The effect of coffee consumption on blood pressure and the development of hypertension: a systematic review and meta-analysis

The Role of Diet in the Prevention of Hypertension and Management of Blood Pressure: An Umbrella Review of Meta-Analyses of Interventional and Observational Studies

High blood pressure (BP) is a major pathological risk factor for the development of several cardiovascular diseases. Diet is a key modifier of BP, but the underlying relationships are not clearly demonstrated. This is an umbrella review of published meta-analyses to critically evaluate the wide range of dietary evidence from bioactive compounds to dietary patterns on BP and risk of hypertension. PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials were searched from inception until October 31, 2021, for relevant meta-analyses of randomized controlled trials or meta-analyses of observational studies. A total of 175 publications reporting 341 meta-analyses of randomized controlled trials (145 publications) and 70 meta-analyses of observational studies (30 publications) were included in the review. The methodological quality of the included publications was assessed using Assessment of Multiple Systematic Reviews 2 and the evidence quality of each selected meta-analysis was assessed using NutriGrade. This umbrella review supports recommended public health guidelines for prevention and control of hypertension. Dietary patterns including the Dietary Approaches to Stop Hypertension and the Mediterranean-type diets that further restrict sodium, and moderate alcohol intake are advised. To produce high-quality evidence and substantiate strong recommendations, future research should address areas where the low quality of evidence was observed (for example, intake of dietary fiber, fish, egg, meat, dairy products, fruit juice, and nuts) and emphasize focus on dietary factors not yet conclusively investigated.

The effects of caffeine supplementation on blood pressure in adults: A systematic review and dose-response meta-analysis

BACKGROUND AND AIMS

Hypertension is a serious complication linked to a higher risk for organs. Caffeine is a natural component that affects the cardiovascular system, while the mechanisms of its effects are not fully established. Therefore, we aimed to examine the impact of caffeine supplementation on blood pressure (BP) by conducting a systematic review and dose-response meta-analysis of randomized controlled clinical trials (RCTs).

METHODS AND RESULTS

We searched online databases using relevant keywords up to July 2022 to identify RCTs using caffeine on systolic (SBP) and diastolic BP (DBP) in adults. Inclusion criteria were adult participants ≥18 years old for subjects, examining the effect of caffeine supplementation on BP, and RCTs studies. A random-effects model was used to estimate the weighted mean difference (WMD) and 95% confidence (CI). The pooled of 11 effect sizes analysis of 8 studies demonstrated significant increases in SBP (WMD:1.94 mmHg; 95%CI:0.52, 3.35; p = 0.007) and DBP (WMD:1.66 mmHg; 95% CI:0.75, 2.57; p = 0.000) after caffeine supplementation. The subgroup analysis showed that caffeine supplementation more effectively increased SBP and DBP in males than females. Moreover, meta-regression analysis demonstrated a significant relationship between the dose of caffeine intake and changes in SBP (p = 0.000), DBP (p = 0.000), and duration of the trial in SBP (p = 0.005), and DBP (p = 0.001). The non-linear dose-response analysis detected the dosage of supplementation >400 mg/day is effective for increasing DBP (p = 0.034), and the duration of supplementation of more than nine weeks makes increasing in both SBP and DBP.

CONCLUSION

This meta-analysis shows that caffeine supplementation significantly increased SBP and DBP in adults.

Caffeine - Essentials for anaesthesiologists: A narrative review

Caffeine has a multitude of uses in anaesthesia, and numerous studies have evaluated its efficacy and usefulness in various aspects of anaesthesia and medical practice. Its various applications in anaesthesia include its role in awakening from anaesthesia, managing post-dural puncture headache, managing post-sedation paradoxical hyper-activity in children, post-operative bowel paralysis, and apnoea in paediatric populations, that is, apnoea in infancy, paediatric obstructive apnoea, and post-anaesthetic apnoea in pre-mature infants. Though the effects of caffeine on bronchial smooth muscle, neurological, and cardio-vascular systems are well known, the relatively little-known effects on the endocrine and gastro-intestinal (GI) system have been recently taking primacy for eliciting its therapeutic benefits. The literature shows encouraging evidence in favour of caffeine, but unambiguous evidence of caffeine benefits for patients is lacking and needs further investigation. In this narrative review of literature, we summarise the available literature to provide insights into the pharmacokinetics, pharmacodynamics, clinical application of caffeine in modern anaesthetic practice, and evidence available in this field to date. An awareness of the various physiological effects, adverse effects, reported applications, and their evidence will widen the horizon for anaesthesiologists to increase its rational use and advance research in this field. Well-designed randomised controlled trials regarding the various outcomes related to caffeine use in anaesthesia should be planned to generate sound evidence and formulate recommendations to guide clinicians.

Caffeine Drug Interactions and its Clinical Implication After Acute Coronary Syndrome: A Literature Review

The hemodynamic and cardiovascular impacts of coffee and caffeine have long been controversial. However, due to the worldwide popularity of coffee and caffeinated beverages, it is essential to understand how they affect the cardiovascular system, specifically in patients with a history of acute coronary syndrome. This literature review was conducted to explore the cardiovascular effects of coffee and caffeine and their interactions with common drugs after acute coronary syndrome and percutaneous coronary intervention. The evidence suggests that moderate coffee and caffeine consumption is not associated with cardiovascular disease in healthy individuals and patients with a history of acute coronary syndrome. The interactions of coffee or caffeine with common medications after acute coronary syndrome or percutaneous coronary intervention are less studied. However, based on the current human studies in this field, the only interaction is with the protective effect of statins on cardiac ischemia.

Coffee intake and hypertension in Korean adults: results from KNHANES 2012-2016

BACKGROUND

Coffee is the most popular and widely consumed drink in the world. Coffee consumption seems to have both benefits and risk with respect to hypertension; results from studies evaluating effect of frequency of coffee consumption on risk of hypertension are mixed and inconsistent. Hence, we investigated the association of coffee consumption and hypertension in Korean adults.

METHODS

Data from Korean National Health and Nutrition Examination Survey (KNHANES) 2012-2016 was obtained and 12,133 eligible participants were selected. The coffee consumption was attained using a food frequency questionnaire. Subsequently coffee intake was grouped into two categories: ≤2 and > 2 servings per day. Hypertension status was defined as systolic blood pressure ≥ 140 mmHg or diastolic blood pressure ≥ 90 mmHg, use of antihypertensive drug treatment, or both. Multivariable logistic regression analysis was used to examine the association of coffee consumption and hypertension.

RESULTS

Logistic regression analysis showed that consumption of more than two servings of coffee a day was inversely associated with hypertension with odds ratio (OR) 0.84 (95% confidence interval [CI], 0.73-0.99). Similar results were seen in the propensity score-matched analysis (OR, 0.83; 95% CI, 0.69-0.98). Adults having age more than median value (OR, 0.76; 95% CI, 0.65-0.89) and normal cholesterol (OR, 0.84; 95% CI, 0.70-0.99) had significantly inverse association with hypertension, when coffee consumption was more than two servings daily.

CONCLUSIONS

More than two servings of coffee intake per day was inversely associated with hypertension as compared to consumption of ≤ 2 servings coffee per day.

Coffee Consumption and Risk of Hypertension in Adults: Systematic Review and Meta-Analysis

OBJECTIVES

The association between coffee intake and hypertension (HTN) risk is controversial. Therefore, this systematic review and meta-analysis aimed at summarizing the current evidence on the association of coffee with hypertension risk in observational studies.

METHODS

PubMed/Medline and Web of Science were searched for observational studies up to February 2023. Observational studies which assessed the risk of HTN in the highest category of coffee consumption in comparison with the lowest intake were included in the current meta-analysis (registration number: CRD42022371494). The pooled effect of coffee on HTN was evaluated using a random-effects model.

RESULTS

Twenty-five studies i.e., thirteen cross-sectional studies and twelve cohorts were identified to be eligible. Combining 13 extracted effect sizes from cohort studies showed that higher coffee consumption was associated with 7% reduction in the risk of HTN (95% CI: 0.88, 0.97; I²: 22.3%), whereas combining 16 effect sizes from cross-sectional studies illustrated a greater reduction in HTN risk (RR = 0.79, 95% CI: 0.72, 0.87; I² = 63.2%). These results varied by studies characteristics, such as the region of study, participants' sex, study quality, and sample size.

CONCLUSIONS

An inverse association was found between coffee consumption and hypertension risk in both cross-sectional and cohort studies. However, this association was dependent on studies characteristics. Further studies considering such factors are required to confirm the results of this study.

Coffee consumption and associations with blood pressure, LDL-cholesterol and echocardiographic measures in the general population

Coffee, next to water the most widespread beverage, is attributed both harmful and protective characteristics concerning cardiovascular health. This study aimed to evaluate associations of coffee consumption with cardiac biomarkers, echocardiographic, electrocardiographic parameters and major cardiovascular diseases. We performed a cross-sectional analysis of 9009 participants of the population-based Hamburg City Health Study (HCHS), enrolled between 2016 and 2018 median age 63 [IQR: 55; 69] years. Coffee consumption was classified into three groups: < 3 cups/day (low), 3-4 cups/day (moderate), > 4 cups/day (high). In linear regression analyses adjusted for age, sex, body mass index, diabetes, hypertension, smoking, and additives, high coffee consumption correlated with higher LDL-cholesterol (β = 5.92; 95% CI 2.95, 8.89; p < 0.001). Moderate and high coffee consumption correlated with lower systolic (β = - 1.91; 95% CI - 3.04, - 0.78; p = 0.001; high: β = - 3.06; 95% CI - 4.69, - 1.44; p < 0.001) and diastolic blood pressure (β = - 1.05; 95% CI - 1.67, - 0.43; p = 0.001; high: β = - 1.85; 95% CI - 2.74, - 0.96; p < 0.001). Different levels of coffee consumption did neither correlate with any investigated electrocardiographic or echocardiographic parameter nor with prevalent major cardiovascular diseases, including prior myocardial infarction and heart failure. In this cross-sectional analysis, high coffee consumption correlated with raised LDL-cholesterol levels and lower systolic and diastolic blood pressure. However, major cardiovascular diseases including heart failure and its diagnostic precursors were not associated with coffee consumption, connoting a neutral role of coffee in the context of cardiovascular health.

Coffee consumption, health benefits and side effects: a narrative review and update for dietitians and nutritionists

Coffee is one of the most popular beverages worldwide; however, its impact on health outcomes and adverse effects is not fully understood. The current review aims to establish an update about the benefits of coffee consumption on health outcomes highlighting its side effects, and finally coming up with an attempt to provide some recommendations on its doses. A literature review using the PubMed/Medline database was carried out and the data were summarized by applying a narrative approach using the available evidence based on the literature. The main findings were the following: first, coffee may contribute to the prevention of inflammatory and oxidative stress-related diseases, such as obesity, metabolic syndrome and type 2 diabetes; second, coffee consumption seems to be associated with a lower incidence of several types of cancer and with a reduction in the risk of all-cause mortality; finally, the consumption of up to 400 mg/day (1-4 cups per day) of caffeine is safe. However, the time gap between coffee consumption and some drugs should be taken into account in order to avoid interaction. However, most of the data were based on cross-sectional or/and observational studies highlighting an association of coffee intake and health outcomes; thus, randomized controlled studies are needed in order to identify a causality link.

The impact of coffee subtypes on incident cardiovascular disease, arrhythmias, and mortality: long-term outcomes from the UK Biobank

AIMS

Epidemiological studies report the beneficial effects of habitual coffee consumption on incident arrhythmia, cardiovascular disease (CVD), and mortality. However, the impact of different coffee preparations on cardiovascular outcomes and survival is largely unknown. The aim of this study was to evaluate associations between coffee subtypes on incident outcomes, utilizing the UK Biobank.

METHODS AND RESULTS

Coffee subtypes were defined as decaffeinated, ground, and instant, then divided into 0, <1, 1, 2-3, 4-5, and >5 cups/day, and compared with non-drinkers. Cardiovascular disease included coronary heart disease, cardiac failure, and ischaemic stroke. Cox regression modelling with hazard ratios (HRs) assessed associations with incident arrhythmia, CVD, and mortality. Outcomes were determined through ICD codes and death records. A total of 449 563 participants (median 58 years, 55.3% females) were followed over 12.5 ± 0.7 years. Ground and instant coffee consumption was associated with a significant reduction in arrhythmia at 1-5 cups/day but not for decaffeinated coffee. The lowest risk was 4-5 cups/day for ground coffee [HR 0.83, confidence interval (CI) 0.76-0.91, P < 0.0001] and 2-3 cups/day for instant coffee (HR 0.88, CI 0.85-0.92, P < 0.0001). All coffee subtypes were associated with a reduction in incident CVD (the lowest risk was 2-3 cups/day for decaffeinated, P = 0.0093; ground, P < 0.0001; and instant coffee, P < 0.0001) vs. non-drinkers. All-cause mortality was significantly reduced for all coffee subtypes, with the greatest risk reduction seen with 2-3 cups/day for decaffeinated (HR 0.86, CI 0.81-0.91, P < 0.0001); ground (HR 0.73, CI 0.69-0.78, P < 0.0001); and instant coffee (HR 0.89, CI 0.86-0.93, P < 0.0001).

CONCLUSION

Decaffeinated, ground, and instant coffee, particularly at 2-3 cups/day, were associated with significant reductions in incident CVD and mortality. Ground and instant but not decaffeinated coffee was associated with reduced arrhythmia.

Coffee Intake and Risk of Hypertension: A Meta-Analysis of Cohort Studies

BACKGROUND

It remains unclear whether coffee intake is associated with the risk of hypertension. This study aimed to investigate the association between coffee intake and the risk of hypertension by using a meta-analysis of cohort studies.

METHODS

PubMed and Embase were searched using keywords in September 2022 to identify studies on coffee intake and the risk of hypertension.

RESULTS

We included a total of 13 longitudinal cohort studies, which involved a total of 64,650 incident cases of hypertension among 314,827 participants. In a random effects model meta-analysis of all the studies, coffee intake was not significantly associated with the risk of hypertension (relative risk [RR], 0.97; 95% confidence interval [CI], 0.90–1.05; I² = 58.0%; n = 13). In the subgroup meta-analysis, coffee intake was associated with a decreased risk of hypertension in studies conducted in America (RR, 0.93; 95% CI, 0.87-0.98; I² = 4.6%; n = 5) and in low-quality studies (RR, 0.92; 95% CI, 0.88-0.96; I² = 0.0%; n = 7). In the remaining subgroup meta-analyses by amount of coffee intake, gender, type of coffee (decaffeinated vs. caffeinated), smoking, and years of follow-up, coffee intake was not significantly associated with the risk of hypertension.

CONCLUSION

The current meta-analysis showed that coffee intake is not associated with the risk of hypertension.

The association between caffeine exposure during pregnancy and risk of gestational hypertension/preeclampsia: A meta-analysis and systematical review

BACKGROUND

The potential effect of caffeine exposure during pregnancy on gestational hypertension (GH)/preeclampsia has attracted attention but remains unclear.

METHODS

A systematic literature search of PubMed, Embase, and Cochrane Library databases was performed until March 2022. Observational studies assessing the association between caffeine exposure during pregnancy and the risk of GH/preeclampsia were included. The study protocol was registered in PROSPERO: CRD42022322387.

RESULTS

Ten studies involving 114 984 pregnant women (2548 diagnosed with GH and 2473 diagnosed with preeclampsia) were included. Comparing caffeine exposure with noncaffeine exposure, no significant association was found between caffeine exposure during pregnancy and the risk of GH (odds ratio [OR] = 0.99, 95% confidence interval [CI]: 0.90-1.08, p = 0.800) and preeclampsia (OR = 1.13, 95% CI: 0.97-1.31, p = 0.114). Subgroup analyses comparing low to moderate doses with no/lowest doses showed that caffeine exposure during pregnancy was not significant associated with GH (OR = 1.00, p = 0.987) or preeclampsia (OR = 1.03, p = 0.648). Besides, subgroup analyses comparing high doses with no/lowest doses showed that caffeine exposure during pregnancy was not significant associated with GH (OR = 1.06, p = 0.623) or preeclampsia (OR = 1.18, p = 0.192).

CONCLUSION

This study found that caffeine exposure during pregnancy was not significantly associated with the risk of GH/preeclampsia.

The magical smell and taste: Can coffee be good to patients with cardiometabolic disease?

Coffee is a beverage consumed globally. Although few studies have indicated adverse effects, it is typically a beneficial health-promoting agent in a range of diseases, including depression, diabetes, cardiovascular disease, and obesity. Coffee is rich in caffeine, antioxidants, and phenolic compounds, which can modulate the composition of the gut microbiota and mitigate both inflammation and oxidative stress, common features of the burden of lifestyle diseases. This review will discuss the possible benefits of coffee on complications present in patients with diabetes, cardiovascular disease and chronic kidney disease, outwith the social and emotional benefits attributed to caffeine consumption.

Caffeine and rheumatoid arthritis: A complicated relationship

The current ideal goal of rheumatoid arthritis (RA) management is to resolve joint and systemic inflammation by using pharmacological interventions, assuming this will correspondingly lead to overall well-being. Nonetheless, it has emerged that a substantial number of RA patients do not reach optimal disease control. Thus suggesting the holistic management of subjective symptoms might be overlooked. This poses significant medical challenges; hence the proposal of incorporating lifestyle interventions as part of a multidimensional approach. Among these aspects, both patients and physicians perceive the important role of nutrition. This review shall examine how caffeine, one of the most studied bioactive components of the most widely consumed beverages, may potentially interfere with RA management. In particular, the mechanism by which caffeine affects RA pathogenesis, as a trigger for RA onset or flare, including its influence on rheumatic drug metabolism and the most common RA comorbidities and constitutional symptoms are outlined, highlighting important knowledge gaps and unmet research needs.

Prevalence of Hypertension and Related Characteristics: Perspectives from an Outpatient Podiatric Medical Clinic

BACKGROUND

Hypertension is a highly prevalent condition in the general population, conferring a high risk of significant morbidity and mortality. Associated with the condition are many well-characterized controllable and noncontrollable risk factors. This study aimed to identify the prevalence of hypertension in the outpatient podiatric medical clinic setting and to determine the relevance of hypertension risk factors in this setting.

METHODS

A survey tool was created to characterize relevant risk factors, and systolic and diastolic blood pressures were recorded. Descriptive statistics were generated after conclusion of enrollment. Analysis was also performed to determine the relationship between individual risk factors and systolic blood pressure.

RESULTS

Of the 176 patients, 56 (31.8%) had an incidentally high blood pressure at intake, including 18.5% of patients without a known history of hypertension and 38.5% with a known history of hypertension. Three risk factors were found to be significantly associated with increasing systolic blood pressure: weight (P = .022), stress level (P = .017), and presence of renal artery stenosis (P = .021). There was also a near-statistically significant inverse relationship between systolic blood pressure and amount of time spent exercising (P = .068).

CONCLUSIONS

Overall, a relatively high prevalence of incidental hypertension was identified, including among patients not previously diagnosed as having hypertension. Consideration of risk factors and awareness of the prevalence of the condition can be useful for practitioners, even as they manage presenting podiatric medical concerns. Future investigations may consider interventional or preventive strategies in the outpatient clinic setting.

Metabolic Disorders in Patients with Chronic Hepatitis B Virus Infection: Coffee as a Panacea? (ANRS CO22 Hepather Cohort)

People living with chronic hepatitis B virus (HBV) infection are at high risk of liver disease progression, which is positively associated with metabolic disorders, but inversely associated with dyslipidemia. Diet, including dietary antioxidants, is a lever of metabolic disorder management. In particular, elevated coffee consumption is associated with different metabolic outcomes in the general population. We aimed to test whether such associations occur in HBV-infected people. Based on cross-sectional data from the ANRS CO22 Hepather cohort, we performed logistic regression models with (i) dyslipidemia, (ii) hypertension, and (iii) diabetes as outcomes, and with demographic, clinical, and socio-behavioral (including coffee consumption) data as explanatory variables. Among 4746 HBV-infected patients, drinking ≥3 cups of coffee per day was associated with a higher risk of dyslipidemia (adjusted odds ratio [95% confidence interval] 1.49 [1.10–2.00], p = 0.009) and a lower risk of hypertension (0.64 [0.50–0.82], p = 0.001). It was not associated with diabetes. Elevated coffee consumption was associated with a higher risk of dyslipidemia and a lower risk of hypertension in HBV-infected patients, two effects expected to be associated with favorable clinical outcomes. Further studies should test whether such metabolic benefits translate into reduced mortality risk in this population.

Investigating the Relations Between Caffeine-Derived Metabolites and Plasma Lipids in 2 Population-Based Studies

OBJECTIVE

To investigate the relations between caffeine-derived metabolites (methylxanthines) and plasma lipids by use of population-based data from 2 European countries.

METHODS

Families were randomly selected from the general population of northern Belgium (FLEMENGHO), from August 12, 1985, until November 22, 1990, and 3 Swiss cities (SKIPOGH), from November 25, 2009, through April 4, 2013. We measured plasma concentrations (FLEMENGHO, SKIPOGH) and 24-hour urinary excretions (SKIPOGH) of 4 methylxanthines-caffeine, paraxanthine, theobromine, and theophylline-using ultra-high-performance liquid chromatography-tandem mass spectrometry. We used enzymatic methods to estimate total cholesterol, high-density lipoprotein cholesterol, and triglyceride levels and the Friedewald equation for low-density lipoprotein cholesterol levels in plasma. We applied sex-specific mixed models to investigate associations between methylxanthines and plasma lipids, adjusting for major confounders.

RESULTS

In both FLEMENGHO (N=1987; 1055 [53%] female participants) and SKIPOGH (N=990; 523 [53%] female participants), total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels increased across quartiles of plasma caffeine, paraxanthine, and theophylline (total cholesterol levels by caffeine quartiles in FLEMENGHO, male participants: 5.01±0.06 mmol/L, 5.05±0.06 mmol/L, 5.27±0.06 mmol/L, 5.62±0.06 mmol/L; female participants: 5.24±0.06 mmol/L, 5.15±0.05 mmol/L, 5.25±0.05 mmol/L, 5.42±0.05 mmol/L). Similar results were observed using urinary methylxanthines in SKIPOGH (total cholesterol levels by caffeine quartiles, male participants: 4.54±0.08 mmol/L, 4.94±0.08 mmol/L, 4.87±0.08 mmol/L, 5.27±0.09 mmol/L; female participants: 5.12±0.07 mmol/L, 5.21±0.07 mmol/L, 5.28±0.05 mmol/L, 5.28±0.07 mmol/L). Furthermore, urinary caffeine and theophylline were positively associated with high-density lipoprotein cholesterol in SKIPOGH male participants.

CONCLUSION

Plasma and urinary caffeine, paraxanthine, and theophylline were positively associated with plasma lipids, whereas the associations involving theobromine were less clear. We postulate that the positive association between caffeine intake and plasma lipids may be related to the sympathomimetic function of methylxanthines, mitigating the overall health-beneficial effect of caffeine intake.

Association between hypertension and coffee drinking based on CYP1A2 rs762551 single nucleotide polymorphism in Taiwanese

Background

Hypertension increases the likelihood of cardiovascular diseases (CVDs). Cytochrome P450 1A2 (CYP1A2) single nucleotide polymorphism (SNP) is related to caffeine metabolism and the risk of CVD among coffee drinkers. CYP1A2 rs762551 influenced the risk of stroke among hypertensive patients. We examined the relationship between hypertension and coffee drinking based on CYP1A2 rs762551 SNP in Taiwanese adults.

Methods

We used data contained in the Taiwan Biobank database (2011–2018) and included 19,133 participants having complete information on hypertension, rs762551 polymorphism, coffee intake, etc. The risk of hypertension was determined using multiple logistic regression.

Results

Coffee intake was significantly associated with a lower risk of hypertension. The odds ratio (OR), 95% confidence interval (CI), and p-value were 0.877, 0.807–0.954, and 0.0032, respectively. CYP1A2 rs762551 was not significantly associated with the risk of hypertension, but it had a significant interactive association with coffee drinking (p value = 0.0303). After stratification by rs762551 genotypes, the inverse coffee drinking-hypertension association was retained, but significant results were observed only in those with the AC + CC genotype (OR 0.678, 95% CI 0.722–900, p value = 0.0001). According to the combination of coffee drinking and rs762551 genotypes (reference group: no coffee drinking and rs762551 AA), the coffee drinking-AC + CC group had a lower risk of hypertension (OR 0.888, 95% CI 0.789–0.999, p value = 0.0483).

Conclusion

Coffee drinking, particularly among individuals with the CYP1A2 rs762551 AC + CC genotype was associated with lower odds of hypertension.

Coffee and Arterial Hypertension

Purpose of Review

Coffee is a very popular drink and an estimated 2.25 billion cups worldwide are consumed daily. Such popularity of coffee makes it the most consumed drink next to water. Numerous studies have shown a beneficial effect of habitual and moderate coffee consumption on the functioning of the nervous, digestive, and cardiovascular systems, as well as on kidney function. Taking into account the very high prevalence of arterial hypertension in the world (31.1% of adults), much controversy has been raised about the influence of coffee consumption on blood pressure and the risk of arterial hypertension. Moreover, there have been extensive discussions about the safety of coffee consumption for hypertensive persons.

Recent Findings

There are over 1000 chemical compounds in coffee. The best characterized of these are caffeine, chlorogenic acid, trigonelline, kahweol, cafestol, ferulic acid, and melanoidins. These compounds have bidirectional influences on blood pressure regulation. The results of numerous studies and meta-analyses indicate that moderate and habitual coffee consumption does not increase and may even reduce the risk of developing arterial hypertension. Conversely, occasional coffee consumption has hypertensinogenic effects. Moderate habitual coffee consumption in hypertensive persons does not appear to increase the risk of uncontrolled blood pressure and may even reduce the risk of death from any cause.

Summary

Moderate and habitual consumption of coffee (1-–3 cups / day) does not adversely affect blood pressure in most people, including those with arterial hypertension.

Significant Impact of Coffee Consumption on MR-Based Measures of Cardiac Function in a Population-Based Cohort Study without Manifest Cardiovascular Disease

Subclinical effects of coffee consumption (CC) with regard to metabolic, cardiac, and neurological complications were evaluated using a whole-body magnetic resonance imaging (MRI) protocol. A blended approach was used to estimate habitual CC in a population-based study cohort without a history of cardiovascular disease. Associations of CC with MRI markers of gray matter volume, white matter hyperintensities, cerebral microhemorrhages, total and visceral adipose tissue (VAT), hepatic proton density fat fraction, early/late diastolic filling rate, end-diastolic/-systolic and stroke volume, ejection fraction, peak ejection rate, and myocardial mass were evaluated by linear regression. In our analysis with 132 women and 168 men, CC was positively associated with MR-based cardiac function parameters including late diastolic filling rate, stroke volume (p < 0.01 each), and ejection fraction (p < 0.05) when adjusting for age, sex, smoking, hypertension, diabetes, Low-density lipoprotein (LDL), triglycerides, cholesterol, and alcohol consumption. CC was inversely associated with VAT independent of demographic variables and cardiovascular risk factors (p < 0.05), but this association did not remain significant after additional adjustment for alcohol consumption. CC was not significantly associated with potential neurodegeneration. We found a significant positive and independent association between CC and MRI-based systolic and diastolic cardiac function. CC was also inversely associated with VAT but not independent of alcohol consumption.

Effects of supplementation with main coffee components including caffeine and/or chlorogenic acid on hepatic, metabolic, and inflammatory indices in patients with non-alcoholic fatty liver disease and type 2 diabetes: a randomized, double-blind, placebo-controlled, clinical trial

Background

Non-alcoholic fatty liver disease (NAFLD) is much more frequent and more severe, including cirrhosis, hepatocellular carcinoma in patients with type 2 diabetes. Coffee is a complex beverage with hundreds of compounds whereas caffeine and chlorogenic acid are the most abundant bioactive compounds. The published epidemiological data demonstrating beneficial associations between all categories of coffee exposure and ranges of liver outcomes are rapidly growing; however, the main contributors and cause-effect relationships have not yet been elucidated. To address existing knowledge gaps, we sought to determine the efficacy and safety of 6 months chlorogenic acid and/or caffeine supplementation in patients with type 2 diabetes affected by NAFLD.

Methods

This trial was carried out at two Diabetes Centers to assess the effects of supplementation with daily doses of 200 mg chlorogenic acid, 200 mg caffeine, 200 mg chlorogenic acid plus 200 mg caffeine or placebo (starch) in patients with type 2 diabetes and NAFLD. The primary endpoint was reduction of hepatic fat and stiffness measured by FibroScan, and changes in serum hepatic enzymes and cytokeratin − 18 (CK-18) levels. Secondary endpoints were improvements in metabolic (including fasting glucose, homeostasis model assessment-estimated insulin resistance (HOMA-IR), hemoglobin A1c (HBA1C), C-peptide, insulin and lipid profiles) and inflammatory (including nuclear factor k-B (NF-KB), tumor necrosis factor (TNF-α), high sensitive- C reactive protein(hs-CRP)) parameters from baseline to the end of treatment.

Results

Neither chlorogenic acid nor caffeine was superior to placebo in attenuation of the hepatic fat and stiffness and other hepatic outcomes in patients with diabetes and NAFLD. Except for the lower level of total cholesterol in caffeine group (p = 0.04), and higher level of insulin in chlorogenic acid plus caffeine group (p = 0.01) compared with placebo, there were no significant differences among the treatment groups.

Conclusion

These findings do not recommend caffeine and/or chlorogenic acid to treat NAFLD in type 2 diabetes patients.

Trial registration

IRCT201707024010N21. Registered 14 September 2017.

Effect of coffee and cocoa-based confectionery containing coffee on markers of cardiometabolic health: results from the pocket-4-life project

PURPOSE

Coffee is an important source of bioactive compounds, including caffeine, trigonelline, and phenolic compounds. Several studies have highlighted the preventive effects of coffee consumption on major cardiometabolic (CM) diseases, but the impact of different coffee dosages on markers of CM risk in a real-life setting has not been fully understood. This study aimed to investigate the effect of coffee and cocoa-based confectionery containing coffee consumption on several CM risk factors in healthy subjects.

METHODS

In a three-arm, crossover, randomized trial, 21 volunteers were assigned to consume in a random order for 1 month: 1 cup of espresso coffee/day, 3 cups of espresso coffee/day, and 1 cup of espresso coffee plus 2 cocoa-based products containing coffee, twice per day. At the last day of each treatment, blood samples were collected and used for the analysis of inflammatory markers, trimethylamine N-oxide, nitric oxide, blood lipids, and markers of glucose/insulin metabolism. Moreover, anthropometric parameters and blood pressure were measured. Finally, food consumption during the interventions was monitored.

RESULTS

After 1 month, energy intake did not change among treatments, while significant differences were observed in the intake of saturated fatty acids, sugars, and total carbohydrates. No significant effect on CM markers was observed following neither the consumption of different coffee dosages nor after cocoa-based products containing coffee.

CONCLUSIONS

The daily consumption of common dosages of coffee and its substitution with cocoa-based products containing coffee showed no effect on CM risk factors in healthy subjects.

TRIAL REGISTRATION NUMBER

Registered at clinicaltrials.gov as NCT03166540, May 21, 2017.

Effects of coffee consumption on arterial stiffness and endothelial function: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Endothelial function (EF) and arterial stiffness (AS) are predictors of cardiovascular disease. As previous research concerning the effect of coffee intake on EF and AS was controversial, we conducted a systematic review and meta-analysis to synthesize research.

METHODS

We performed a systematic search in PubMed, Scopus and Web of Science to find clinical trials investigating the effect of coffee intake on EF or AS up to March 2020.Random-effects models were used to estimate the pooled weighted mean difference (WMD) between intervention and control groups for randomized controlled trials (RCTs). Between study heterogeneity was estimated using Cochran's Q and the I ²-inconsistency index. Internal validity of included randomized trials was determined with the Cochrane Collaboration's tool for assessing the risk of bias.

RESULTS

Twenty-three articles were included for qualitative and 11 articles for quantitative synthesis. Meta-analysis of 14 RCTs (nine articles) indicated a positive short-term (postprandial) effect of coffee intake on flow-mediated dilation (FMD) as a measure of EF (WMD: 1.93%[95% CI: 1.10-2.75]; I ²= 97.9%). Meta-analysis of three long-term RCTs(two articles) found no such effect on FMD (WMD: -0.08% [-3.82 to 3.66]; I ²= 61.4%).Most short-term information was from studies at low or unclear risk of bias, while the proportion of long-term information from studies at high risk of bias was considerable.

CONCLUSION

The results from this meta-analysis suggest a beneficial short-term effect of coffee intake on EF as measured by FMD. However, there might be unfavorable effects on AS. Our findings must be interpreted cautiously as the number of studies were low and included studies had a considerable risk of bias.

Coffee consumption and risk of hypertension: A prospective analysis in the cohort study

BACKGROUND

Coffee is one of the most widely consumed beverages around the world. Dietary habits, specifically, coffee consumption has long been a suspected cause of hypertension. However, previous findings on coffee consumption and its association with the incidence of hypertension are not homogeneous and still inconsistent.

PURPOSE

To examine the association of habitual coffee consumption with the risk of developing hypertension in a middle-aged Brazilian cohort.

METHODS

Data were from the multicenter prospective cohort "Brazilian Longitudinal Study for Adult Health - ELSA-Brasil". The cohort comprises 15,105 civil servants, aged 35-74 years at baseline, who were sampled from universities located in six Brazilian cities. For the present study, we analyzed data from 8780 participants initially free of hypertension during a mean follow-up of 3.9 years. The consumption of coffee was obtained at baseline using a previously validated semi-quantitative food frequency questionnaire (FFQ). Subsequently coffee intake was categorized into four categories (cups/day): never/almost never, ≤1, 1-3, and >3. Hypertension status was defined as a systolic blood pressure ≥140 mmHg or a diastolic blood pressure ≥90 mmHg, use of antihypertensive drug treatment, or both. Poisson regression model with a robust variance was performed to estimate relative risk (RR) and confidence interval (95% CI) for hypertension according to baseline coffee consumption. The effect of interaction between coffee consumption and smoking status was assessed.

RESULTS

Most participants (90%) drank coffee, and the median total coffee intake was 150 mL/day. A total of 1285 participants developed hypertension. Compared to participants who never or almost never drink coffee, the risk of hypertension was lower for individuals consuming 1-3 cups/day (RR 0.82, 95% CI: 0.68-0.97) (P for interaction=0.018). After stratification by smoking status the analysis revealed a decreased risk of hypertension in never smokers drinking 1-3 cups of coffee per day (RR 0.79, 95% CI: 0.64-0.98), whereas the hypertension risk among former and current smokers was not associated with coffee consumption significantly. Moreover, upper category of coffee drinking (>3 cups/day) the association was not significant for risk of hypertension.

CONCLUSION

The association between coffee consumption and incidence of hypertension was related to smoking status. The beneficial effect of moderate coffee intake (1-3 cups/day) on risk of hypertension was observed only in never smokers.

Impact of Tea and Coffee Consumption on Cognitive Performance: An fNIRS and EDA Study

Coffee and tea are two of the most popular beverages in the world and have been consumed for more than a thousand years. They have become an integral part of the day for many consumers and may aid not only increased social interactions but also productivity. However, there is no conclusive evidence of their comparative effect on cognitive ability. This study investigated the impact of tea and coffee products on cognitive performance in typical office work-related tasks using brain, body, and behavioral measures. In a controlled multi-day study, we explored the effects of both traditional and cognition-enhancing hot beverages through task performance and self-reported measures. A total of 120 participants completed three work-related tasks from different cognitive domains and consumed either a traditional or cognition-enhancing hot beverage. During the study, we measured brain activity in the prefrontal cortex using functional near-infrared spectroscopy (fNIRS) as well as arousal from skin conductance through electrodermal activity (EDA) while participants completed cognitive tasks and consumed the beverages. Neural efficiency was used to evaluate cognitive performance in the tasks. Neural efficiency was calculated from a composite score of behavioral efficiency and cognitive effort, and emotional arousal was estimated from EDA activity. Results indicated that for different cognitive domains, the enhanced hot beverages showed improved neural efficiency over that of a traditional hot beverage. This is the first study to assess the impact of both traditional and cognition-enhancing drinks using a multimodal approach for workplace-related assignments.

Dietary Research on Coffee: Improving Adjustment for Confounding

Meta-analyses have reported higher levels of coffee consumption to be associated with lower mortality. In contrast, some systematic reviews have linked coffee consumption to increased risks for lung cancer and hypertension. Given these inconsistencies, this narrative review critically evaluated the methods and analyses of cohort studies investigating coffee and mortality. A specific focus was adjustment for confounding related to smoking, healthy and unhealthy foods, and alcohol. Assessment of 36 cohort samples showed that many did not adequately adjust for smoking. Consuming 1-5 cups of coffee per day was related to lower mortality among never smokers, in studies that adjusted for pack-years of smoking, and in studies adjusting for healthy and unhealthy foods. Possible reduced health benefits for coffee with added sugar have not been adequately investigated. Research on coffee and health should report separate analyses for never smokers, adjust for consumption of healthy and unhealthy foods, and for sugar added to coffee.

Drug-Induced Hypertension

Untoward side effects of pharmaceuticals can result in considerable morbidity and expense to the health care system. There is likely a sizable fraction of the hypertensive population with disease either induced or exacerbated by polypharmacy. The elevation of blood pressure in drug-induced hypertension occurs through a variety of mechanisms, most notably, sodium and fluid retention, activation of the renin-angiotensin-aldosterone system, alteration of vascular tone, or a combination of these pathways. Recognition of common medications causing drug-induced hypertension is important to effectively control blood pressure. The epidemiology, pathophysiology, and management of these agents are discussed.

Caffeine and blood pressure: a critical review perspective

The WHO reported that high blood pressure (BP) is one of the primary causes of death worldwide. Hypertension (HPT) is a major risk factor for CVD and related diseases as well as for diseases, leading to a considerable increase in cardiovascular risk. Since BP response could also be influenced by caffeine, which is widely consumed with coffee and other items, it is important to define the possible effects associated with caffeine intake. The most recent findings aimed at clarifying the role of caffeine consumption on BP and HPT risk/incidence are conflicting and difficult to interpret. Therefore, in the present narrative review, we aimed to examine various methodological inaccuracies/aspects and factors that make studies difficult to be compared, in order to obtain a single consensus on the effects of caffeine intake on the risk of BP and HPT. We observed that this heterogeneity in results could be due to the presence of: (i) several variables affecting BP (such as age, sex, genetic and lifestyle aspects); (ii) different caffeine content of food and beverages; and (iii) caffeine metabolism. Moreover, different methodological aspects in the evaluation of daily dietary caffeine intake and in the BP measurement could add some other bias in the interpretation of results. Therefore, it is mandatory to consider all methodological aspects and confounding factors to generate a standardised methodology in order to increase cross-study consistency and minimise confounding effects of different variables on the relationship between BP response and HPT risk/incidence after caffeine intake.

The Impact of Coffee and Caffeine on Multiple Sclerosis Compared to Other Neurodegenerative Diseases

Background: The literature concerning the effect of coffee and caffeine on Multiple Sclerosis (MS) with focus on fatigue is investigated in this review. Potentially clinically relevant effects were also assessed in studies concerning comparable neurodegenerative diseases, such as Parkinson's disease (PD) and amyotrophic lateral sclerosis (ALS). Since the existing studies obtained very inconclusive results, we systematically reviewed these studies to summarize the evidence on the possible effects of coffee and caffeine on those disease entities. Previous studies suggested that coffee and caffeine intake is associated with a reduced risk of developing MS and other neurological diseases.

Methods: The PubMed database was searched using the keywords “coffee” OR “caffeine” in combination with keywords for each of the different diseases. Besides the keyword search, we included studies by reference list search. Studies on the effects of coffee and caffeine on the single neurological diseases were included for this review. A total of 51 articles met our inclusion criteria. The reviewed articles assessed the impact of coffee and caffeine on the susceptibility for neurological diseases, as well as the effect of coffee and caffeine on disease progression and possible symptomatic effects like on performance enhancement.

Results: Higher intake of coffee and caffeine was associated with a lower risk of developing PD. In some of the MS studies there, is evidence for a similar effect and experimental studies confirmed the positive impact. Interestingly in MS coffee and caffeine may have a stronger impact on disease course compared to effects on disease susceptibility. In ALS no such beneficial effect could be observed in the clinical and experimental studies.

Conclusion: This literature assessment revealed that coffee and especially caffeine could have a preventative role in the development of several neurodegenerative diseases if provided in comparatively high doses. The systematic assessment indicates that coffee and caffeine intake must not be considered as a health risk. Additional clinical studies are needed to fully understand how far coffee and caffeine intake should be considered as a potential therapeutic approach for certain disease entities and conditions.

Effects of Coffee Intake on Incident Chronic Kidney Disease: A Community-Based Prospective Cohort Study

BACKGROUND

Drinking coffee can raise public health problems, but the association between coffee and kidney disease is unknown. We studied whether coffee intake can affect the development of chronic kidney disease in the general population.

METHODS

We analyzed 8717 subjects with normal renal function recruited from the Korean Genome and Epidemiology Study (KoGES) cohort. Based on a food frequency questionnaire, coffee consumption was categorized into 5 groups: 0 per week, <1 cup per week, 1-6 cups per week, 1 cup per day, and ≥2 cups per day. The primary outcome was incident chronic kidney disease, defined as an estimated glomerular filtration rate <60 mL/min/1.73 m².

RESULTS

The mean age (standard deviation) of study subjects was 52.0 (8.8) years, and 47.8% were male. Among the subjects, 52.8% were daily coffee consumers. During a mean follow-up of 11.3 (range, 5.9-11.5) years, 9.5% of participants developed chronic kidney disease. The incident chronic kidney disease occurred less in daily coffee consumers. Unadjusted hazard ratios (HRs) was significantly lower in daily coffee consumers. In multivariable Cox model even after adjustment of blood pressure, hypertension, cardiovascular disease, diabetes, and amount of daily intake for caffeine-containing foods such as tea and chocolate, coffee consumers with 1 cup per day (HR, 0.76; 95% confidence interval, 0.63-0.92) and ≥2 cups per day (HR, 0.80; 95% confidence interval, 0.65-0.98) were associated with a lower risk of chronic kidney disease development than nondrinkers. Time-averaged and time-varying Cox models yielded similar results. The rates of decline in glomerular filtration were lower in daily coffee consumers.

CONCLUSIONS

Our findings suggest that daily coffee intake is associated with decreased risk of the development of chronic kidney disease.

Coffee consumption and total mortality in a Mediterranean prospective cohort

Background

The relation of coffee consumption with total mortality is controversial, because the available evidence is still inconsistent.

Objective

This study aimed to assess this association in a highly educated, middle-aged Mediterranean cohort.

Design

We analyzed data from 201,055 person-years of follow-up arising from 19,888 participants. Coffee consumption was obtained at baseline with the use of a previously validated semiquantitative food-frequency questionnaire. Information on mortality was ascertained by permanent contact with the "Seguimiento Universidad de Navarra" (SUN) participants and their families, postal authorities, and consultation of the National Death Index. We used Cox regression models to estimate HRs and 95% CIs for mortality according to baseline total coffee consumption adjusted for potential confounders. Sex, age, and baseline adherence to the Mediterranean diet were considered as potential effect modifiers.

Results

Among the 19,888 participants, 337 died. Overall, in the multivariable adjusted analysis, we found a 22% lower risk of all-cause mortality for each 2 additional cups of total coffee per day (HR: 0.78; 95% CI: 0.66, 0.93). This association was stronger for participants aged ≥55 y (HR: 0.67; 95% CI: 0.52, 0.86) than for younger participants, who showed no significant association (P-interaction = 0.002).

Conclusion

In a Mediterranean cohort, we found an inverse linear association between total coffee consumption and the risk of all-cause mortality that was strongest among participants older than 54 y.

Association of Coffee and Tea with Ferritin: Data from the Korean National Health and Nutrition Examination Survey (IV and V)

There have been few studies that have evaluated the association between coffee intake and iron in Korean population. Data from the Korean National Health and Nutrition Examination Survey (IV and V; 2007–2012) was used to investigate the association between coffee and green tea intake and serum ferritin levels in Korean adults. Beverage intake was assessed using a food frequency questionnaire. Multivariate linear regression was performed to evaluate the relationship between coffee and tea intake and serum ferritin levels, after adjusting for age, body mass index, education level, smoking status, alcohol consumption, physical activity, hypertension, diabetes mellitus, and daily iron intake. Coffee intake was negatively related to serum ferritin levels in both sexes. The multivariate-adjusted geometric mean of serum ferritin level was 100.7 ng/mL (95% confidence interval [CI]: 98.2–103.4) in men drinking <1 coffee/day, and 92.2 ng/mL (95% CI: 89.7–94.8) in those drinking ≥3 coffees/day. In women, the equivalent serum ferritin levels were 35.6 ng/mL (95% CI: 34.8–36.4) and 28.9 ng/mL (95% CI: 27.8–30.1). However, green tea intake was not related to serum ferritin levels. In conclusion, coffee consumption was associated with lower serum ferritin levels in Korean adults.

Relationship of Time-Activity-Adjusted Particle Number Concentration with Blood Pressure

Emerging evidence suggests long-term exposure to ultrafine particulate matter (UFP, aerodynamic diameter < 0.1 µm) is associated with adverse cardiovascular outcomes. We investigated whether annual average UFP exposure was associated with measured systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), and hypertension prevalence among 409 adults participating in the cross-sectional Community Assessment of Freeway Exposure and Health (CAFEH) study. We used measurements of particle number concentration (PNC, a proxy for UFP) obtained from mobile monitoring campaigns in three near-highway and three urban background areas in and near Boston, Massachusetts to develop PNC regression models (20-m spatial and hourly temporal resolution). Individual modeled estimates were adjusted for time spent in different micro-environments (time-activity-adjusted PNC, TAA-PNC). Mean TAA-PNC was 22,000 particles/cm³ (sd = 6500). In linear models (logistic for hypertension) adjusted for the minimally sufficient set of covariates indicated by a directed acyclic graph (DAG), we found positive, non-significant associations between natural log-transformed TAA-PNC and SBP (β = 5.23, 95%CI: −0.68, 11.14 mmHg), PP (β = 4.27, 95%CI: −0.79, 9.32 mmHg), and hypertension (OR = 1.81, 95%CI: 0.94, 3.48), but not DBP (β = 0.96, 95%CI: −2.08, 4.00 mmHg). Associations were stronger among non-Hispanic white participants and among diabetics in analyses stratified by race/ethnicity and, separately, by health status.

Are coffee's alleged health protective effects real or artifact? The enduring disjunction between relevant experimental and observational evidence

BACKGROUND

There is a large corpus of observational evidence claiming that coffee is health protective and a similarly large corpus of experimental psychopharmacological evidence to suggest that habitual caffeine consumption may be harmful to health.

AIM

The purpose of this study was to examine the disjunction between observational and experimental findings with specific reference to the implications of coffee/caffeine consumption for elevated blood pressure, cardiovascular disease, type 2 diabetes and neurodegenerative disease.

METHOD

Illustrative recent major reviews alleging health protective effects from coffee consumption were examined in light of findings from relevant experimental studies of caffeine.

FINDINGS

Decades-long coffee consumption is but one of countless lifestyle variables that may benefit or harm health. Contradictions concerning the implications of coffee/caffeine consumption for health between observational and experimental research are attributable mostly to poor control over potential confounders in observational studies.

CONCLUSION

When considered in the context of experimental evidence concerning caffeine's known pharmacological actions, there is reason to be sceptical about observational findings alleging health-protective effects from coffee consumption. Long-term randomised trials are needed to end the enduring interpretative disjunction between observational and experimental evidence concerning coffee/caffeine consumption and health.

Coffee Consumption and Cardiovascular Disease: A Condensed Review of Epidemiological Evidence and Mechanisms

Coffee is one of the most widely consumed beverages, and some studies have suggested it may be related to cardiovascular disease (CVD), the leading cause of poor health in the world. This review evaluates the evidence on the effect of habitual coffee consumption on CVD incidence and mortality. The review is based mostly on observational studies and meta-analyses of the literature. In healthy people, in comparison to not consuming coffee, habitual consumption of 3-5 cups of coffee per day is associated with a 15% reduction in the risk of CVD, and higher consumption has not been linked to elevated CVD risk. Moreover, in comparison to no coffee intake, usual consumption of 1-5 cups/day is associated with a lower risk of death. In people who have already suffered a CVD event, habitual consumption does not increase the risk of a recurrent CVD or death. However, hypertensive patients with uncontrolled blood pressure should avoid consuming large doses of caffeine. In persons with well-controlled blood pressure, coffee consumption is probably safe, but this hypothesis should be confirmed by further investigations.

Effect of individualised dietary advice for weight loss supplemented with walnuts on blood pressure: the HealthTrack study

BACKGROUND/OBJECTIVES

In addition to weight-loss, healthy dietary patterns and lower sodium intakes can help reduce blood pressure (BP), but individualised dietary advice may be necessary to achieve these effects. This study aimed to examine the impact of individualised dietary advice on BP in the intensive phase of a weight-loss trial.

SUBJECTS/METHODS

Secondary analysis of baseline and 3-month data from the HealthTrack randomised controlled trial (n = 211). Participants were randomly assigned to one of three dietary advice groups: general advice (control), individualised advice (intervention group, I), or intervention group supplemented with 30 g walnuts/day (IW). Resting BP and 24-h urine sodium and potassium were measured. Dietary intake was evaluated through diet history interviews.

RESULTS

Unadjusted SBP reduced significantly in all groups (IW and I groups P < 0.001; control group P = 0.002) and DBP in IW and I groups (P < 0.001). Compared to controls, the reductions in BP were 3-4 mmHg greater in the I and IW groups, but this only reached significance for DBP in the I group (-3.3 mmHg; P = 0.041). After controlling for age, sex, medication, weight-loss, physical activity and smoking, only the IW group showed a significant association between SBP reduction and increased urinary potassium (β = -0.101, P = 0.044), decreased sodium:potassium ratio (β = 2.446, P = 0.037) and increased consumption of seed and nut products and dishes (β = -0.108, P = 0.034).

CONCLUSIONS

Dietary patterns with distinctive foods and lower sodium:potassium ratios may enhance the effects of weight-loss on BP. The patterns were best achieved with individualised dietary advice and food supplements.

Coffee for Cardioprotection and Longevity

Coffee, a complex brew containing hundreds of biologically active compounds, exerts potent effects on long-term human health. Recently, a plethora of studies have been published focusing on health outcomes associated with coffee intake. An inverse association between coffee consumption and all-cause mortality has been seen consistently in large prospective studies. Habitual coffee consumption is also associated with lower risks for cardiovascular (CV) death and a variety of adverse CV outcomes, including coronary heart disease (CHD), congestive heart failure (HF), and stroke; coffee's effects on arrhythmias and hypertension are neutral. Coffee consumption is associated with improvements in some CV risk factors, including type 2 diabetes (T2D), depression, and obesity. Chronic coffee consumption also appears to protect against some neurodegenerative diseases, and is associated with improved asthma control, and lower risks for liver disease and cancer. Habitual intake of 3 to 4 cups of coffee appears to be safe and is associated with the most robust beneficial effects. However, most of the studies regarding coffee's health effects are based on observational data, with very few randomized controlled trials. Furthermore, the possible benefits of coffee drinking must be weighed against potential risks, which are generally due to its high caffeine content, including anxiety, insomnia, headaches, tremulousness, and palpitations. Coffee may also increase risk of fracture in women, and when consumed in pregnancy coffee increases risk for low birth weight and preterm labor.

Dietary Phytoestrogen Intake is Inversely Associated with Hypertension in a Cohort of Adults Living in the Mediterranean Area

Background: Dietary polyphenols, including phytoestrogens are abundantly present in a balanced diet. Evidence for their role in preventing non-communicable diseases is emerging. Methods: We examined the association between estimated habitual intakes of dietary phytoestrogens and hypertension in a cohort study. The baseline data included 1936 men and women aged 18 years and older. Intakes of total phytoestrogens, isoflavones, and lignans were calculated from validated food frequency questionnaire. Data on the polyphenols content in foods were retrieved from the Phenol-Explorer database. Results: Individuals in the highest quartile of dietary phytoestrogens intake were less likely to be hypertensive (OR: 0.66, 95% CI: 0.44–0.98); moreover, the association showed a significant decreasing trend. Isoflavones and lignans were not associated with lower odds of hypertension; however, some individual compounds, such as biochanin A and pinoresinol showed an independent inverse association with hypertension. Conclusions: Dietary phytoestrogens are associated with lower likelihood of hypertension in adults living in the Mediterranean area. Future studies are needed to confirm the present findings (i.e., prospective cohort studies) and to better understand the mechanisms underlying such associations.

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.

Relationship between Coffee Consumption and Metabolic Syndrome in Korean Adults: Data from the 2013-2014 Korea National Health and Nutrition Examination Survey

Background

The gradually increasing demand for coffee worldwide has prompted increased interest in the relationship between coffee and health issues as well as a need for research on metabolic syndrome in adults.

Methods

Data from 3,321 subjects (1,268 men and 2,053 women) enrolled in the 2013–2014 Korean National Health and Nutrition Examination Survey were analyzed. The subjects were divided into three groups according to their daily coffee consumption. The odds ratios (ORs) and 95% confidence intervals (95% CIs) for metabolic syndrome in the coffee-drinking groups were calculated using multiple logistic regression analysis by adjusting for confounding variables.

Results

The prevalence of metabolic syndrome was 15.5%, 10.7%, and 9.7% in men and 3.0%, 7.1%, and 6.5% in women according to their coffee consumption (less than one, one or two, or more than three cups of coffee per day), respectively. Compared with the non-coffee consumption group, the ORs (95% CIs) for metabolic syndrome in the group that consumed more than three cups of coffee was 0.638 (0.328–1.244) for men and 1.344 (0.627–2.881) for women after adjusting for age, body mass index, household income, education, smoking, alcohol, regular exercise, and daily caloric intake.

Conclusion

The OR of metabolic syndrome was not statistically significant in both men and women.