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

Evidence on the use of alternative substances and therapies in hypertension

OBJECTIVE

Review of some of the best-known biological and non-biological complementary/alternative therapies/medicines (CAM) and their relationship with blood pressure (BP) and hypertension (HT).

SEARCH STRATEGY

Narrative review assessing a recent series of systematic reviews, meta-analyses, and clinical trials published in recent years, focusing on the effects of CAM on BP and HT.

SELECTION OF STUDIES

We searched EMBASE, MEDLINE, Cochrane Library and Google Scholar, obtaining a total of 4336 articles, finally limiting the search to 181 after applying filters.

SYNTHESIS OF RESULTS

Some studies on biological therapies show some usefulness in BP reduction with an adequate benefit-risk balance, although there is a scarcity of high-quality trials that support these results. Some mind-body therapies have shown hypothetical benefit; in contrast, others lack robust evidence.

CONCLUSIONS

Although some therapies present a reasonable risk-benefit ratio, they should in no case replace pharmacological treatment when indicated.

Acute Effects of Coffee Consumption on Blood Pressure and Endothelial Function in Individuals with Hypertension on Antihypertensive Drug Treatment: A Randomized Crossover Trial

INTRODUCTION

Coffee is a complex brew that contains several bioactive compounds and some of them can influence blood pressure (BP) and endothelial function (EF), such as caffeine and chlorogenic acids (CGAs).

AIM

This study aimed to evaluate the acute effects of coffee on BP and EF in individuals with hypertension on drug treatment who were habitual coffee consumers.

METHODS

This randomized crossover trial assigned 16 adults with hypertension to receive three test beverages one week apart: caffeinated coffee (CC; 135 mg caffeine, 61 mg CGAs), decaffeinated coffee (DC; 5 mg caffeine, 68 mg CGAs), and water. BP was continuously evaluated from 15 min before to 90 min after test beverages by digital photoplethysmography. Reactive hyperemia index (RHI) assessed by peripheral arterial tonometry evaluated EF before and at 90 min after test beverages. At the same time points, microvascular reactivity was assessed by laser speckle contrast imaging. Repeated-measures-ANOVA evaluated the effect of time, the effect of beverage, and the interaction between time and beverage (treatment effect).

RESULTS

Although the intake of CC produced a significant increase in BP and a significant decrease in RHI, these changes were also observed after the intake of DC and were not significantly different from the modifications observed after the consumption of DC and water. Microvascular reactivity did not present significant changes after the 3 beverages.

CONCLUSION

CC in comparison with DC and water neither promoted an acute increase in BP nor produced an improvement or deleterious effect on EF in individuals with hypertension on drug treatment who were coffee consumers.

Variables Affecting the Extraction of Antioxidants in Cold and Hot Brew Coffee: A Review

Coffee beans are a readily available, abundant source of antioxidants used worldwide. With the increasing interest in and consumption of coffee beverages globally, research into the production, preparation, and chemical profile of coffee has also increased in recent years. A wide range of variables such as roasting temperature, coffee grind size, brewing temperature, and brewing duration can have a significant impact on the extractable antioxidant content of coffee products. While there is no single standard method for measuring all of the antioxidants found in coffee, multiple methods which introduce the coffee product to a target molecule or reagent can be used to deduce the overall radical scavenging capacity. In this article, we profile the effect that many of these variables have on the quantifiable concentration of antioxidants found in both cold and hot brew coffee samples. Most protocols for cold brew coffee involve an immersion or steeping method where the coffee grounds are in contact with water at or below room temperature for several hours. Generally, a higher brewing temperature or longer brewing time yielded greater antioxidant activity. Most studies also found that a lower degree of coffee bean roast yielded greater antioxidant activity.

Potential Benefits of Coffee Consumption on Improving Biomarkers of Oxidative Stress and Inflammation in Healthy Individuals and Those at Increased Risk of Cardiovascular Disease

Cardiovascular diseases (CVDs) are considered the predominant cause of death globally. An abnormal increase in biomarkers of oxidative stress and inflammation are consistently linked with the development and even progression of metabolic diseases, including enhanced CVD risk. Coffee is considered one of the most consumed beverages in the world, while reviewed evidence regarding its capacity to modulate biomarkers of oxidative stress and inflammation remains limited. The current study made use of prominent electronic databases, including PubMed, Google Scholar, and Scopus to retrieve information from randomized controlled trials reporting on any association between coffee consumption and modulation of biomarkers of oxidative stress and inflammation in healthy individuals or those at increased risk of developing CVD. In fact, summarized evidence indicates that coffee consumption, mainly due to its abundant antioxidant properties, can reduce biomarkers of oxidative stress and inflammation, which can be essential in alleviating the CVD risk in healthy individuals. However, more evidence suggests that regular/prolonged use or long term (>4 weeks) consumption of coffee appeared to be more beneficial in comparison with short-term intake (<4 weeks). These positive effects are also observed in individuals already presenting with increased CVD risk, although such evidence is very limited. The current analysis of data highlights the importance of understanding how coffee consumption can be beneficial in strengthening intracellular antioxidants to alleviate pathological features of oxidative stress and inflammation to reduce CVD risk within the general population. Also covered within the review is essential information on the metabolism and bioavailability profile of coffee, especially caffeine as one of its major bioactive compounds.

The impact of genetic variability on the relationship between caffeine and cardiometabolic outcomes: A systematic review

The relationship between caffeine consumption and cardiometabolic health has been reported, however with heterogenous results. Discrepancies in study results may be due to inter-individual variability between study participants. This systematic review aimed to identify the impact of genetics on the relationship between caffeine consumption and cardiometabolic outcomes. Electronic databases (PubMed and EMBASE) were searched for studies published until July 2021. Selected studies were of both intervention and observational design and included (1) analysis of at least one of the selected cardiometabolic outcome (type 2 diabetes, glucose/insulin levels, cardiovascular disease [CVD], blood pressure [BP] or hypertension, and blood lipid and catecholamine levels), (2) adults aged 18-65 years, and (3) genetic analysis of individuals consuming caffeine. Seventeen studies were included: four randomised controlled trials and an interventional and quasi-experimental study, six population-based prospective cohort studies, three cross-sectional studies, and three case-control studies. CYP1A2 rs762551 and ADORA rs5751876 were associated with glucose response when caffeine was consumed with carbohydrates. CYP1A2 rs762551 moderated the association between coffee intake and hypertension. Moreover, ADORA2A rs5751876 and the ADRA2B I variants moderated the associations between caffeine and BP. Studies that investigated the effects of genetic variations on CVD and caffeine consumption reported equivocal findings (CYP1A2) or warrant replication (COMT, ADORA and TRIB1). Elucidating the extent to which these genes moderate the association between caffeine and cardiometabolic outcomes will enable caffeine consumption advice to be tailored to specific individuals to optimise health.

Time-dependent effect of intense capsule-coffee and bleaching on the color of resin-infiltrated enamel white spot lesions: an in vitro study

Background and Objectives

White spot lesions (WSLs) are a common problem that can be conservatively managed by resin infiltration. Consumption of dark beverages such as coffee causes staining of dental hard tissues, which can deteriorate the esthetic qualities of treated WSLs. The aims of this study were to investigate the effect of dark coffee heavy consumption on ICON^® resin infiltrated WSLs and the influence of bleaching on them after staining.

Methods

Twenty surfaces from sound human extracted third molars were used in the study. Two square-shaped buccal and lingual window areas had artificially created WSLs (received buccal resin infiltration afterward). Using VITA Easyshade, the baseline ΔE was recorded. Espresso coffee was used to immerse all surfaces for 8 days. The color coordinates according to CIE LAB were recorded for all surfaces at 2, 4, 6, and 8 days of immersion, and ΔE was calculated at each timepoint. After 8 days, in-office bleaching was applied to all surfaces according to the manufacturer's instructions and the color. Coordinates and ΔE were recorded. For statistical analysis, an independent sample t-test was used to compare each group. A general linear mixed model (GLMM) repeated measure ANOVA was applied for statistical analysis of L^*and changes due to staining over time.

Results

Analysis of time as a main effect on the L values of surfaces was statistically highly significant (p < 0.01). The interaction of time with surfaces under investigation and type of surface (test vs. control) as a main effect were non-significant (p = 0.47 and p = 0.35, respectively). Bleaching showed a significant difference in color lightness in both test and control surfaces compared to the mean L value at 8 days of staining (p < 0.01).

Conclusion

Capsule-coffee consumption gradually influences the esthetic of resin infiltration on treated teeth. However, bleaching materials might restore an esthetic shade.

The relationship of coffee consumption and CVD risk factors in elderly patients with T2DM

Objective

Clinical studies suggest increasing prevalence of cardiovascular disease (CVD) risk factors and diabetes among the elderly. Meanwhile, some food compounds, such as coffee, can also have beneficial effects on CVD risk factors. The aim of the present study was to examine the relationship between coffee consumption and CVD risk factors in the elderly with type 2 diabetes mellitus (T2DM).

Methods

This cross-sectional study was performed during 2017 on 300 elderly people above 60 years of age with T2DM in Isfahan, Iran. Dietary assessment was performed using a food frequency questionnaire. Coffee consumption was classified into three groups including < 1, 1–3, and > 3 cups/day. Partial correlation test was used to investigate the relationship between CVD risk factors and usual coffee consumption.

Results

The mean age and body mass index of participants were 70.04 ± 4.87 years and 24.74 ± 3.34 kg/m² respectively. Coffee consumption had a significant inverse relationship with fasting plasma glucose (FPG) and diastolic blood pressure (DBP) in the elderly with T2DM (r: − 0.117, 0.134; p: 0.046, 0.022). Triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) had a significant positive relationship with coffee consumption levels (r: 0.636, 0.128; p: 0.028, 0.029). These results were obtained after controlling for potential confounders.

Conclusion

Increasing coffee consumption was linked to improved status of some CVD risk factors including FPG, HDL-C, and DBP in the elderly with T2DM. Nevertheless, increasing coffee consumption was also associated with higher TG level and had no significant effect on other risk factors. Further studies are required to confirm these results.

Longitudinal study of the relationship between coffee consumption and type 2 diabetes in Chinese adult residents: Data from China Health and Nutrition Survey

BACKGROUND

Increasing coffee intake was inversely associated with risk of type 2 diabetes in Western countries. However, in China where coffee consumption and diabetes population has been growing fast in recent years, studies on the impact of coffee intakes on the onset of type 2 diabetes are lacking. This study attempts to determine the associations between coffee consumption and type 2 diabetes in Chinese adults.

METHODS

This longitudinal study analyzed 10447 adults who had participated in at least two rounds of the China Health and Nutrition Survey (CHNS), which is a survey database of multistage, random cluster process during 1993-2011. Coffee consumption and type 2 diabetes incidence were measured in the survey. Body mass index (BMI), age, sex, place of residence, waves, education level, smoking, drinking alcohol and tea drinking frequency were adjusted as covariate. We used longitudinal fixed effects regression models to assess changes within person.

RESULTS

After adjusting confounding factors, lower risk of diabetes is observed among Chinese adults who drink coffee occasionally (Adjusted Odds Ratio (AOR)  = 0.13, 95% CI = 0.05, 0.34) and drink almost every day (AOR = 0.61, 95% CI = 0.45, 0.83), compared with those who do not or hardly drink. In the subgroup analysis, among women aged 45-59 who drink coffee one to three times a week (AOR = 0.21, 95% CI = 0.08, 0.52) and men over 60 who drink coffee almost every day (AOR = 0.19, 95% CI = 0.07, 0.53), protective effects were found. For young men aged 19-29, drinking coffee almost every day showed a risk effect (AOR = 20.21, 95% CI = 5.96-68.57).

CONCLUSIONS

Coffee drinking habit is an independent protective factor for adult on type 2 diabetes in China. And it varies among people with different ages and genders. The rapid growth of coffee consumption in China in recent years may help reduce the risk of type 2 diabetes, but at the same time, the risk of type 2 diabetes in adolescents needs attention.

Electrochemically facilitated oxidative C–H amination enables access to fluorescent N9-fused tricyclic xanthines

An electrochemically enabled intramolecular C−H amination route for accessing a broad range of fluorescent N9-fused tricyclic xanthines with various substitution patterns under simple, green, and mild condition is developed.

Long-Term Coffee Consumption is Associated with Fecal Microbial Composition in Humans

Coffee consumption has been related to a preventive effect against several non-transmissible pathologies. Due to the content of this beverage in phytochemicals and minerals, it has been proposed that its impact on health may partly depend on gut microbiota modulation. Our aim was to explore the interaction among gut microbiota, fecal short chain fatty acids, and health-related parameters in 147 healthy subjects classified according to coffee consumption, to deepen the association of the role of the (poly)phenol and alkaloid content of this beverage. Food daily intake was assessed by an annual food frequency questionnaire (FFQ). Coffee consumption was categorized into three groups: non-coffee-consumers (0–3 mL/day), moderate consumers (3–45 mL/day) and high-coffee consumers (45–500 mL/day). Some relevant groups of the gut microbiota were determined by qPCR, and concentration of fecal short chain fatty acids by gas chromatography. Serum health related biomarkers were determined by standardized methods. Interestingly, a higher level of Bacteroides–Prevotella–Porphyromonas was observed in the high consumers of coffee, who also had lower levels of lipoperoxidation. Two groups of coffee-derived (poly)phenol, methoxyphenols and alkylphenols, and caffeine, among alkaloids, were directly associated with Bacteroides group levels. Thus, regular consumption of coffee appears to be associated with changes in some intestinal microbiota groups in which dietary (poly)phenol and caffeine may play a role.

Beneficial Impact of Semicarbazide-Sensitive Amine Oxidase Inhibition on the Potential Cytotoxicity of Creatine Supplementation in Type 2 Diabetes Mellitus

Creatine supplementation of the population with type 2 diabetes mellitus (T2DM) combined with an exercise program is known to be a possible therapy adjuvant with hypoglycemic effects. However, excessive administration of creatine leads to the production of methylamine which is deaminated by the enzyme semicarbazide-sensitive amine oxidase (SSAO) and as a result, cytotoxic compounds are produced. SSAO activity and reaction products are increased in the serum of T2DM patients. Creatine supplementation by diabetics will further augment the activity of SSAO. The current review aims to find a feasible way to ameliorate T2DM for patients who exercise and desire to consume creatine. Several natural agents present in food which are involved in the regulation of SSAO activity directly or indirectly are reviewed. Particularly, zinc-α2-glycoprotein (ZAG), zinc (Zn), copper (Cu), histamine/histidine, caffeine, iron (Fe), and vitamin D are discussed. Inhibiting SSAO activity by natural agents might reduce the potential adverse effects of creatine metabolism in population of T2DM.

Combined Effect Of Coffee Consumption And Cigarette Smoking On Serum Levels Of Vitamin B12, Folic Acid, And Lipid Profile In Young Male: A Cross-Sectional Study

OBJECTIVE

To investigate the associations of coffee consumption and/or smoking on certain clinical outcomes including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), vitamin B12, and folic acid in a population of young healthy men.

METHOD

This cross-sectional study was conducted in Amman, Jordan, over 4 months. Participants were approached for study participation and asked to fill a questionnaire about their anthropometric information, habitual smoking, and coffee consumption during the last 3 months. Their fasting blood samples were taken to measure TC and LDL-C.

RESULTS

Healthy male participants (n=117) in the age range of 18 to 26 years were recruited. Mean serum TC was higher in heavy coffee consumers (C++) group (≥3 cups/day) with or without smoking (M= 179.9±34.59 mg/dL and 195.94±23.69 mg/dL) in comparison with moderate coffee consumers (C+) group (1-2 cups/day) (M= 158.1±24.82 mg/dL and 177.23±34.17 mg/dL), and the mean level was higher in subjects who were coffee consumers only than smokers who were coffee consumers. LDL-C levels were higher in participants who were coffee consumers (M= 103.06±34.82mg/dL and 118.06±19.31 mg/dL) than smokers who were coffee consumers (M= 88.6±22.40 mg/dL and 108.26±37.57 mg/dL). No significant difference was noted regarding HDL-C, vitamin B12, and folic acid.

CONCLUSION

Our findings showed that heavy coffee consumption was more associated with hyperlipidemia than cigarette smoking. Accordingly, we conclude that moderate coffee consumption may reduce the risk of cardiovascular diseases or their consequences in male.

Estrogenic Activity of Coffee Constituents

Here, the constituents of coffee with estrogenic activity are summarized by a comprehensive literature search, and their mechanisms of action for their physiological effects are discussed at the molecular and cellular levels. The estrogenic activity of coffee constituents, such as acids, caramelized products, carbohydrates, lignin, minerals, nitrogenous compounds, oil (lipids), and others, such as volatile compounds, was first evaluated by activity assays, such as animal tests, cell assay, ligand-binding assay, protein assay, reporter-gene assay, transcription assay, and yeast two-hybrid assay. Second, the health benefits associated with the estrogenic coffee constituents, such as bone protection, cancer treatment/prevention, cardioprotection, neuroprotection, and the improvement of menopausal syndromes, were summarized, including their potential therapeutic/clinical applications. Inconsistent results regarding mixed estrogenic/anti-estrogenic/non-estrogenic or biphasic activity, and unbeneficial effects associated with the constituents, such as endocrine disruption, increase the complexity of the effects of estrogenic coffee constituents. However, as the increase of the knowledge about estrogenic cell signaling, such as the types of specific signaling pathways, selective modulations of cell signaling, signal crosstalk, and intercellular/intracellular networks, pathway-based assessment will become a more realistic means in the future to more reliably evaluate the beneficial applications of estrogenic coffee constituents.

Niacin, alkaloids and (poly)phenolic compounds in the most widespread Italian capsule-brewed coffees

Coffee is one of the most popular beverages worldwide and, nowadays, one of the most practical way for its preparation is by prepacked capsules. The aim of this study was comparing the content in caffeine, trigonelline, N-methylpyridinium (NMP), niacin, and chlorogenic acids of 65 different capsule-brewed coffees, commercialised by 5 of the most representative brands in Italy. Coffees were prepared from capsules following manufacturer’s instructions and analysed with an optimized UHPLC-MS/MS method able to assess all these phytochemicals in one single run. Inter-lot and capsule variability were also studied for a subset of coffee capsules. Except for decaffeinated coffees, caffeine amount accounted between 54 and 208 mg/serving. Regular espresso coffees showed higher trigonelline, NMP, and niacin concentrations than large (lungo) and decaffeinated samples, with average serving amounts of 17.96, 1.78, and 0.66 mg, respectively. Regarding chlorogenic acids, caffeoylquinic acids were the most relevant ones (20–117 mg/serving). Feruloylquinic acids were quantified between 8 and 50 mg/serving. Coumaroylquinic acids, hydroxycinnamate dimers, caffeoylshikimic acids, and caffeoylquinic lactones were also present at lower concentrations. Multivariate analysis provided comprehensive information on the phytochemical profile of the different types of coffee, showing a great variability among coffees with some brand-related insights. This study supports the need for accurately characterizing espresso coffees while investigating the beneficial effects of coffee on human health.

Theobromine and related methylxanthines as inhibitors of Primary Amine Oxidase

Methylxanthines are among the most widely consumed drugs in the world and evidence of their health benefits has been growing in recent years. Primary Amine Oxidase (PrAO) has been recognized as a therapeutic target for the amelioration of inflammatory, vascular, and neurodegenerative diseases. Previous work in our laboratories showed that caffeine inhibited Bovine PrAO with a Ki of 1.0 mM using benzylamine as substrate. This study aimed to extend our previous work and explore the possibility that related methylxanthines might influence PrAO activity. While paraxanthine, theophylline, and 7-methylxanthine had little effect on PrAO, theobromine was a noncompetitive inhibitor with a Ki of 276 ± 44 µM. The specific structural elements of methylxanthines that are required for inhibition allow us to suggest that their binding site on PrAO may be a target for therapeutics. The health benefits associated with dietary methylxanthine consumption could involve PrAO inhibition. PRACTICAL APPLICATIONS: Inhibition of PrAO by methylxanthines may be significant in conferring health benefits. The design of PrAO inhibitors based on the structural motifs identified in this study (N-methylation at specific locations) is indicated. Existing therapeutics based on a core xanthine structure can be evaluated for their effects on PrAO. PrAO inhibition must be considered as a potential mediator of the beneficial health effects of some methylxanthines. If inhibition in human tissues is comparable to, or greater than, that found in these studies it points to an important role for these compounds in human health.

Food Bioactive HDAC Inhibitors in the Epigenetic Regulation of Heart Failure

Approximately 5.7 million U.S. adults have been diagnosed with heart failure (HF). More concerning is that one in nine U.S. deaths included HF as a contributing cause. Current HF drugs (e.g., β-blockers, ACEi) target intracellular signaling cascades downstream of cell surface receptors to prevent cardiac pump dysfunction. However, these drugs fail to target other redundant intracellular signaling pathways and, therefore, limit drug efficacy. As such, it has been postulated that compounds designed to target shared downstream mediators of these signaling pathways would be more efficacious for the treatment of HF. Histone deacetylation has been linked as a key pathogenetic element for the development of HF. Lysine residues undergo diverse and reversible post-translational modifications that include acetylation and have historically been studied as epigenetic modifiers of histone tails within chromatin that provide an important mechanism for regulating gene expression. Of recent, bioactive compounds within our diet have been linked to the regulation of gene expression, in part, through regulation of the epi-genome. It has been reported that food bioactives regulate histone acetylation via direct regulation of writer (histone acetyl transferases, HATs) and eraser (histone deacetylases, HDACs) proteins. Therefore, bioactive food compounds offer unique therapeutic strategies as epigenetic modifiers of heart failure. This review will highlight food bio-actives as modifiers of histone deacetylase activity in the heart.

Food Patterns and Framingham Risk Score in Iranian Adults: Tehran Lipid and Glucose Study: 2005-2011

BACKGROUND

Healthy dietary habits can prevent cardiovascular diseases (CVD). The aim of this study was to investigate the association between dietary patterns and predicted risk of CVD development using Framingham Risk Score (FRS) in Iranian population over 6 years of follow-up.

METHODS

In this prospective study, 2333 individuals aged 30-74 years with a 10-year predicted risk <10% and without a CVD diagnosis at baseline were recruited from participants in the third survey of Tehran Lipid and Glucose Study. Usual dietary intake was assessed using a validated semiquantitative food frequency questionnaire. Dietary patterns were identified using factor analysis. The risk of developing CVD was evaluated using FRS questionnaire. The association between dietary patterns and risk of development of CVD was evaluated using binary logistic regression models.

RESULTS

Three major dietary patterns were identified, which explained 32% of total variance in dietary intake of participants. The healthy dietary pattern was characterized by high intake of fruits, fruit juices, vegetables, liquid oils, and nuts and lower intake of refined grains. The western dietary pattern was characterized by high intake of fast foods, soft drinks, sweets and sugars, and red meat, organ meat, and egg. The traditional dietary pattern was characterized by high intake of legumes and vegetables and low intake of high-fat dairy products. After adjustment for all confounding factors, participants in the highest tertile of the healthy dietary pattern had a lower risk of CVD development (odds ratio [OR]: 0.67; 95% CI: 0.51-0.87, P-trend: 0.003).

CONCLUSION

Our findings in a large cohort of Iranian population confirm the current recommendation regarding consuming healthy dietary pattern for primary prevention of CVDs.

The Effect of Time, Roasting Temperature, and Grind Size on Caffeine and Chlorogenic Acid Concentrations in Cold Brew Coffee

The extraction kinetics and equilibrium concentrations of caffeine and 3-chlorogenic acid (3-CGA) in cold brew coffee were investigated by brewing four coffee samples (dark roast/medium grind, dark roast/coarse grind, medium roast/medium grind, medium roast/coarse grind) using cold and hot methods. 3-CGA and caffeine were found at higher concentrations in cold brew coffee made with medium roast coffees, rather than dark roast. The grind size did not impact 3-CGA and caffeine concentrations of cold brew samples significantly, indicating that the rate determining step in extraction for these compounds did not depend on surface area. Caffeine concentrations in cold brew coarse grind samples were substantially higher than their hot brew counterparts. 3-CGA concentrations and pH were comparable between cold and hot brews. This work suggests that the difference in acidity of cold brew coffee is likely not due to 3-CGA or caffeine concentrations considering that most acids in coffee are highly soluble and extract quickly. It was determined that caffeine and 3-CGA concentrations reached equilibrium according to first order kinetics between 6 and 7 hours in all cold brew samples instead of 10 to 24 hours outlined in typical cold brew methods.