Nutraceuticals for body-weight management: The role of green tea catechins

Green Tea Intake Reduces High-Fat Diet-Induced Sensory Neuropathy in Mice by Upregulating the Antioxidant Defense System in the Spinal Cord

One of the most common complications of obesity is peripheral nerve damage, which progresses to sensory neuropathy. Green tea (GT) intake has been associated with weight loss and metabolic biomarkers modulation due to its antioxidant properties. The present work characterized the effects of GT in high-fat diet (HFD)-induced neuropathy and investigated the mechanisms involved. C57BL/6J male mice were fed an HFD or control diet, associated with GT or vehicle intake for 16 weeks. Weight, blood glucose, and nociceptive thresholds were assessed. Morphological and morphometric analyses of the sciatic nerves were performed. Activation of the cellular antioxidant system in the spinal cord was assessed by real-time PCR. GT intake reduced weight gain, hyperglycemia, and the development of sensory neuropathy. Furthermore, in HFD-fed mice that consumed GT, the morphology of the sciatic nerve was preserved. RT-qPCR analysis showed that HFD-fed mice ingesting GT had higher spinal levels of superoxide dismutase, catalase, glutathione peroxidase, and nuclear factor erythroid 2-related factor 2 (NRF2) mRNA compared to the HFD-fed mice ingesting vehicle, suggesting that the endogenous antioxidant system was more activated in response to GT consumption. In conclusion, the data suggest that GT intake reduces HFD-induced neuropathy, probably by upregulating antioxidant gene expression.

The effect of coffee consumption on three main bone disorders: a Mendelian randomization trial

INTRODUCTION

Despite a large number of observational studies examining the effect of coffee consumption(CC) on bone disorders(BDs), particularly, osteoarthritis(OA), osteoportic fracture(OF), and rheumatoid arthritis(RA), the conclusions are highly controversial. Thus, it is essential to examine the causal association between CC and BDs.

MATERIALS AND METHODS

Mendelian randomization (MR) analysis was performed to assess the causal influence of CC on OF, RA, and OA. The main endpoint was the odds ratio (OR) of the inverse variance weighted (IVW) approach. In addition, the weighted median (WM), MR-Egger regressions, MR-pleiotropy residual sum and outlier (MR-PRESSO) and multivariable MR (MVMR) were included in sensitivity analyses. Furthermore, the function of causal SNPs was evaluated by gene ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and protein-protein interaction networks.

RESULTS

Primary MR analysis based on the IVW method suggested that changes in CC alter risk of OF (OR = 1.383, 95%CI 1.079-1.853, P = 0.039), RA(OR: 1.623, 95%CI 1.042-2.527, P = 0.032) and HOA (hip osteoarthritis, OR = 1.536, 95% CI 1.044-2.259, P = 0.021). However, these causal relationships were not robust in sensitivity analyses. In contrast, there is a positive causal relationship between increased CC and the risk of KOA (knee osteoarthritis, OR: 2.094, 95%CI: 1.592-2.754, P = 1.41 × 10-7), as evidenced by the IVW using random effect. A similar effect size was observed across all MR sensitivity analyses, with no evidence of horizontal pleiotropy.

CONCLUSION

Based on our MR analysis, increased CC was causally linked to an increase in the risk of KOA. Genetic predictions suggested that CC reduction may have benefits for bone health.

Association of Serum Bile Acid Profile with Diet and Physical Activity Habits in Japanese Middle-Aged Men

BACKGROUND/OBJECTIVES

Circulating bile acid (BA) profiles change with lifestyle and are closely related to intestinal BA metabolisms such as deconjugation and conversion to secondary BAs. The composition of BA in the blood is involved in systemic nutrient metabolism and intestinal health. Herein, we explored the associations of lifestyle and physical fitness with the circulating BA profile of middle-aged men.

METHODS

Data of 147 male participants (aged 50-64 years; BMI < 26 kg/m2; no medication for diabetes or dyslipidemia) from the Japan Multi-Institutional Collaborative Cohort study were analyzed. Serum concentrations of 15 types of BAs were examined for associations with variables on dietary habits, physical-activity habits, and physical fitness.

RESULTS

Green tea intake was positively associated with the deconjugation ratio of total BAs (p = 0.028) and negatively associated with secondary BA levels (free deoxycholic acid [DCA] (p = 0.078), glyco-DCA (p = 0.048), and tauro-DCA (p = 0.037)). In contrast, physical activity was negatively associated with the deconjugation ratio (p = 0.029) and secondary BA levels (free DCA (p = 0.098), and free lithocholic acid (p = 0.009)). Grip strength was also negatively associated with secondary BA levels (tauro-DCA (p = 0.041)) but was not associated with the deconjugation ratio. Energy and fat intake and skeletal muscle mass were not associated with the deconjugation ratio or secondary BA levels.

CONCLUSIONS

The study findings suggest that lifestyle-associated changes in serum deconjugated and secondary BAs indicate improvements in nutrient metabolism and the intestinal environment.

Effects of Differently Processed Tea on the Gut Microbiota

Tea is a highly popular beverage, primarily due to its unique flavor and aroma as well as its perceived health benefits. The impact of tea on the gut microbiome could be an important means by which tea exerts its health benefits since the link between the gut microbiome and health is strong. This review provided a discussion of the bioactive compounds in tea and the human gut microbiome and how the gut microbiome interacts with tea polyphenols. Importantly, studies were compiled on the impact of differently processed tea, which contains different polyphenol profiles, on the gut microbiota from in vivo animal feeding trials, in vitro human fecal fermentation experiments, and in vivo human feeding trials from 2004-2024. The results were discussed in terms of different tea types and how their impacts are related to or different from each other in these three study groups.

Caffeine: a potential mechanism for anti-obesity

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.

The Role of Green Tea on the Regulation of Gut Microbes and Prevention of High-Fat Diet-Induced Metabolic Syndrome in Mice

Green tea is a popular non-alcoholic beverage consumed worldwide and has been shown to be beneficial for human health. However, further exploration is needed to fully understand its function in reducing obesity and regulating gut microbes. Here, we investigated the modulatory effects of green tea and its functional components on high-fat diet (HF)-induced metabolic alterations and gut microbiota in obese mice. Our results showed that 1%, 2%, and 4% of green tea promotes weight loss, with the 2% and 4% groups exhibiting distinct gut microflora clusters compared to the HF group. These results were comparable to those observed in the tea polyphenols (TPP)-treated group, suggesting the TPP in green tea plays a crucial role in body weight control and gut microbiota regulation. Additionally, 32 bacteria were identified as potential obesity markers via 16S rRNA gene sequencing. The 16SrDNA gene is a chromosomal gene present in all bacterial species, highly conserved in structure and function, that can reflect the differences between different taxa. The 16S rRNA-based analysis revealed that Akkermansia, a gut-beneficial bacteria, significantly increased in the TPP group.

Comparing and contrasting different herbal products intended for the management of obesity approved in the Palestinian markets

BACKGROUND

The use of conventional medical therapies has proven to have many setbacks and safety concerns that need further improvement. However, herbal medicine has been used for over 2000 years, and many studies have proven the use of herbs to be effective and safe. This article discussed the efficacy of different herbal products used in the management of obesity. To evaluate the efficacy of seven herbal-based weight loss products currently available on the Palestinian market, using in vitro assays to screen for antioxidants, anti-amylase, and anti-lipase effects for each product.

METHOD

Pancreatic lipase and salivary amylase inhibitory activities, as well as antioxidant analysis, were tested in vitro on a variety of herbal products. Then the IC₅₀ was measured for each test.

RESULTS

The anti-lipase assay results, IC₅₀ values in (μg/mL) of each of the seven products (Product A, product B, product C, product D, product E, product F, and product G) were 114.78, 532.1, 60.18, 53.33, 244.9, 38.9, and 48.97, respectively. The IC₅₀ value for orlistat (Reference) was 12.3 μg/ml. On the other hand, the IC₅₀ value for alpha amylase inhibition of the seven products (Product A, product B, product C, product D, product E, product F, and product F) were 345.93, 13,803.84 (Inactive), 73.79, 130.91, 165.95, 28.18, and 33.11 μg/ml respectively, while acarbose (Reference) was 23.38 μg/ml. The antioxidant activity (IC₅₀ values) for the seven products (Product A, product B, product C, product D, product E, product F, and product F) were 1258.92, 707.94, 79.43, 186.20, 164.81, 17.53, and 10.47 μg/ml respectively. While the IC₅₀ value for Trolox was 2.70 μg/ml.

CONCLUSION

It can be concluded that the seven products showed varied anti-lipase, anti-amylase, and antioxidant effects. However, products F and G showed superiority in all categories.

Bioaccessibility and Bioavailability of (-)-Epigallocatechin Gallate in the Bread Matrix with Glycemic Reduction

Bread has a high glycemic index (GI) and rich contents of quickly digestible carbohydrates, which is associated with insulin resistance and the risk of chronic diseases. (-)-Epigallocatechin Gallate (EGCG) is the primary catechin component that inhibits starch hydrolases, while the low release and absorption rates limit its utilization. In this study, EGCG was added to the bread matrix for fortification to reduce its glycemic index compared to white bread. EGCG fortification at 4% decreased the starch digestion rate of baked bread by 24.43% compared to unfortified bread and by 14.31% compared to white bread, with an identical amount of EGCG outside the matrix. Moreover, the predicted GI (pGI) was reduced by 13.17% compared to white bread. Further, 4% EGCG-matched bread enhanced the bioaccessibility and bioavailability of EGCG by 40.38% and 47.11%, respectively, compared to the control. The results of molecular docking demonstrated that EGCG had a higher binding affinity with α-amylase than with α-glucosidase, indicating that EGCG may effectively inhibit the accumulation of carbs during starch digestion. Thus, EGCG can be used as a functional ingredient in bread to reduce its glycemic potential, and the bread matrix can be used as a carrier for EGCG delivery to enhance its bioaccessibility and bioavailability.

A Prospective Non-Randomized Open-Label Comparative Study of The Effects of Matcha Tea on Overweight and Obese Individuals: A Pilot Observational Study

Matcha tea has been used as an adjunct in weight loss programs. The weight loss effects of matcha tea were evaluated in a prospective non-randomized open-label comparative study of overweight and obese individuals who followed a specified low-calorie diet (LCD) plan. A total of 40 participants were enrolled and assigned to either matcha tea or control groups. The matcha tea group followed a LCD plan and received matcha tea once daily, whereas the control group followed only the LCD diet plan. The study lasted 12 weeks. The main outcome measures included anthropometric measurements, fasting blood glucose, hemoglobin A1c (HbA1c), lipid profile, obesity-related hormone peptides, pro-inflammatory and anti-inflammatory cytokines, and oxidative stress biomarkers. Thirty-four participants had completed the study. The matcha tea and control groups showed significant reductions in body weight, body mass index, waist circumference, water content, minerals, and fat mass at week 12. The post-treatment body composition and anthropometric measurements were not significantly different between the two groups. The matcha tea group showed a potential increase in HDL-C, a potential decrease in blood glucose, and a potential increase in HbA1c. Furthermore, the study indicated a potential decrease in insulin and leptin levels, a potential increase in the activity of superoxide dismutase, and a potential decreased activity of glutathione peroxidase. IL-10 was increased by matcha tea consumption. The data suggest that matcha tea may have some potential effect on weight loss, along with anti-inflammatory properties. The findings of this study will be used to design a multicenter randomized clinical trial to examine the potential weight loss benefits of matcha tea.

Concomitant medications, functional foods, and supplements: An Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) 2022

Background

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) is intended to provide clinicians an overview of the body weight effects of concomitant medications (i.e., pharmacotherapies not specifically for the treatment of obesity) and functional foods, as well as adverse side effects of supplements sometimes used by patients with pre-obesity/obesity.

Methods

The scientific information for this CPS is based upon published scientific citations, clinical perspectives of OMA authors, and peer review by the Obesity Medicine Association leadership.

Results

This CPS outlines clinically relevant aspects of concomitant medications, functional foods, and many of the more common supplements as they relate to pre-obesity and obesity. Topics include a discussion of medications that may be associated with weight gain or loss, functional foods as they relate to obesity, and side effects of supplements (i.e., with a focus on supplements taken for weight loss). Special attention is given to the warnings and lack of regulation surrounding weight loss supplements.

Conclusions

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) on concomitant medications, functional foods, and supplements is one of a series of OMA CPSs designed to assist clinicians in the care of patients with the disease of pre-obesity/obesity. Implementation of appropriate practices in these areas may improve the health of patients, especially those with adverse fat mass and adiposopathic metabolic consequences.

Increased dosage and treatment time of Epigallocatechin-3-gallate (EGCG) negatively affects skeletal parameters in normal mice and Down syndrome mouse models

Bone abnormalities affect all individuals with Down syndrome (DS) and are linked to abnormal expression of DYRK1A, a gene found in three copies in people with DS and Ts65Dn DS model mice. Previous work in Ts65Dn male mice demonstrated that both genetic normalization of Dyrk1a and treatment with ~9 mg/kg/day Epigallocatechin-3-gallate (EGCG), the main polyphenol found in green tea and putative DYRK1A inhibitor, improved some skeletal deficits. Because EGCG treatment improved mostly trabecular skeletal deficits, we hypothesized that increasing EGCG treatment dosage and length of administration would positively affect both trabecular and cortical bone in Ts65Dn mice. Treatment of individuals with DS with green tea extract (GTE) containing EGCG also showed some weight loss in individuals with DS, and we hypothesized that weights would be affected in Ts65Dn mice after EGCG treatment. Treatment with ~20 mg/kg/day EGCG for seven weeks showed no improvements in male Ts65Dn trabecular bone and only limited improvements in cortical measures. Comparing skeletal analyses after ~20mg/kg/day EGCG treatment with previously published treatments with ~9, 50, and 200 mg/kg/day EGCG showed that increased dosage and treatment time increased cortical structural deficits leading to weaker appendicular bones in male mice. Weight was not affected by treatment in mice, except for those given a high dose of EGCG by oral gavage. These data indicate that high doses of EGCG, similar to those reported in some treatment studies of DS and other disorders, may impair long bone structure and strength. Skeletal phenotypes should be monitored when high doses of EGCG are administered therapeutically.

Influence of 8-week daily consumption of a new product combining green coffee hydroxycinnamates and beta-glucans on polyphenol bioavailability in subjects with overweight and obesity

Nutraceuticals based on plant extracts rich in polyphenols, as well as dietary fibres, are new means to fight overweight/obesity and associated diseases. However, to understand the potential effects of polyphenols on health it is critical to study their bioavailability and metabolic fate. Consumption of a green coffee phenolic extract (GCPE) in combination with oat beta-glucan (BG) could affect the pharmacokinetic profile of the main polyphenols present in coffee (hydroxycinnamates). Moreover, the regular intake of the combination could also induce changes. Nine overweight men and women consumed a novel nutraceutical product containing 300 mg of green coffee hydroxycinnamic acids and 2.5 g of BG twice a day for 8 weeks. A pharmacokinetic study was carried out in blood and urine samples taken before (baseline) and at week 8 after the nutraceutical intervention, collecting samples at different times in a 0-24 h interval. Faecal samples were also obtained at 0 and 24 h after the intake of the nutraceutical at baseline and week 8. Phenolic metabolites were analysed by LC-MS-QToF. Results showed that polyphenols were differentially absorbed and extensively metabolized throughout the gastrointestinal tract. An apparent reduction in the excretion of small intestinal metabolites was accompanied by a tendency to increase colonic metabolites after sustained intake (p = 0.052). In conclusion, continued consumption of the GCPE/BG nutraceutical appears to enhance the absorption of hydroxycinnamates by increasing the colonic bioavailability of their derived metabolites compared to baseline, although the regular intake of the nutraceutical did not modify the metabolite profile in any of the biological samples.

Epicatechin Gallate as Xanthine Oxidase Inhibitor: Inhibitory Kinetics, Binding Characteristics, Synergistic Inhibition, and Action Mechanism

Epicatechin gallate (ECG) is one of the main components of catechins and has multiple bioactivities. In this work, the inhibitory ability and molecular mechanism of ECG on XO were investigated systematically. ECG was determined as a mixed xanthine oxidase (XO) inhibitor with an IC50 value of 19.33 ± 0.45 μM. The promotion of reduced XO and the inhibition of the formation of uric acid by ECG led to a decrease in O2- radical. The stable ECG-XO complex was formed by hydrogen bonds and van der Waals forces, with the binding constant of the magnitude of 104 L mol-1, and ECG influenced the stability of the polypeptide skeleton and resulted in a more compact conformation of XO. Computational simulations further characterized the binding characteristics and revealed that the inhibitory mechanism of ECG on XO was likely that ECG bound to the vicinity of flavin adenine dinucleotide (FAD) and altered the conformation of XO, hindering the entry of substrate and the diffusion of catalytic products. ECG and allopurinol bound to different active sites of XO and exerted a synergistic inhibitory effect through enhancing their binding stability with XO and changing the target amino acid residues of XO. These findings may provide a theoretical basis for the further application of ECG in the fields of food nutrition and functional foods.

The anti-obesity and health-promoting effects of tea and coffee

This paper reviews provenance, chemical composition and properties of tea (Camelia sinensis L.) and coffee (Coffee arabica, L. and Coffeacaniphora, L.), their general health effects, as well as the currently available knowledge concerning their action on fat storage, physiological mechanisms of their effects, as well as their safety and recommended dosage for treatment of obesity. Both tea and coffee possess the ability to promote health and to prevent, to mitigate and to treat numerous disorders. This ability can be partially due to presence of caffeine in both plants. Further physiological and medicinal effects could be explained by other molecules (theaflavins, catechins, their metabolites and polyphenols in tea and polyphenol chlorogenic acid in coffee). These plants and plant molecules can be efficient for prevention and treatment of numerous metabolic disorders including metabolic syndrome, cardiovascular diseases, type 2 diabetes and obesity. Both plants and their constituents can reduce fat storage through suppression of adipocyte functions, and support of gut microbiota. In addition, tea can prevent obesity via reduction of appetite, food consumption and food absorption in gastrointestinal system and through the changes in fat metabolism.

Genotype-guided dietary supplementation in precision nutrition

Achieving adequate micronutrient status, while avoiding deficiencies, represents a challenge for people globally. Consequently, many individuals resort to oral nutrient supplementation (ONS) in order to correct suboptimal dietary intakes. Advances in the fields of nutrigenetics and nutritional genomics have identified differences in response to micronutrient supplementation according to genetic makeup, adding dietary supplement use to the clinician's toolkit in the precision nutrition era. This review focuses on published evidence linking genetic variants to the responses associated with some of the most popular dietary supplements. With an increasing number of health professionals becoming involved in the prescription of ONS, identifying and matching individuals to the appropriate dietary supplement according to their genotype is important for achieving optimal health benefits and micronutrient equilibrium, while reducing the adverse events and financial costs often associated with excessive ONS.

The effect of green tea supplementation on obesity: A systematic review and dose-response meta-analysis of randomized controlled trials

The effects of green tea (GT) in obese subjects have been evaluated in different studies, but no consensus has been obtained due to the heterogeneity of the results. The dosage, the type of extract, and the duration of the intervention are the main contributors to the heterogeneity of the results. Therefore, the present systematic review and meta-analysis aimed to evaluate the efficacy and dose-response relationship of GT. Several databases were searched from inception to September 2019 to identify clinical trials that examined the influence of GT supplements on obesity indices in humans. Combined results using the random-effects model indicated that body weight (WMD: -1.78 kg, 95% CI: -2.80, -0.75, p = .001) and body mass index (BMI) (WMD: -0.65 kg/m2 , 95% CI: -1.04, -0.25, p = .001) did change significantly following GT administration. The reduction in waist circumference (WC) after GT consumption was significant in subjects in trials employing GT ≥800 mg/day (WMD: -2.06 cm) and with a treatment duration <12 weeks (WMD: -2.39 cm). Following the dose-response evaluation, GT intake did alter body weight, with a more important reduction when the GT dosage was <500 mg/day and the treatment duration was of 12 weeks. The results of present meta-analysis study support the use of GT for the improvement of obesity indices. Thus, we suggest that the use of GT can be combined with a balanced and healthy diet and regular physical exercise in the management of obese patients.

Oral administration of Flavonifractor plautii attenuates inflammatory responses in obese adipose tissue

Adipose tissue inflammation enhances the symptoms of metabolic syndrome. Flavonifractor plautii, a bacterium present in human feces, has been reported to participate in the metabolism of catechin in the gut. The precise function of F. plautii remains unclear. We assessed the immunoregulatory function of F. plautii both in vitro and in vivo. In vitro, we showed that both viable and heat-killed F. plautii attenuated TNF-α transcript accumulation in lipopolysaccharide-stimulated RAW 264.7 cells. For the in vivo experiment, male C57BL/6 were placed on a high-fat diet (HFD) for 11 weeks. During the final two weeks on the HFD, the animals were administered with F. plautii by once-daily oral gavage. The oral administration of F. plautii attenuated the increase in TNF-α transcription otherwise seen in the epididymal adipose tissue of HFD-fed obese mice (HFD + F. plautii). The composition of the microbial population (at the genus level) in the cecal contents of the HFD + F. plautii mice was altered considerably. In particular, the level of Sphingobium was decreased significantly, and that of Lachnospiraceae was increased significantly, in the HFD + F. plautii group. Obesity is closely associated with the development of inflammation in adipose tissue. F. plautii may be involved in inhibition of TNF-α expression in inflammatory environments. Our results demonstrated that F. plautii may be useful for alleviating the inflammatory responses of adipose tissue.

Mixtures of Tea and Citrus maxima (pomelo) Alleviate Lipid Deposition in HepG2 Cells Through the AMPK/ACC Signaling Pathway

Tea and citrus maxima are natural, medicinal homologous plants, typically used for making beverages, which have anticancer, antiobesity, and antioxidation properties. Green tea, yellow tea, and black tea were combined with citrus maxima to obtain green tea and Citrus maxima (GTCM), yellow tea and Citrus maxima (YTCM), and black tea and Citrus maxima (BTCM). The biochemical components of these mixtures were analyzed, and their possible effects and mechanisms on relieving liver lipid deposition were explored. The tea polyphenols, free amino acids, phenolamine ratio, and caffeine were comparable in YTCM and GTCM, being significantly higher than those in BTCM. In addition, the content of esterified catechins, nonesterified catechins, and total catechins in YTCM was significantly higher than those in GTCM and BTCM. All three mixtures of Citrus maxima tea significantly reduced lipid deposition in HepG2 cells, with GTCM and YTCM being slightly more effective than BTCM. Regarding the possible mechanism, Western blot analysis revealed that the three Citrus maxima tea mixtures could activate the AMPK/ACC signaling pathway, upregulate the expression of p-AMPK, p-ACC, and CPT-1 proteins, and downregulate the expression of SREBP1c and fatty acid synthase proteins to inhibit fat synthesis, thereby relieving lipid deposition in liver cells. In conclusion, as a novel and healthy beverage, Citrus maxima tea has the potential to alleviate liver lipid deposition, and further could be responsible for obesity treatment.

Nutraceuticals: Reviewing their Role in Chronic Disease Prevention and Management

Over half the adult population in many Western countries consume nutraceuticals because of their purported therapeutic benefits, accessibility and convenience. Several studies have demonstrated that they may also serve as a useful adjunct to pharmaceuticals to better manage chronic conditions or offset negative side effects. Individuals are advised to consult their physician before using nutraceuticals, but this advice is often overlooked. Thus, the community pharmacist plays an increasingly important role in assisting consumers with selecting a nutraceutical that is safe and for which there is evidence of therapeutic efficacy. Therefore, the aim of this review is to summarise the clinical evidence, safety and purported mechanisms of action for selected nutraceuticals in the management of chronic diseases, including obesity, diabetes, hypertension, hypercholesterolemia and inflammatory-based diseases.

Green tea improves the metabolism of peripheral tissues in β3-adrenergic receptor-knockout mice

Our goal was to establish the requirement of β3 adrenoceptor (β3Adr) for green tea (GT) effects on the energy metabolism of obese mice. This study was carried out in wild-type (WT) and β3Adr knockout (KO) male mice fed with a standard diet or a high-fat diet (HFD/16 weeks) treated or not with GT (0.5 g/kg of body weight (BW)/12 weeks). GT-treatment attenuated final BW, BW gain, and adiposity index increased by HFD, improving insulin resistance (IR) and FGF21 level, without changing the food intake of WT mice. GT-treatment of β3AdrKO mice attenuated only IR, denoting GT-effects independent of β3Adr. We observed increased lipolysis accompanied by decreased adipocyte size in white adipose tissue (WAT) as well as browning of the subcutaneous WAT induced by GT in a way dependent on β3Adr. In brown adipose tissue (BAT) mRNA levels of lipolytic/oxidative genes, including β3Adr/Ucp1 and energy expenditure (EE) was increased by GT dependent on β3Adr. GT-treatment increased adiponectin independent of β3Adr. Also, independent of β3Adr pathway GT promoted an increase in β2Adr/Ucp1 mRNA levels and EE in BAT whereas; in the liver, GT has a dual role in increasing lipid synthesis and oxidation. These data lead us to suggest that GT uses β3Adr pathway activation to achieve some of its beneficial health effects.

High Compared with Moderate Protein Intake Reduces Adaptive Thermogenesis and Induces a Negative Energy Balance during Long-term Weight-Loss Maintenance in Participants with Prediabetes in the Postobese State: A PREVIEW Study

BACKGROUND

Weight loss has been associated with adaptations in energy expenditure. Identifying factors that counteract these adaptations are important for long-term weight loss and weight maintenance.

OBJECTIVE

The aim of this study was to investigate whether increased protein/carbohydrate ratio would reduce adaptive thermogenesis (AT) and the expected positive energy balance (EB) during weight maintenance after weight loss in participants with prediabetes in the postobese state.

METHODS

In 38 participants, the effects of 2 diets differing in protein/carbohydrate ratio on energy expenditure and respiratory quotient (RQ) were assessed during 48-h respiration chamber measurements ∼34 mo after weight loss. Participants consumed a high-protein (HP) diet (n = 20; 13 women/7 men; age: 64.0 ± 6.2 y; BMI: 28.9 ± 4.0 kg/m 2) with 25:45:30% or a moderate-protein (MP) diet (n = 18; 9 women/9 men; age: 65.1 ± 5.8 y; BMI: 29.0 ± 3.8 kg/m 2) with 15:55:30% of energy from protein:carbohydrate:fat. Predicted resting energy expenditure (REEp) was calculated based on fat-free mass and fat mass. AT was assessed by subtracting measured resting energy expenditure (REE) from REEp. The main outcomes included differences in components of energy expenditure, substrate oxidation, and AT between groups.

RESULTS

EB (MP = 0.2 ± 0.9 MJ/d; HP = -0.5 ± 0.9 MJ/d) and RQ (MP = 0.84 ± 0.02; HP = 0.82 ± 0.02) were reduced and REE (MP: 7.3 ± 0.2 MJ/d compared with HP: 7.8 ± 0.2 MJ/d) was increased in the HP group compared with the MP group (P < 0.05). REE was not different from REEp in the HP group, whereas REE was lower than REEp in the MP group (P < 0.05). Furthermore, EB was positively related to AT (rs = 0.74; P < 0.001) and RQ (rs = 0.47; P < 0.01) in the whole group of participants.

CONCLUSIONS

In conclusion, an HP diet compared with an MP diet led to a negative EB and counteracted AT ∼34 mo after weight loss, in participants with prediabetes in the postobese state. These results indicate the relevance of compliance to an increased protein/carbohydrate ratio for long-term weight maintenance after weight loss. The trial was registered at clinicaltrials.gov as NCT01777893.

Acute Ingestion of a Mixed Flavonoid and Caffeine Supplement Increases Energy Expenditure and Fat Oxidation in Adult Women: A Randomized, Crossover Clinical Trial

This randomized, double-blinded, crossover study measured the acute effect of ingesting a mixed flavonoid-caffeine (MFC) supplement compared to placebo (PL) on energy expenditure (EE) and fat oxidation (FATox) in a metabolic chamber with premenopausal women (n = 19, mean ± SD, age 30.7 ± 8.0 year, BMI 25.7 ± 3.4 kg/m²). The MFC supplement (658 mg flavonoids, split dose 8:30, 13:00) contained quercetin, green tea catechins, and anthocyanins from bilberry extract, and 214 mg caffeine. Participants were measured twice in a metabolic chamber for a day, four weeks apart, with outcomes including 22 h EE (8:30-6:30), substrate utilization from the respiratory quotient (RQ), plasma caffeine levels (16:00), and genotyping for the single-nucleotide polymorphism (SNP) rs762551. Areas under the curve (AUC) for metabolic data from the MFC and PL trials were calculated using the trapezoid rule, with a mixed linear model (GLM) used to evaluate the overall treatment effect. The 22 h oxygen consumption and EE were significantly higher with MFC than PL (1582 ± 143, 1535 ± 154 kcal/day, respectively, p = 0.003, trial difference of 46.4 ± 57.8 kcal/day). FATox trended higher for MFC when evaluated using GLM (99.2 ± 14.0, 92.4 ± 14.4 g/22 h, p = 0.054). Plasma caffeine levels were significantly higher in the MFC versus PL trial (5031 ± 289, 276 ± 323 ng/mL, respectively, p < 0.001). Trial differences for 22 h EE and plasma caffeine were unrelated after controlling for age and body mass (r = -0.249, p = 0.139), and not different for participants with the homozygous allele 1, A/A, compared to C/A and C/C (p = 0.50 and 0.56, respectively). In conclusion, EE was higher for MFC compared to PL, and similar to effects estimated from previous trials using caffeine alone. A small effect of the MFC on FATox was measured, in contrast to inconsistent findings previously reported for this caffeine dose. The trial variance for 22 h EE was not significantly related to the variance in plasma caffeine levels or CYP1A2*1F allele carriers and non-carriers.

A Comprehensive Insight on the Health Benefits and Phytoconstituents of Camellia sinensis and Recent Approaches for Its Quality Control

Tea, Camellia sinensis, which belongs to the family Theaceae, is a shrub or evergreen tree up to 16 m in height. Green tea is very popular because of its marked health benefits comprising its anticancer, anti-oxidant, and antimicrobial activities, as well as its effectiveness in reducing body weight. Additionally, it was recognized by Chinese people as an effective traditional drink required for the prophylaxis against many health ailments. This is due to the complex chemical composition of green tea, which comprises different classes of chemical compounds, such as polyphenols, alkaloids, proteins, minerals, vitamins, amino acids, and others. The beneficial health effects of green tea ultimately led to its great consumption and increase its liability to be adulterated by either low-quality or non-green tea products with concomitant decrease in activity. Thus, in this review, green tea was selected to highlight its health benefits and phytoconstituents, as well as recent approaches for its quality-control monitoring that guarantee its incorporation in many pharmaceutical industries. More research is needed to find out other more biological activities, active constituents, and other simple and cheap techniques for its quality assurance that ascertain the prevention of its adulteration.

Functional Foods and Bioactive Compounds: A Review of Its Possible Role on Weight Management and Obesity's Metabolic Consequences

Background: Weight management and obesity prevention is a basic aim of health organizations in order to decrease the prevalence of various metabolic disorders. The aim of the present review article was the evaluation of the possible role of functional foods and their bioactive compounds as alternative way to promote weight management and prevent obesity and its metabolic consequences. Methods: Approximately 100 articles were selected from Scopus, PubMed, Google Scholar, and Science Direct, by using relative key words, and based mainly on recent animal, clinical or epidemiological studies. Results: The literature review highlighted the possible effect of specific functional foods such as coffee, green tea, berries, nuts, olive oil, pomegranate, avocado, and ginger. Specific bioactive compounds of those foods—such as caffeine, catechins, gallic acid, anthocyanins, ascorbic acid, polyphenols, oleuropein, capsaicin, and quercetin—may contribute to weight management, obesity prevention, and obesity’s metabolic consequences. The possible mechanisms include effect on satiety, lipid absorption, fatty acids beta oxidation, stimulation of thermogenesis, etc. Conclusions: Functional foods, as part of a balanced diet, could be useful in the direction of weight management and decrease of obesity’s’ metabolic consequences. However, the scientific evidence is unclear and in most cases controversial and more clinical and epidemiological studies are needed in order to further investigate the mechanisms of their possible effect.

Interactions of tea polyphenols with intestinal microbiota and their implication for cellular signal conditioning mechanism

Tea polyphenols (TP) is the main functional substances in tea. It has been reported that TP can modulate the composition of gut microbes in the human body, in addition, after the bio-transformation by intestinal flora, the metabolites of TP also have positive effects on the health of the host. Lots of researches have shown that TP have possible therapeutic effect against high fat diet induced obesity, which is closely related to the gut flora of the host. Therefore, this review focused on the interactions of TP with intestinal microbiota and their implication for cellular signal conditioning mechanism that will enable us to better study the two-way effects of TP and intestinal microbiota on host health improvement. PRACTICAL APPLICATIONS: TP have been widely concerned for their health care properties. As the functional food components, TP have strong antioxidant and physiological activities for human body. A better understanding on the interactions of TP with intestinal microbiota and their implication for cellular signal conditioning mechanism will lead us to better evaluate the contribution of the microbial metabolites of TP, as well as the regulation of intestinal bacterial diversity and abundance for host health.

Effect of yerba mate and green tea on paraoxonase and leptin levels in patients affected by overweight or obesity and dyslipidemia: a randomized clinical trial

Background

This study aimed to evaluate the effect of the intake of yerba mate (YM) and green tea (GT) on serum levels of leptin and paraoxonase-1 (PON-1), compared to control.

Methods

Controlled, randomized clinical trial (RCT) that evaluated 142 men and women affected by overweight or obesity aged 35–60 years, untreated dyslipidemia and no history of coronary artery disease. Participants were randomized to ingest 1000 mL GT, YM or apple tea (AT, control group) daily, during eight weeks. Serum PON-1 and leptin levels were analyzed by ELISA immunoassay at the beginning (baseline) and after eight weeks of intervention.

Results

The intake of 1 l of YM/day resulted in significant increase in serum levels of PON-1 (9.7%; p = 0.005). The consumption of GT induced no significant difference in the levels of PON-1 (p = 0.154) and leptin (p = 0.783). Intergroup analysis showed a significant difference (p = 0.036) in the variation of PON-1 levels in the YM group when compared to GT and AT groups. In addition, the increase in PON-1 levels in the YM group was significantly associated with increased HDL-c (p = 0.004).

Conclusions

The intake of yerba mate increased the antioxidant capacity by increasing serum levels of PON-1 and was positively associated with increased HDL-c, stressing the protective role of this beverage against atherosclerotic diseases. GT intake had no significant effect on serum levels of PON-1 and leptin.

Trial registration

This study is registered with ClinicalTrials.gov under protocol number NCT00933647.

Anti-inflammatory effect of green tea petiole extracts in poly(I:C)–stimulated human epidermal keratinocytes and a human 3D skin equivalent

Green tea is one of the most popular non-alcoholic beverage crops worldwide. Leaf extracts of the green tea, Camellia sinensis, are known to have natural anti-oxidant and anti-inflammatory effects. However, relatively few studies have focused on the biological activities of green tea petiole (GTP) (the stalk that attaches the leaf blade to the stem, currently considered waste material) compared with other parts of the tree, such as the leaf, root, and flower. Here, we report the first investigation of the anti-inflammatory effect of GTP extract against poly(I:C)–stimulated human keratinocytes (a model of skin inflammatory conditions) and EpiDerm (a three-dimensional skin equivalent). Our results reveal that GTP extract suppresses the induction of the messenger ribonucleic acids (mRNAs) encoding pro-inflammatory cytokines (tumor necrosis factor alpha (TNF-α), Interleukin 1 beta (IL-1β), and Interleukin-8 (IL-8)) and matrix metalloproteinase-1 (MMP-1). These findings indicate that GTP extract could prove useful in protecting skin cells from inflammatory conditions and skin aging.

Matcha Green Tea Drinks Enhance Fat Oxidation During Brisk Walking in Females

Intake of the catechin epigallocatechin gallate and caffeine has been shown to enhance exercise-induced fat oxidation. Matcha green tea powder contains catechins and caffeine and is consumed as a drink. We examined the effect of Matcha green tea drinks on metabolic, physiological, and perceived intensity responses during brisk walking. A total of 13 females (age: 27 ± 8 years, body mass: 65 ± 7 kg, height: 166 ± 6 cm) volunteered to participate in the study. Resting metabolic equivalent (1-MET) was measured using Douglas bags (1-MET: 3.4 ± 0.3 ml·kg^-1·min^-1). Participants completed an incremental walking protocol to establish the relationship between walking speed and oxygen uptake and individualize the walking speed at 5- or 6-MET. A randomized, crossover design was used with participants tested between Days 9 and 11 of the menstrual cycle (follicular phase). Participants consumed three drinks (each drink made with 1 g of Matcha premium grade; OMGTea Ltd., Brighton, UK) the day before and one drink 2 hr before the 30-min walk at 5- (n = 10) or 6-MET (walking speed: 5.8 ± 0.4 km/hr) with responses measured at 8-10, 18-20, and 28-30 min. Matcha had no effect on physiological and perceived intensity responses. Matcha resulted in lower respiratory exchange ratio (control: 0.84 ± 0.04; Matcha: 0.82 ± 0.04; p < .01) and enhanced fat oxidation during a 30-min brisk walk (control: 0.31 ± 0.10; Matcha: 0.35 ± 0.11 g/min; p < .01). Matcha green tea drinking can enhance exercise-induced fat oxidation in females. However, when regular brisk walking with 30-min bouts is being undertaken as part of a weight loss program, the metabolic effects of Matcha should not be overstated.

Phytochemicals That Influence Gut Microbiota as Prophylactics and for the Treatment of Obesity and Inflammatory Diseases

Gut microbiota (GM) plays several crucial roles in host physiology and influences several relevant functions. In more than one respect, it can be said that you “feed your microbiota and are fed by it.” GM diversity is affected by diet and influences metabolic and immune functions of the host's physiology. Consequently, an imbalance of GM, or dysbiosis, may be the cause or at least may lead to the progression of various pathologies such as infectious diseases, gastrointestinal cancers, inflammatory bowel disease, and even obesity and diabetes. Therefore, GM is an appropriate target for nutritional interventions to improve health. For this reason, phytochemicals that can influence GM have recently been studied as adjuvants for the treatment of obesity and inflammatory diseases. Phytochemicals include prebiotics and probiotics, as well as several chemical compounds such as polyphenols and derivatives, carotenoids, and thiosulfates. The largest group of these comprises polyphenols, which can be subclassified into four main groups: flavonoids (including eight subgroups), phenolic acids (such as curcumin), stilbenoids (such as resveratrol), and lignans. Consequently, in this review, we will present, organize, and discuss the most recent evidence indicating a relationship between the effects of different phytochemicals on GM that affect obesity and/or inflammation, focusing on the effect of approximately 40 different phytochemical compounds that have been chemically identified and that constitute some natural reservoir, such as potential prophylactics, as candidates for the treatment of obesity and inflammatory diseases.

Food Components in Health Promotion and Disease Prevention

The current obesity epidemic with its deleterious effects on public health and the increase in the prevalence of non-communicable diseases in our aging society have dramatically increased public awareness of nutrition-related health issues. On one hand, food components, such as fat, sugar, flavors, and spices, are major determinants of the hedonic value of food, and the constant and almost ubiquitous availability of good-tasting food in our affluent societies promotes overeating and weight gain. On the other hand, several food components, including flavoring compounds and the active ingredients of many plants, such as spices and herbs (e.g., polyphenols and capsaicinoids) or thylakoids, supposedly can decrease food intake and affect gastrointestinal function and metabolism. These substances may act as antioxidants, may stimulate the release of incretins and, hence, insulin, and may improve insulin sensitivity or decrease plasma levels of lipids. Such beneficial effects are often difficult to demonstrate in epidemiological studies because they may occur only at supraphysiological doses and/or when the purified compounds are administered, but they can be present under certain circumstances. This review discusses the putative mechanisms of the health-promoting and disease-preventing effects of some food components and their potential physiological relevance, primarily with respect to counteracting obesity and type 2 diabetes.

Green tea supplementation upregulates uncoupling protein 3 expression in severe obese women adipose tissue but does not promote weight loss

This study aims (i) to verify expression of the UCPs, PLIN1, PPARG2, and ADRB3 genes in the abdominal subcutaneous adipose tissue of obese women at baseline and after 8 weeks of supplementation with decaffeinated green tea extract, and (ii) to associate findings with clinical parameters. This is a longitudinal study during which 11 women with obesity grade III were submitted to supplementation with 450 mg of (-)-epigallocatechin gallate (EGCG) (intervention group); the control group consisted of 10 eutrophic women. Anthropometric parameters [weight, height, and body mass index (BMI)], resting metabolic rate (RMR, measured by indirect calorimetry), and gene expression (measured by real-time PCR, RT-qPCR) were determined before and after supplementation. After 8 weeks, clinical parameters and UCP1, PLIN1, PPARG2, and ADRB3 expression remained unaltered in the intervention group (p > .05). Genetic analysis also showed that the UCP3 gene was upregulated (p = .026), but its upregulation did not promote weight loss.

Safety Evaluation of Green Tea Polyphenols Consumption in Middle-aged Ovariectomized Rat Model

This work evaluates chronic safety in middle-aged ovariectomized rats supplemented with different dosages of green tea polyphenols (GTP) in drinking water. The experiment used 6-mo-old sham (n = 39) and ovariectomized (OVX, n = 143) female rats. All sham (n = 39) and 39 of the OVX animals received no GTP treatment and their samples were collected for outcome measures at baseline, 3 mo, and 6 mo (n = 13 per group for each). The remaining OVX animals were randomized into 4 groups receiving 0.15%, 0.5%, 1%, and 1.5% (n = 26 for each) of GTP (wt/vol), respectively, in drinking water for 3 and 6 mo. No mortality or abnormal treatment-related findings in clinical observations or ophthalmologic examinations were noted. No treatment-related macroscopic or microscopic findings were noted for animals administered 1.5% GTP supplementation. Throughout the study, there was no difference in the body weight among all OVX groups. In all OVX groups, feed intake and water consumption significantly decreased with GTP dose throughout the study period. At 6 mo, GTP intake did not affect hematology, clinical chemistry, and urinalysis, except for phosphorus and blood urea nitrogen (increased), total cholesterol, lactate dehydrogenase, and urine pH (decreased). This study reveals that the no-observed-adverse-effect level (NOAEL) of GTP is 1.5% (wt/vol) in drinking water, the highest dose used in this study.

Green tea extract does not affect exogenous glucose appearance but reduces insulinemia with glucose ingestion in exercise recovery

We reported that supplementation with green tea extract (GTE) lowered the glycemic response to an oral glucose load following exercise, but via an unknown mechanism (Martin BJ, MacInnis MJ, Gillen JB, Skelly LE, Gibala MJ. Appl Physiol Nutr Metab 41: 1057-1063, 2016. Here we examined the effect of supplementation with GTE on plasma glucose kinetics on ingestion of a glucose beverage during exercise recovery. Eleven healthy, sedentary men (21 ± 2 yr old; body mass index = 23 ± 4 kg/m², peak O₂ uptake = 38 ± 7 ml·kg^-1·min^-1; means ± SD) ingested GTE (350 mg) or placebo (PLA) thrice daily for 7 days in a double-blind, crossover design. In the fasted state, a primed constant infusion of [U-¹³C₆]glucose was started, and 1 h later, subjects performed a graded exercise test (25 W/3 min) on a cycle ergometer. Immediately postexercise, subjects ingested a 75-g glucose beverage containing 2 g of [6,6-²H₂]glucose, and blood samples were collected every 10 min for 3 h of recovery. The rate of carbohydrate oxidation was lower during exercise after GTE vs. PLA (1.26 ± 0.34 vs. 1.48 ± 0.51 g/min, P = 0.04). Glucose area under the curve (AUC) was not different between treatments after drink ingestion (GTE = 1,067 ± 133 vs. PLA = 1,052 ± 91 mM/180 min, P = 0.91). Insulin AUC was lower after GTE vs. PLA (5,673 ± 2,153 vs. 7,039 ± 2,588 µIU/180 min, P = 0.05), despite similar rates of glucose appearance (GTE = 0.42 ± 0.16 vs. PLA = 0.43 ± 0.13 g/min, P = 0.74) and disappearance (GTE = 0.43 ± 0.14 vs. PLA = 0.44 ± 0.14 g/min, P = 0.57). We conclude that short-term GTE supplementation did not affect glucose kinetics following ingestion of an oral glucose load postexercise; however, GTE was associated with attenuated insulinemia. These findings suggest GTE lowers the insulin required for a given glucose load during postexercise recovery, which warrants further mechanistic studies in humans.