Polyphenol Levels Are Inversely Correlated with Body Weight and Obesity in an Elderly Population after 5 Years of Follow Up (The Randomised PREDIMED Study)

Bitter taste receptors: Key target to understand the effects of polyphenols on glucose and body weight homeostasis. Pathophysiological and pharmacological implications

Experimental and clinical research has reported beneficial effects of polyphenol intake on high prevalent diseases such as type 2 diabetes and obesity. These phytochemicals are ligands of taste 2 receptors (T2Rs) that have been recently located in a variety of organs and extra-oral tissues. Therefore, the interaction between polyphenol and T2Rs in brain structures can play a direct effect on appetite/satiety regulation and food intake. T2Rs are also expressed along the digestive tract, and their interaction with polyphenols can induce the release of gastrointestinal hormones (e.g., ghrelin, GLP-1, CCK) influencing appetite, gastrointestinal functionally, and glycemia control. Intestinal microbiota can also influence on network effects of polyphenols-T2Rs interaction and vice versa, impacting innate immune responses and consequently on gut functionally. Furthermore, polyphenols binding to T2Rs present important effects on adipose tissue metabolism. Interestingly, T2R polymorphism could, at least partially, explain the inter-individual variability of the effects of polyphenols on glucose and body weight homeostasis. Together, these factors can contribute to understand the beneficial effects of polyphenol-rich diets but also might aid in identifying new pharmacological pathway targets for the treatment of diabetes and obesity.

Polyphenols: Secondary Metabolites with a Biological Impression

Polyphenols are natural compounds which are plant-based bioactive molecules, and have been the subject of growing interest in recent years. Characterized by multiple varieties, polyphenols are mostly found in fruits and vegetables. Currently, many diseases are waiting for a cure or a solution to reduce their symptoms. However, drug or other chemical strategies have limitations for using a treatment agent or still detection tool of many diseases, and thus researchers still need to investigate preventive or improving treatment. Therefore, it is of interest to elucidate polyphenols, their bioactivity effects, supplementation, and consumption. The disadvantage of polyphenols is that they have a limited bioavailability, although they have multiple beneficial outcomes with their bioactive roles. In this context, several different strategies have been developed to improve bioavailability, particularly liposomal and nanoparticles. As nutrition is one of the most important factors in improving health, the inclusion of plant-based molecules in the daily diet is significant and continues to be enthusiastically researched. Nutrition, which is important for individuals of all ages, is the key to the bioactivity of polyphenols.

Long-Term Impact of Nutritional Intervention with Increased Polyphenol Intake and Physical Activity Promotion on Oxidative and Inflammatory Profiles in Patients with Metabolic Syndrome

Obesity and overweight pose significant risks to health, contributing to the prevalence of chronic conditions like type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVD). The current study aimed to assess the impact of a 6-year nutritional and lifestyle intervention on oxidative and inflammatory markers in individuals aged 55 to 75, specifically those at high risk of CVD. A study was carried out in a group of 80 participants with metabolic syndrome (MetS) residing in Mallorca, Spain, who underwent nutritional intervention based on a low-calorie Mediterranean diet (MedDiet) and promotion of physical activity. Before and after the intervention, several parameters including anthropometric data, haematological factors, blood pressure, and physical activity level were measured. Oxidative and inflammatory biomarkers in plasma were analysed. After the 6-year intervention, participants who managed to reduce their body mass index (BMI) had greater reductions in abdominal obesity, waist to heigh ratio (WHtR), diastolic blood pressure, and glucose levels, and increased high density protein cholesterol (HDL-c) compared to those who did not reduce BMI. This higher reduction in BMI was related to reduced energy intake and increased adherence to MedDiet, with greater polyphenol intake, and total physical activity (PA). Furthermore, improvements in oxidative stress and proinflammatory status were observed in participants who reduced their BMI. Significant reductions in the activity of the prooxidant enzyme, myeloperoxidase (MPO), levels of the lipid oxidation marker, malondialdehyde (MDA), and the proinflammatory chemokine, monocyte chemoattractant protein-1 (MCP-1,) were found in those who reduced their BMI. In contrast, participants who did not improve their BMI exhibited higher levels of proinflammatory markers such as MCP-1 and tumour necrosis factor α (TNFα), as well as increased activity of the antioxidant enzyme catalase (CAT). Current findings suggest that an effective way to reduce BMI is a hypocaloric MedDiet combined with tailored physical activity to improve oxidative stress and proinflammatory status, and potentially reducing the risk of CVD.

A polyphenol fraction from Rosa multiflora var. platyphylala reduces body fat in overweight humans through appetite suppression - a randomized, double-blind, placebo-controlled trial

BACKGROUND

Rosa species are rich sources of polyphenols with physiological functions. In this study a polyphenol-rich Rosa multiflora (var. platyphylala) petal extract (RoseFit™) was investigated for weight loss in humans.

METHODS

In a randomized, placebo-controlled, parallel-group, double-blind clinical trial seventy overweight male and female subjects (20-50 years) with body mass index (BMI) 25-30 kg/m2 were randomly allocated to the active treatment group (RoseFit) and placebo group in a 1:1 ratio. The subjects received 300 mg capsules twice daily for 12 weeks. The primary efficacy outcome measures included body weight, BMI, and body composition, as determined using Dual-energy X-ray absorptiometry (DEXA). Secondary measures consisted of serum lipid profile and appetite marker (leptin and ghrelin) analyses. Safety analyses included biochemical and hematological assessments.

RESULTS

At the end of the study, a marked reduction in body weight (-1.20 ± 2.62 kg, p < 0.05) and BMI from baseline was observed in the RoseFit group. In addition, the body fat % (RoseFit = -1.69 ± 2.59%, placebo = 0.96 ± 3.21%; p < 0.001) and fat mass (RoseFit = -1.75 ± 1.80 kg, placebo = 1.61 ± 3.82 kg; p < 0.001) were significantly abated in RoseFit group. Importantly, the lean mass was maintained during the intervention. RoseFit ingestion significantly increased the serum leptin levels compared to the placebo (4.85%; p < 0.05). Further, RoseFit group showed reduction in the hunger hormone ghrelin level (2.27%; p < 0.001) from baseline to the end of study, compared to the placebo. The subjective evaluation of appetite using visual analog scale (VAS) questionnaires further confirmed the appetite-suppression effects of RoseFit. The lipid profile significantly improved in RoseFit-treated subjects. No serious adverse events were observed during the study, indicating the tolerability of RoseFit.

CONCLUSIONS

Supplementation with RoseFit significantly impacts body weight management and can thus be a potential nutraceutical ingredient for sustainable weight loss.

TRIAL REGISTRATION

CTRI/2019/10/021584 dated 09/10/2019.

The Perfect Cup? Coffee-Derived Polyphenols and Their Roles in Mitigating Factors Affecting Type 2 Diabetes Pathogenesis

Type 2 diabetes (T2D) is a growing health concern with an estimated 462 million people having been diagnosed worldwide. T2D is characterized by chronically elevated blood glucose and insulin resistance, which culminate in a diminished function of the β-cell mass in its later stages. This can be perpetuated by and result in inflammation, excess reactive oxygen species production, obesity, and the dysregulation of multiple cellular pathways. Many naturally occurring small molecules have been investigated in terms of their roles in modulating glucose homeostasis and β-cell function. Many of these compounds can be found in commonly used sources of food and drink. Interestingly, a correlation has been observed between coffee consumption and T2D incidence. However, the specific compounds responsible for this correlation and their mechanisms are still somewhat undetermined. This paper reviews recent research findings on the effects of several polyphenols that are either found in coffee or are metabolites of compounds found in coffee (enterodiol, enterolactone, matairesinol, secoisolariciresinol, kaempferol, quercetin, and chlorogenic acid) on glucose homeostasis and health complications associated with glucose dysregulation, with a special emphasis on their potential anti-diabetic effects. The factors that affect polyphenol content in coffee are also addressed.

Plasma Concentration of 36 (Poly)phenols and Prospective Body Weight Change in Participants from the EPIC Cohort

INTRODUCTION

Dietary intake of (poly)phenols has been linked to reduced adiposity and body weight (BW) in several epidemiological studies. However, epidemiological evidence on (poly)phenol biomarkers, particularly plasma concentrations, is scarce. We aimed to investigate the associations between plasma (poly)phenols and prospective BW change in participants from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort.

METHODS

This study included 761 participants with data on BW at baseline and after 5 years of follow-up. Plasma concentrations of 36 (poly)phenols were measured at baseline using liquid chromatography-tandem mass spectrometry. Associations were assessed through general linear mixed models and multinomial logistic regression models, using change in BW as a continuous or as a categorical variable (BW loss, maintenance, gain), respectively. Plasma (poly)phenols were assessed as log2-transformed continuous variables. The false discovery rate (FDR) was used to control for multiple comparisons.

RESULTS

Doubling plasma (poly)phenol concentrations showed a borderline trend towards a positive association with BW loss. Plasma vanillic acid showed the strongest association (-0.53 kg/5 years; 95% confidence interval [CI]: -0.99, -0.07). Similar results were observed for plasma naringenin comparing BW loss versus BW maintenance (odds ratio: 1.1; 95% CI: 1.0, 1.2). These results did not remain significant after FDR correction.

CONCLUSION

Higher concentrations of plasma (poly)phenols suggested a tendency towards 5-year BW maintenance or loss. While certain associations seemed promising, they did not withstand FDR correction, indicating the need for caution in interpreting these results. Further studies using (poly)phenol biomarkers are needed to confirm these suggestive protective trends.

Olive Oil Consumption and Cardiovascular Protection: Mechanism of Action

Cardiovascular diseases (CVDs) are still the leading cause of death and disability worldwide, and they could be prevented by a diet modification and a healthy lifestyle. Dietary modifications include a reduction in the consumption of saturated fatty acids and replacing them with mono or polyunsaturated fatty acids. Olive oil is a monounsaturated fatty acid and its increased consumption has been associated with a significant reduction of CVDs. Its significant cardiovascular benefits have been attributed to its high content of vitamin E, polyphenols, and other ingredients that possess significant anti-inflammatory and antioxidant properties. Several prospective and epidemiological studies have reported an inverse association between olive oil consumption and the incidence of CVD, hypertension, and type 2 diabetes mellitus. Also, a seminal study demonstrated that the use of a Mediterranean diet, which is rich in olive oil, fruits, vegetables, and fish, and low in red meat, was associated with significant reductions in CVD and mortality. However, despite its proven cardiovascular benefits, olive oil is scarcely used in the United States and other Western countries. To determine the current use of olive oil in the United States and other Western countries, a Medline search of the English literature between 2012 and January 2022 was conducted, and 36 pertinent articles were selected. The data from these articles, together with collateral literature, will be discussed in this concise review.

Anti-Inflammatory Mechanisms of Curcumin and Its Metabolites in White Adipose Tissue and Cultured Adipocytes

The plant-derived polyphenol curcumin alleviates the inflammatory and metabolic effects of obesity, in part, by reducing adipose tissue inflammation. We hypothesized that the benefits of curcumin supplementation on diet-induced obesity and systemic inflammation in mice occur through downregulation of white adipose tissue (WAT) inflammation. The hypothesis was tested in adipose tissue from high-fat diet-induced obese mice supplemented with or without curcumin and in 3T3-L1 adipocytes treated with or without curcumin. Male B6 mice were fed a high-fat diet (HFD, 45% kcal fat) with or without 0.4% (w/w) curcumin supplementation (HFC). Metabolic changes in these mice have been previously reported. Here, we determined the serum levels of the curcumin metabolites tetrahydrocurcumin (THC) and curcumin-O-glucuronide (COG) using mass spectrometry. Moreover, we determined interleukin 6 (IL-6) levels and proteomic changes in LPS-stimulated 3T3-L1 adipocytes treated with or without curcumin by using immunoassays and mass spectrometry, respectively, to gain further insight into any altered processes. We detected both curcumin metabolites, THC and COG, in serum samples from the curcumin-fed mice. Both curcumin and its metabolites reduced LPS-induced adipocyte IL-6 secretion and mRNA levels. Proteomic analyses indicated that curcumin upregulated EIF2 and mTOR signaling pathways. Overall, curcumin exerted anti-inflammatory effects in adipocytes, in part by reducing IL-6, and these effects may be linked to the upregulation of the mTOR signaling pathway, warranting additional mechanistic studies on the effects of curcumin and its metabolites on metabolic health.

A Review of the Anti-Obesity Effects of Wild Edible Plants in the Mediterranean Diet and Their Active Compounds: From Traditional Uses to Action Mechanisms and Therapeutic Targets

Obesity is a long-term condition resulting from a continuous imbalance between the amount of energy consumed and expended. It is associated with premature mortality and contributes to a large portion of the global chronic disease burden, including diabesity, cardiovascular disease, hypertension, and some cancers. While lifestyle changes and dietary adjustments are the primary ways to manage obesity, they may not always be sufficient for long-term weight loss. In these cases, medication may be necessary. However, the options for drugs are limited due to their potential side effects. As a result, there is a need to identify safe and effective alternative treatments. Recently, dietary compounds, plants, and bioactive phytochemicals have been considered as promising sources for discovering new pharmacological agents to treat obesity and its related complications. These natural products can function independently or synergistically with other plants to augment their effects at various levels of the body. They can modulate appetite, lipase activity, thermogenesis and fat synthesis and degradation, satiation, adipogenesis, and adipocyte apoptosis. Additionally, targeting adipocyte growth and differentiation with diverse medicinal plants/diet is a significant strategy for devising new anti-obesity drugs that can intervene in preadipocytes, maturing preadipocytes, and mature adipocytes. Clinical trials have shown that the wild edible plants in the Mediterranean diet can reduce the risk of obesity and its related diseases. This review examines the effectiveness of the common components of the Mediterranean diet in managing obesity and its associated health issues. We conducted a comprehensive literature review using PubMed, Science Direct, Google Scholar, and Medline Plus to gather data on the therapeutic effects of the Mediterranean diet and phytochemicals in treating obesity and its associated diseases.

Total (poly)phenol analysis by the Folin-Ciocalteu assay as an anti-inflammatory biomarker in biological samples

The Folin-Ciocalteu method is a well-established and widely used assay for measuring total (poly)phenol content in food/plant products. In recent years, there has been growing interest in applying this method to human samples due to its simplicity and efficacy. However, biological matrices such as blood and urine contain several interference substances that must be eliminated beforehand. This mini-review summarizes the current state of knowledge regarding the use of the Folin-Ciocalteu assay to measure total phenolic content in human urine and blood samples, as well as the preceding cleaning methods to remove interferences. Higher total (poly)phenol levels measured by the Folin-Ciocalteu method have been associated with a decrease in mortality and several risk variables. We focus on the application of this sustainable assay as a biomarker of poly(phenol) intake and its potential use as an anti-inflammatory biomarker in clinical laboratories. The Folin-Ciocalteu method, with a clean-up extraction step, is a reliable tool for determining total (poly)phenol consumption. Here, we also recommend using the Folin-Ciocalteu assay as means to measure anti-inflammatory activity.

Association between classes and subclasses of polyphenol intake and 5-year body weight changes in the EPIC-PANACEA study

OBJECTIVE

The aim of this study was to evaluate the associations among the intake of total polyphenols, polyphenol classes, and polyphenol subclasses and body weight change over 5 years.

METHODS

A total of 349,165 men and women aged 25 to 70 years were recruited in the Physical Activity, Nutrition, Alcohol, Cessation of Smoking, Eating Out of Home and Obesity (PANACEA) project of the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort from nine European countries. Body weight was measured at baseline and at follow-up after a median time of 5 years. Polyphenol intake, including four main polyphenol classes and eighteen subclasses, was estimated using validated dietary questionnaires and Phenol-Explorer. Multilevel mixed linear regression models were used to estimate the associations.

RESULTS

Participants gained, on average, 2.6 kg (±5.0 kg) over 5 years. Total flavonoids intake was inversely associated with body weight change (-0.195 kg/5 years, 95% CI: -0.262 to -0.128). However, the intake of total polyphenols (0.205 kg/5 years, 95% CI: 0.138 to 0.272) and intake of hydroxycinnamic acids (0.324 kg/5 years, 95% CI: 0.267 to 0.381) were positively associated with body weight gain. In analyses stratified by coffee consumption, hydroxycinnamic acid intake was positively associated with body weight gain in coffee consumers (0.379 kg/5 years, 95% CI: 0.319 to 0.440), but not in coffee nonconsumers (-0.179 kg/5 years, 95% CI: -0.490 to 0.133).

CONCLUSIONS

Higher intakes of flavonoids and their subclasses are inversely associated with a modest body weight change. Results regarding hydroxycinnamic acids in coffee consumers require further investigation.

Insights on Dietary Polyphenols as Agents against Metabolic Disorders: Obesity as a Target Disease

Obesity is a condition that leads to increased health problems associated with metabolic disorders. Synthetic drugs are available for obesity treatment, but some of these compounds have demonstrated considerable side effects that limit their use. Polyphenols are vital phytonutrients of plant origin that can be incorporated as functional food ingredients. This review presents recent developments in dietary polyphenols as anti-obesity agents. Evidence supporting the potential application of food-derived polyphenols as agents against obesity has been summarized. Literature evidence supports the effectiveness of plant polyphenols against obesity. The anti-obesity mechanisms of polyphenols have been explained by their potential to inhibit obesity-related digestive enzymes, modulate neurohormones/peptides involved in food intake, and their ability to improve the growth of beneficial gut microbes while inhibiting the proliferation of pathogenic ones. Metabolism of polyphenols by gut microbes produces different metabolites with enhanced biological properties. Thus, research demonstrates that dietary polyphenols can offer a novel path to developing functional foods for treating obesity. Upcoming investigations need to explore novel techniques, such as nanocarriers, to improve the content of polyphenols in foods and their delivery and bioavailability at the target sites in the body.

Anti-inflammatory mechanisms of polyphenols in adipose tissue: role of gut microbiota, intestinal barrier integrity and zinc homeostasis

Obesity is associated with an imbalance of micro-and macro-nutrients, gut dysbiosis, and a "leaky" gut phenomenon. Polyphenols, such as curcumin, resveratrol, and anthocyanins may alleviate the systemic effects of obesity, potentially by improving gut microbiota, intestinal barrier integrity (IBI), and zinc homeostasis. The essential micronutrient zinc plays a crucial role in the regulation of enzymatic processes, including inflammation, maintenance of the microbial ecology, and intestinal barrier integrity. In this review, we focus on IBI- which prevents intestinal lipopolysaccharide (LPS) leakage - as a critical player in polyphenol-mediated protective effects against obesity-associated white adipose tissue (WAT) inflammation. This occurs through mechanisms that block the movement of the bacterial endotoxin LPS across the gut barrier. Available research suggests that polyphenols reduce WAT and systemic inflammation via crosstalk with inflammatory NF-κB, the mammalian target of rapamycin (mTOR) signaling and zinc homeostasis.

Polyphenols in Metabolic Diseases

Polyphenols (PPs) are a large group of phytochemicals containing phenolic rings with two or more hydroxyl groups. They possess powerful antioxidant properties, multiple therapeutic effects, and possible health benefits in vivo and in vitro, as well as reported clinical studies. Considering their free-radical scavenging and anti-inflammatory properties, these substances can be used to treat different kinds of conditions associated with metabolic disorders. Many symptoms of metabolic syndrome (MtS), including obesity, dyslipidemia, atherosclerosis, elevated blood sugar, accelerating aging, liver intoxication, hypertension, as well as cancer and neurodegenerative disorders, are substantially relieved by dietary PPs. The present study explores the bioprotective properties and associated underlying mechanisms of PPs. A detailed understanding of these natural compounds will open up new opportunities for producing unique natural PP-rich dietary and medicinal plans, ultimately affirming their health benefits.

Dietary anthocyanins balance immune signs in osteoarthritis and obesity - update of human in vitro studies and clinical trials

Anthocyanins are known to change ligand-receptor bindings, cell membrane permeability, and intracellular signaling pathways. The beneficial effects of dietary anthocyanins have been chronologically demonstrated in interventional and observational studies, including fourteen human chondrocyte studies and related cell culture assays, nineteen human clinical trials in osteoarthritis patients, seven in vivo obesity assays, nineteen in vitro assays in preadipocytes and related cells, and twenty-two clinical trials in overweight/obese subjects, which are critically discussed in this update. Strawberries, cherries, berries, pomegranate, tropical fruits, rosehip, purple rice, purple corn, red beans, and black soybean, together with cyanidin, delphinidin, malvidin, peonidin, some 3-O-glycosides, metabolites, and acylated anthocyanins from a potato cultivar have shown the best outcomes. The set of these five key tests and clinical trials, taken together, contributes to the understanding of the underlying mechanisms and pathways involved. Furthermore, this set shows the value of anthocyanins in counteracting the progression of osteoarthritis/obesity. The interplay between the inflammation of osteoarthritis and obesity, and the subsequent regulation/immunomodulation was performed through isolated and food anthocyanins. The antioxidant, anti-inflammatory, and immunomodulatory properties of anthocyanins explain the findings of the studies analyzed. However, further interventional studies should be conducted to finally establish the appropriate doses for anthocyanin supplementation, dose-response, and length of consumption, to include dietary recommendations for osteoarthritis/obese patients for preventive and management purposes.

Modulatory Impact of Lamiaceae Metabolites on Apoptosis of Human Leukemia Cells

Lamiaceae species are rich sources of biologically active compounds which have been applied in medicine since ancient times. Especially their antineoplastic properties have been thoroughly studied with respect to their putative application in chemoprevention and adjuvant therapy of cancer. However, the most known biological effects of Lamiaceae have been ascribed to their essential oil fractions, whereas their (poly)phenolic metabolites being also abundant in these plants, are much less recognized, nevertheless contributing to their beneficial properties, such as anti-cancer actions. The aim of this study was to evaluate the impact of dried aqueous extracts from common thyme (Thymus vulgaris L.) (ExTv), wild thyme (Thymus serpyllum L.) (ExTs), sweet marjoram (Origanum majorana L.) (ExOm), and peppermint (Mentha × piperita L.) (ExMp), as well as (poly)phenolic compounds: caffeic acid (CA), rosmarinic acid (RA), lithospermic acid (LA), luteolin-7-O-β-glucuronide (Lgr), luteolin-7-O-rutinoside (Lr), eriodictyol-7-O-rutinoside (Er), and arbutin (Ab), on unstimulated Jurkat cells, in comparison with their effect on staurosporine-stimulated Jurkat cells. Jurkat T cells were incubated with different concentrations of ExTv, ExTs, ExOm, ExMp, Lgr, LA, Er, Lr, RA, CA, or Ab. Subsequently, staurosporine was added to half of the samples and flow cytometry combined with fluorescence-activated cell sorting analysis was conducted, which allowed for the selection of early and late apoptotic cells. Both ExTs and ExOm stimulated apoptosis of Jurkat cells and enhanced the proapoptotic effect of staurosporine. Conversely, ExTv and ExMp demonstrated no clear effect on apoptosis. CA and RA raised the staurosporine-induced apoptotic effect. The impact of Er and Lgr on Jurkat cells showed fluctuations depending on the compound concentration. Neither Er nor Ab altered staurosporine-induced apoptosis in Jurkat cells, whereas Lgr seemed to weaken the proapoptotic action of staurosporine. The most evident observation in this study was the pro-apoptotic action of ExTs and ExOm observed both in staurosporine-unstimulated and stimulated Jurkat cells. Additionally, an enhancement of staurosporine-induced apoptosis by caffeic and rosmarinic acids was reported. Therefore, it might be concluded that these are the mixtures of biologically active polyphenols which often exert more pronounced beneficial effects than purified molecules.

The association between dietary polyphenol intake and cardiometabolic factors in overweight and obese women: a cross-sectional study

OBJECTIVE

The previous evidence shows that there is an association between total dietary polyphenols intake (DPI) and its subclasses and lower risk of metabolic Syndrome (MetS). This cross-sectional study aims to evaluate associations between DPI and cardiometabolic factors in Iranian women.

METHODS

A total of 404 Iranian women were included in this study. Dietary intakes and polyphenols intakes were measured using a validated semi-quantitative food frequency questionnaire (FFQ) and the Phenol-Explorer database, respectively. Biochemical variables and blood pressure were evaluated using Pars Azmoon kits and mercury sphygmomanometer.

RESULTS

The mean intake of total polyphenol was 2533.96 ± 1223.67 g. While there were significant negative associations between stilbenes and lignans intake and body mass index (BMI) (P-value = 0.04; P-value = 0.02, respectively), beverages containing phenolic acids and hip circumference (HC) (P-value = 0.02), total polyphenols intake and weight to hip ratio (WHR) (P-value = 0.04). Also there was significant negative associations between stilbenes intake and cholesterol (CHOL) level (P-value = 0.03), other polyphenols intake and triglyceride (TG) ((P-value = 0.01), lignan intake and homeostasis model assessment insulin resistance (HOMA-IR) (P-value = 0.03).

CONCLUSION

These findings demonstrated that dietary polyphenols were associated with cardiometabolic factors in Iranian women. Prospective and interventional studies in both genders, different populations and ethnicities need to be conducted to further the knowledge about examine associations between consumption of polyphenols and metabolic component.

Changes in Phenolic Profiles and Inhibition Potential of Macrophage Foam Cell Formation during Noni (Morinda citrifolia Linn.) Fruit Juice Fermentation

The dynamic changes in phenolic composition and antioxidant activity, and the potential effect on foam cell formation and cholesterol efflux during noni (Morinda citrifolia Linn.) fruit juice fermentation were investigated in this study. The composition of phenolic compounds was significantly different at various fermentation times. Rutin, quercetin, and isoquercitrin were the major phenolics in fermented noni fruit juice based on a quantitative analysis of representative phenolics. The contents of caffeic acid, 2,4-dihydroxybenzoic acid, p-coumaric acid, rutin, and quercetin tended to increase, while those of isoquercitrin decreased during the fermentation process. Fermented noni juice extracts showed high antioxidant activities against 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), hydroxyl radical scavenging activity, and ferric reducing antioxidant power. Notably, the highest antioxidant activity was observed after 28 days of fermentation. Furthermore, the treatment of fermented noni juice extracts was shown to reduce foam cell formation, intracellular cholesterol level, and the cholesterol esterification ratio. A correlation analysis indicated a strong positive relationship between the phenolic composition, antioxidant activity, and the ratio of cholesterol ester and total cholesterol. This study may provide a theoretical basis for the quality improvement and standardized production of fermented noni fruit juice, thus promoting the development of the noni food industry.

Hypericum lanceolatum Lam. Medicinal Plant: Potential Toxicity and Therapeutic Effects Based on a Zebrafish Model

Hypericum lanceolatum Lam. (H. lanceolatum) is a traditional medicinal plant from Reunion Island used for its pleiotropic effects mainly related to its antioxidant activity. The present work aimed to 1) determine the potential toxicity of the plant aqueous extract in vivo and 2) investigate its putative biological properties using several zebrafish models of oxidative stress, regeneration, estrogenicity, neurogenesis and metabolic disorders. First, we characterized the polyphenolic composition by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and identified chlorogenic acid isomers, quercetin and kaempferol derivatives as the major compounds. We then evaluated for the first time the toxicity of an aqueous extract of H. lanceolatum and determined a maximum non-toxic concentration (MNTC) in zebrafish eleutheroembryos from 0 to 96 hpf following OECD (Organization for Economic Cooperation and Development) guidelines. This MNTC test was also determined on hatched eleutheroembryos after 2 days of treatment (from 3 to 5 dpf). In our study, the anti-estrogenic effects of H. lanceolatum are supported by the data from the EASZY assay. In a tail amputation model, we showed that H. lanceolatum at its MNTC displays antioxidant properties, favors immune cell recruitment and tissue regeneration. Our results also highlighted its beneficial effects in metabolic disorders. Indeed, H. lanceolatum efficiently reduces lipid accumulation and body mass index in overfed larva- and adult-models, respectively. In addition, we show that H. lanceolatum did not improve fasting blood glucose levels in a hyperglycemic zebrafish model but surprisingly inhibited neurogenesis impairment observed in diabetic conditions. In conclusion, our study highlights the antioxidant, pro-regenerative, anti-lipid accumulation and pro-neurogenic effects of H. lanceolatum in vivo and supports the use of this traditional medicinal plant as a potential alternative in the prevention and/or treatment of metabolic disorders.

Differential associations between a priori diet quality scores and markers of cardiovascular health in women: cross-sectional analyses from TwinsUK

CVD is the leading cause of death worldwide and, after dementia, is the second biggest cause of death for women. In England, it accounts for one in four of all deaths. Lifestyle modifications represent the primary route both to reduce CVD risk factors and prevent CVD outcomes. Diet constitutes one of the key modifiable risk factors in the aetiology of CVD. We investigated the relationship between nine main dietary indices and a comprehensive range of CVD risk factors in 2590 women from TwinsUK. After adjustment for multiple testing, we found that the Dietary Approaches to Stop Hypertension (DASH) diet was inversely correlated with some of the most common CVD risk factors (BMI, visceral fat (VF), TAG, insulin, homoeostasis model assessment of insulin resistance (HOMA2-IR) and atherosclerotic CVD (ASCVD) risk) with PFDR ranging from 6·28 × 10-7 to 5·63 × 10-4. Similar association patterns were detected across most of the dietary indices analysed. In our post hoc investigation, to determine if any specific food groups were driving associations between the DASH score and markers of cardiometabolic risk, we found that increased BMI, VF, HOMA2-IR, ASCVD risk, insulin and TAG levels were directly correlated with red meat consumption (PFDR ranging from 4·65 × 10-9 to 7·98 × 10-3) and inversely correlated with whole-grain cereal consumption (PFDR ranging from 1·26 × 10-6 to 8·28 × 10-3). Our findings revealed that the DASH diet is associated with a more favourable CVD risk profile, suggesting that this diet may be a candidate dietary pattern to supplement current UK dietary recommendations for CVD prevention.

Punicalagin in Cancer Prevention-Via Signaling Pathways Targeting

The extract of pomegranate (Punica granatum) has been applied in medicine since ancient times due to its broad-spectrum health-beneficial properties. It is a rich source of hydrolyzable tannins and anthocyanins, exhibiting strong antioxidative, anti-inflammatory, and antineoplastic properties. Anticancer activities of pomegranate with reference to modulated signaling pathways in various cancer diseases have been recently reviewed. However, less is known about punicalagin (Pug), a prevailing compound in pomegranate, seemingly responsible for its most beneficial properties. In this review, the newest data derived from recent scientific reports addressing Pug impact on neoplastic cells are summarized and discussed. Its attenuating effect on signaling circuits promoting cancer growth and invasion is depicted. The Pug-induced redirection of signal-transduction pathways from survival and proliferation into cell-cycle arrest, apoptosis, senescence, and autophagy (thus compromising neoplastic progression) is delineated. Considerations presented in this review are based mainly on data obtained from in vitro cell line models and concern the influence of Pug on human cervical, ovarian, breast, lung, thyroid, colorectal, central nervous system, bone, as well as other cancer types.

Obesity and aging: Molecular mechanisms and therapeutic approaches

The epidemic of obesity is a major challenge for health policymakers due to its far-reaching effects on population health and potentially overwhelming financial burden on healthcare systems. Obesity is associated with an increased risk of developing acute and chronic diseases, including hypertension, stroke, myocardial infarction, cardiovascular disease, diabetes, and cancer. Interestingly, the metabolic dysregulation associated with obesity is similar to that observed in normal aging, and substantial evidence suggests the potential of obesity to accelerate aging. Therefore, understanding the mechanism of fat tissue dysfunction in obesity could provide insights into the processes that contribute to the metabolic dysfunction associated with the aging process. Here, we review the molecular and cellular mechanisms underlying both obesity and aging, and how obesity and aging can predispose individuals to chronic health complications. The potential of lifestyle and pharmacological interventions to counter obesity and obesity-related pathologies, as well as aging, is also addressed.

The Mediterranean diet from past to future: Key concepts from the second "Ancel Keys" International Seminar

The year 2020 celebrated the tenth anniversary of the recognition of the Mediterranean Diet as Intangible Cultural Heritage of Humanity by the UNESCO Intergovernmental Committee. This event represented a milestone in the history of nutrition, as the Mediterranean diet was the first traditional food practice to receive such award. Since then, a lot has been discussed not only on the beneficial aspects of the Mediterranean diet, but also on its complex role as a lifestyle model that includes a set of skills, knowledge and intercultural dialogue. This process ended up with the recognition in 2019 of Mediterranean diet as a possibly universal model of healthy diet from the EAT-Lancet Commission. These concepts were widely debated at the 2019 "Ancel Keys" International Seminar, held in Ascea (Italy) (for more information see: www.mediterraneandietseminar.org) with the aim to stimulate interest and awareness of a young group of participants on the current problems inherent to the effective implementation of the Mediterranean diet. The present article collects the contributions of several lecturers at the Seminar on key issues such as methodological and experimental approach, sustainability, molecular aspects in disease prevention, future exploitation, without neglecting a historical view of the Seven Countries Study. From the Seminar conclusions emerged a still vibrant and modern role of Mediterranean diet. The years to come will see national and international efforts to reduce the barriers that limit adherence to Mediterranean diet in order to plan for multi-factorial and targeted interventions that would guide our populations to a sustainable healthy living.

Dietary polyphenols in lipid metabolism: A role of gut microbiome

Polyphenols are a class of non-essential phytonutrients, which are abundant in fruits and vegetables. Dietary polyphenols or foods rich in polyphenols are widely recommended for metabolic health. Indeed, polyphenols (i.e., catechins, resveratrol, and curcumin) are increasingly recognized as a regulator of lipid metabolism in host. The mechanisms, at least in part, may be highly associated with gut microbiome. This review mainly discussed the beneficial effects of dietary polyphenols on lipid metabolism. The potential mechanisms of gut microbiome are focused on the effect of dietary polyphenols on gut microbiota compositions and how gut microbiota affect polyphenol metabolism. Together, dietary polyphenols may be a useful nutritional strategy for manipulation of lipid metabolism or obesity care.

Polyphenols in Urine and Cardiovascular Risk Factors: A Cross-Sectional Analysis Reveals Gender Differences in Spanish Adolescents from the SI! Program

(1) Background: Epidemiological studies have shown an inverse association between polyphenol intake and cardiovascular risk factors (CVRFs) in adults, but few have provided information about adolescents. The aim of this study was to evaluate the relationship between urinary total polyphenol excretion (TPE) and CVRFs in adolescents. (2) Methods: A cross-sectional study was performed in 1194 Spanish adolescents from the SI! (Salud Integral) program. TPE in urine samples was determined by the Folin-Ciocalteu method, after solid-phase extraction, and categorized into quartiles. The association between TPE and CVRFs was estimated using mixed-effect linear regression and a structural equation model (SEM). (3) Results: Linear regression showed negative associations among the highest quartile of TPE and body fat percentage (B = -1.75, p-value = <0.001), triglycerides (TG) (B = -17.68, p-value = <0.001), total cholesterol (TC) (B = -8.66, p-value = 0.002), and low-density lipoprotein (LDL)-cholesterol (LDL-C) (B = -4.09, p-value = 0.008) in boys, after adjusting for all confounder variables. Negative associations between TPE quartiles and systolic blood pressure (SBP), diastolic blood pressure (DBP), and TC were also found in girls. Moreover, a structural equation model revealed that TPE was directly associated with body composition and blood glucose and indirectly associated with blood pressure, TG, LDL-C, and high-density lipoprotein-cholesterol (HDL-C) in boys. (4) Conclusions: Higher concentrations of TPE were associated with a better profile of cardiovascular health, especially in boys, while in girls, the association was not as strong.

Effects of polyphenols on crystallization of amorphous sucrose lyophiles

The crystallization of amorphous sucrose in food products can greatly affect the quality of foods. This study investigated the effects of polyphenols on the crystallization of amorphous sucrose lyophiles. Monoglycosylated, polyglycosylated, and aglycones with differing polyphenol backbones were studied, in addition to bulk food ingredients containing a high concentration of polyphenols. Solutions containing sucrose with and without polyphenols (1 and 5%) were lyophilized, stored in RH-controlled desiccators, and analyzed by x-ray diffraction. Moisture sorption studies, Karl Fischer titration, and differential scanning calorimetry were also completed. Polyphenol addition delayed sucrose crystallization by up to 6.4x compared to the control. Structure played the most significant role in efficacy of polyphenols in delaying sucrose crystallization, more than T_g or hygroscopicity. Glycosylated polyphenols were more effective than aglycones, polyphenols with (2,1) glycosidic linkages were more effective than those with (6,1) linkages, and bulk food ingredients were the most effective at delaying sucrose crystallization.

Potential health benefits of (poly)phenols derived from fruit and 100% fruit juice

(Poly)phenol-rich diets have been associated with reduced risk of various diseases. Coffee and tea are typically identified as dietary sources of chlorogenic acid and flavan-3-ols; however, 100% fruit juice greatly contributes to anthocyanin, flavonol, flavan-3-ols, and flavanone intake, making them complementary sources of dietary (poly)phenols. Thus, the aim of this narrative review was to provide an overview of fruit (poly)phenols and their potential health benefits. Fruit (poly)phenols have been associated with several health benefits (eg, reduced risk of cardiovascular disease and neurocognitive benefits). Although perspectives on 100% fruit juice consumption are controversial due to the perception of sugar content, growing evidence supports the role of fruit in whole and 100% juice forms to provide consumer benefits in alignment with dietary guidance. However, differences in (poly)phenol profiles and bioavailability likely exist between whole fruit and 100% fruit juice due to processing and the presence/absence of fiber. Ongoing studies are better defining similarities and differences between whole fruit and 100% fruit juice to elucidate protective mechanisms and align with processing and consumer products.

Anti-Obesity Effects of Polyphenol Intake: Current Status and Future Possibilities

The prevalence of obesity has steadily increased worldwide over the past three decades. The conventional approaches to prevent or treat this syndrome and its associated complications include a balanced diet, an increase energy expenditure, and lifestyle modification. Multiple pharmacological and non-pharmacological interventions have been developed with the aim of improving obesity complications. Recently, the use of functional foods and their bioactive components is considered a new approach in the prevention and management of this disease. Due to their biological properties, polyphenols may be considered as nutraceuticals and food supplement recommended for different syndromes. Polyphenols are a class of naturally-occurring phytochemicals, some of which have been shown to modulate physiological and molecular pathways involved in energy metabolism. Polyphenols could act in the stimulation of β-oxidation, adipocyte differentiation inhibition, counteract oxidative stress, etc. In this narrative review, we considered the association between polyphenols (resveratrol, quercetin, curcumin, and some polyphenolic extracts) and obesity, focusing on human trials. The health effects of polyphenols depend on the amount consumed and their bioavailability. Some results are contrasting, probably due to the various study designs and lengths, variation among subjects (age, gender, ethnicity), and chemical forms of the dietary polyphenols used. But, in conclusion, the data so far obtained encourage the setting of new trials, necessary to validate benefic role of polyphenols in obese individuals.

Targeting Carbohydrates and Polyphenols for a Healthy Microbiome and Healthy Weight

Purpose of Review

In this review, we focus on microbiota modulation using non-digestible carbohydrate and polyphenols (i.e., prebiotics) that have the potential to modulate body weight.

Recent Findings

Prebiotics derived from plants have gained the interest of public and scientific communities as they may prevent diseases and help maintain health.

Summary

Maintaining a healthy body weight is key to reducing the risk of developing chronic metabolic complications. However, the prevalence of obesity has increased to pandemic proportions and is now ranked globally in the top five risk factors for death. While diet and behavioral modification programs aiming to reduce weight gain and promote weight loss are effective in the short term, they remain insufficient over the long haul as compliance is often low and weight regain is very common. As a result, novel dietary strategies targeting the gut microbiota have been successful in decreasing obesity and metabolic disorders via different molecular mechanisms.

The Effects of Polyphenol Supplementation in Addition to Calorie Restricted Diets and/or Physical Activity on Body Composition Parameters: A Systematic Review of Randomized Trials

Background: Both, calorie restricted diets (CRD) and physical activity (PA) are conventional obesity therapies but their effectiveness is usually limited in the long-term. Polyphenols are bioactive compounds that have shown to possess some anti-obesity properties. The synergic effects between dietary polyphenols and CRD or PA on body weight and fat are supported by several animal studies, but evidence in human is still inconsistent. Thus, our aim was to review the combined effects of polyphenol supplementation with CRD and/or PA on body weight and fat, body mass index (BMI) and waist circumference (WC) in overweight or obese adults. Methods: Electronic databases (PubMed, Web of Science and Cochrane CENTRAL) were searched for randomized clinical trials (RCT) examining the combination of polyphenols with CRD and/or PA (up to December 31st, 2019). Articles were included if they had a duration of intervention ≥ 4 weeks. Both, quality and risk of bias of the included studies were assessed using the Cochrane RoB2 Tool. Results: The review included 4 and 11 RCTs investigating the anti-obesity effects of polyphenol supplementation combined with CRD and PA, respectively. Isoflavone supplementation may increase fat loss during exercise among post-menopausal women in non-Asian studies. In the rest of RCTs regarding polyphenol supplementation and CRD or PA, no additive changes were found. Conclusion: The results do not yet support polyphenol supplementation as a complementary strategy for enhancing the effectiveness of CRD and PA on weight and fat loss. However, this review suggests that isoflavone and soy products combined with lifestyle changes, especially exercise, provide additional anti-obesity effects in postmenopausal women. The potential role of polyphenols alone or, especially, in addition to conventional therapies (CRD and PA) mostly remains uncertain; and therefore, larger and longer RCTs examining these effects are needed. Protocol Registration: PROSPERO CRD42020159890.

Recent progress in the use of functional foods for older adults: A narrative review

The number and proportion of older adults are increasing globally, and it is predicted that in 2020, there will be 723 million people worldwide aged 66 and older. In recent decades, numerous studies showed that healthy eating is positively associated with better nutritional status and quality of life, and the decreased incidence of noncommunicable diseases. As older adults become health conscious, the demand for foods and beverages rich in nutrients and bioactive compounds has increased. The increased demand for healthy food stimulated a recent rapid increase in designing, producing, and marketing functional foods to prevent or correct nutrient deficiencies and to improve the nutritional status of older adults. These functional products contain and/or are enriched with dietary fiber; omega-3 polyunsaturated fatty acids; phytoestrogens; polyphenols; carotenoids such as alpha- and beta-carotene; lutein and zeaxanthin; pre-, pro-, and synbiotics; and plant sterols and stanols. A limited number of publications have thoroughly addressed the effect of functional foods on the nutritional status of older adults. The goal of this review was to review existing recent research on the role of functional foods in healthy and active aging.

The Fluid Aspect of the Mediterranean Diet in the Prevention and Management of Cardiovascular Disease and Diabetes: The Role of Polyphenol Content in Moderate Consumption of Wine and Olive Oil

A growing interest has emerged in the beneficial effects of plant-based diets for the prevention of cardiovascular disease, diabetes and obesity. The Mediterranean diet, one of the most widely evaluated dietary patterns in scientific literature, includes in its nutrients two fluid foods: olive oil, as the main source of fats, and a low-to-moderate consumption of wine, mainly red, particularly during meals. Current mechanisms underlying the beneficial effects of the Mediterranean diet include a reduction in inflammatory and oxidative stress markers, improvement in lipid profile, insulin sensitivity and endothelial function, as well as antithrombotic properties. Most of these effects are attributable to bioactive ingredients including polyphenols, mono- and poly-unsaturated fatty acids. Polyphenols are a heterogeneous group of phytochemicals containing phenol rings. The principal classes of red wine polyphenols include flavonols (quercetin and myricetin), flavanols (catechin and epicatechin), anthocyanin and stilbenes (resveratrol). Olive oil has at least 30 phenolic compounds. Among them, the main are simple phenols (tyrosol and hydroxytyrosol), secoroids and lignans. The present narrative review focuses on phenols, part of red wine and virgin olive oil, discussing the evidence of their effects on lipids, blood pressure, atheromatous plaque and glucose metabolism.

Binding of Plant Polyphenols to Serum Albumin and LDL: Healthy Implications for Heart Disease

Cardiovascular disease (CVD) is the leading cause of death in industrialized nations. The initiating event in atherosclerosis, or hardening of the arteries, is oxidation of low density lipoprotein (LDL). Binding with serum albumin and LDL of 41 polyphenols (major antioxidants in plant foods) constituting four classes of flavonoids, three types of phenolic acids, and seven polyphenol conjugate metabolites was investigated indirectly by fluorescence quenching and directly by affinity separation/high-performance liquid chromatography (four of the polyphenols). Stern-Volmer plots yielded K values for the two proteins. Polyphenol binding was significantly stronger for albumin than with LDL. K values were highly correlated with the lipophilicity of the polyphenols. The number of polyphenol molecules determined by quenching was ∼1 for both proteins. Direct analysis under saturation conditions yielded from 2 to 13 molecules of polyphenols/LDL particle. Multiple substituent effects on binding were analyzed. Evidence was put forward that binding of polyphenols to these proteins is protective for CVD by multiple mechanisms.

Visceral fat reduction is positively associated with blood pressure reduction in overweight or obese males but not females: an observational study

BACKGROUND

Visceral adiposity has been reported to play a key role in hypertension compared with other measurements of regional or general obesity. The aim of current study was to evaluate the relationship between visceral fat reduction and changes in blood pressure in a group of overweight or obese Chinese individuals.

METHODS

An observational study was conducted with 168 participants (ChiCTR-OOC-17012000). Body composition, blood parameters and blood pressure were assessed at the beginning and end of the intervention. Males and females were categorized separately into quartiles according to changes in visceral fat during the intervention. Multiple linear regression models were used to assess the associations of changes in systolic and diastolic blood pressure with changes of visceral fat area, adjusted for potential confounders.

RESULTS

Changes in visceral fat was significantly associated with systolic and diastolic blood pressure in men for systolic (β = 0.234, 95% CI: 0.103, 0.365; p = 0.001) and diastolic blood pressure (β = 0.237; 95% CI: 0.127, 0.346; p <0.001), but not in women after adjustment for the same potential confounders for systolic blood (β = - 0.003, 95% CI: - 0.260, 0.255; p = 0.984) and diastolic blood pressure (β = 0.101, 95% CI: - 0.072, 0.273; p = 0.249).

CONCLUSIONS

A positive association was observed between reduction in visceral fat and improvements in both systolic blood and diastolic blood pressures in males but not females in a 12-week meal replacement intervention.

TRIAL REGISTRATION

The Ethics Committee of Peking University Health Science Center approved the study protocol on 6 July 2017. The authors confirm that all ongoing and related trials for this intervention were carried out following the rules of the Declaration of Helsinki of 1975 and registered (ChiCTR-OOC-17012000). http://www.chictr.org.cn/showprojen.aspx?proj=20426.

Body Mass Index as a Determinant of Systemic Exposure to Gallotannin Metabolites during 6-Week Consumption of Mango (Mangifera indica L.) and Modulation of Intestinal Microbiota in Lean and Obese Individuals

SCOPE

This human clinical pilot trial investigated pharmacokinetics of gallotannin-metabolites and modulation of intestinal microbiota in healthy lean and obese individuals after 6 weeks of daily mango consumption.

METHODS AND RESULTS

Participants are divided into three groups: Lean Mango (LM: n = 12; BMI = 22.9 kg m^-2 ), Obese Mango (OM: n = 9; BMI = 34.6 kg m^-2 ), and Lean Control (LC: n = 11; BMI = 22.1 kg m^-2 ). LM and OM consumed 400 g of mango per day for 6 weeks. LC consumed mango only on Days 0 and 42. After 6 weeks, LM experienced increased systemic exposure (AUC_0-8h ) to gallotannin-metabolites, 1.4-fold (p = 0.043). The greatest increase is 4-O-methyl-gallic acid, 3.3-fold (p = 0.0026). Cumulative urinary excretion of gallotannin-metabolites significantly increased in LM and OM, but not LC. For OM, qPCR data show increased levels of tannase-producing Lactococcus lactis and decreased levels of Clostridium leptum and Bacteroides thetaiotaomicron, bacteria associated with obesity. LM experienced an increased trend of fecal levels of butyric (1.3-fold; p = 0.09) and valeric acids (1.5-fold; p = 0.056). Plasma endotoxins showed a decreased trend in LM and OM.

CONCLUSION

Continuous mango intake significantly increased systemic exposure to gallotannin- metabolites and induced an increased trend for fecal short-chain fatty acids in lean but not obese individuals. This pharmacokinetic discrepancy may result in BMI-associated reduced gallotannin-derived health benefits.

Relationship between Mediterranean Dietary Polyphenol Intake and Obesity

Obesity is a multifactorial and complex disease defined by excess of adipose mass and constitutes a serious health problem. Adipose tissue acts as an endocrine organ secreting a wide range of inflammatory adipocytokines, which leads to systemic inflammation, insulin resistance, and metabolic disorders. The traditional Mediterranean diet is characterized by a high phenolic-rich foods intake, including extra-virgin olive oil, nuts, red wine, vegetables, fruits, legumes, and whole-grain cereals. Evidence for polyphenols’ effect on obesity and weight control in humans is inconsistent and the health effects of polyphenols depend on the amount consumed and their bioavailability. The mechanisms involved in weight loss in which polyphenols may have a role are: activating β-oxidation; a prebiotic effect for gut microbiota; inducing satiety; stimulating energy expenditure by inducing thermogenesis in brown adipose tissue; modulating adipose tissue inhibiting adipocyte differentiation; promoting adipocyte apoptosis and increasing lipolysis. Even though the intake of some specific polyphenols has been associated with body weight changes, there is still no evidence for the effects of total polyphenols or some polyphenol subclasses in humans on adiposity.

Association of plasma and urine viscosity with cardiometabolic risk factors and oxidative status. A pilot study in subjects with abdominal obesity

There is increasing interest in the search for accurate, repeatable and widely applicable clinical biomarkers for the early detection of cardiometabolic alterations and oxidative status. Viscosity is a promising tool in that sense, although most studies have used simple viscosimeters, providing limited information, and have not considered oxidative status. The aim of this study was to assess whether viscosity determinations were associated with cardiometabolic and oxidative status in subjects at a primary stage of cardiometabolic risk. A pilot study (n = 20) was conducted in subjects with abdominal obesity, determining urine and plasma viscosity with a rotational rheometer at different shear rates (10000-1000 s-1 in plasma and 1000-50 s-1 in urine). Simple regression showed that urine viscosity was significantly (p< 0.05) associated with markers of oxidative status, and plasma viscosity with blood glucose. Categorical Principal Component Analysis plots showed that urine viscosity measurements at different shear rates clustered in three groups (low, intermediate and high shear rates) were selectively associated with uric acid, polyphenols and antioxidant capacity respectively. Plasma viscosity did not seem to be a relevant clinical marker in subjects with abdominal obesity. Therefore, urine viscosity could potentially serve as a complimentary marker in the evaluation of oxidative status.

Effects of Polyphenol-Rich Foods on Human Health

Recent evidence has suggested that polyphenol-rich foods intake may be associated with decreased risk of chronic diseases. The Special Issue “Effects of Polyphenol-Rich Foods on Human Health” comprised 64 peer-reviewed papers on the most recent evidence regarding the dietary intake of polyphenols and polyphenol-rich foods, as well as their effect toward the prevention and treatment of non-communicable diseases. Original contributions and literature reviews demonstrated the potential protective effects of polyphenol-rich foods and their extracts toward cardiovascular diseases, certain cancers, and neurodegenerative diseases, mostly through anti-oxidant and chemo-preventive properties.

Polyphenols, food and pharma. Current knowledge and directions for future research

Polyphenols are a large family of phytochemicals with great chemical diversity, known to be bioactive compounds of foods, species, medicinal plants and nutraceuticals. These compounds are ingested through the diet in significant amounts, around 1 g per day, an amount that be may be increased through supplements. The in vitro action of many representative polyphenols has been reported. However, their beneficial effects and their role in modulating the risk of high-prevalence diseases are difficult to demonstrate due to the wide variability of polyphenol structures and bioactive actions; the complexity of estimating the polyphenol content of food as a result of their variability in foods and cooked dishes; the potential modulation of the effects of polyphenols by food matrices; the addition of polyphenols and their synergistic interactions with each other and with other dietary bioactive components; the modulation of polyphenol bioavailability as a consequence of food composition and culinary techniques; their metabolism by the human body and the polyphenol gut microbiota metabolism in each metabotypes. Computational strategies, including virtual screening, shape-similarity-screening and molecular docking, were recently used to identify potential targets of polyphenols and thus gain a better understanding of the therapeutic effects exerted of polyphenols and modify natural polyphenol structures to potentiate specific activities. Here, we present the most relevant current knowledge and propose directions for future research in these fields, from the culinary world to the clinical setting. We hope this commentary will prompt scientists and clinicians to consider the therapeutic value of bioactive polyphenols and help shed some light on how much scientific truth lies in Hippocrates' famous quote: "Let your food be your medicine".

No Additive Effects of Polyphenol Supplementation and Exercise Training on White Adiposity Determinants of High-Fat Diet-Induced Obese Insulin-Resistant Rats

One of the major insulin resistance instigators is excessive adiposity and visceral fat depots. Individually, exercise training and polyphenol intake are known to exert health benefits as improving insulin sensitivity. However, their combined curative effects on established obesity and insulin resistance need further investigation particularly on white adipose tissue alterations. Therefore, we compared the effects on different white adipose tissue depot alterations of a combination of exercise and grape polyphenol supplementation in obese insulin-resistant rats fed a high-fat diet to the effects of a high-fat diet alone or a nutritional supplementation of grape polyphenols (50 mg/kg/day) or exercise training (1 hr/day to 5 days/wk consisting of treadmill running at 32 m/min for a 10% slope), for a total duration of 8 weeks. Separately, polyphenol supplementation and exercise decreased the quantity of all adipose tissue depots and mesenteric inflammation. Exercise reduced adipocytes' size in all fat stores. Interestingly, combining exercise to polyphenol intake presents no more cumulative benefit on adipose tissue alterations than exercise alone. Insulin sensitivity was improved at systemic, epididymal, and inguinal adipose tissues levels in trained rats thus indicating that despite their effects on adipocyte morphological/metabolic changes, polyphenols at nutritional doses remain less effective than exercise in fighting insulin resistance.

Association between dietary flavonoids intake and obesity in a cohort of adults living in the Mediterranean area

Dietary polyphenols, including flavonoids, are abundantly present in a healthy and balanced diet. Evidence for their role in preventing non-communicable diseases is emerging. We examined the association between estimated habitual intake of dietary flavonoid and obesity in a cohort study. After adjusting for potential confounding factors, inverse association between total flavonoid intake and excess weight (BMI ≥25) was found (OR = 0.66, 95% CI: 0.45, 0.99); among individual classes of flavonoids, only flavanones were inversely associated with excess body weight (OR = 0.68, 95% CI: 0.48, 0.97). However, when considering adjustment for dietary factors (adherence to the Mediterranean diet), the associations were no more significant. When considering obesity as the outcome (BMI ≥30), individuals with high intake of total flavonoids and flavonols resulted less likely to be obese (OR = 0.38, 95% CI: 0.21, 0.66 and OR = 0.63, 95% CI: 0.39, 0.99, respectively), even after adjustment for confounding factors. The results of the present study add to the current literature further evidence of the association between higher flavonoid intake and decreased body weight. Further studies are needed to confirm retrieved association.

The antioxidant potential of the Mediterranean diet in patients at high cardiovascular risk: an in-depth review of the PREDIMED

Cardiovascular disease (CVD) is the leading global cause of death. Diet is known to be important in the prevention of CVD. The PREDIMED trial tested a relatively low-fat diet versus a high-fat Mediterranean diet (MedDiet) for the primary prevention of CVD. The resulting reduction of the CV composite outcome resulted in a paradigm shift in CV nutrition. Though many dietary factors likely contributed to this effect, this review focuses on the influence of the MedDiet on endogenous antioxidant systems and the effect of dietary polyphenols. Subgroup analysis of the PREDIMED trial revealed increased endogenous antioxidant and decreased pro-oxidant activity in the MedDiet groups. Moreover, higher polyphenol intake was associated with lower incidence of the primary outcome, overall mortality, blood pressure, inflammatory biomarkers, onset of new-onset type 2 diabetes mellitus (T2DM), and obesity. This suggests that polyphenols likely contributed to the lower incidence of the primary event in the MedDiet groups. In this article, we summarize the potential benefits of polyphenols found in the MedDiet, specifically the PREDIMED cohort. We also discuss the need for further research to confirm and expand the findings of the PREDIMED in a non-Mediterranean population and to determine the exact mechanisms of action of polyphenols.