 in this review. The search was limited to English language.

Results

Among 27 articles identified for this review, only 9 studies met the inclusion criteria, all of which were cohort studies. When using all cohort studies, the pooled relative risk (RR) of stroke for the highest vs. lowest category of coffee consumption was 0.83 (95% confidence interval [CI], 0.76 to 0.91). When subgroup analysis was performed, for Europeans, increased coffee drinking showed a preventive effect on stroke occurrence with RR 0.82 (95% CI, 0.74 to 0.92); RR for women 0.81 (95% CI, 0.70 to 0.93); for ischemic stroke 0.80 (95% CI, 0.71 to 0.90); and for those drinking 4 cups or more per day 0.83 (95% CI, 0.75 to 0.91).

Conclusion

We found that coffee consumption of 4 cups or more per day showed a preventive effect on stroke in this meta-analysis.

Inverse correlation between coffee consumption and prevalence of metabolic syndrome: baseline survey of the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study in Tokushima, Japan

Background

It is unclear whether consumption of coffee and green tea is associated with metabolic syndrome.

Methods

This cross-sectional study enrolled 554 adults who had participated in the baseline survey of the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study in Tokushima Prefecture, Japan. Consumption of coffee and green tea was assessed using a questionnaire. Metabolic syndrome was diagnosed using the criteria of the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) and the Japan Society for the Study of Obesity (JASSO). Logistic regression analysis was used to examine the association between consumption of coffee and green tea and prevalence of metabolic syndrome and its components.

Results

After adjustment for sex, age, and other potential confounders, greater coffee consumption was associated with a significantly lower prevalence of metabolic syndrome, as defined by NCEP ATP III criteria (P for trend = 0.03). Participants who drank more coffee had a lower odds ratio (OR) for high serum triglycerides (P for trend = 0.02), but not for increased waist circumference or high blood pressure. Using JASSO criteria, moderate coffee consumption (1.5 to <3 cups/day) was associated with a significantly lower OR for high plasma glucose (OR = 0.51, 95% CI 0.28-0.93). Green tea consumption was not associated with the prevalence of metabolic syndrome or any of its components.

Conclusions

Coffee consumption was inversely correlated with metabolic syndrome diagnosed using NCEP ATP III criteria, mainly because it was associated with lower serum triglyceride levels. This association highlights the need for further prospective studies of the causality of these relationships.

Sleep-disordered breathing and caffeine consumption: results of a community-based study

BACKGROUND

Sleepiness is one of the most burdensome symptoms of sleep-disordered breathing (SDB). While caffeine is frequently used to avert sleepiness, the association between SDB and caffeine use has not been thoroughly explored. The current study examined whether SDB is associated with caffeine consumption and if factors such as sex, age, and daytime sleepiness explain or modify the association.

METHODS

Data from the Sleep Heart Health Study, a community-based study on the consequences of SDB, were used to characterize the association between SDB and caffeine intake. SDB was assessed with full-montage polysomnography. Caffeine use was quantified as the number of cans of soda or the cups of coffee or tea consumed daily. The Epworth Sleepiness Scale was used to assess daytime sleepiness. Multivariable negative binomial regression models were used to characterize the independent association between SDB and caffeine use.

RESULTS

Caffeinated soda, but not tea or coffee, intake was independently associated with SDB severity. Compared with participants without SDB, the relative ratios for caffeinated soda consumption in women with mild, moderate, and severe SDB were 1.20 (CI, 1.03-1.41), 1.46 (CI, 1.14-1.87), and 1.73 (CI, 1.23-2.42), respectively. For men, an association was only noted with severe SDB and caffeinated soda use. Age did not modify the SDB-caffeine association, and sleepiness could not explain the observed associations.

CONCLUSIONS

SDB is independently associated with caffeinated soda use in the general community. Identifying excessive caffeine used in SDB has potential significance given the cardiovascular effects of caffeine and untreated SDB.

Habitual coffee consumption and risk of heart failure: a dose-response meta-analysis

BACKGROUND

There have been discrepant findings on the association between coffee consumption and risk of incident heart failure.

METHODS AND RESULTS

We conducted a systematic review and a dose-response meta-analysis of prospective studies that assessed the relationship between habitual coffee consumption and the risk of heart failure. We searched electronic databases (MEDLINE, Embase, and CINAHL) from January 1966 through December 2011, with the use of a standardized protocol. Eligible studies were prospective cohort studies that examined the association of coffee consumption with incident heart failure. Five independent prospective studies of coffee consumption and heart failure risk, including 6522 heart failure events and 140 220 participants, were included in the meta-analysis. We observed a statistically significant J-shaped relationship between coffee and heart failure. Compared with no consumption, the strongest inverse association was seen for 4 servings/day and a potentially higher risk at higher levels of consumption. There was no evidence that the relationship between coffee and heart failure risk varied by sex or by baseline history of myocardial infarction or diabetes.

CONCLUSIONS

Moderate coffee consumption is inversely associated with risk of heart failure, with the largest inverse association observed for consumption of 4 servings per day.

Relationship between coffee consumption and prevalence of metabolic syndrome among Japanese civil servants

Background

Metabolic syndrome has become a major worldwide public health problem. We examined the relationship between coffee consumption and the prevalence of metabolic syndrome among Japanese civil servants.

Methods

The study participants were 3284 employees (2335 men and 948 women) aged 20 to 65 years. Using data from their 2008 health checkup records, we analyzed the relationship between coffee consumption and the prevalence of metabolic syndrome. Metabolic syndrome was defined according to the Japanese criteria.

Results

Metabolic syndrome was diagnosed in 374 of the 2335 men (16.0%) and 32 of the 948 women (3.4%). In univariate and multiple logistic regression analyses, the odds ratios (ORs) among men for the presence of metabolic syndrome were 0.79 (95% CI: 0.56–1.03) and 0.61 (0.39–0.95), respectively, among moderate (≥4 cups of coffee per day) coffee drinkers as compared with non-coffee drinkers. Among all components of metabolic syndrome, high blood pressure and high triglyceride level were inversely associated with moderate coffee consumption in men, after adjusting for age, body mass index, smoking status, drinking status, and exercise. However, in women, moderate coffee consumption was not significantly associated with the prevalence of metabolic syndrome or its components.

Conclusions

Moderate coffee consumption was significantly associated with lower prevalence of metabolic syndrome in Japanese male civil servants.

The effect of coffee on blood pressure and cardiovascular disease in hypertensive individuals: a systematic review and meta-analysis

BACKGROUND

The effect of coffee and caffeine on blood pressure (BP) and cardiovascular disease (CVD) in hypertensive persons is uncertain.

OBJECTIVE

The objective was to summarize the evidence on the acute and longer-term effects of caffeine and coffee intake on BP and on the association between habitual coffee consumption and risk of CVD in hypertensive individuals.

DESIGN

A systematic review and meta-analysis of publications identified in a PubMed and EMBASE search up to 30 April 2011 was undertaken. Data were extracted from controlled trials on the effect of caffeine or coffee intake on BP change and from cohort studies on the association between habitual coffee consumption and CVD.

RESULTS

In 5 trials, the administration of 200-300 mg caffeine produced a mean increase of 8.1 mm Hg (95% CI: 5.7, 10.6 mm Hg) in systolic BP and of 5.7 mm Hg (95% CI: 4.1, 7.4 mm Hg) in diastolic BP. The increase in BP was observed in the first hour after caffeine intake and lasted ≥3 h. In 3 studies of the longer-term effect (2 wk) of coffee, no increase in BP was observed after coffee was compared with a caffeine-free diet or was compared with decaffeinated coffee. Last, 7 cohort studies found no evidence of an association between habitual coffee consumption and a higher risk of CVD.

CONCLUSIONS

In hypertensive individuals, caffeine intake produces an acute increase in BP for ≥3 h. However, current evidence does not support an association between longer-term coffee consumption and increased BP or between habitual coffee consumption and an increased risk of CVD in hypertensive subjects.