Coffee Polyphenols Research Articles

Structural modification and functional improvement of lactoferrin through non-covalent and covalent binding to coffee polyphenol

Studies have suggested that milk may enhance or neutralize the bioavailability of coffee polyphenols, possibly due to reversible and irreversible interactions between coffee polyphenols and milk proteins. The effects of non-covalent and covalent binding of lactoferrin (BLF) to caffeic acid (CAA) on protein structure and function were investigated. SDS-PAGE analysis confirmed the covalent interaction between BLF and CAA. Multispectral experiments characterized the BLF-CAA complexes and conjugates, revealing alterations in the tertiary structure of the proteins in the BLF-CAA conjugates. Molecular docking and kinetics results demonstrated that hydrogen bonding, electrostatic interaction, and hydrophobic forces were the primary internal forces between CAA and BLF. When combined with CAA, the covalent conjugates exhibited superior functional properties including solubility, oxidation resistance, thermal stability, emulsification and foamability, bioaccessibility, and antimicrobial properties. This study offers a theoretical foundation and technical benchmark for the preparation of protein-based delivery vectors with synergistic effects.

The impact of coffee consumption on human health

Coffee consumption is a key aspect of modern lifestyle. Caffeine, the major component of coffee, has an impact on various human tissues and organs after being absorbed in the gastrointestinal tract. Its beneficial effects on reducing both the incidence of many diseases, including cancer, and overall mortality has been described. According to most cohort studies, coffee has a positive impact on cardiovascular diseases as it lowers the risk of cardiovascular diseases and does not increase blood pressure. Meta-analyses suggest a protective effect of caffeine contained in coffee on neurological disorders such as migraines, dementia, and slowing the progression of Alzheimer’s disease and Parkinson’s disease. However, research on malignant tumour development in humans is inconsistent. On the one hand, caffeine contained in coffee has been shown to significantly reduce the risk of breast cancer, endometrial cancer and prostate cancer. On the other hand, most meta-analyses have shown an association between coffee intake and an increased prevalence of lung cancer. In some cases, it can even lead to significant rise in morbidity. The positive impact of chlorogenic acid (a polyphenol in coffee) administered with doxorubicin has been described in in vitro and in vivo lung cancer studies.

Potential Risk of Caffeoylquinic Acids, the Main Polyphenol Components in Coffee, on the Health of Piglets.

As the main coffee polyphenols, caffeoylquinic acids (CQAs) are abundant in coffee-derived products and have the potential to act as novel feed additives for animals. However, research on the side effects of dietary CQAs supplementation is scarce, especially in young animals. Here, we explore the safety of CQAs derived from green coffee beans. Results showed that ingesting 50, 125, 250, and 500 mg/kg of dietary CQAs for 55 days is associated with greater final body weight, average daily gain, and feed efficiency in piglets compared with the control group (P < 0.05). CQAs also increased the apparent digestibility of dry matter, crude protein, and gross energy at a dose over 50 mg/kg (P < 0.05). Interestingly, CQAs supplementation with 500 mg/kg increased the white blood cell count (P < 0.05). Moreover, CQAs supplementation at a dose over 50 mg/kg decreased the serum total cholesterol concentration but increased the immunoglobulin M level in serum (P < 0.05). Importantly, CQAs supplementation had no side effects on organ histopathology and organ weight (P > 0.05). These results suggest that CQAs could serve as a secure and effective additive to improve growth performance without negatively affecting the organs of piglets.

Investigation of synergistic effect and mechanism of green tea extract and coffee extract on α‐amylase and α‐glucosidase inhibition

SummaryTo address the adverse effects of current hypoglycaemic drugs and the limited effect of individual extracts, this research investigated the inhibitory effect of combined green tea extract (GTE) and coffee (CE) on α‐amylase (α‐AMY) and α‐glucosidase (α‐GLU) and their inhibitory mechanisms. The inhibitory effects of single extracts and the complexes on α‐AMY and α‐GLU activities were compared by the principle of equivalence line. The results showed that the complexes had a good synergistic inhibition effect on both α‐AMY and α‐GLU at GTE: CE = 4:1 (w/w). Fluorescence spectroscopy and circular dichroism spectroscopy indicated that the complexes of GTE: CE = 4:1 (w/w) altered the secondary and tertiary structures of α‐AMY and α‐GLU more than the individual extracts, resulting in a synergistic inhibitory effect. The orthogonal experiments showed that tea polyphenols (TP) and coffee polyphenols (CP) were the main components responsible for the synergistic inhibitory effect of the two extracts.

Coffee polyphenols ameliorate early-life stress-induced cognitive deficits in male mice

Stress exposure during the sensitive period of early development has been shown to program the brain and increases the risk to develop cognitive deficits later in life. We have shown earlier that early-life stress (ES) leads to cognitive decline at an adult age, associated with changes in adult hippocampal neurogenesis and neuroinflammation. In particular, ES has been shown to affect neurogenesis rate and the survival of newborn cells later in life as well as microglia, modulating their response to immune or metabolic challenges later in life. Both of these processes possibly contribute to the ES-induced cognitive deficits. Emerging evidence by us and others indicates that early nutritional interventions can protect against these ES-induced effects through nutritional programming. Based on human metabolomics studies, we identified various coffee-related metabolites to be part of a protective molecular signature against cognitive decline in humans. Caffeic and chlorogenic acids are coffee-polyphenols and have been described to have potent anti-oxidant and anti-inflammatory actions. Therefore, we here aimed to test whether supplementing caffeic and chlorogenic acids to the early diet could also protect against ES-induced cognitive deficits. We induced ES via the limited nesting and bedding paradigm in mice from postnatal(P) day 2–9. On P2, mice received a diet to which 0.02% chlorogenic acid (5-O-caffeoylquinic acid) + 0.02% caffeic acid (3′,4′-dihydroxycinnamic acid) were added, or a control diet up until P42. At 4 months of age, all mice were subjected to a behavioral test battery and their brains were stained for markers for microglia and neurogenesis. We found that coffee polyphenols supplemented early in life protected against ES-induced cognitive deficits, potentially this is mediated by the survival of neurons or microglia, but possibly other mechanisms not studied here are mediating the effects. This study provides additional support for the potential of early nutritional interventions and highlights polyphenols as nutrients that can protect against cognitive decline, in particular for vulnerable populations exposed to ES.

Anti-diabetic Potentials of Coffee Polyphenols: A Narrative Review

Abstract: Coffee is one of the most popular beverages in the world, with potential health benefits and anti-diabetic qualities. Numerous bioactive substances found in coffee have been studied for their possible therapeutic benefits in controlling blood glucose. Given the ubiquitous use of coffee, this article aims to review the anti-diabetic characteristics of various coffee bioactive compounds such as chlorogenic acids, caffeic acid, quinic acid, ferulic acid, and caffeine. The modulation of glucose homeostasis, improvement of insulin sensitivity, suppression of gluconeogenesis, anti-inflammatory properties, and antioxidant activity are only a few of the several mechanisms of action that have been suggested. These qualities allow coffee polyphenols to potentially have anti-- diabetic effects, opening the door to prospective medicinal uses. The molecular mechanisms underpinning the effects of coffee polyphenols on insulin signaling pathways and glucose metabolism have been clarified by in vitro investigations. In animal studies, coffee polyphenols have positively affected pancreatic function, insulin resistance, and glucose regulation. Human studies have linked drinking coffee to a lower incidence of type 2 diabetes, better glycaemic management, and increased insulin sensitivity.

DNA Mutagenicity of Hydroxyhydroquinone in Roasted Coffee Products and Its Suppression by Chlorogenic Acid, a Coffee Polyphenol, in Oxidative-Damage-Sensitive SAMP8 Mice.

Hydroxyhydroquinone (HHQ) is an oxidative component produced by roasting coffee beans and has been reported to generate relatively large amounts of reactive oxygen species (ROS). In this study, we used senescence-accelerated mouse prone 8 (SAMP8) mice to determine whether HHQ consumption increases oxidative-stress-induced injury, because in SAMP8 mice, the activity of 8-oxoguanine DNA glycosylase 1, which repairs oxidative modifications in DNA, is decreased. The results showed that two out of twelve (16.7%) HHQ-treated mice presented polyuria and glucosuria around 2 months after the start of treatment, indicating that HHQ may act as a mutagen against SAMP8 mice, which is sensitive to oxidative damage. No abnormalities were observed in the chlorogenic acid (coffee polyphenol, CPP)-treated group. The concentration of hydrogen peroxide in the serum of SAMP8 mice was significantly higher than that in SAMR1 (senescence-resistant) control mice, and the concentration was further increased in the HHQ-treated group. CPP, when coexisting with HHQ at the rate contained in roasted coffee, decreased the amount of hydrogen peroxide in the serum of SAMP8 mice. Although CPP can act both oxidatively and antioxidatively as a polyphenol, CPP acts more antioxidatively when coexisting with HHQ. Thus, the oxidative effect of HHQ was shown to be counteracted by CPP.

Coffee's protective mechanisms against neurodegeneration.

A widely consumed beverage, coffee has emerged as a potential protective natural agent against neurodegenerative diseases. This chapter explores the intricate mechanisms by which coffee and its bioactive compounds exert neuroprotective effects. The antioxidant properties of coffee polyphenols, such as chlorogenic acid and caffeic acid, mitigate oxidative stress and neuroinflammation. Coffee modulates neurotransmitter systems, including dopaminergic, cholinergic, and glutamatergic pathways implicated in neurodegeneration. Additionally, coffee activates neuroprotective signaling cascades, such as the Nrf2 pathway, and inhibits pro-inflammatory pathways like NF-κB. Coffee components also influence mitochondrial function, biogenesis, and energy metabolism, thereby promoting neuronal survival. Furthermore, coffee suppresses microglial activation and modulates microglial phenotypes, reducing neuroinflammatory responses. Epidemiological studies and clinical trials provide insights into the potential benefits of coffee consumption on cognitive function and neurodegenerative disease risk. However, future research should focus on identifying specific coffee bioactive compounds and their mechanism of action. This chapter highlights the multifaceted neuroprotective mechanisms of coffee, paving the way for future research and potential therapeutic interventions.

Improvement of emulsifying stability of coconut globulin by noncovalent interactions with coffee polyphenols

Coconut milk is an unstable emulsion system, mainly stabilized by proteins, which limits the development of the food industry. The aim of this study was to investigate mechanisms for increasing emulsion stability through the interaction between coffee polyphenols (CPs) and coconut globulin (CG), the main protein in coconut milk. Caffeic acid (CA), chlorogenic acid (CHA), and ferulic acid (FA) were selected as CP models. The results showed that hydrogen bond interactions mainly occurred between CG and CPs (CG-FA < CG-CA < CG-CHA). CHA containing quinic acid preferentially formed a strong interaction with CG. The interaction changed the lipophilicity of CG and facilitated the formation of a dense and thick interfacial film at the oil–water interface. Furthermore, the emulsion stabilized by CG-CPs showed excellent stability after storage, centrifugation, pH, and salt treatment, especially CG-CHA. This study could provide a theoretical basis for improving the stability of coconut milk products.

The Potency of Polyphenols Extract of Robusta Coffee Bean (Coffea robusta) on COX-2 Inhibition in Neutrophil Cells

Inflammation is a physiological response to various stimuli including infection and tissue injury. One cause of inflammation is gram-negative bacteria that release various toxins, e.g. lipopolysaccharide endotoxin (LPS). The first body defense response is neutrophils. Body defense response is expressed by the cyclooxygenase (COX) enzyme that functions to transform arachidonic acid into prostaglandin. Polyphenols extract from Robusta coffee bean is known to play an anti-inflammatory role, but the mechanism for inhibiting COX-2 remains unknown. This study aimed to determine the potential of polyphenols extracted from Robusta coffee beans on COX-2 inhibition in neutrophils exposed to E. coli LPS. The research design was experimental in vitro with a post-test-only control group design. The sample consisted of 6 treatment groups, neutrophil isolates was incubated in concentrations of Robusta coffee polyphenols extract of 3.13%, 6.25%, 12.5%, and 25% and exposed to E. coli LPS. Measurement of COX-2 expression was conducted using immunohistochemical methods. ANOVA and LSD test results showed COX-2 expression in the treatment groups, namely neutrophils which were incubated with Robusta coffee polyphenols extract and exposed to E. coli LPS, was lower than the neutrophil group exposed only to E. coli LPS. The conclusion of this study is that the polyphenols extract of the Robusta coffee bean can inhibit COX-2 expression on neutrophils exposed to E. coli LPS.

Purification of Coffee Polyphenols Extracted from Coffee Pulps (Coffee arabica L.) Using Aqueous Two-Phase System.

Coffee pulp is an abundant residue from the coffee industry, but it still contains large amounts of valuable compounds such as polyphenols. The extraction of polyphenols from coffee pulp by the conventional method is accompanied by contaminated compounds. This study, therefore, applied an aqueous two-phase system consisting of different ratios of ethanol/ammonium sulfate to eliminate impurities from coffee-pulp crude extract. The purification efficiency was evaluated via total polyphenol content, antioxidant activity and two major polyphenols in coffee pulps including chlorogenic acid and caffeic acid. Results showed that phenolic compounds mostly predominated in the alcohol-rich phase in which the antioxidant activity was greatly increased after the purification process. Compared to un-purified crude-coffee extract, the antioxidant activity of the purified samples increased approximately 34%, which was assumed to occur due to the slight increase of chlorogenic acid and caffeic acid. Fourier-transform infrared spectroscopy supported the effectiveness of the purification process by eliminating some impurities.

Laser-Induced Graphene Electrodes for Electrochemistry Education and Research

Many aspects of electrochemical education, such as electroanalysis demonstrations, require three-electrode-cell experimental setups. Many researchers and educators use screen-printed electrochemical electrodes, which are miniature and disposable but are relatively expensive and use proprietary fabrication components. The present article describes how to laser-scribe complete three-electrode graphene-based electrodes that can compete with (and, in some regards, even rival) commercial screen-printed electrodes. The process of optimization of the lasing procedure to produce laser-induced graphene using almost any laser cutter available to the reader is described. A way to form a Ag/AgCl pseudoreference electrode on the graphene trace to complete the three-electrode cell, without usage of commercial inks or complicated printing technologies, is demonstrated. Electrochemical characterization of the electrode surface, reference electrode stability, and student practice demonstration of analytic applications of the produced cells (determination of dopamine concentration and coffee polyphenols) are described. These experiments and procedures act both as a method of fabrication of laser-scribed electrodes and as an educational material for introduction to electrodeposition, voltammetry, and electroanalysis.

Dietary Supplements Containing Oat Beta-Glucan and/or Green Coffee (Poly)phenols Showed Limited Effect in Modulating Cardiometabolic Risk Biomarkers in Overweight/Obese Patients without a Lifestyle Intervention.

Obesity has reached pandemic proportions and has become a major health concern worldwide. Therefore, it is necessary to find new strategies against this condition and its associated comorbidities. Green coffee polyphenols (GCP) and oat beta-glucans (BGs) have proven their hypolipidaemic and hypoglycaemic effects. This study aimed to examine the effects of the long-term consumption of supplements containing GCP, BG or the novel GCP/BG combination on lipid and glucose metabolism biomarkers in overweight/obese subjects who maintained their dietary habits and physical activity, hence addressing the difficulty that this population faces in adapting to lifestyle changes. A randomised, crossover, blind trial was carried out in 29 volunteers who consumed either GCP (300 mg), BG (2.5 g) or GCP/BG (300 mg + 2.5 g) twice a day for 8 weeks. Blood samples were collected, and blood pressure and body composition were measured at the beginning and end of each intervention. Total cholesterol, triglycerides, high-density lipoprotein (HDL-C), low-density lipoprotein (LDL-C), very low-density lipoprotein (VLDL-C) cholesterol, glycated haemoglobin, fasting glucose, insulin, aspartate transaminase, alanine transaminase and different hormones and adipokines were analysed. Only VLDL-C (p = 0.01) and diastolic blood pressure (p = 0.027) decreased after the intervention, especially with the BG supplement. There were no other significant changes in the analysed biomarkers. In conclusion, the regular intake of GCP, BG and GCP/BG without lifestyle changes is not an efficient strategy to improve lipid and glucose homeostasis in overweight/obese subjects.

A metabolomic platform to identify and quantify polyphenols in coffee and related species using liquid chromatography mass spectrometry.

Products of plant secondary metabolism, such as phenolic compounds, flavonoids, alkaloids, and hormones, play an important role in plant growth, development, stress resistance. The plant family Rubiaceae is extremely diverse and abundant in Central America and contains several economically important genera, e.g. Coffea and other medicinal plants. These are known for the production of bioactive polyphenols (e.g. caffeine and quinine), which have had major impacts on human society. The overall goal of this study was to develop a high-throughput workflow to identify and quantify plant polyphenols. First, a method was optimized to extract over 40 families of phytochemicals. Then, a high-throughput metabolomic platform has been developed to identify and quantify 184 polyphenols in 15 min. The current metabolomics study of secondary metabolites was conducted on leaves from one commercial coffee variety and two wild species that also belong to the Rubiaceae family. Global profiling was performed using liquid chromatography high-resolution time-of-flight mass spectrometry. Features whose abundance was significantly different between coffee species were discriminated using statistical analysis and annotated using spectral databases. The identified features were validated by commercially available standards using our newly developed liquid chromatography tandem mass spectrometry method. Caffeine, trigonelline and theobromine were highly abundant in coffee leaves, as expected. Interestingly, wild Rubiaceae leaves had a higher diversity of phytochemicals in comparison to commercial coffee: defense-related molecules, such as phenylpropanoids (e.g., cinnamic acid), the terpenoid gibberellic acid, and the monolignol sinapaldehyde were found more abundantly in wild Rubiaceae leaves.

Association of coffee intake and its polyphenols with mammographic findings in women who visited the Brazilian Public Health Service.

Objective: this study aimed to evaluate if there is an association of intake of coffee and its polyphenols with mammographic findings in women treated at a breast care service unit of the Unified Health System (SUS), Brazil. Research methods and procedures: this was a cross-sectional study with 532 women treated at a health service. The participants were divided according to their mammographic reports into two groups: without and with altered findings. Two 24-h dietary recalls were applied and coffee consumption was categorized into three groups (less than 1 cup, 1 to 3 cups, and more than 3 cups). Phenolic acids were determined using the Phenol Explorer program. The intake of polyphenols was calculated by adding the values obtained from the total amount of coffee consumed during the day. The Multiple Source Method (MSM) was applied to analyze the usual intake. Results: of the 532 women, 178 (33.5 %) had altered mammographic findings. The participants' average daily coffee intake was 193.4 mL. No significant association was found between coffee consumption and mammographic findings. However, it was found that the second tertile of polyphenols was a protective factor for breast changes. Conclusion: Coffee polyphenols are protective against breast changes in the group evaluated and, thus, can help prevent breast cancer.

Antibacterial Activity of Bioactive Compounds of Green Coffee Beans on Periodontogenic and Nosocomial Bacteria

The emergence of antimicrobial resistance and the side effects of synthetic drugs have raised an interest in searching for new antimicrobial compounds. The present study aims to evaluate in vitro antibacterial activity of green coffee and its active compounds (chlorogenic acid extract and caffeine extract) against some periodontogenic and nosocomial bacteria. The bioactive compounds, viz. chlorogenic acid and caffeine, were extracted through soxhlet extraction using methanol and water, respectively, and HPLC UV quantified these compounds. The study reported 3 CQA, 4 CQA, and 5 CQA as the significant chlorogenic acids in green coffee beans. Aqueous extract of green coffee beans (AGCB), which is dominant in caffeine, has been found to be the least effective against both periodontal and nosocomial bacteria. The result of our study revealed that the methanol extract of green coffee bean (MGCB), rich in chlorogenic acid, exhibits the highest inhibitory activity against periodontogenic bacteria, followed by the ethanol extract of green coffee bean (EGCB) and AGCB extract. EGCB extract was significantly effective against Staphylococcus epidermidis among selected nosocomial pathogens. AGCB extract was least effective against all bacteria. The results highlight that green coffee polyphenols, especially chlorogenic acid, could be used as antimicrobial agents in different biotechnological applications. The antibacterial property of green coffee highlights its potential as a naturally active antibacterial compound.

Prediagnostic plasma polyphenol concentrations and colon cancer risk: The JPHC nested case–control study

Epidemiological studies that assessed the associations between dietary polyphenol intakes and colon cancer risk have reported largely null results, possibly due to measurement error associated with dietary assessment. We adopted an objective approach by measuring prediagnostic plasma concentrations of 35 polyphenols and assessing associations with colon cancer risk. We conducted a nested-case control study within the Japan Public Health Center-based prospective study (JPHC Study) utilizing plasma samples collected at the time of a five-year follow-up survey between 1995 and 1999. We identified colon cancer cases who developed cancer during the follow-up from the time of blood collection. Controls were matched by age, sex, area code, population size of the area, season of blood collection, year of blood collection, and duration of fasting time before the blood collection. Prediagnostic concentrations of 35 polyphenols from 375 incident colon cancer cases (followed until 2012) and 710 matched controls were measured by tandem mass spectrometry coupled with ultra-high-pressure liquid chromatography. We used multivariable conditional logistic regression models adjusted for established colon cancer risk factors to estimate odds ratios (ORs) and 95% confidence intervals (CIs). In sexes combined log2-transformed multivariable models, circulating levels of 3,4-dihydroxyphenylpropionic acid (P=0.02), ferulic acid (P=0.02), and caffeic acid (P=0.03) were inversely, and 3-hydroxybenzoic acid (P=0.03) was positively, associated with colon cancer risk. For men only, circulating levels of 3,4-dihydroxyphenylpropionic acid was inversely, and 3,5-dihydroxyphenylpropionic acid, gallic acid, (+)-epigallocatechin, 3-hydroxybenzoic acid, and epicatechin were positively, associated with colon cancer risk. In women, plasma caffeic acid and ferulic acid concentration were inversely associated with colon cancer risk. However, all these associations were nonsignificant after adjustment for multiple comparisons. The remaining polyphenols were not associated with colon cancer risk. Coffee-derived 3,4-dihydroxyphenylpropionic acid, ferulic acid, and caffeic acid concentrations were inversely associated with colon cancer risk although the association were nonsignificant after adjustment for multiple comparisons. These results support a possible role of coffee polyphenols in preventing colorectal cancer.

Coffee Polyphenol, Chlorogenic Acid, Suppresses Brain Aging and Its Effects Are Enhanced by Milk Fat Globule Membrane Components.

Mice feed with coffee polyphenols (CPP, chlorogenic acid) and milk fat globule membrane (MFGM) has increased survival rates and helps retain long-term memory. In the cerebral cortex of aged mice, CPP intake decreased the expression of the proinflammatory cytokine TNF-α, and lysosomal enzyme cathepsin B. The suppression of inflammation in the brain during aging was thought to result in the suppression of the repressor element 1-silencing transcription factor (REST) and prevention of brain aging. In contrast, CPP increased the expression of REST, cAMP-responsive element binding (CREB) and transforming growth factor β1 (TGF-β1) in the young hippocampus. The increased expression of these factors may contribute to the induction of neuronal differentiation and the suppression of memory decline with aging. Taken together, these results suggest that CPP increases CREB in the young hippocampus and suppresses inflammation in the old brain, resulting in a preventive effect on brain aging. The endotoxin levels were not elevated in the serum of aged mice. Although the mechanism of action of MFGM has not yet been elucidated, the increase in survival rate with both CPP and MFGM intake suggests that adding milk to coffee may improve not only the taste, but also the function.

Chlorogenic Acid Activates Nrf2/SKN-1 and Prolongs the Lifespan of Caenorhabditis elegans via the Akt-FOXO3/DAF16a-DDB1 Pathway and Activation of DAF16f.

Chlorogenic acid (CGA) is the most abundant polyphenol in coffee. It has been widely reported to exhibit antioxidant activity by activating nuclear factor erythroid 2-related factor 2 (Nrf2) potentially via the canonical Kelch-like-ECH-associated protein 1 (Keap1)-Nrf2 pathway. We herein demonstrated that the knockdown of WD40 repeat protein 23 (WDR23), but not Keap1, abolished the effects of CGA on the activation of Nrf2. CGA decreased the expression of DDB1, an adaptor for WDR23-Cullin 4A-RING ligase (CRL4AWDR23). FOXO3, a major target for inactivation by the PI3K/Akt pathway, was identified as the transcription factor responsible for the basal and CGA-inhibited expression of the DDB1 gene. CGA blocked FOXO3 binding to importin-7 (IPO7), thereby inhibiting the nuclear accumulation of FOXO3, down-regulating the expression of DDB1, inhibiting the activity of CRL4WDR23, and ultimately increasing that of Nrf2. This pathway was conserved in Caenorhabditis elegans, and CGA extended the lifespan partly through this pathway. We found that in C. elegans, the isoform DAF-16a, but not DAF-16f, regulated the expression levels of ddb-1 mRNA and SKN-1 protein. CGA prolonged the mean lifespan of DAF-16a- and DAF-16f-rescued worms by 24% and 9%, respectively, suggesting that both isoforms involve in lifespan-extending effects of CGA, with DAF-16a being more important than DAF-16f. Based on these results, we established a novel Akt-FOXO3/DAF16a-DDB1 axis that links nutrient sensing and oxidative stress response pathways. Our results also provide a novel molecular mechanism for Nrf2/SKN-1 activation by CGA and the increased lifespan of C. elegans by CGA via this pathway.

Regular Consumption of Green Coffee Phenol, Oat β-Glucan and Green Coffee Phenol/Oat β-Glucan Supplements Does Not Change Body Composition in Subjects with Overweight and Obesity.

Many in vitro and in vivo studies support that green coffee polyphenols (GCP) and beta-glucans (BG) present important hypolipidaemic and hypoglycaemic effects. However, their weight-management/-reducing properties are less clear. Considering that these compounds act on different metabolic pathways, their combination could increase their beneficial health effects. The aim of the present study was to investigate the effects of regularly consuming supplements containing GCP, BG or the novel GCP/BG combination on body composition in overweight/obese subjects without changing their dietary and physical activity habits, hence addressing the difficulty to adapt to lifestyle changes. A randomised, cross-over, blind trial was carried out in 29 volunteers who consumed GCP (300 mg), BG (2.5 g) or GCP/BG (300 mg + 2.5 g) twice a day for 8 weeks. At the beginning and end of each of the interventions, body weight, body mass index, body fat%, intracellular and extracellular water, skinfolds (tricipital, bicipital, subscapularis, suprailiac, leg and thigh) and body circumferences (waist, hip, thigh, calf, branchial) were measured. Along the study, volunteers filled out 72 h dietary records, and physical activity was measured using accelerometers. The results show that dietary intake and physical activity were unchanged throughout the study; however, there were no changes in any of the body composition parameters analysed with any of the food supplements. In conclusion, the regular intake of GCP, BG and GCP/BG, without changes in diet and physical activity, is not an efficient strategy to lose weight or induce other positive changes in body composition, although results should be taken with caution as the study was underpowered.