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Coffee, diabetes, and weight control
Abstract
Several prospective epidemiologic studies over the past 4 y concluded that ingestion of caffeinated and decaffeinated coffee can reduce the risk of diabetes. This finding is at odds with the results of trials in humans showing that glucose tolerance is reduced shortly after ingestion of caffeine or caffeinated coffee and suggesting that coffee consumption could increase the risk of diabetes. This review discusses epidemiologic and laboratory studies of the effects of coffee and its constituents, with a focus on diabetes risk. Weight loss may be an explanatory factor, because one prospective epidemiologic study found that consumption of coffee was followed by lower diabetes risk but only in participants who had lost weight. A second such study found that both caffeine and coffee intakes were modestly and inversely associated with weight gain. It is possible that caffeine and other constituents of coffee, such as chlorogenic acid and quinides, are involved in causing weight loss. Caffeine and caffeinated coffee have been shown to acutely increase blood pressure and thereby to pose a health threat to persons with cardiovascular disease risk. One short-term study found that ground decaffeinated coffee did not increase blood pressure. Decaffeinated coffee, therefore, may be the type of coffee that can safely help persons decrease diabetes risk. However, the ability of decaffeinated coffee to achieve these effects is based on a limited number of studies, and the underlying biological mechanisms have yet to be elucidated.
... The primary and most widespread form of caffeine consumption is through coffee beverages, estimated to reach an impressive 2.25 billion cups consumed worldwide daily-approximately 530 million liters/day [1]. It is believed that the consumption of coffee originated in the northeastern region of Africa and gradually spread across the Middle East during the 15th century, eventually making its way to Europe [2]. The coffee beverage has a highly complex composition, comprising numerous chemical constituents, often reaching several hundred in number. ...
... Its properties include serving as a neurostimulant aid, enhancing energy substrate levels, and improving general exercise performance [5]. Caffeine (1,3,7trimethylxanthine), after ingestion, is demethylated into three pharmacologically active dimethylxanthines: theophylline, theobromine, and paraxanthine-all of them with similar molecular adenosine structure-with paraxanthine being the primary metabolite in blood after caffeine absorption [2]. Table 1. ...
... Caffeine exerts its effects through four described mechanisms (Table 1 and Fig adenosine receptor antagonism (1) and increased catecholamine concentrations plasma concentrations of 5-10 µmol/L, caffeine partially blocks the function of ade receptors (1), which contributes to its stimulant properties. Additionally, caffeine c the blood-brain barrier and raises circulating concentrations of epinephrine/adre (2). The proposed mechanisms of caffeine as a phosphodiesterase inhibitor (3 stimulator of calcium-release channels (4) are considered less significant, as these a require higher concentrations of caffeine, typically in the range of 500-5000 µmol/L, are significantly higher than the concentrations achieved through regular consumption (representing 5-20 µmol caffeine/day) [2]. ...
The consumption of coffee and caffeine (1,3,7-trimethylxanthine) is part of many cultures worldwide. Their properties include serving as a neurostimulant aid, enhancing energy substrate levels, and improving general exercise performance. Both present therapeutic effects that can also be used to control chronic and metabolic diseases due to four mechanisms: adenosine receptor antagonism, increased catecholamine concentrations, a phosphodiesterase inhibitor, and a stimulator of calcium-release channels. Despite the individual genetic variabilities, distinct mechanisms have been demonstrated to improve physical performance, thermogenesis, lipolysis, insulin sensitivity, and hormonal modulation. Thus, coffee consumption and caffeine supplementation may enhance physical and mental performance and may improve metabolic variables, reducing oxidative stress, inflammation, and insulin resistance. Current data reveal vital aspects of coffee and caffeine consumption in specific populations, although further studies are needed to define clinical interventions with caffeine in obesity and chronic conditions.
... For example, Watanabe et al. (2019), on healthy, overweight men and women showed daily consumption of coffee for 12 weeks significantly decreased the visceral fat area, total abdominal fat area, body weight and WC (Watanabe et al., 2019). In a review article, Greenberg et al. (2006) suggested that caffeine and CGA have a body weight-reducing effect (Greenberg et al., 2006). Previous studies reported benefits related to increased CGA content, such as reductions in glucose absorption, body weight and body fat (Greenberg et al., 2006;Thom, 2007). ...
... For example, Watanabe et al. (2019), on healthy, overweight men and women showed daily consumption of coffee for 12 weeks significantly decreased the visceral fat area, total abdominal fat area, body weight and WC (Watanabe et al., 2019). In a review article, Greenberg et al. (2006) suggested that caffeine and CGA have a body weight-reducing effect (Greenberg et al., 2006). Previous studies reported benefits related to increased CGA content, such as reductions in glucose absorption, body weight and body fat (Greenberg et al., 2006;Thom, 2007). ...
... In a review article, Greenberg et al. (2006) suggested that caffeine and CGA have a body weight-reducing effect (Greenberg et al., 2006). Previous studies reported benefits related to increased CGA content, such as reductions in glucose absorption, body weight and body fat (Greenberg et al., 2006;Thom, 2007). To our knowledge, fewer studies have described the influence of RT with CGA on body fat or abdominal visceral fat such as VAI and BAI. ...
Background
Green coffee supplementation has demonstrated beneficial anti-inflammatory and anti-obesity effects. Accordingly, we examined the effects of a green coffee (GC) extract concurrent to elastic band resistance training (EBRT) on insulin resistance, adiposity indices [Visceral (VAI), Body (BAI)] TyG-related indicators (TyG-BMI and TyG-WC) in obese women.
Methods
Obese participants (N=60, 30-50y, BMI >30 kg/m²) were randomized equally into a randomized, double-blind, placebo-controlled trial: (1) Placebo (PLA), (2) PLA+ Resistance training, (3) PLA+R, (4) GC, GC+Resistance training (GC+R). Treatment capsules contained 500 mg of GC and 50% chlorogenic acid (250 mg) for 8-wks. Resistance training consisted of 3 sessions per/wk/60-min. Paired-sample t-test and two-factor ANOVA were used for within and between-group comparisons.
Results
We observed a significant pre/post reduction for HOMA-IR (Primary Outcome; mean (SD) for the PLA+R (3.67±0.70 vs. 3.22±0.74 mg/dL) and GC+R (3.88±0.54 vs. 3.21±0.61, both p<0.001), but not GC 3.79±0.77 vs. 3.54±0.71, P=0.058) and PLA 3.41±0.76 vs. 3.69±0.95, P=0.21). Both GC+R (P=0.005) and PLA+R were significant vs. PLA (P=0.011). Secondary outcomes included a significant reduction in glucose for PLA+R (94.61±8.12 vs. 89.08±9.70 mg/dL) and GC+R (94.36±10.67 vs. 84.5±11.02 mg/dL, both P<0.001), but not GC (94.07±7.39 vs. 91.79±8.50 mg/dL, P=0.07) and PLA (91.46±10.28 vs. 99.92±20.12 mg/dL, P=0.053). Both GC+R (P=0.002) and PLA+R were significantly different (P=0.019) vs. PLA. Finally, Apo A-I significantly improved for GC+R compared vs. PLA, P=0.033) and BAI significantly improved for. PLA+R (P=0.021), GC+R (P=0.006) and GC vs. PLA.
Conclusion
Despite no synergistic exercise and green coffee treatment effects, exercise improved most TyG parameters and lipid profiles in obese women.
... Coffee's role as a preventive and therapeutic agent for type 2 diabetes has long been debated. Coffee consumption, both caffeinated and non-caffeinated, lowers the risk of developing type 2 diabetes, but some argue that coffee consumption raises the risk (Greenberg et al. 2006). These results suggest that the acute response to coffee consumption on an empty stomach (without the consumption of other foods) lowers blood glucose levels by decreasing cortisol secretion with a slight increase in insulin levels in healthy women. ...
... Cafestol in coffee increases insulin secretion in skeletal muscle cells by 34-68 percent while decreasing blood glucose levels (Costa and Reis 2019). Caffeine in coffee has an immediate effect on pancreatic beta cells, increasing insulin secretion, decreasing insulin sensitivity, and decreasing glucose tolerance (Greenberg et al. 2006). Acute consumption of caffeine causes hyperinsulinemia and also hyperlipidemia (Shearer and Graham 2014). ...
This research was aimed at analyzing the acute effects of Arabica black coffee consumption on blood glucose, insulin, and serum cortisol levels, as well as determining the pharmacological effects of black coffee as an antihyperglycemic. A randomized control trial with healthy female subjects was used in this study. There were 20 volunteers in total: 9 as the control group and 11 as the trial group. The treatment included brewing 10 grams of Gayo Arabica black coffee powder with 150 ml of boiling water. Blood glucose, insulin, and cortisol levels were measured twice, before and after 60 minutes of coffee consumption. An independent sample t-test (p < 0.05), Pearson correlation test (p < 0.05), and simple linear correlation test (p < 0.05) were used to analyze the data. Blood glucose levels and serum cortisol levels decreased significantly after coffee consumption in the trial group (p = 0.002* and p = 0.001*). There was no significant negative correlation between glucose and insulin levels (r = -0.122; p = 0.721). On the other hand, there was a significant positive correlation between cortisol levels and blood glucose (r = 0.651; p = 0.002*). In conclusion, a single cup of Gayo Arabica black coffee reduces blood sugar and serum cortisol levels, but does not increase serum insulin levels. Blood glucose levels correlate positively with serum cortisol levels in healthy female.
... Its consumption has been linked DOI: 10.1002/mnfr.201801341 to beneficial health effects including reduced risk of type 2 diabetes, cardiovascular and Alzheimer's disease, and of some human cancers. [1,2] Coffee is a complex mixture of more than 1000 compounds, including many different aromatic compounds. The heterocyclic aromatic compounds found in coffee, which include furans, pyrazines, and pyridines, are supposed to be of particular relevance for the beverage's quality and health effects. ...
... mg kg −1 . The second and third most abundant pyrazines are 2,5-DMeP and 2,6-dimethylpyrazine (2,, which occur at levels of 10.3-28.1 mg kg −1 and 10.3-30.0 mg kg −1 , respectively. ...
... Table 9 details the demographic profile of 800 respondents, who had an average age of 34.60 y ±8.20, with 52.00% of them were female, 70.00% residing in urban areas, an average monthly income of 12.70 ±4.00 million Vietnamese Dong and 85.00% held at least a technical or college-level education. The loss rate was consistent with similar market surveys [26]. A B Participants assessed the product using five-point Likert scale, with average ratings of 4.20 ±0.60 for aroma, 4.00 ±0.70 for taste and 3.70 ±0.80 for price. ...
Background and Objective: Obesity is an increasing public health issue that needs practical and scientifically supported nutritional interventions. This study aimed to formulate functional coffees enriched with fermented lotus leaves (Nelumbo nucifera) using Bacillus subtilis to enhance polyphenol concentration and lipase enzyme activity. Additional components included breadfruit leaves (Artocarpus altilis), lotus seeds, notoginseng flowers (Panax notoginseng), caterpillar fungi (Cordyceps militaris), and collagen, selected for their complementary effects on metabolic functions, immune supports, sensory attributes and market feasibility. Material and Methods: The multiple component formulation was optimized using mixture design integrated with response surface methodology. Efficacy was assessed through a 6-m randomized controlled trial involving 127 overweight adults. The trial used a double-blind placebo-controlled design to ensure reliability and minimize bias. Additionally, a consumer acceptance survey involving 800 participants was carried out to assess repurchase intention and product perception. Results and Conclusion: Fermentation (10⁷ CFU.g-1 , 35 °C, 65.00-70.00% relative humidity, 72 h) led to a 2.5-fold increase in polyphenol content and doubled lipase enzyme activity. In the clinical trial, participants consuming the nutritional coffee showed average weight increases of 1.40 kg, decreases in low-density lipoprotein cholesterol C by approximately 10.00 mg.dl-1 and increases in high-density lipoprotein cholesterol by nearly 3.00 mg.dl-1. These improvements were statistically significant (p < 0.05) and were not associated with serious adverse effects. The consumer survey indicated a 65.00% repurchase intention, suggesting promising market potential. Although the study included limitations such as those of sample size, dropout rate and intervention time, the findings demonstrated metabolic benefits and industrial feasibility. This study provides a solid foundation for the development and commercialization of functional coffee targeting weight management and cardiovascular support. These findings provide valuable insights for researchers and industries worldwide interested in developing innovative functional beverages aimed at managing obesity and improving cardiovascular health. Conflict of interest: The authors declare no conflict of interest. Article Information
... Further Coffee consumption might result in weight loss by increasing thermogenesis, fat oxidation, and lipolysis. [79] It has been demonstrated that plasma concentrations of free fatty acid (FFA) and urinary catecholamine excretion increase after caffeine or coffee ingestion. [80,81] The increased lipolysis was partly because of the enhanced release of catecholamine. ...
Background
Findings from cross-sectional studies on the association between coffee consumption and odds of obesity are inconsistent. We aimed to perform a meta-analysis of earlier cross-sectional studies on the association between coffee consumption and odds of obesity.
Materials and Methods
The online databases of PubMed, ISI Web of Science, Scopus, Science Direct, and EMBASE were systematically searched to identify relevant publications up to April 2023. Cross-sectional studies that considered coffee as the exposure and general and abdominal obesity as the outcome were included. Studies that had reported odds ratios (ORs) as effect size were included in the meta-analysis. To pool data, a random-effects model was used.
Results
In total, 23 studies were included in our systematic review. Twelve publications on general obesity and 15 publications on abdominal obesity were examined in the meta-analysis. Overall, 207551 individuals aged ≥19 years were included. With regards to general obesity, pooling 13 effect sizes from 12 cross-sectional studies showed that coffee intake was not associated with odds of general obesity (overall OR: 1.11; 95% CI: 0.92, 1.33). In subgroup analysis by gender, we found a significant positive association between coffee consumption and odds of general obesity in women (OR: 1.84; 95% CI: 1.51, 2.24). Concerning abdominal obesity, combining 18 effect sizes from 15 studies, we failed to find a significant association between coffee consumption and odds of abdominal obesity (OR: 1.03; 95% CI: 0.92, 1.15).
Conclusion
No significant association was found between coffee intake and odds of obesity. However, gender-stratified analyses revealed significant relationships.
... Caffeine consumption is associated with improved memory, mood, and cognitive performance (6)(7)(8)(9). In addition to physiological studies, epidemiological studies have suggested that caffeine consumption might benefit human health, and a noticeable reduction of risk of chronic diseases, such as type 2 diabetes mellitus, Parkinson's disease, and liver disease, has been observed among habitual coffee consumers (10,11). ...
Background
Saudi and Turkish coffee consumption in Saudi Arabia is increasing considerably, and the nationwide consumption patterns need elucidation to determine the contributions of Saudi and Turkish coffee toward nutrition and health.
Aim
To describe the frequency and quantity of Saudi and Turkish coffee consumption and assess their association with sociodemographic factors.
Methods
This cross-sectional study included 1,030 participants (Saudi Arabia) recruited via an online questionnaire study that collected information on general characteristics and coffee consumption. The caffeine content in Saudi and Turkish coffees was quantified using a standard laboratory technique. The total caffeine intake and exposure were calculated. Associations between the different parameters were assessed.
Results
Significant differences were observed in several demographic and sociodemographic factors according to the frequency of coffee intake. Specifically, individuals who consumed Saudi coffee almost every day (approximately 40% of respondents) were more likely to differ in age, body mass index, marital status, work status, monthly income, and region compared to those who consumed it less frequently. Additionally, one-third of the respondents consumed Turkish coffee, and the frequency of its consumption showed significant differences according to age, nationality, marital status, educational level, and region. Notably, the highest caffeine exposures were 0.95 mg/kg/d for Saudi coffee, 1.31 mg/kg/d for Turkish coffee, and 2.07 mg/kg/d for both coffees combined. The mean contribution to the 400 mg daily caffeine intake limit was significantly higher for Saudi coffee compared to Turkish coffee (p < 0.05).
Conclusion
Saudi and Turkish coffee consumption patterns vary across sociodemographic characteristics, where Saudi coffee is generally more consumed. Our study may form a basis for nutrient education in terms of coffee consumption to promote a healthy lifestyle.
... Moreover, caffeine Numerous weight-loss "supplements" sold to the public contain caffeine, which is frequently described as an "appetite suppressant" and "thermogenic assistance" [280,281]. There is evidence that these compounds can help lose weight [282]. In cohort studies, dietary caffeine consumption has been related to decreaselong-term weight gain. ...
... In the 90-day repeat dose oral toxicity study, there was no mortality reported in rats that received paraxanthine at doses up to 185 mg/kg bw, while mortality was observed in two rats that received the same dose of caffeine. Although a reduction in body weight gain was observed in paraxanthine-treated rats, reductions in body weight gain have also been noted in other studies where stimulant ingredients have been evaluated, including caffeine (Zheng G. et al., 2004;Greenberg et al., 2006;Tabrizi et al., 2019;Sirotkin and Kolesárová, 2021). In fact, phytochemicals, such as methylxanthines, have been reported to promote body fat Ovaries n/a n/a n/a 0.16256 ± 0.02231 0.12835 ± 0.02348* 0.16897 ± 0.00657 ...
Introduction: Caffeine, one of the most ubiquitous ingredients found in beverages and other ingested food products, has a long history of safe use. As a member of the methylxanthine class of stimulants, caffeine is not devoid of unwanted side effects at any serving level. Caffeine safety has been the subject of a safety workshop by FDA and the Institute of Medicine in the past decade. Thus, investigation into an alternate stimulant with similar pharmacology but improved safety is warranted. Paraxanthine (1,7-dimethylxanthine) is the predominant metabolite of caffeine in humans with similar stimulant properties. The few toxicity studies that are available for paraxanthine suggest that the molecule is relatively safe, although thorough characterization of its safety is required prior to widespread incorporation into foods/beverages.
Methods: The aim of this study was to evaluate the toxicity of paraxanthine (Rarebird, Inc.) relative to caffeine through a battery of toxicological studies conducted in accordance with international guidelines. These studies evaluated the potential mutagenicity (bacterial reverse mutation, in vitro mammalian chromosomal aberration), genetic toxicity ( in vitro mammalian cell gene mutation) and acute, sub-acute and sub-chronic oral toxicity of paraxanthine in Sprague Dawley rats.
Results/Discussion: There was no evidence of genetic toxicity or mutagenicity in the in vitro studies. An acute oral LD 50 of 829.20 mg/kg body weight (bw) was established. There was no mortality or treatment-related adverse effects in the 14-day repeat dose oral toxicity study, wherein rats received low, mid, or high doses of paraxanthine (50, 100, or 150 mg/kg bw, n = 5 rats/sex/group). The same findings were observed in the subchronic repeat-dose 90-day oral toxicity study at daily doses of paraxanthine of 100, 150, or 185 mg/kg bw which were compared to caffeine at 150 or 185 mg/kg bw ( n = 10 animals/sex/group). However, mortality was reported in two animals in the high dose caffeine-treated animals. Therefore, the no observed adverse effect level (NOAEL) from the 90-day study was determined to be 150 mg/kg bw for caffeine and 185 mg/kg bw for paraxanthine for both male and female Sprague Dawley rats. These findings may suggest that paraxanthine could be a safer alternative to caffeine in humans.
... Caffeine has been shown to increase thermogenesis, lipolysis, and fat oxidation, which can lead to significant weight loss in nonobese people. Coffee's non-caffeinated compounds may also aid weight loss, which could explain the epidemiological finding that increased decaffeinated coffee consumption is linked to weight loss (James A Greenberg [9]). The link between decaffeinated coffee and weight loss suggests that coffee's benefit is due to something other than caffeine. ...
Citation: Raghad AlShoqiran and Noorah Saleh Al-Sowayan. Caffeinated and Decaffeinated Coffee Have Different Effects on Weight, Sleeplessness, and Blood Pressure. Biomed J Sci & Tech Res 47(4)-2022. BJSTR. MS.ID.007533. The majority of people nowadays drink coffee in some form or another in the morning. Coffee includes chlorogenic acid, which inhibits the formation of new fat cells and reduces the generation of glucose in the body, aiding weight loss and lowering BMI and body fat. What effect does caffeine have on the human body? Is the effect on weight and body mass, sleeplessness and blood pressure, and heart rate favorable or negative if there is one?. Results: Our results in this study were that there was no difference between high caffeine content in coffee and decaffeinated coffee on weight, body mass, insomnia and blood pressure. Conclusion: There was no effect on healthy people if they drank coffee at a rate of 400 mg per day, because it is a safe dose. Also, coffee, whether it is caffeinated or decaffeinated, does not affect weight and insomnia and blood pressure.
... Roasted coffee is a common form of coffee. The beneficial effects of coffee are mainly attributed to its caffeine content [16], whereas green coffee bean extracts are considered a novel thermogenic dietary supplement in humans because they are rich in caffeoylquinic acid (CQA; 45-55% in green coffee bean extracts) [17]. The phenolic acid structure of CQA with high polarity leads to poor oral absorption and low bioavailability [18]. ...
Objective
High intake of caffeoylquinic acid (CQA)-rich dietary supplements, such as green coffee bean extracts, offers health-promoting effects on maintaining metabolic homeostasis. Similar to many active herbal ingredients with high pharmacological activities but low bioavailability, CQA has been reported as a promising thermogenic agent with anti-obesity properties, which contrasts with its poor oral absorption. Intestinal tract is the first site of CQA exposure and gut microbes might react quickly to CQA. Thus, it is of interest to explore the role of gut microbiome and microbial metabolites in the beneficial effects of CQA on obesity-related disorders.
Results
Oral CQA supplementation effectively enhanced energy expenditure by activating browning of adipose and thus ameliorated obesity-related metabolic dysfunctions in high fat diet-induced obese (DIO) mice. Here, 16S rRNA gene amplicon sequencing revealed that CQA treatment remodeled the gut microbiota to promote its anti-obesity actions, as confirmed by antibiotic treatment and fecal microbiota transplantation. CQA enriched the gut commensal species Limosilactobacillus reuteri ( L. reuteri ) and stimulated the production of short-chain fatty acids, especially propionate. Mono-colonization of L. reuteri or low-dose CQA treatment did not reduce adiposity in DIO mice, while their combination elicited an enhanced thermogenic response, indicating the synergistic effects of CQA and L. reuteri on obesity. Exogenous propionate supplementation mimicked the anti-obesity effects of CQA alone or when combined with L. reuteri , which was ablated by the monocarboxylate transporter (MCT) inhibitor 7ACC1 or MCT1 disruption in inguinal white adipose tissues to block propionate transport.
Conclusions
Our data demonstrate a functional axis among L. reuteri , propionate, and beige fat tissue in the anti-obesity action of CQA through the regulation of thermogenesis. These findings provide mechanistic insights into the therapeutic use of herbal ingredients with poor bioavailability via their interaction with the gut microbiota.
... Several biological mechanisms have been reported for multiple bioactive compounds of coffee (e.g. caffeine, phenolics) for an improved metabolic profile, including improved insulin and glucose homeostasis (9), antioxidative (10), thermogenic (11), and anti-inflammatory effects (12), and improved gut microbiota diversity (4,8,13). Findings from clinical trials focusing on the effect of caffeine on glucose metabolism have suggested the effect may depend on follow-up duration; in the short term, caffeine was related to insulin resistance (4) whereas, in the long term, coffee consumption improved glucose metabolism in general (8). ...
Background:
Females with a history of gestational diabetes mellitus (GDM) are at higher risk of developing type 2 diabetes mellitus (T2D) later in life.
Objective:
This study prospectively examined whether greater habitual coffee consumption was related to a lower risk of T2D among females with a history of GDM.
Methods:
We followed 4522 participants with a history of GDM in the NHS II for incident T2D between 1991 and 2017. Demographic, lifestyle factors including diet, and disease outcomes were updated every 2-4 y. Participants reported consumption of caffeinated and decaffeinated coffee on validated FFQs. Fasting blood samples were collected in 2012-2014 from a subset of participants free of diabetes to measure glucose metabolism biomarkers (HbA1c, insulin, C-peptide; n = 518). We used multivariable Cox regression models to calculate adjusted HRs and 95% CIs for the risk of T2D. We estimated the least squares mean of glucose metabolic biomarkers according to coffee consumption.
Results:
A total of 979 participants developed T2D. Caffeinated coffee consumption was inversely associated with the risk of T2D. Adjusted HR (95% CI) for ≤1 (nonzero), 2-3, and 4+ cups/d compared with 0 cup/d (reference) was 0.91 (0.78, 1.06), 0.83 (0.69, 1.01), and 0.46 (0.28, 0.76), respectively (P-trend = 0.004). Replacement of 1 serving/d of sugar-sweetened beverage and artificially sweetened beverage with 1 cup/d of caffeinated coffee was associated with a 17% (risk ratio [RR] = 0.83, 95% CI: 0.75, 0.93) and 9% (RR = 0.91, 95% CI: 0.84, 0.99) lower risk of T2D, respectively. Greater caffeinated coffee consumption was associated with lower fasting insulin and C-peptide concentrations (all P-trend <0.05). Decaffeinated coffee intake was not significantly related to T2D but was inversely associated with C-peptide concentrations (P-trend = 0.003).
Conclusions:
Among predominantly Caucasian females with a history of GDM, greater consumption of caffeinated coffee was associated with a lower risk of T2D and a more favorable metabolic profile.
... Ferulic and chlorogenic acids showed antidiabetic effects through the stimulation of glucose transporters via the same mechanism [33]. There is much evidence of the beneficial effects of coffee consumption by type 2 diabetics [44,45], mainly due to the presence of chlorogenic acid. Chlorogenic acid likely inhibits Na + -dependent glucose transporters, SGLT1 and SGLT2, interacting with glucose absorption from the intestine. ...
In the bi-hormonal model, insulin and glucagon are the two major glucoregulatory hormones responsible for glucose disappearance and glucose appearance, respectively. The metabolic imbalance triggered by chronic hyperglycemia and hyperlipidemia may result in the impairment of glucose-induced insulin secretion, eventually resulting in the development of diabetes mellitus (DM). Persistent or chronic cases of DM can silently lead to serious complications such as autonomic neuropathy, peripheral neuropathy, nephropathy, atherosclerotic cardiovascular disease, retinopathy, peripheral arterial disease, cerebrovascular events, and increased susceptibility to infections. A range of agents have been approved for the clinical management of DM, but certain limitations remain, including the incidence of adverse drug reactions (ADRs) for almost all antidiabetic medications and a high cost for certain drug classes. Phytonutrients can play a vital role in the maintenance of health and wellness by protecting against chronic degenerative disorders including DM. Having a favorable safety profile and a low cost, they can be used effectively in the form of extracts or as isolated compounds, allowing them to serve as alternate therapeutic agents in glucose metabolic disorders. Thousands of herbs have been suggested for the treatment of DM, and a plethora of combinations of these products are marketed for the purpose of lowering blood glucose levels and for the treatment of diabetes-associated comorbid conditions. With further developments in the available literature, it is possible that one or more of these agents may become a part of conventional antidiabetic therapies. The present chapter highlights the potential hypoglycemic roles of phytonutrients including phenolic compounds, alkaloids, sulfides, phytosterols, dietary fibers, and carotenoids.
... It has been reported that cinnamon extract induces the glycogen synthase and insulin receptor kinase, triggers glucose uptake with inhibitory action on glycogen synthase kinase-3 beta anddephosphorylation of the insulin receptor thus enhance insulin sensitivity . Coffee extract rich in chlorogenic acid that has beneficial effects on type -2 diabetes, reason being chlorogenic acid inhibits Na 1 -dependent glucose transporters, SGLT1 and SGLT2 by interacting with the absorption of glucose from the intestine (Bassoli et al., 2008;Greenberg et al., 2006;Johnston et al., 2005;McCarty, 2005). The study also suggests that elevated extraction time may reduce the amount of TPC and at 100 % oC some of phenols get destroyed . ...
Plant extracts contain a varied range of chemicals such as terpenoids, phenolic compounds, alkaloids, glucosinolates, and various organic acids. These chemicals are responsible for their unique nature and perceived biological activity of plant extracts. Owing to the wide acclaimed biological activities of plant extracts, they have been used as natural ingredients and have received significant renewed interest recently. Several plant extracts have been used as commercial preservatives in food because of their green image. The current chapter discusses various chemicals present in plant extracts and emphasizes the structure activity relationship of these chemicals.
... It has been reported that cinnamon extract induces the glycogen synthase and insulin receptor kinase, triggers glucose uptake with inhibitory action on glycogen synthase kinase-3 beta anddephosphorylation of the insulin receptor thus enhance insulin sensitivity (Lin et al., 2016). Coffee extract rich in chlorogenic acid that has beneficial effects on type -2 diabetes, reason being chlorogenic acid inhibits Na 1 -dependent glucose transporters, SGLT1 and SGLT2 by interacting with the absorption of glucose from the intestine (Bassoli et al., 2008;Greenberg et al., 2006;Johnston et al., 2005;McCarty, 2005). The study also suggests that elevated extraction time may reduce the amount of TPC and at 100 % oC some of phenols get destroyed (Xu et al., 2008). ...
In recent years, great interest has been focused on using natural extracts of plant origin because of the possible adverse effects associated with the consumption of synthetic products being manufactured in the markets. A variety of plant extracts are known to have rich source of vitamins, minerals, phenolic compounds, antioxidants, alkaloids, and many other secondary metabolites. The interest in these natural components is not only due to their biological value but also to their economic impact. These secondary metabolites have the potential to cure various chronic diseases. Being an integral part of traditional medicine, these extracts need to be explored for various phytochemcial characterization, isolation, and their mechanism.
... Chlorogenic acids and other compounds might reduce hepatic glucose output and reduce intestinal glucose absorption, although high coffee consumption does not appear to be convincingly related to insulin or glucose levels in humans [4,48,[101][102][103]. Furthermore, caffeine might increase thermogenesis and energy metabolism and thus induce weight loss, while the proposed antioxidant properties of coffee could shield β-cells against oxidative stress [40,104,105]. A potential reduction in blood glucose levels, lower weight or less β-cell oxidative stress due to coffee consumption would in theory decrease the risk of type 2 diabetes. ...
PurposeHigh coffee consumption is associated with low risk of mortality and morbidity, but the causality remains unclear. This review aims to discuss findings from observational studies on coffee consumption in context of Mendelian randomization studies.Methods
The PubMed database was searched for all Mendelian randomization studies on coffee consumption and corresponding observational studies.ResultsHigh coffee consumption is associated with low risk of all-cause and cardiovascular mortality in observational studies (HRs of 0.85–0.90 vs. no/low consumers), with no support of causality in Mendelian randomization studies. Moderate/high consumption is associated with low risk of cardiometabolic diseases, including ischemic heart disease (HRs of 0.85–0.90 vs. no/low consumption), stroke (HRs of approximately 0.80 vs. no/low consumption), type 2 diabetes (HRs of approximately 0.70 vs. no/low consumption) and obesity in observational studies, but not in Mendelian randomization studies. High consumption is associated with low risk of endometrial cancer and melanoma and high risk of lung cancer in observational studies, but with high risk of colorectal cancer in Mendelian randomization studies. In observational and Mendelian randomization studies, high coffee consumption is associated with low risk of gallstones (HRs of 0.55–0.70 for high vs. no/low self-reported and 0.81 (0.69–0.96) for highest vs. lowest genetic consumption).Conclusion
High coffee consumption is associated with low risk of mortality, cardiometabolic diseases, some cancers and gallstones in observational studies, with no evidence to support causality from Mendelian randomization studies for most diseases except gallstones.
... In Western populations, caffeinated and decaffeinated coffee consumption is associated with a reduced risk of type II diabetes [13]. The ingesting of caffeinated coffee has been found to be associated with a 4% lower risk of type II diabetes [14]. ...
Information regarding the spread and effect of coffee and caffeine intake by individuals with type II diabetes remains unclear. This study aims to identify the amount and sources of habitual caffeine intake by individuals with type II diabetes and to investigate its association with other health outcomes, especially HbA1c. This is a cross-sectional survey involving 100 people medically defined as having type II diabetes comprising both genders, recruited from a care centre. All participants completed a caffeine semi-quantitative food frequency questionnaire (C-FFQ) to estimate their caffeine consumption, a two day 24-h recall, and a detailed questionnaire. The average caffeine intake was calculated from all sources and the differences in mean by gender were tested using a regression model (adjusted to important confounders). Regression models were used to verify the association between average caffeine intake on HbA1c and other health outcomes with adjustment for important confounders. A p value < 0.05 represented statistical significance. Arabic coffee (gahwa) and tea were the most common sources of caffeine among Saudi adults living with diabetes. Average caffeine intake for the whole sample was 194 ± 165 mg/day, which is 2.3 ± 2 mg/kg. There was an inverse association between caffeine intake and age: difference in mean −3.26 mg/year (95%CI: −5.34, −1.18; p = 0.003). Males had significantly higher consumption of caffeine compared to females: difference in mean 90.7 mg/day (95%CI: 13.8, 167.6; p = 0.021). No association was found between average caffeine intake and HbA1C or any other cardiovascular risk factors. This information can help public health practitioners and policy makers when assessing the risk of caffeine consumption among this vulnerable group.
... The protective effects of coffee drinking against CVD and mortality in patients with type 2 diabetes may be related to caffeine or other components exist in coffee, including minerals, phytochemicals, and antioxidants [7]. First, studies have shown that caffeine can induce thermogenesis and weight loss and thereby improve insulin sensitivity and glucose-induced insulin secretion [57,58]. Coffee consumption can increase release of glucagon-like peptide-1 [59] and glucose-dependent insulinotropic polypeptide [60], the two important mediators in insulin secretion and satiety [61,62]. ...
Aims
To evaluate the long-term consequences of coffee drinking in patients with type 2 diabetes.
Data synthesis
PubMed, Scopus, and Web of Sciences were searched to November 2020 for prospective cohort studies evaluating the association of coffee drinking with risk of cardiovascular disease (CVD) and mortality in patients with type 2 diabetes. Two reviewers extracted data and rated the certainty of evidence using GRADE approach. Random-effects models were used to estimate the hazard ratios (HRs) and 95% CIs. Dose-response associations were modeled by a one-stage mixed-effects meta-analysis. Ten prospective cohort studies with 82,270 cases were included. Compared to those with no coffee consumption, the HRs for consumption of 4 cups/d were 0.79 (95%CI: 0.72, 0.87; n=10 studies) for all-cause mortality, 0.60 (95%CI: 0.46, 0.79; n=4) for CVD mortality, 0.68 (95%CI: 0.51, 0.91; n=3) for coronary heart disease (CHD) mortality, 0.72 (95%CI: 0.54, 0.98; n=2) for CHD, and 0.77 (95%CI: 0.61, 0.98; n=2) for total CVD events. There was no significant association for cancer mortality and stroke. There was an inverse monotonic association between coffee drinking and all-cause and CVD mortality, and inverse linear association for CHD and total CVD events. The certainty of evidence was graded moderate for all-cause mortality, and low or very low for other outcomes.
Conclusions
Drinking coffee may be inversely associated with the risk of mortality in patients with type 2 diabetes. However, more research is needed considering type of coffee, sugar and cream added to coffee, and history of CVD to present more confident results.
Registry and registry number
The protocol of this systematic review was registered at Open Science Framework (https://osf.io/8uaf3, registered form: osf.io/xur76, registration DOI: 10.17605/OSF.IO/8UAF3).
... Moreover, chlorogenic acid anԁ magnesium in green coffee reduce insulin resistance, ԝhich plays an important role in diabetes. [31,166] ...
Green Coffee Extract (GCE) is a food product and/or supplements that are derived from raw or unroasted, green coffee beans. It is also present in roasted coffee, but much of the active principle is destroyed during the roasting process. The GCE contained chlorogenic acid as a major ingredient and mediate many of the health benefits. Oral ingestion of GCE may reduce body weight in overweight and obese persons. But mechanisms of chlorogenic acids still unknown, although it thought to be related with the preventing carbohydrate uptake from the intestines after a meal. Chlorogenic acid protects neurons from hydrogen peroxide induced stress through a powerful antioxidant activity, ԝhich fights against the free radicals produced in our body as a byproduct of metabolism. It lowers the risk of liver, colon, breast, skin anԁ rectal cancers but the molecular mechanisms and target underlying the chemopreventive effects remain unknown. Ferulic acid, which is a metabolite of GCE containing chlorogenic acid, decreases blood pressure and improves vasoreactivity. GCE may be considered a novel antihypertensive food component. It reduces the risk of gylcemic disorders like Type 2 diabetes mellitus (DM), ԝhen people consume it for a long time, by inhibiting glucose-6-phosphatase enzyme, that promotes sugar formation in the liver by glycogenesis. GCE as supplemental or food products, may cause occupational type I allergies have been noted to be associated with green coffee dust, which may be due to the presence of a „Cof A 1‟ allergin and appears to be present in the plants Coffea canephora, Coffea Arabica and Coffea liberica.
... The mechanism(s) explaining the association between coffee intake and serum uric and gout remains poorly understood. Some animal and human studies have suggested as a plausible mechanism that coffee may confer its protective effect on serum uric acid by reducing glucose, insulin concentration, and insulin resistance [21][22][23]. Caffeine, a major ingredient of coffee belongs to the family of methylxanthines and is a competitive inhibitor of xanthine oxidase, an enzyme responsible for the production of uric acid [24]. A modest significant association was shown between decaffeinated coffee and uric acid [25] suggesting that components of coffee other than caffeine may also contribute to the putative protective effect of coffee on uric acid. ...
Background
Accruing evidence suggests an inverse relationship between coffee intake and serum uric acid. The mechanism(s) explaining this inverse relationship remains elusive. The aim of this study was to assess if the association between coffee intake and hyperuricemia is mediated via serum ferritin in women.
Methods
We pooled data from the 2003 to 2006 National Health and Nutrition Examination Survey (NHANES). We included women with complete information on all key variables. Coffee intake was classified as none, <1 cup/day, 1-3 cups/day, and ≥4 cups/day. Hyperuricemia was defined as serum uric acid >5.7 mg/dL. We assessed the association between coffee intake and hyperuricemia using logistic regression. Path analysis was used to examine whether serum ferritin mediated the effect of coffee on hyperuricemia.
Results
Among 2,139 women (mean age: 31.2 years [SD: 9.2]), mean serum uric acid was 4.4 mg/dL (SD: 1.0), and 227 (10.6%) had hyperuricemia. In multivariate logistic regression models, intake of ≥4 cups/day of coffee was associated with lower odds of hyperuricemia (OR 0.28 [95% CI: 0.09, 091], P=0.035). The total direct and indirect effect of coffee on hyperuricemia via serum ferritin was −0.16, P=0.009 and −8.1 × 10⁻³, P=0.204, respectively.
Conclusion
Among women, moderate coffee consumption was inversely related to hyperuricemia by direct effect, rather than indirectly through the effects of serum ferritin. These findings suggest that serum ferritin does not mediate the inverse association between coffee and hyperuricemia in women.
... Chlorogenic Acid in Green Coffee have health benefits. People take green coffee by mouth for obesity, diabetes, high blood pressure, Alzheimer's disease, and bacterial infections (Greenberg et al., 2006;Watanabe et al., 2006;Almeida et al., 2006;Bassoli et al., 2008;Oboh et al., 2013). Even though it's already proven that the plant have health-promoting phytochemicals, the researchers still aim to identify the effect of H.malayana ethanolic crude leaf extract against S.aureus. ...
Human waste is one of the great potentials to produce fertilizer for plants. Manure fertilizer called biosolid fertilizer. Biosolid fertilizer can increase crop yields and supply nutrients for plants. The use of biosolids for vegetables is considered very good economically. The potential for this biosolid fertilizer is very large applied to vegetable crops to increase vegetable productivity in Bengkulu province. The purpose of this study is to analyze what factors influence the intention to consume vegetables derived from biosolid fertilizer. The study was conducted in several traditional markets in the city of Bengkulu. The traditional markets are Pasar Minggu and Panorama Market. The research location was chosen purposively because the two markets are centers of vegetable sales in the city of Bengkulu. The study was conducted on June 2019. The data collected was analyzed quantitatively (Partial least square) and descriptive approach. The results obtained are Attitude toward the behavior significantly influences the intention to consume vegetables from biosolid fertilizer with a T-count value of 2.170. Subjective Norm has a significant effect on the intention to consume vegetables from biosolid fertilizer with a T-count value of 6.294 as well as the Perceived Behavior Control significantly influence the intention to consume vegetables from biosolid fertilizer with a T-count value of 2.530.
... 42 En cuanto a la dieta mediterránea (alto contenido de frutas, verduras, cereales integrales y nueces y aceite de oliva como principales fuentes de grasa) (101) , el estudio PREDIMED (102) concluyó que la dieta reduce la aparición de DM2 hasta un 40 %, sin necesidad de reducción de peso. Respecto a los componentes individuales de la dieta, el consumo de productos lácteos bajos en grasa, fibra, nueces, alcohol (77) , café (103,104) , café descafeinado y té verde a largo plazo disminuyen el riesgo de DM2. ...
... The decrease in body weight observed in both study groups may be mainly attributed to the content of CGA in the coffee blend, according to a recent review by Gökcen and Sanlier [10] among others [8,9,26]. Green coffee extract may regulate adipogenesis, as well as genes and proteins associated with lipid metabolism in white adipose tissue and liver, leading to loss of body weight. The slimming role of CGA is also supported by Roshan et al. [27], who described that decaffeinated green coffee supplementation could decrease weight about twice as much as the placebo by inhibiting adipogenesis and by contributing to controlling appetite, which was evaluated through a scored questionnaire. ...
In previous studies, after regularly consuming a green/roasted coffee blend, body weight, body fat%, glucose, plasminogen activator inhibitor-1 (PAI-1), resistin, leptin, ghrelin, diastolic (DBP) and systolic blood pressure (SBP) significantly changed in healthy and hypercholesterolemic subjects. However, glucagon, total-cholesterol (T-C), triglycerides (TG), LDL-cholesterol (LDL-C) and Homeostasis Model Assessment index to estimate insulin resistance (HOMA-IR) only changed in the hypercholesterolemics. This work looks into the antiobesity effects of coffee blend and into the relationship of antiobesity with the aforementioned cardiometabolic modifications in hypercholesterolemics. (1) Methods: Tricipital and subscapular skinfolds, hip, thigh, arm and waist circumference (WC) were measured in normocholesterolemic and hypercholesterolemics. To understand the relationship between cardiometabolic and antiobesity results in hypercholesterolemics, factor analysis was carried out using baseline values of the variables that changed. (2) Results: WC, WC/hip and WC/height showed significant coffee×group interaction, and in hypercholesterolemics tended to decrease. After factor analysis, three factors emerged, accounting for 29.46, 13.13 and 11.79% of variance. Only factor 1 (main loadings: WC, DBP and SBP, body weight, WC/hip and WC/height ratios, TG and ghrelin, inversely) decreased after coffee intake. (3) Conclusion: Regularly consuming green/roasted coffee may help to control body weight, and in hypercholesterolemics, may reduce cardiovascular risk by reducing abdominal adiposity and blood pressure.
... Previous studies suggested that caffeine could improve insulin resistance by stimulating insulin secretion from pancreatic β cells [40]. In addition to insulin secretion, caffeine increases thermogenesis, lipolysis, and β-oxidation [41]. Magnesium supplementation has reduced the development of type 2 diabetes and improved glucose disposal in experimental studies [42,43], and cohort studies have reported a significant inverse association between magnesium intake and type 2 diabetes risk [44]. ...
Habitual coffee consumption and its association with health outcomes may be modified by genetic variation. Adults aged 40 to 69 years who participated in the Korea Association Resource (KARE) study were included in this study. We conducted a genome-wide association study (GWAS) on coffee consumption in 7868 Korean adults, and examined whether the association between coffee consumption and the risk of prediabetes and type 2 diabetes combined was modified by the genetic variations in 4054 adults. In the GWAS for coffee consumption, a total of five single nucleotide polymorphisms (SNPs) located in 12q24.11-13 (rs2074356, rs11066015, rs12229654, rs11065828, and rs79105258) were selected and used to calculate weighted genetic risk scores. Individuals who had a larger number of minor alleles for these five SNPs had higher genetic risk scores. Multivariate logistic regression models were used to estimate the odds ratios (ORs) and 95% confidence intervals (95% CIs) to examine the association. During the 12 years of follow-up, a total of 2468 (60.9%) and 480 (11.8%) participants were diagnosed as prediabetes or type 2 diabetes, respectively. Compared with non-black-coffee consumers, the OR (95% CI) for ≥2 cups/day by black-coffee consumers was 0.61 (0.38–0.95; p for trend = 0.023). Similarly, sugared coffee showed an inverse association. We found a potential interaction by the genetic variations related to black-coffee consumption, suggesting a stronger association among individuals with higher genetic risk scores compared to those with lower scores; the ORs (95% CIs) were 0.36 (0.15–0.88) for individuals with 5 to 10 points and 0.87 (0.46–1.66) for those with 0 points. Our study suggests that habitual coffee consumption was related to genetic polymorphisms and modified the risk of prediabetes and type 2 diabetes combined in a sample of the Korean population. The mechanisms between coffee-related genetic variation and the risk of prediabetes and type 2 diabetes combined warrant further investigation.
... [11] Additionally, 5-CQA reduces food craving, daily calorie intake, and induces body fat loss by the organism. [12] The literature reports the studies on the antioxidant properties of 5-CQA which are examined for a definite period of time. [13][14][15] In many articles on 5-CQA activity the researchers evaluating the antioxidant activities of plant extract (containing CQA) associate these properties with 5-CQA contents whereas very few articles are devoted to the changes of the pure antioxidant during the radical neutralization. ...
Reactive oxygen species including free radicals are responsible for noxious changes in living organisms which can be associated with many diseases for e.g. cardiovascular, neurodegenerative, and inflammatory diseases or cancer. In the struggle against free radicals the organism is supported by antioxidants. As they are often provided by nature, they can be considered safe. 5-Caffeoylquinic acid is one of main chlorogenic acids found in vegetables and fruits. The main objective of the presented article was monitoring the changes of 5-caffeoylquinic acid during the reaction with colorful radicals. The experiments were conducted at different molar ratios of radicals to antioxidant using liquid chromatography–mass spectrometry. Irrespective of the applied molar ratios, the obtained results proved that the antioxidant takes part in the reaction for three days. Additionally, during the radical neutralization the formation of semiquinones and/or quinones, methoxy adduct of caffeoylquinic acid, and quinones adduct with methanol was observed.
... In addition to the stimulant effect of caffeine on the central nervous system, it has also been demonstrated to have a pharmacological effect on the cardiovascular system [47]. However, the mechanism of the action as to how it increases blood pressure is not known. ...
Elevated blood pressure affects a great part of the elderly population and is the leading risk factor for cardiovascular disease. New approaches have been taken in the fight against this growing problem, in the form of diets (Mediterranean, Dietary Approaches to Stop Hypertension (DASH) and intermittent fasting). Recent research has shown the promising results regarding diets and their effect on the prevention and improvement of elevated blood pressure. This review attempts to take this a step further, reviewing 26 studies in the search for dietary elements that may be causing this improvement. Although good evidence was found in favor of lycopene, Docosahexaenoic acid (DHA), fiber and anthocyanin, further evidence is needed before any conclusions can be made. In contrast, the evidence shows that licorice increases blood pressure.
This review provides a comprehensive synthesis of longitudinal observational and interventional studies on the cardiometabolic effects of coffee consumption. It explores biological mechanisms, and clinical and policy implications, and highlights gaps in the evidence while suggesting future research directions. It also reviews evidence on the causal relationships between coffee consumption and cardiometabolic outcomes from Mendelian randomization (MR) studies. Findings indicate that while coffee may cause short-term increases in blood pressure, it does not contribute to long-term hypertension risk. There is limited evidence indicating that coffee intake might reduce the risk of metabolic syndrome and non-alcoholic fatty liver disease. Furthermore, coffee consumption is consistently linked with reduced risks of type 2 diabetes (T2D) and chronic kidney disease (CKD), showing dose-response relationships. The relationship between coffee and cardiovascular disease is complex, showing potential stroke prevention benefits but ambiguous effects on coronary heart disease. Moderate coffee consumption, typically ranging from 1 to 5 cups per day, is linked to a reduced risk of heart failure, while its impact on atrial fibrillation remains inconclusive. Furthermore, coffee consumption is associated with a lower risk of all-cause mortality, following a U-shaped pattern, with the largest risk reduction observed at moderate consumption levels. Except for T2D and CKD, MR studies do not robustly support a causal link between coffee consumption and adverse cardiometabolic outcomes. The potential beneficial effects of coffee on cardiometabolic health are consistent across age, sex, geographical regions, and coffee subtypes and are multi-dimensional, involving antioxidative, anti-inflammatory, lipid-modulating, insulin-sensitizing, and thermogenic effects. Based on its beneficial effects on cardiometabolic health and fundamental biological processes involved in aging, moderate coffee consumption has the potential to contribute to extending the healthspan and increasing longevity. The findings underscore the need for future research to understand the underlying mechanisms and refine health recommendations regarding coffee consumption.
Obesity refers to the excessive accumulation of fat caused by a long-term imbalance between energy intake (EI) and energy expenditure (EE). Over recent years, obesity has become a major public health challenge. Caffeine is a natural product that has been demonstrated to exert anti-obesity effects; however, the mechanisms responsible for the effect of caffeine on weight loss have yet to be fully elucidated. Most obesity-related deaths are due to cardiovascular disease. Recent research has demonstrated that caffeine can reduce the risk of death from cardiovascular disease; thus, it can be hypothesized that caffeine may represent a new therapeutic agent for weight loss. In this review, we synthesize data arising from clinical and animal studies over the last decade and discuss the potential mechanisms by which caffeine may induce weight loss, focusing particularly on increasing energy consumption, suppressing appetite, altering lipid metabolism, and influencing the gut microbiota. Finally, we summarize the major challenges associated with caffeine and anti-obesity research and highlight possible directions for future research and development.
This article gives a brief account of the origins and evolution of coffee and its important role in human society for the last 1200 years. Fast forward to today, and 66% of Americans consume coffee daily. In the last few decades, a multitude of studies has researched the claims that coffee drinking offers cardiovascular, neurologic, metabolic, carcinogenic, and reproductive protections. This review evaluates and summarizes these findings, including the latest discoveries on the impact of caffeine on human health and the protection of human body systems.
Dendrimers, branched polymer structures, have been widely studied as efficient drug carriers. Scientists are trying to find new dendrimer-based formulations with the properties needed for biomedical applications such as improved bioavailability, low toxicity and high transfection profiles. The unique drug delivery properties of carbosilane dendrimers have already been demonstrated. Their efficacy has been further improved by conjugation with polyphenols, plant secondary metabolites with a wide range of biological activities, including antioxidant effects that are beneficial for human health. The present study focuses on synthesis and characterization of two new types of carbosilane dendritic systems, one family presents one or two caffeic acid units and ammonium groups on the surface to make them water soluble. The other family has, in addition to the two mentioned functionalities, one or two polyethylene glycol (PEG) chains in the structure to increase the biocompatibility of the system. Carbosilane dendrimers with caffeic acid have low toxicity and protect erythrocytes against oxidative hemolysis. These dendrimers also decrease AAPH-induced ROS production in human fibroblasts.
Various techniques demonstrating such antioxidant activities have been applied in the current research. The best antioxidant properties were shown for the dendrimer with two PEG-caffeic acid moieties. Further aspects of the biochemical characterization of the dendrimers are also considered and discussed.
Caffeine is a secondary metabolite extensively studied for its stimulatory properties and presumed association with specific pathologies. This alkaloid is typically consumed through coffee, tea, and other plant products but is also an additive in many medications and confectionaries. Nonetheless, despite its worldwide consumption and acceptance, there is controversial evidence as to whether its effects on the central nervous system should be interpreted as stimulatory or as an addiction in which typical withdrawal effects are canceled out with its daily consumption. The following discussion is the product of an extensive review of current scientific literature, which aims to describe the most salient topics associated with caffeine's purpose in nature, biosynthesis, metabolism, physiological effects, toxicity, extraction, industrial use and current plant breeding approaches for the development of new caffeine deficient varieties as a more economical option to the industrially decaffeinated coffees currently available to caffeine intolerant consumers. Keywords: biosynthesis, decaffeination, extraction, metabolism, physiological effects, plant breeding.
The current study was conducted to identify the effects of different doses of Arabic coffee, black tea and Coca-Cola syrup on the possibility of birth defects in Swiss white mice embryos. (25) pregnant female mice were used in the study, divided into five experimental groups, including the control group dosed with distilled water, and four experimental groups were dosed with concentrations (4000-2500-2000-1000) mg/kg body weight for Arabic coffee and black tea and (2,3,4,6 ml/kg) for Coca-Cola syrup; once a day, from the seventh day until the eighteenth day of pregnancy. The results of the current study showed cases of abortion and fetal death at varying degrees and many abnormalities in white mouse embryos due to the different concentrations of the beverages used were characterized by the appearance of elongated and enlarged embryos. The elongation and deformation of the fetus, And the embryos mutated. Small embryos folded like a ball and curved in the shape of letter C, and the severity of the deformities increased by the appearance of mutated embryos resembling the body of a fish and deformed embryos similar to a water mermaid and not fully developed and the appearance of the head in the shape of a blurred triangle, as well as forward with a pointed end resembling a bird's beak, and brain deformation through depression in the posterior cranial region of the skull, and for the first time a new deformation is a cerebral Meningomyelocele in the form of a cystic tumor in the posterior brain region.
This work deals with the rapid simultaneous determination of caffeine and the three most abundant chlorogenic acid isomers (3-, 4-, and 5-O-caffeoylquinic acids) present in 64 samples of regular (un)roasted and decaffeinated (un)roasted coffee beans using reversed-phase high-performance liquid chromatography with spectrophotometric detection. In the developed method, the target analytes were separated in just 6 min with a resolution higher than 1.2. Afterwards, factor analysis and principal component analysis were employed to reveal the relationships between the samples and the content of monitored compounds. The samples were successfully divided into three discrete groups (decaffeinated, roasted, and unprocessed) by these methods. Finally, the impact of sample roasting and decaffeination on the content of chlorogenic acid isomers was investigated. The decrease in 5-O-caffeoylquinic acid concentration during the decaffeination process was found not as significant as during the roasting process. Regarding caffeine isolation, dichloromethane was the best extraction solvent because it did not cause significant losses of chlorogenic acid isomers or changes in the coffee beans colour and its extraction efficiency reached 85%.
Lipids a source of energy and can also be stored in body cells for proper cellular functions. Defects in lipid metabolism can lead to a wide range of metabolic disorders. A number of risk factors are generally responsible for the dysregulation of lipid metabolism and subsequently the development of metabolic diseases. In this chapter, the pathophysiology of several lipid-metabolism-related diseases has been discussed, and the therapeutic potential of different phytochemicals or plant-derived phytonutrients in managing these disorders are highlighted. There are several medicinal secondary metabolites, which could be highly significant to manage the lipid profile and prevent the development of serious outcomes of lipid-metabolism abnormalities such as hyperchylomicronemia, hypercholesterolemia, atherosclerosis, cancer, obesity, insulin sensitivity, and resistance. Many phytonutrients isolated from fruits, vegetables, and plant sources have presented their broad spectrum of medicinal activities to modulate metabolic processes and are also involved in lipid metabolism and the management of cholesterol levels in body. Bioactive compounds such as small molecular phytonutrients from natural sources have suggested prospective treatments against lipid-metabolism-related abnormalities and have been defined in this chapter. Considering diverse physiochemical properties and therapeutic value of phytonutrients, it is highly recommended to introduce more vegetables, and fruits in the dietary regimen to intake food containing fewer fats and high fibers so that it could significantly aid the management of lipid-metabolism-related diseases.
The elaboration of therapeutic protocols using natural compounds can help in improving the outcomes of many human conditions such as malignant disorders, neurodegenerative diseases, and systemic disorders. Recently, the attention of scientists was more focused on nutraceuticals as potential candidates that can be administered in the management strategy of various pathologies. This rise in nutraceutical applications is due to their relative safety and their pleiotropic effects. Several studies suggest the use of dietary regimens and food-derived substances for the prevention and treatment of many metabolic disorders that affect the central nervous system. The neuroprotective actions offered by these substances are mediated by their pertinent antiapoptotic, antiinflammatory, and antioxidative potentials. Some compounds may also intervene in the promotion of individuals’ health via the regulation of the process of autophagy and via the enhancement of the functionality of intracellular organelles such as mitochondria. Furthermore, healthy diet and the use of dietary supplements can directly influence the functions and the progeny of neural stem cells and the metabolism of microglial cells and can influence the polarization of macrophages in the nervous tissue resulting in better outcomes in some pathologic situations. In this chapter, we review the different roles and applications of nutraceuticals in the treatment of the major brain disorders that can affect human beings.
Metabolic diseases are devastating abnormalities that address human lives toward death if they are not correctly managed. Obesity and diabetes mellitus are the prime factors that induce insulin resistance to signaling pathways and increase the risk of cardiovascular diseases. Phytonutrients are the biologically active agents derived from natural sources such as vegetables, fruits, grains, cereals, and medicinal plants, and present the ability to boost the immune system of patients with metabolic disease and also enhance the conditions by the management of lipid profiles, insulin resistance and glucose homeostasis, and chemopreventive events in case of cancer disease. This chapter highlights some phytonutrients that may have issues with the gene and produce healthy and unhealthy interactions. However, the interaction between genetic and environmental factors such as intake of particular healthy and sufficient diet plans with a good lifestyle encourages the development and pathogenesis of diseases of polygenic dietary components. Phytonutrients are critical tools for the modulation of gene expressions involved in signaling pathways and phenotypes linked with metabolic diseases. It is also noted that human health is also affected by dietary nutrients having carcinogens and aflatoxin attached with them and influence the genetic variants. As the knowledge of carcinogen and anticarcinogen increases, nutritional science leads to promising therapeutics for cancer management by healthy diet plans. This chapter has depicted essential aspects of phytonutrients and their interactions with genes in metabolic disease prevention and treatments.
In spite of the advanced researches, preventive measures, and treatment options, cancer remains a growing ailment all over the world and its prevalence is estimated to increase in future. Cellular metabolic alterations have been documented as a hallmark of cancer. Metabolic regulation is an intricately coupled process whose deregulation leads to tumor progression as well as metastasis. In order to thrive in the living system, cancer cells adapt different metabolic pathways (bioenergetics and biosynthesis). They replenish their metabolic demands by switching from normal metabolism to cancer metabolism by the process of metabolic rewiring. Recent researches suggest that starving cancer cells by the use of nontoxic chemical entities can give promising results regarding cancer proliferation. Natural products, especially those of plant origin, offer different chemical scaffolds to target cancer via modulation of multiple cell signaling cascades. Phytonutrients, the secondary metabolites from the plants, constitute edible phytochemicals which are abundantly found in vegetables, whole grains, and fruits. The growing numbers of evidences suggest that phytonutrients exhibit anticancer as well as chemopreventive activities of these bioactive molecules against several cancers by targeting the various significant enzymes of glycolysis, the PPP pathway, TCA cycle, and serine metabolism. This book chapter presents an update for the scientific community about targeting the cancer metabolism by phytonutrients. The alterations in the cancer metabolism in the context of bioenergetics, biosynthesis, and mitochondrial functions have been discussed while presenting the impact of phytonutrients as modulators of potential metabolic effectors in the cancer metabolism.
Mitochondria are the main organelles responsible for generating cellular energy. The common symptom of mitochondrial disorders is extreme fatigue. The lowered mitochondrial activity owing to lack of chemical transmembrane capacity, changes in the electron transport chain’s function, the maintenance of the inner mitochondrial membrane’s electrical and decrease in essential metabolites transport to the mitochondria. The change in mitochondrial activity is brought about by the reduction of adenosine-5′-triphosphate (ATP) and oxidative phosphorylation. The mitochondrial activity needs regular replacement of natural phytochemicals and supplementations that help to maintain the energy level. The efficacy of oral alternative nutrients like reduced nicotinamide adenine dinucleotide (NADH), alpha-lipoic acid, coenzyme Q10, alpha-lipoic acid carnitine, membrane phospholipids, and other supplements was evaluated in clinical studies and were found effective against mitochondrial disorders. Combinations of these supplements can substantially alleviate weakness and other symptoms associated with mitochondrial disorders in patients. The frequent intake of these nutrients can also help to reduce the onset of various neurological disorders along with mitochondrial dysfunction. These results have significant effects on the welfare of both the civilian and military communities.
Kafein, dünyada yaygın olarak tüketilen, farmakolojik olarak aktif bir gıda bileşenidir. Kafeinin alımının büyük çoğunluğu kahve ve çay yoluyla olmaktadır. Besinlerdeki kafein konsantrasyonu; tarımsal ve çevresel faktörlere, tüketilen yiyeceğin ya da içeceğin çeşidine, miktarına ve hazırlama yöntemine bağlı olarak değişmektedir. Farklı miktarlarda olmakla beraber kahve, çay, alkolsüz içecekler, enerji içecekleri, çikolata ürünleri, bazı ilaçlar (ağrı kesiciler gibi), diyet takviyeleri ve reçetesiz uyarıcılarda psikostimülan pürin benzeri bitkisel alkaloid olan kafein bulunmaktadır. Acı bir tadı olan kafeinin suda yüksek oranda çözünür olmasından dolayı ağızdan alımını takiben 15-45 dakika içinde basit difüzyonla gastrointestinal sistemden hızla emilmekte ve tüm dokulara dağılmaktadır. Yağda çözünen bir madde olması sebebiyle, hücre geçişi sırasında birçok maddenin kandan beyin, testis ve fetüse geçmesini engelleyen bariyeri kafein kolaylıkla aşar ve tüm vücuda yayılmaktadır. Kafeininin dengeli tüketimi sağlandığında sağlıklı yetişkinlerde güvenli olduğu düşünülmektedir. Ancak zararsız bir bileşik değildir, önemli toksisiteye neden olabilir. Gıda ve İlaç İdaresi (FDA) ve Avrupa Gıda güvenliği kurumu (EFSA) toplam günlük 400 mg kadar kafein alımının zararsız olduğunu bildirmiştir ancak fazla tüketimi toksisiteye neden olabilir. Kafeinin öncelikle termojenez ve lipit oksidasyonunu artırarak enerji dengesini sağlayabileceği ve obezite, metabolik sendrom ve kardiyovasküler hastalıkların önlenmesinde önemli role sahip olabileceği düşünülmektedir. Bu derleme kafeinin enerji metabolizması üzerine etkisini ve bu konuda yapılmış çalışmaları araştırmak amacıyla hazırlanmıştır.
Latar Belakang: Konsumsi kopi dilaporkan meningkat selama pandemi COVID-19. Status gizi seseorang seringkali dikaitkan dengan kebiasaan konsumsi kopi. Meningkatnya konsumsi kopi dapat mempengaruhi jumlah kafein yang masuk dalam tubuh sehingga dapat memberikan efek samping yaiut perubahan status gizi. Pada peningkatan status gizi dapat menurunkan produktivitas, khususnya pekerja yang melakukan pekerjaan dari rumah (WFH).Tujuan: Penelitian ini bertujuan untuk menganalisis hubungan antara konsumsi kopi dan status gizi pada petugas WFH di Surabaya.Metode: Penelitian ini menggunakan desain cross sectional dengan sampel sebanyak 55 pekerja WFH di Surabaya. Pengambilan sampel menggunakan metode accidental sampling. Data dikumpulkan secara online termasuk usia, jenis kelamin, pekerjaan, pendapatan, aktivitas fisik, konsumsi kopi (jenis dan frekuensi), berat badan, dan tinggi badan. Data yang terkumpul dianalisis menggunakan Uji Korelasi Spearman.Hasil: Sebagian besar responden mengonsumsi kopi (67,3%) dengan frekuensi 1-3 kali / minggu (49,1%). Jenis kopi yang paling banyak dikonsumsi sehari-hari adalah kopi hitam (10,9%) dan kopi instan merek Kapal Api (9,1%). Sebanyak 23,6% responden mengalami obesitas, namun tidak terdapat hubungan yang bermakna antara konsumsi kopi dengan status gizi (p = 0,797).Kesimpulan: Tidak ada keterkaitan antara konsumsi kopi dengan status gizi petugas WFH. Pada penelitian lebih lanjut dapat digali lebih dalam tentang hal-hal yang berkaitan dengan karakteristik pekerjaan dan riwayat konsumsi kopi pada saat pandemi di kalangan pekerja WFH. Kata kunci: konsumsi kopi, status gizi, pekerja WFH ABSTRACTBackground: Coffee consumption is reported to have increased during the COVID-19 pandemic. A person's nutritional status is often related to coffee consumption habits. Increased coffee consumption can affect the amount of caffeine that enters the body so that it can have side effects, namely changes in nutritional status. Increasing nutritional status can reduce productivity, especially workers who do work from home (WFH).Objectives: This purposes of the research to analyze the connection between coffee consumption and nutritional status of WFH workers in Surabaya. Methods: This research used a cross sectional design with a sample of 55 WFH workers in Surabaya. Sampling using accidental sampling method. Data was collected online including age, gender, occupation, income, physical activity, coffee consumption (type and frequency), body weight, and height. Collected data were analyzed using the Spearman Correlation Test. Result: Most of the respondents consumed coffee (67.3%) with a frequency of 1-3 times/week (49.1%). The types of coffee most consumed daily were black coffee (10.9%) and instant coffee with the Kapal Api brand (9.1%). As many as 23.6% of respondents were obese, but there was insignificant relationship between coffee consumption and nutritional status (p = 0.797). Conclusions: There is no link between coffee consumption and the nutritional status of WFH workers. In further research, it can be explored more deeply about matters related to job characteristics and the history of coffee consumption during the pandemic among WFH workers.Keywords: coffee consumption, nutritional status, WFH workers
The purinergic signalling has a well-established role in the regulation of energy homeostasis, but there is growing evidence of its implication in the control of food intake. In this review, we provide an integrative view of the molecular mechanisms leading to changes in feeding behaviour within hypothalamic neurons following purinergic receptor activation. We also highlight the importance of purinergic signalling in metabolic homeostasis and the possibility of targeting its receptors for therapeutic purposes.
In newer times, great advances has been made by the discovery of the newer products from the natural sources. Towards the growing awareness in the treatment of the human degenerative disorders, polyphenols comes into play. Polyphenols are bioactive compounds that are commonly evacuated from natural, synthetic and semi-synthetic sources. They have a collective functions like antimicrobial properties and free radical scavenging activity. Polyphenols has an additional ability to reduce the oxidative damage of various compounds such as carbohydrates, lipids proteins etc. They mainly occurs as glycosides and are combined with varying organic acids. These glycosides helps in combating against the aggressive pathogenic organisms. They are found in a mixed state naturally. The natural polyphenols exemplifies a novel and relevant strategy in the treatment of human degenerative disorders. They play an important role by promoting the growth of Bifidobacterium sp. in the human GI tract. This bacteria reduces the pH in the intestinal area and henceforth provides protection there. There are certain metabolic products of polyphenols that are demarked separately as they provide improvised actions against IBD patients. The herbal polyphenols gets hydrolysed through the intestinal brush border cells and thereby able to reduce the enzyme produced toxicity. This property shows a promising characteristic of the polyphenols that has the ability of modulating the human gut micro flora and enhancing certain friendly mechanisms within. On the line parallel to this, focus will also be on other human degenerative disorders that can be prevented by the action of the polyphenols.
Globally, coffee is consumed as a functional beverage due to its nutraceutical value and positive physiological effects. Coffee is an important source of several nutritious and therapeutic phytoconstituents including lipids, carbohydrates, minerals, vitamins, and nitrogenous compounds, along with bioactive compounds like cafestol and kahweol diterpenes, caffeine, and chlorogenic acid (CGA), which all possess great therapeutic potential. Coffee is claimed to be an ancient wonder drug that is endowed with a variety of phytobiomolecules of therapeutic potential. The bioavailability of green coffee beans (GCB) and their active principles need to be ameliorated by modern nanoencapsulation and coffee capsule techniques. The role of CGA, caffeine, and other components in a variety of ailments such as cancer, inflammatory diseases, hepatitis, obesity, neurodegenerative disorders, and cardiovascular diseases has been well documented and supported using a mechanistic rationale. Furthermore, the risk–benefit ratio and health assessment need to be speculated on in the light of toxicological interventions and fortification of GCB with different permutations and combinations that could be obtained in the future.
Introduction
The impact of consuming green tea or coffee on mortality in patients with diabetes is controversial. We prospectively investigated the impact of each beverage and their combination on mortality among Japanese patients with type 2 diabetes.
Research design and methods
In all, 4923 patients (2790 men, 2133 women) with type 2 diabetes (mean age, 66 years) were followed prospectively (median, 5.3 years; follow-up rate, 99.5%). We evaluated the amount of green tea and coffee consumed using self-administered questionnaires.
Results
During the follow-up period, 309 participants died. The consumption of green tea, coffee, and a combination of the beverages was associated with reduced all-cause mortality. Multivariable-adjusted hazard ratios (95% CIs) for green tea were as follows: none 1.0 (referent); 0.85 (0.60–1.22) for ≤1 cup/day; 0.73 (0.51–1.03) for 2–3 cups/day; 0.60 (0.42–0.85) for ≥4 cups/day; and P for trend, 0.002. For coffee, they were: none 1.0 (referent); 0.88 (0.66–1.18) for <1 cup/day; 0.81 (0.58–1.13) for 1 cup/day; 0.59 (0.42–0.82) for ≥2 cups/day; P for trend, 0.002. With the combination they were 1.0 (referent) for no consumption of green tea and coffee; 0.49 (0.24–0.99) for 2–3 cups/day of green tea with ≥2 cups/day of coffee; 0.42 (0.20–0.88) for ≥4 cups/day of green tea with 1 cup/day of coffee; and 0.37 (0.18–0.77) for ≥4 cups/day of green tea with ≥2 cups/day of coffee.
Conclusions
Higher consumption of green tea and coffee was associated with reduced all-cause mortality: their combined effect appeared to be additive in patients with type 2 diabetes.
The objective of this study was to investigate the relationship between coffee consumption and obesity in Korean women. We included 5,995 women who participated in a health screening examination at the Korean National Cancer Center between 2007 and 2016. Daily coffee consumption was evaluated using the food frequency questionnaire. Obesity was assessed by body mass index (BMI), and abdominal obesity was assessed by waist circumference (WC). A multiple logistic regression model was used to calculate the odds ratio (OR) of obesity according to coffee consumption. After multivariate adjustment, high coffee consumption was positively associated with obesity measured by BMI (≥ 3 cups vs. no drinks, OR = 2.52; 95% confidence interval (CI) = 1.91-3.34; P for the trend < 0.001) and abdominal obesity measured by WC (≥ 3 cups vs. no drinks, OR = 2.11; 95% CI = 1.59-2.79; P for the trend < 0.001). The positive association between daily coffee consumption and obesity prevalence was not altered by menopause. The amount of coffee consumed per day by Korean women was positively correlated with the prevalence of obesity, but the mechanism underlying this phenomenon remains to be elucidated.
The current literature has mainly focused on benefits and risks deriving from the consumption of caffeinated coffee and its implications for inflammation, cardiovascular diseases, neurodegenerative disorders, and cancer. Today, data about the role of caffeine in many disorders are controversial and the attention has increasingly focused on decaffeinated coffee and its non-caffeine compounds, which could have mainly beneficial effects. In fact, coffee phenolic compounds not only exhibit well-known antioxidant properties, but they can also antagonize some negative effects of caffeine, for example in inflammatory pathway and in glucose metabolism and homeostasis. In this review, we consider the literature of the last two decades and critically discuss the effects of decaffeinated coffee compounds on systemic disorders, mainly inflammation, cardiovascular diseases, hepatic dysfunctions, and cancer.
Background:
Most persons with type 2 diabetes are overweight and obesity worsens the metabolic and physiologic abnormalities associated with diabetes.
Objective:
The objective of this review is to assess the effectiveness of lifestyle and behavioral weight loss and weight control interventions for adults with type 2 diabetes.
Methods:
Search methods: Studies were obtained from computerized searches of multiple electronic bibliographic databases, supplemented with hand searches of selected journals and consultation with experts in obesity research.
Selection criteria:
Studies were included if they were published or unpublished randomized controlled trials in any language, and examined weight loss or weight control strategies using one or more dietary, physical activity, or behavioral interventions, with a follow-up interval of at least 12 months.
Data collection and analysis:
Effects were combined using a random effects model.
Main results:
The 22 studies of weight loss interventions identified had a 4,659 participants and follow-up of 1 to 5 years. The pooled weight loss for any intervention in comparison to usual care among 585 subjects was 1.7 kg (95 % confidence interval [CI] 0.3 to 3.2), or 3.1% of baseline body weight among 517 subjects. Other main comparisons demonstrated non significant results: among 126 persons receiving a physical activity and behavioral intervention, those who also received a very low calorie diet lost 3.0 kg (95% CI -0.5 to 6.4), or 1.6% of baseline body weight, more than persons receiving a low-calorie diet. Among 53 persons receiving identical dietary and behavioral interventions, those receiving more intense physical activity interventions lost 3.9 kg (95% CI -1.9 to 9.7), or 3.6% of baseline body weight, more than those receiving a less intense or no physical activity intervention. Comparison groups often achieved significant weight loss (up to 10.0 kg), minimizing between-group differences. Changes in glycated hemoglobin generally corresponded to changes in weight and were not significant when between-group differences were examined. No data were identified on quality of life and mortality.
Authors conclusions:
Weight loss strategies using dietary, physical activity, or behavioral interventions produced small between-group improvements in weight. These results were minimized by weight loss in the comparison group, however, and examination of individual study arms revealed that multicomponent interventions including very low calorie diets or low calorie diets may hold promise for achieving weight loss in adults with type 2 diabetes.
Caffeine is a common substance in the diets of most athletes and it is now appearing in many new products, including energy drinks, sport gels, alcoholic beverages and diet aids. It can be a powerful ergogenic aid at levels that are considerably lower than the acceptable limit of the International Olympic Committee and could be beneficial in training and in competition. Caffeine does not improve maximal oxygen capacity directly, but could permit the athlete to train at a greater power output and/or to train longer. It has also ben shown to increase speed and/or power output in simulated race conditions. These effects have been found in activities that last as little as 60 seconds or as long as 2 hours. There is less information about the effects of caffeine on strength; however, recent work suggests no effect on maximal ability, but enhanced endurance or resistance to fatigue. There is no evidence that caffeine ingestion before exercise leads to dehydration, ion imbalance, or any other adverse effects. The ingestion of caffeine as coffee appears to be ineffective compared to doping with pure caffeine. Related compounds such as theophylline are also potent ergogenic aids. Caffeine may act synergistically with other drugs including ephedrine and anti-inflammatory agents. It appears that male and female athletes have similar caffeine pharmacokinetics, i.e., for a given dose of caffeine, the time course and absolute plasma concentrations of caffeine and its metabolites are the same. In addition, exercise or dehydration does not affect caffeine pharmacokinetics. The limited information available suggests that caffeine non-users and users respond similarly and that withdrawal from caffeine may not be important. The mechanism(s) by which caffeine elicits its ergogenic effects are unknown, but the popular theory that it enhances fat oxidation and spares muscle glycogen has very little support and is an incomplete explanation at best. Caffeine may work, in part, by creating a more favourable intracellular ionic environment in active muscle. This could facilitate force production by each motor unit.
1) In normal subjects, oral administration of regular coffee and of caffeine increases NEFA plasma concentration without modifying
blood glucose, plasma insulin, cortisol and growth hormone concentration; 2) this NEFA mobilizing effect of caffeine and regular
coffee is not observed in obese people; 3) in normal subjects, caffeine administration improves oral glucose tolerance and
potentiates the insulinogenic effect of orally administered glucose.
1) Bei Normalpersonen verursacht die Verabreichung von gewöhnlichem Kaffee oder von Koffein eine Steigerung der NEFA-Konzentration
im Plasma ohne Blutzucker-, Plasmainsulin-, Kortisol- oder Wachstumshormonspiegel zu beeinflussen; 2) die lipolytische Wirkung
des Koffeins und des Kaffees wird bei Adipösen nicht beobachtet; 3) bei Normalpersonen verbessert die Verabreichung von Koffein
die Glukosetoleranz und potenziert den insulinogenen Effekt oral verabreichter Glukose.
1) En individuos normales el suministro oral de café normal y de cafeína detérmina un aumento de los NEFA sin modificar la
glucemia, la insulinemia, la cortisolemia y la somatotropinemia; 2) en los individuos obesos no se observa el efecto movilizador
de los NEFA, ejercido por el café normal y por la cafeína; 3) en los individuos normales el suministro de cafeína mejora la
tolerancia glucídica y potencia el efecto insulinógeno de la glucosa p.o.
1) Chez les sujets normaux, l’administration orale de café ordinaire ou de caféine entrîne un accroissement du taux des acides
gras libres plasmatiques sans modifications de la glycémie, de l’insulinémie, de la cortisolémie et du taux plasmatique de
l’hormone de croissance; 2) l’effet lipolytique de la caféine et du café ne s’observe pas chez les sujets obèses; 3) chez
les sujets normaux, l’administration de caféine ameliore la tolérance glucidique et potentialise l’effet insulinogénique du
glucose administré par voie orale.
1) Nei soggetti normali, la somministrazione orale di caffè normale e di caffeina determina aumento dei livelli plasmatici
dei NEFA, senza modificare la glicemia, l’insulinemia, la cortisolemia e la somatotropinemia; 2) questo effetto mobilizzante
i NEFA, esercitato dal caffè normale e dalla caffeina, non si osserva nei soggetti obesi; 3) nei soggetti normali, la somministrazione
di caffeina migliora la tolleranza glicidica e potenzia l’effetto insulinogeno del glucosio p.o.
We determined whether intraportal caffeine infusion, at rates designed to create concentrations similar to that seen with normal dietary intake, would enhance net hepatic glucose uptake (NHGU) during a glucose load. Dogs (n = 15) were implanted with sampling and infusion catheters as well as flow probes >16 d before the studies. After a basal sampling period, dogs were administered a somatostatin infusion (0-150 min) as well as intraportal infusions of glucose [18 micromol/(kg . min)], basal glucagon [0.5 ng/(kg . min)], and insulin [8.3 pmol/(kg . min)] to establish mild hyperinsulinemia. Arterial glucose was clamped at 10 mmol/L with a peripheral glucose infusion. At 80 min, either saline (Control; n = 7) or caffeine [1.5 micromol/(kg . min); n = 8] was infused into the portal vein. Arterial insulin, glucagon, norepinephrine, and glucose did not differ between groups. In dogs infused with caffeine, NHGU was significantly higher than in controls [21.2 +/- 4.3 vs. 11.2 +/- 1.6 micromol/(kg . min)]. Caffeine increased net hepatic lactate output compared with controls [12.5 +/- 3.8 vs. 5.5 +/- 1.5 micromol/(kg . min)]. These findings indicate that physiologic circulating levels of caffeine can enhance NHGU during a glucose load, and the added glucose consumed by the liver is in part converted to lactate.
Eighty-five patients, age 48 to 77 y with postmenopausal crush fracture osteoporosis, were investigated using a 7-d combined calcium balance and 47Ca tracer-kinetic turnover method taking the dermal calcium loss into account. Individual dietary records were obtained based on a 4-d registration at home before hospital admission and on questioning by a dietitian. The following dietary constituents were estimated: energy content, protein, methionine, cysteine, calcium, phosphate, magnesium, coffee, fiber and vitamin C. All patients were served individual diets based on the dietary records during study. Dietary calcium was measured in duplicates of all the meals served. All urine and feces were collected and analyzed for calcium content. The 47Ca kinetic data were analyzed according to a modification of the expanding calcium pool model. The overall calcium balance correlated significantly to energy content (r = 0.31, P less than 0.005), protein (r = 0.22, P less than 0.05), calcium (r = 0.28, P less than 0.01), phosphate (r = 0.27, P less than 0.02) and coffee (r = -0.21, P less than 0.05). However, a multiple backward linear regression analysis disclosed that only calcium (rp = 0.38, P less than 0.0005) and coffee intake (rp = -0.25, P less than 0.05) significantly influenced calcium balance. The equation was: calcium balance (mmol/d) = 0.14 x (dietary calcium, mmol/d) - 0.0016 x (coffee intake, mL/d) - 3.62. A coffee intake in excess of 1000 mL could induce an extra calcium loss of 1.6 mmol calcium/d, whereas intakes of 1-2 cups of coffee per day would have little impact on calcium balance.
In a double-blind, random-order, cross-over study the effects of placebo and 100 mg of caffeine on postprandial sitting and erect blood pressure and heart rate were studied in 20 frail elderly subjects (mean age 84, range 75–93 years) after a standardized 400 K-calorie glucose drink. Maximal postprandial reduction in sitting systolic blood pressure occurred, at 60 minutes post-placebo, of − 11 mmHg (95% confidence interval −5 to −17 mmHg, P<0.01), and was attenuated by caffeine (P<0.05) with changes in systolic blood pressure, at 60 minutes post-drink, of 1 mmHg (95% CI −6 to 7 mmHg, not significant). Four subjects developed symptomatic postprandial hypotension after placebo which was prevented by caffeine. There were no significant changes in erect systolic blood pressure, postural systolic blood pressure change, sitting and erect, diastolic blood pressure and heart rate between treatment phases.
Caffeine attenuates the postprandial fall in sitting blood pressure in frail elderly subjects and in particular prevented symptomatic blood pressure reductions in subjects with postprandial hypotension.
Single-dose oral administration of 100 mg caffeine increased the resting metabolic rate of both lean and postobese human volunteers by 3-4% (p less than 0.02) over 150 min and improved the defective diet-induced thermogenesis observed in the postobese subjects. Measurements of energy expenditure (EE) in a room respirometer indicate that repeated caffeine administration (100 mg) at 2-h intervals over a 12-h day period increased the EE of both subject groups by 8-11% (p less than 0.01) during that period but had no influence on the subsequent 12-h night EE. The net effect was a significant increase (p less than 0.02) in daily EE of 150 kcal in the lean volunteers and 79 kcal in the postobese subjects. Caffeine at commonly consumed doses can have a significant influence on energy balance and may promote thermogenesis in the treatment of obesity.
Caffeine is the most popular psychoactive substance in the world, and one of the widest-traded commodities in the forms of coffee, tea and cola soft drinks. But is consumption of caffeine safe in terms of physical and mental health? Addressing this question, the author traces how caffeine consumption evolved as well as how caffeine is absorbed, distributed and metabolized in our bodies. He then discusses the effects of caffeine on: psychomotor and cognitive performance; psychological well-being; blood pressure and cardiovascular health; carcinogenic potentials; pregnancy and perinatal health; athletic performance; and diagnostic and therapeutic applications. The book addresses the question of whether caffeine is a drug of abuse, and summarizes the main conclusions to be drawn from the vast body of relevant science.
In mouse islet grafts under the kidney capsule, the potentiating responsiveness to acetylcholine was markedly attenuated after a few weeks. The question arose as to whether transplanted islets show an decreased responsiveness to potentiators in general. The effect of caffeine on glucose-induced insulin secretion was, therefore, examined. Intrastrain transplantation was performed in NMRI and BALB/c mice, and islet grafts were removed and perifused in vitro after 3 and 12 wk. In grafts from both NMRI and BALB/c mice, 16.7 mmol/L glucose induced a biphasic insulin release. When 1 or 5 mmol/L caffeine was included in the perifusion medium, there was a marked potentiation of the glucose-induced insulin release that was at least as responsiveness as fresh untransplanted islets. In the absence of caffeine, 3-wk-old BALB/c grafts reacted less strongly to acetylcholine than did untransplanted islets. The addition of 1 mmol/L caffeine did not enhance the potentiating effect of acetylcholine, whether in untransplanted or transplanted islets. Rather, the interaction between caffeine and acetylcholine appeared negative. We concluded that the glucose-induced insulin secretion exhibits a diminished potentiatory responsiveness to acetylcholine but not to caffeine. The displacement and denervation of transplanted islets is likely to affect either the cholinergic receptors or their mediated influence on intracellular calcium. Copyright © 1997 Elsevier Science Inc.
This paper summarises the occurrence in foods and beverages of the cinnamic acids, their associated conjugates and transformation products. Quantitative data are lacking for some commodities known to contain them, but it is clear that for many people coffee will be the major source. The daily dietary intake of total cinnamates may vary substantially from almost zero to perhaps close to 1 g. The data relating to their absorption and metabolism are presented along with a consideration of their possible in vivo effects. Data for true bioavailability are incomplete: in particular it is not clear whether availability differs markedly with the form of the conjugate, and whether as a consequence some dietary sources may be superior to others. (C) 2000 Society of Chemical Industry.
Coffee is a major source of caffeine, which has been shown to acutely reduce sensitivity to insulin, but also has potentially beneficial effects. We prospectively investigated the association between coffee consumption and risk of clinical type 2 diabetes in a population-based cohort of 17 111 Dutch men and women aged 30-60 years. During 125 774 person years of follow-up, 306 new cases of type 2 diabetes were reported. After adjustment for potential confounders, individuals who drank at least seven cups of coffee a day were 0-50 (95% CI 0.35-0.72, p=0.0002) times as likely as those who drank two cups or fewer a day to develop type 2 diabetes. Coffee consumption was associated with a substantially lower risk of clinical type 2 diabetes.
(95% CI, 0.26 to 0.82; P 0.007 for trend), respectively. The corresponding multivariate relative risks in women were 1.00, 1.16, 0.99, 0.70, and 0.71 (CI, 0.56 to 0.89; P < 0.001 for trend), respectively. For decaffeinated coffee, the multivariate relative risks comparing persons who drank 4 cups or more per day with nondrinkers were 0.74 (CI, 0.48 to 1.12) for men and 0.85 (CI, 0.61 to 1.17) for women. Total caffeine intake from coffee and other sources was associated with a statistically significantly lower risk for diabetes in both men and women. Conclusions: These data suggest that long-term coffee consumption is associated with a statistically significantly lower risk for type 2 diabetes.
This paper summarises the occurrence in foods and beverages of the cinnamic acids, their associated conjugates and transformation products. Quantitative data are lacking for some commodities known to contain them, but it is clear that for many people coffee will be the major source. The daily dietary intake of total cinnamates may vary substantially from almost zero to perhaps close to 1 g. The data relating to their absorption and metabolism are presented along with a consideration of their possible in vivo effects. Data for true bioavailability are incomplete: in particular it is not clear whether availability differs markedly with the form of the conjugate, and whether as a consequence some dietary sources may be superior to others.© 2000 Society of Chemical Industry
Caffeine is metabolized extensively (on average 80%) to paraxanthine. With regular caffeine consumption, average serum levels of paraxanthine are two thirds those of caffeine. Both caffeine and paraxanthine competitively and nonselectively inhibit adenosine receptors in vitro. To examine the contribution of paraxanthine to the pharmacologic activity of caffeine, we administered to 12 subjects in a crossover design oral caffeine (2 or 4 mg/kg) versus placebo or oral paraxanthine (same dose as caffeine) versus placebo, each after 3 days of methylxanthine abstinence. Both caffeine and paraxanthine significantly increased diastolic blood pressure, plasma epinephrine levels, and free fatty acids. Caffeine and paraxanthine produced a similar magnitude of response at 4 mg/kg; however, caffeine appeared to produce greater responses than paraxanthine at 2 mg/kg. Caffeine and paraxanthine have similar sympathomimetic actions. The activity of paraxanthine needs to be considered in understanding the clinical pharmacology of caffeine, particularly with chronic, repetitive caffeine consumption.
The teratogenic effect of caffeine has been clearly demonstrated in rodents. The sensitivity of different animals species is variable. Malformations have been demonstrated in mice at 50–75 mg/kg of caffeine, whereas the lowest dose usually needed to induce malformations is 80 mg/kg in rats. However, when caffeine is administered in fractioned amounts during the day, 330 mg/kg/day are necessary to reach teratogenicity in rats. In rodents, the most frequently observed malformations are those of the limbs and digits, ectrodactyly, craniofacial malformations (labial and palatal clefts) and delays in ossification of limbs, jaw and sternum. Nevertheless, even in rodents, caffeine can be considered as a weak teratogenic agent, given the quite large quantities of caffeine necessary to induce malformations and the small number of animals affected. In humans, caffeine does not present any teratogenic risk. The increased risk of the most common congenital malformations entailed by moderate consumption of caffeine is very slight. However, caffeine potentiates the teratogenic effect of other substances, such as tobacco, alcohol, and acts synergistically with ergotamine and propranolol to induce materno-fetal vasoconstrictions leading to malformations induced by ischemia. Therefore, even though caffeine does not seem to be harmful to the human fetus when intake is moderate and spread out over the day, some associations, especially with alcohol, tobacco, and vasoconstrictive or anti-migraine medications should be avoided.Maternal consumption of caffeine affects brain composition, especially in case of a low-protein diet and also seems to interfere with zinc fixation in brain. Maternal exposure to caffeine induces also long-term consequences on sleep, locomotion, learning abilities, emotivity, and anxiety in rat offspring, whereas in humans, more studies are needed to ascertain long-term behavioral effects of caffeine ingestion by pregnant mothers.
Eight normal humans were subjected to paired standard rapid intravenous glucose tolerance tests one hour following the ingestion, on one occasion, of nondecaffeinated and, on a second occasion, of decaffeinated coffee under identical conditions. Nondecaffeinated coffee elevates fasting blood glucose, impairs glucose tolerance as reflected by a lessened fractional blood glucose disappearance rate and relative hyperglycemia, and blunts the insulinogenic response of blood glucose elevation compared to decaffeinated coffee. These effects of nondecaffeinated coffee appeared to be inversely related to the subjects control glucose tolerance.
The effect of coffee, decaffeinated coffee and a control beverage on plasma FFA was studied in a group of normal human subjects. The effect of caffeine sodium benzoate was also studied in the dog. Significant elevations in FFA were observed after coffee and caffeine which usually reached their peak in 3 or 4 hours. The administration of sucrose significantly reduced the immediate FFA response. The FFA effects with decaffeinated coffee were markedly less than with regular coffee and were similar to that of the control beverage. These effects are considered to be of importance, particularly in that they may be related to other disturbances in lipid metabolism.
Using a double-blind, randomized, cross-over protocol, we studied the effect of a single dose of oral caffeine on plasma renin activity, catecholamines and cardiovascular control in nine healthy, young, non-coffee drinkers maintained in sodium balance throughout the study period. Caffeine (250 mg) or placebo was administered in a methylxanthine-free beverage to overnight-fasted supine subjects who had had no coffee, tea or cola in the previous three weeks. Caffeine increased plasma renin activity by 57 per cent, plasma norepinephrine by 75 per cent and plasma epinephrine by 207 per cent. Urinary normetanephrine and metanephrine were increased 52 per cent and 100 per cent respectively. Mean blood pressure rose 14/10 mm Hg one hour after caffeine ingestion. There was a slight fall and then a rise in heart rate. Plasma caffeine levels were usually maximal one hour after ingestion but there was considerable individual variation. A 20 per cent increase in respiratory rate correlated well with plasma caffeine levels. Under the conditions of study caffeine was a potent stimulator of plasma renin activity and adrenomedullary secretion. Whether habitual ingestion has similar effects remains to be determined.
It has been suggested that adenosine may be a physiologically important modulator of lipolysis. In the present study it was found that adenosine inhibited lipolysis stimulated by low (0.03 micrometer) concentrations of noradrenaline (NA). Lipolysis stimulated by higher concentrations (0.3 and 3 micrometer) of NA was inhibited to a minor degree or not at all. Theophylline (1 micromete)-induced lipolysis was inhibited by adenosine (IC50 approximately 10 micrometer). Inhibition of theophylline-induced lipolysis was tested for several analogues of adenosine. Some N6-substituted adenosine analogues and 2-Cl-adenosine were more potent inhibitors. Adenine-nucleotides (ATP, ADP, AMP) were about equipotent with adenosine. Several adenosine analogues, including its breakdown products were considerably less potent or ineffective. None of the analogues tested inhibited the action of adenosine. Dipyridamol, dilazep and papaverine, which inhibit the uptake of adenosine into cells, caused only a slight enhancement of the antilipolytic effect of adenosine. None of the analogues inhibited the effect of adenosine. It is concluded that adenosine can inhibit lipolysis due to low, "physiological" concentrations of noradrenaline and of low concentration of theophylline via an action on a receptor structure on the cell surface which exhibits structural specificity.
In an effort to assess the effects of caffeine ingestion on metabolism and performance during prolonged exercise, nine competitive cyclists (two females and seven males) exercised until exhaustion on a bicycle ergometer at 80% of Vo2 max. One trial was performed an hour after ingesting decaffeinated coffee (Trial D), while a second trial (C) required that each subject consume coffee containing 330 mg of caffeine 60 min before the exercise. Following the ingestion of caffeine (Trial C), the subjects were able to perform an average of 90.2 (SE +/- 7.2) min of cycling as compared to an average of 75.5 (SE +/- 5.1) min in the D Trial. Measurements of plasma free fatty acids, glycerol and respiratory exchange ratios evidenced a greater rate of lipid metabolism during the caffeine trial as compared to the decaffeinated exercise treatment. Calculations of carbohydrate (CHO) metabolism from respiratory exchange data revealed that the subjects oxidized roughly 240 g of CHO in both trials. Fat oxidation, however, was significantly higher (P less than 0.05) during the C Trial (118 g or 1.31 g/min) than in the D Trial (57 g or 0.75 g/min). On the average the participants rated (Perceived Exertion Scale) their effort during the C Trial to be significantly (P less than 0.05) easier than the demands of the D treatment. Thus, the enhanced endurance performance observed in the C Trial was likely the combined effects of caffeine on lipolysis and its positive influence on nerve impulse transmission.
The sympathomimetic agent ephedrine has potent thermogenic and anti-obesity properties in rodents. The effect is markedly enhanced by caffeine, while caffeine given alone has no effect. This study was undertaken to find out if a similar weight reducing synergism between ephedrine and caffeine is present in obese patients. In a randomized, placebo-controlled, double blind study, 180 obese patients were treated by diet (4.2 MJ/day) and either an ephedrine/caffeine combination (20mg/200mg), ephedrine (20 mg), caffeine (200 mg) or placebo three times a day for 24 weeks. Withdrawals were distributed equally in the four groups, and 141 patients completed the trial. Mean weight losses was significantly greater with the combination than with placebo from week 8 to week 24 (ephedrine/caffeine, 16.6 +/- 6.8 kg vs. placebo, 13.2 +/- 6.6 kg (mean +/- s.d.), P = 0.0015). Weight loss in both the ephedrine and the caffeine groups was similar to that of the placebo group. Side effects (tremor, insomnia and dizziness) were transient and after eight weeks of treatment they had reached placebo levels. Systolic and diastolic blood pressure fell similarly in all four groups. We conclude, that in analogy with animal studies, the ephedrine/caffeine combination is effective, while caffeine and ephedrine separately are ineffective for the treatment of human obesity.
An extract with cholinergic activities was isolated from instant regular and decaffeinated coffees and purified. Intravenous injection of this cholinomimetic extract of coffee produced an abrupt depression in blood pressure and heart rate, changes that were distinct from those of known components of coffee, including caffeine, trigonelline, catechin, and chlorogenic acid. Pretreatment of the animals with naloxone, propranolol, isobutylmethylxanthine, hexamethonium bromide, and hemicholinium-3 chloride or bilateral vagotomy did not affect the cardiodepressive effects of the extract, whereas atropine completely abolished them. Direct injection of the cholinomimetic extract of coffee (20-100 micrograms) into the periaqueductal gray area of the midbrain did not produce any cardiovascular effect. However, the extract of coffee did cause relaxation of isolated rat and rabbit aortic ring preparations that were contracted under norepinephrine. The cholinomimetic extract did not inhibit purified acetylcholinesterase. This pharmacologic profile indicates that the cholinomimetic extract of coffee acts as a direct muscarinic agonist.
In vivo insulin-mediated glucose uptake (IMGU) occurs chiefly in skeletal muscle, where it is determined by the product of arteriovenous glucose difference (delta AVG) and blood flow (BF) rate into muscle. Epinephrine (Epi) reduces the rate of IMGU in whole body. To examine whether this is due to a reduction in delta AVG across or BF into skeletal muscle we constructed insulin dose-response curves for whole body IMGU and leg muscle IMGU- using euglycemic clamp ((+)[3-3H]glucose infusion) and leg balance techniques during insulin infusions ranging from 10 to 1,200 mU.m-2.min-1. We studied six subjects [wt 70 +/- 2 (SE) kg] during an Epi infusion at a single rate of 0.002 mg.kg-1.min-1 and six subjects (70 +/- 3 kg) during a saline infusion alone. Maximum whole body glucose uptake (WBGU) was similar during Epi and saline infusions [71.4 vs. 73.6 mmol.kg-1.min-1, P = not significant (NS)]. Compared with saline, maximum delta AVG was decreased during Epi infusion (1.04 vs. 1.31 mM, P less than 0.01). Compared with saline alone maximum leg BF was increased (5.3 vs. 4.3 dl/min, P less than 0.01) during Epi infusion. Thus maximum leg glucose uptake (LGU) was similar (696 vs. 821 pmol.leg-1.min-1, P = NS) during infusion of Epi and saline, respectively. Half-maximal effective dose for insulin's effect to stimulate WBGU, delta AVG, BF, and LGU was increased two- to threefold during Epi vs. saline infusions (P less than 0.01 for all values).(ABSTRACT TRUNCATED AT 250 WORDS)
In order to evaluate the effects of 'espresso' Italian coffee on resting flow, blood pressure, and peripheral resistance, 15 non-coffee drinking healthy volunteers received 2 cups of regular coffee, 200 mg purified caffeine or placebo in a latin square double-blind crossover protocol. Before and 30, 60, 90 and 120 min after ingestion, segmental resting flow and BP were measured and peripheral resistance was calculated. An echocardiogram was also performed before and 60 and 120 min after caffeine intake. Both regular coffee and caffeine produced a significant decrease in resting flow and a significant increase in resistance; both systolic and diastolic BP also increased, although not significantly. No variation was observed in heart rate and in cardiac contractility. Placebo (highly decaffeinated coffee for regular coffee and china bitter extract for caffeine) did not produce any haemodynamic effect. In five other healthy volunteers used to drinking more than 5 cups of coffee a day, coffee administration had no effect. These data demonstrate that the caffeine contained in espresso Italian coffee is a vasoconstrictor agent whose effects however are completely blunted in usual coffee drinkers as a consequence of adaptation.
An A1-adenosine receptor has been cloned from a rat brain cDNA library using a probe generated by the polymerase chain reaction. The cDNA encodes a protein of 327 amino acids which is 91% identical to a recently cloned dog A1-adenosine receptor (RDC7). Expression of the rat cDNA in COS-6M and NIH 3T3 cells resulted in ligand binding and functional activity characteristics of an A1-adenosine receptor that is coupled to inhibition of adenylyl cyclase. Examination of the distribution of A1-adenosine receptor mRNA by Northern blot analysis showed that it is highly expressed in brain, spinal cord, testis, and white adipose tissue. In situ hybridization studies revealed an extensive hybridization pattern in the central nervous system, with high levels in cerebral cortex, hippocampus, cerebellum, thalamus, brainstem, and spinal cord. The cloned A1-adenosine receptor may thus mediate many of the modulatory actions of adenosine in neural and endocrine systems.
Coffee is consumed in large quantities worldwide and any adverse effects would likely have important public health consequences. Because of the widespread exposure to coffee and other caffeine-containing beverages and because teratogenic effects of caffeine have been recorded in several species since 1960, women are concerned that there may be reason to limit their intake of coffee when pregnant. Several human studies on birth defects have been conducted and the overall results do not implicate coffee as a likely human teratogen. However, there is some evidence that consumption of three or more cups of coffee per day may have a modest effect on lowering infant birth weight. Studies of coffee consumption and increased rates of spontaneous abortion and delayed time to conception are inconsistent and conclusions cannot yet be drawn.
In groups of obese men and women with an abdominal type of fat distribution, we measured fat cell size, lipoprotein lipase (LPL) activity and lipolysis stimulated by norepinephrine (NE) or isoproterenol (ISO) or inhibited by insulin, in subcutaneous abdominal and retroperitoneal (nonportal), as well as in omental and mesenteric (portal) adipose tissues. Both men and women had large intraabdominal adipocytes. No differences were found between the two groups of obese subjects in fat cell size or LPL activity in the different adipose tissue regions. Women had as high NE- or ISO-stimulated lipolysis in the portal as in nonportal fat tissues, equally high as that found in men. In comparisons with a previous study in nonobese men and women, these results show an increased fat cell size in all tissues in obese women and an increased lipolysis in portal tissues in obese women and in nonportal tissues in obese men. Taken together, these results might mean that obese men and abdominally obese women have a large potential to release free fatty acids (FFA) from intraabdominal depots. This might be followed by metabolic derangements seen in such groups of obese subjects.
In humans caffeine stimulates thermogenesis by unknown mechanisms and its effect on body weight has not been studies. The effect of placebo and 100, 200, and 400 mg oral caffeine on energy expenditure, plasma concentrations of substrates and hormones, blood pressure, and heart rate was investigated in a double-blind study in healthy subjects who had a moderate habitual caffeine consumption. Caffeine increased energy expenditure dose dependently and the thermogenic response was positively correlated with the response in plasma caffeine (r = 0.52; p less than 0.018), plasma lactate (r = 0.79; p less than 0.000001), and plasma triglyceride (r = 0.53; p less than 0.02). Stepwise regression analysis with the thermogenic response as the dependent variable excluded plasma caffeine and yielded the following equation: thermic effect (kcal/3 h) = -0.00459 X heart rate + 0.30315 X (triglyceride) + 0.53114 X (lactate) + 15.34 (r = 0.86; p = 0.0001). The results suggest that lactate and triglyceride production and increased vascular smooth muscle tone may be responsible for the major part of the thermogenic effect of caffeine.
In a double-blind placebo-controlled study, we examined the effect of caffeine pretreatment on the haemodynamic and humoral changes after a standardized breakfast in 15 healthy elderly subjects (mean age 75.4±6.6 years). After placebo, the preprandial blood pressure did not change and the postprandial blood pressure declined by a maximum of 6.1%. After oral ingestion of 250 mg caffeine, 60 min before breakfast, the preprandial blood pressure increased by 12.5%. Although the decrease of the postprandial blood pressure was not altered, blood pressure remained above its basal value. The increase in plasma noradrenaline after the meal was similar in the placebo and the caffeine tests. Plasma adrenaline decreased after placebo (−19%) but did not change after caffeine.
Thus, despite the unchanged decrease of the postprandial blood pressure, the preprandial pressor effect of caffeine prevented the decline of the postprandial blood pressure below its baseline value. The clinical relevance of this finding has still to be determined.
The effect of chronic caffeine treatment on lipolysis in rat epididymal adipose tissue was studied. There was a decrease in body weight, epididymal fat pad weight and mean adipocyte diameter in caffeine-treated rats when compared with control rats. No difference in adipocyte triglyceride content or mean adipocyte weight between control and caffeine-treated rats was observed. Lipolysis in adipocytes induced by adenosine deaminase (1 U/ml) decreased by 35% in caffeine-treated rats. This was accompanied by a 2.5-fold increase in the anti-lipolytic potency of 2-chloroadenosine and an increase of adipocyte adenosine A1 receptor number.
We examined the effects of caffeine and meals on blood pressure and heart rate in 12 patients with autonomic failure. The influence of caffeine on plasma norepinephrine, epinephrine, and renin activity was also studied. Caffeine 250 mg, raised blood pressure by 12/6 mm Hg, from 129 +/- 25/78 +/- 12 (mean +/- S.D.) to a maximum of 141 +/- 30/84 +/- 16 mm Hg at 45 minutes (P less than 0.01), but did not change heart rate, levels of norepinephrine, or epinephrine, or plasma renin activity. Blood pressure fell by 28/18 mm Hg after a standardized meal, from 133 +/- 32/80 +/- 15 to a minimum of 105 +/- 21/62 +/- 12 mm Hg at 60 minutes (P less than 0.01). After pretreatment with 250 mg of caffeine, the standardized meal induced a fall of only 11/10 mm Hg, from 140 +/- 33/79 +/- 7 to 129 +/- 31/69 +/- 13 mm Hg at 60 minutes (P less than 0.05 vs. values after the control per day for seven days) in five patients, postprandial blood pressures remained higher after caffeine than after placebo (P less than 0.05). We conclude that caffeine is a pressor agent and attenuates postprandial hypotension in autonomic failure, and that this effect is not primarily due to elevations in sympathoadrenal activity or activation of the renin-angiotensin system. Caffeine may be useful in the treatment of orthostatic hypotension due to autonomic failure, especially in the postprandial state.
In nine volunteers with maturity-onset diabetes blood-glucose levels (after intravenous glucose, 0·5 g. per kg. body-weight) were significantly higher following two cups of " instant " coffee than they were when water had been drunk. Circulating insulin levels were not affected. This finding warrants investigation on a larger scale.
The effect of coffee-drinking on blood composition was studied in 20 healthy volunteers who normally consumed, on average, 560 mg caffeine/day from tea and coffee. After 14 days on decaffeinated coffee (12 mg caffeine/day) there was a reduction in blood glucose, a small rise in plasma cholesterol and phospholipid, and a more substantial fall in triglycerides. The substitution of coffee for decaffeinated coffee (875 mg caffeine/day) for 20 days did not affect blood glucose, but the changes in the plasma lipids were reversed. There was no change in the level of immunoreactive insulin, in platelet adhesiveness, fibrinogen or blood clot lysis time during the course of the experiment. The part played by caffeine and by coffee solids other than caffeine in the induction of these changes does not support the hypothesis that the consumption of coffee is a significant factor in the development of coronary heart disease.Copyright © 1970 S. Karger AG, Basel
The effects of age and chronic caffeine use (approximately 300 mg/day) on the cardiovascular and humoral responses to 250 mg of oral caffeine (the equivalent of 2 to 3 cups of coffee) were examined. Older subjects had greater increases in blood pressure than younger subjects (p less than 0.03), and caffeine nonusers had greater blood pressure increases than caffeine users, regardless of age (p less than 0.05). Caffeine increased the product of systolic blood pressure and heart rate (an estimate of myocardial oxygen demand) in older caffeine nonusers, but this effect was absent in older caffeine users (p less than 0.01). Cardiovascular effects of caffeine could not be related temporally to changes in plasma epinephrine, which were greater in caffeine nonusers and younger subjects, or to plasma norepinephrine, renin activity or vasopressin, which did not change. Thus, age accentuates and moderate prior caffeine use attenuates the cardiovascular effects of oral caffeine; these effects are not mediated solely through the sympathoadrenal system.
This study evaluated the cardiovascular effects and elimination kinetics of coffee and caffeine in 54 volunteers selected according to 3 gradations of daily caffeine consumption, cigarette smoking status and the presence of caffeine intolerance. After 24 hours of caffeine abstinence, subjects received coffee and 2.2 mg/kg of caffeine (equivalent to 2 cups of coffee). Blood pressure, heart rate, systolic time intervals and plasma concentrations of caffeine were measured before and at timed intervals after coffee and caffeine. There were no differences in response to coffee and caffeine. The average systolic/diastolic blood pressure increased 9/10 mm Hg. The maximal decrease in heart rate averaged 10 beats/min, and there were small increases in the systolic time intervals. There were no cardiovascular differences among the various groups. Caffeine in the smokers and heavy caffeine users had a shorter half-life (3.2 and 4.1 hours) than that in nonsmokers and nonusers (5.1 and 5.3 hours). In the caffeine-intolerant group it had a longer half-life, while the cardiovascular effects were similar to those of the other groups. Thus, irrespective of the amount of daily caffeine consumption, smoking status or caffeine intolerance, the cardiovascular responses were similar and tolerance, if present, was gone by 24 hours.