Health Benefits Of Dietary Polyphenols Research Articles

The health benefits of dietary polyphenols on pediatric intestinal diseases: Mechanism of action, clinical evidence and future research progress.

Pediatric intestinal development is immature, vulnerable to external influences and produce a variety of intestinal diseases. At present, breakthroughs have been made in the treatment of pediatric intestinal diseases, but there are still many challenges, such as toxic side effects, drug resistance, and the lack of more effective treatments and specific drugs. In recent years, dietary polyphenols derived from plants have become a research hotspot in the treatment of pediatric intestinal diseases due to their outstanding pharmacological activities such, as anti-inflammatory, antibacterial, antioxidant and regulation of intestinal flora. This article reviewed the mechanism of action and clinical evidence of dietary polyphenols in the treatment of pediatric intestinal diseases, and discussed the influence of physiological characteristics of children on the efficacy of polyphenols, and finally prospected the new dosage forms of polyphenols in pediatrics.

Higher Dietary Polyphenol Intake Is Associated With Lower Blood Inflammatory Markers

BackgroundEvidence suggests a link between polyphenol intake and reduced incidence of several chronic diseases. This could arise through associations between polyphenol intake and reduced systemic oxidative stress and subsequent inflammation. However, confirming this association is difficult, as few large cohorts allow for comprehensive assessments of both polyphenol intake and markers of systemic inflammation. ObjectivesTo address this, polyphenol intake was assessed in the UK-based Airwave cohort using 7-d diet diaries and data from Phenol-Explorer to test for associations between polyphenol intake and blood biomarkers of inflammation. MethodsParticipants included 9008 males and females aged 17–74 y (median age: 42 y) whose data was included in a cross-sectional analysis. Phenol-Explorer was used to estimate individuals’ polyphenol intake from diet data describing the consumption of 4104 unique food items. C-reactive protein (CRP) and fibrinogen were used as blood biomarkers of inflammation. ResultsThere were 448 polyphenols found in reported diet items. Median total polyphenol intake was 1536 mg/d (1058–2092 mg/d). Phenolic acids and flavonoids were the main types of polyphenols, and nonalcoholic beverages, vegetables, and fruit were the primary sources. Variation in energy-adjusted polyphenol intake was explained by age, sex, salary, body mass index, education level, smoking, and alcohol consumption. Linear regressions showed inverse associations between total daily intake and both CRP (β: −0.00702; P < 0.001) and fibrinogen (β: −0.00221; P = 0.038). Associations with specific polyphenol compound groups were also found. Logistic regressions using total polyphenol intake quartiles showed stepwise reductions in the odds of elevated CRP with higher intake (6%, 23%, and 24% compared with quartile 1; P = 0.003), alongside 3% and 7% lower odds per unit of polyphenol consumption equivalent to 1 cup of tea or coffee per day. ConclusionsThis study describes polyphenol intake in a large, contemporary UK cohort. We observed associations between higher intake and lower CRP and fibrinogen. This contributes to evidence supporting the health benefits of dietary polyphenols.

Polyphenol intake beneficially associates with inflammation and cognitive performance, and is mediated by MRI‐derived features

AbstractBackgroundEarly changes to cognitive performance and neurophysiological biomarkers offer insights into one’s future risk of developing Alzheimer’s disease or other dementias. Evidence suggests a link between polyphenol intake and reduced incidence of age‐associated cognitive decline and neurodegeneration. These relationships may be driven by the effect of dietary polyphenols on inflammation and degeneration of critical neurological structures and systems. These relationships are challenging to assess, as few cohorts allow cohesive assessment of polyphenol intake, systemic inflammation, neurophysiological measures and cognition.MethodPolyphenol intake was assessed in two UK cohorts: The Airwave Health Monitoring Study and UK Biobank (UKB). Diet diary and questionnaire data were integrated with polyphenol composition data from Phenol‐Explorer to allow for testing of associations between polyphenol intake, blood biomarkers of inflammation, and cognitive performance. 9008 Airwave participants and 209,163 UKB participants were included in a cross‐sectional analysis. C‐reactive protein (CRP) and fibrinogen were used as blood biomarkers of inflammation, and cognitive assessments included reaction time (milliseconds) and fluid intelligence (score /13). Neuroimaging assessments included grey matter volumes and white matter integrity, and were considered individually and using PCA.ResultLinear regressions showed inverse associations between total polyphenol intake and CRP: ß ‐0.00702 (Airwave) and ß = ‐0.00672 (UKB), both P &lt;0.001, as well as fibrinogen: ß ‐0.00221; P = 0.038 (Airwave only), in addition to biomarker associations with polyphenols at the compound group level. Regarding cognition, linear regressions revealed beneficial associations between total intake and performance in fluid intelligence tests: ß 0.00657; P = 0.009 (Airwave) and ß 0.00715, P &lt;0.001 (UKB), and reaction time ß ‐0.0000977; P = 0.020 (UKB). Mediations of the polyphenol‐fluid intelligence relationship were detected for IDPs including grey matter volumes of hippocampal‐associated regions, and white matter integrity measured using ISOVF.ConclusionWe described polyphenol intake in two large, contemporary UK cohorts, and discovered associations between higher intake and improved inflammatory markers and cognitive performance, as well as mediations of the polyphenol‐cognition relationship by physical neurological markers. This contributes to evidence supporting the health benefits of dietary polyphenols, clarifies the physiological pathways through which they may act, and highlights their relevance when considering preventative interventions for neurodegeneration.

Polyphenol intake beneficially associates with inflammation and cognitive performance, and is mediated by MRI‐derived features

AbstractBackgroundEarly changes to cognitive performance and neurophysiological biomarkers offer insights into one’s future risk of developing Alzheimer’s disease or other dementias. Evidence suggests a link between polyphenol intake and reduced incidence of age‐associated cognitive decline and neurodegeneration. These relationships may be driven by the effect of dietary polyphenols on inflammation and degeneration of critical neurological structures and systems. These relationships are challenging to assess, as few cohorts allow cohesive assessment of polyphenol intake, systemic inflammation, neurophysiological measures and cognition.MethodPolyphenol intake was assessed in two UK cohorts: The Airwave Health Monitoring Study and UK Biobank (UKB). Diet diary and questionnaire data were integrated with polyphenol composition data from Phenol‐Explorer to allow for testing of associations between polyphenol intake, blood biomarkers of inflammation, and cognitive performance. 9008 Airwave participants and 209,163 UKB participants were included in a cross‐sectional analysis. C‐reactive protein (CRP) and fibrinogen were used as blood biomarkers of inflammation, and cognitive assessments included reaction time (milliseconds) and fluid intelligence (score /13). Neuroimaging assessments included grey matter volumes and white matter integrity, and were considered individually and using PCA.ResultLinear regressions showed inverse associations between total polyphenol intake and CRP: β ‐0.00702 (Airwave) and β = ‐0.00672 (UKB), both P &lt;0.001, as well as fibrinogen: β ‐0.00221; P = 0.038 (Airwave only), in addition to biomarker associations with polyphenols at the compound group level. Regarding cognition, linear regressions revealed beneficial associations between total intake and performance in fluid intelligence tests: β 0.00657; P = 0.009 (Airwave) and β 0.00715, P &lt;0.001 (UKB), and reaction time β ‐0.0000977; P = 0.020 (UKB). Mediations of the polyphenol‐fluid intelligence relationship were detected for IDPs including grey matter volumes of hippocampal‐associated regions, and white matter integrity measured using ISOVF.ConclusionWe described polyphenol intake in two large, contemporary UK cohorts, and discovered associations between higher intake and improved inflammatory markers and cognitive performance, as well as mediations of the polyphenol‐cognition relationship by physical neurological markers. This contributes to evidence supporting the health benefits of dietary polyphenols, clarifies the physiological pathways through which they may act, and highlights their relevance when considering preventative interventions for neurodegeneration.

Protective Effects of Diets Rich in Polyphenols in Cigarette Smoke (CS)-Induced Oxidative Damages and Associated Health Implications.

Cigarette smoking has been responsible for causing many life-threatening diseases such as pulmonary and cardiovascular diseases as well as lung cancer. One of the prominent health implications of cigarette smoking is the oxidative damage of cellular constituents, including proteins, lipids, and DNA. The oxidative damage is caused by reactive oxygen species (ROS, oxidants) present in the aqueous extract of cigarette smoke (CS). In recent years, there has been considerable interest in the potential health benefits of dietary polyphenols as natural antioxidant molecules. Epidemiological studies strongly suggest that long-term consumption of diets (fruits, vegetables, tea, and coffee) rich in polyphenols offer protective effects against the development of cancer, cardiovascular diseases, diabetes, osteoporosis, and neurodegenerative diseases. For instance, green tea has chemopreventive effects against CI-induced lung cancer. Tea might prevent CS-induced oxidative damages in diseases because tea polyphenols, such as catechin, EGCG, etc., have strong antioxidant properties. Moreover, apple polyphenols, including catechin and quercetin, provide protection against CS-induced acute lung injury such as chronic obstructive pulmonary disease (COPD). In CS-induced health problems, the antioxidant action is often accompanied by the anti-inflammatory effect of polyphenols. In this narrative review, the CS-induced oxidative damages and the associated health implications/pathological conditions (or diseases) and the role of diets rich in polyphenols and/or dietary polyphenolic compounds against various serious/chronic conditions of human health have been delineated.

Dietary Polyphenol, Gut Microbiota, and Health Benefits.

Polyphenols, which are probably the most important secondary metabolites produced by plants, have attracted tremendous attention due to their health-promoting effects, including their antioxidant, anti-inflammatory, antibacterial, anti-adipogenic, and neuro-protective activities, as well as health properties. However, due to their complicated structures and high molecular weights, a large proportion of dietary polyphenols remain unabsorbed along the gastrointestinal tract, while in the large intestine they are biotransformed into bioactive, low-molecular-weight phenolic metabolites through the residing gut microbiota. Dietary polyphenols can modulate the composition of intestinal microbes, and in turn, gut microbes catabolize polyphenols to release bioactive metabolites. To better investigate the health benefits of dietary polyphenols, this review provides a summary of their modulation through in vitro and in vivo evidence (animal models and humans), as well as their possible actions through intestinal barrier function and gut microbes. This review aims to provide a basis for better understanding the relationship between dietary polyphenols, gut microbiota, and host health.

A Critical Review on Polyphenols and Health Benefits of Black Soybeans.

Polyphenols are plant secondary metabolites containing antioxidant properties, which help to protect chronic diseases from free radical damage. Dietary polyphenols are the subject of enhancing scientific interest due to their possible beneficial effects on human health. In the last two decades, there has been more interest in the potential health benefits of dietary polyphenols as antioxidant. Black soybeans (Glycine max L. Merr) are merely a black variety of soybean containing a variety of phytochemicals. These phytochemicals in black soybean (BSB) are potentially effective in human health, including cancer, diabetes, cardiovascular diseases, cerebrovascular diseases, and neurodegenerative diseases. Taking into account exploratory study, the present review aims to provide up-to-date data on health benefit of BSB, which helps to explore their therapeutic values for future clinical settings. All data of in vitro and in vivo studies of BSB and its impact on human health were collected from a library database and electronic search (Science Direct, PubMed, and Google Scholar). The different pharmacological information was gathered and orchestrated in a suitable spot on the paper.

Nutritional Polyphenol Metabolites’ Kinetics in Plasma, Urine, and Saliva Following Consumption by Normal, Healthy, Subjects

Several studies point to the health benefits of dietary polyphenols yet limited data can be found on the metabolites found in plasma and urine and negligible on saliva from supplemented polyphenol ingredients. Therefore this study was completed to obtain a better understanding of the kinetics of polyphenol ingredients in three fluids (plasma, urine, and saliva). A novel, dietary nutritional supplement containing several polyphenols including resveratrol, quercetin, anthocyanins, heperitin, naringin, d‐limonene combined with fish oil, vitamins, and carotenoids was studied. Healthy subjects (n=6 males and n=6 females) were fed three different acute doses in this cross‐over design, one treatment at a time, with at least a one week washout interval. Blood plasma, saliva and urine samples were collected for metabolite analysis at baseline, 0.5, 1, 2, 3 (only plasma and saliva), 8, and 24 hours post intake. Blood was also collected in PAXgene tubes at baseline, 8, and 24 hours post intake for gene expression analysis. Metabolites analyzed included 3‐hydroxyphenylacetic acid, 4‐hydroxyhippuric acid, hippuric acid, hesperetin, naringenin, naringenin 7‐O‐glucuronide, protocatechuic acid, quercetin, quercetin 3‐O‐glucuronide, resveratrol 3‐O‐glucuronide, resveratrol 4‐O‐glucuronide, trans‐resveratrol, and cis‐resveratrol. Most of the metabolites that were analyzed peaked at 2 and 8 hours and returned to baseline by 24 hours in plasma, urine, and saliva. A dose response was not observed for all metabolites in plasma, urine, and saliva. Female and male kinetics of many of the polyphenols and metabolites appears to be different. This data is important in further understanding the levels of these polyphenols and their metabolites, so that tissue exposure can begin to be assessed.Support or Funding InformationSupported by Nu Skin Enterprises, Provo, Utah

Dietary intake of 20 polyphenol subclasses in a cohort of UK women.

Establishing and linking the proposed health benefits of dietary polyphenols to their consumption requires measurement of polyphenol intake in appropriate samples and an understanding of factors that influence their intake in the general population. This study examined polyphenol intake estimated from 3- and 7-day food diaries in a sample of 246 UK women aged 18-50years. Estimation of the intake of 20 polyphenol subclasses commonly present in foods consumed by the sample studied was done using Phenol-Explorer(®) and USDA polyphenol databases. Women were participants in the Leeds Women's Wellbeing Study (LWW) (n=143), a dietary intervention study aimed at overweight women (mean age 37.2±9.4years; mean BMI 30.8±3.1kg/m(2)), and the Diet and Health Study (DH) (n=103) which aimed to examine the relationship between polyphenol intake and cognitive function (mean age 25.0±9.0years; mean BMI 24.5±4.6kg/m(2)). The estimated intake of polyphenol subclasses was significantly different between the two samples (p<0.01) with consumption of 1292±844 and 808±680mg/day for the LWW and DH groups, respectively. Flavanols and hydroxycinnamic acids were the most important contributors to the polyphenols consumed by both groups, owing to tea and coffee consumption. Other major polyphenol food sources included fruits, vegetables and processed foods. Older women consumed more polyphenol-containing foods and beverages, which was due to the higher coffee and tea consumption amongst the LWW participants.

Regular consumption of Fiit-ns, a polyphenol extract from fruit and vegetables frequently consumed within the Mediterranean diet, improves metabolic ageing of obese volunteers: a randomized, double-blind, parallel trial

Epidemiological studies suggest that metabolic ageing process of overweight and obese populations is associated with an increased risk of developing non-communicable diseases (NCDs). Inflammation, hyper-glycaemia, dyslipidemia and oxidative stress have been associated with early stages of NCDs development whereas cohort surveys have demonstrated health benefits of dietary polyphenols from various dietary sources to reverse such progress. Obese volunteers were included in a double-blind, randomized, parallel pilot trial where they received daily for a 12-week period 900 mg of a polyphenol-rich treatment extracted from fruit and vegetables frequently consumed within the Mediterranean diet. Anthropometric and blood parameters were assessed before and at the end of the intervention period. After 12 weeks, while the silhouette slimmed down, metabolic parameters were significantly improved and general satisfaction considerably ameliorated. These data suggest that over a 12-week period, the synergistic action of bioactives within the treatment improves metabolic ageing process and quality of life in obese volunteers.

An alternative pathway to widespread health benefits of dietary polyphenols: The nitrate-nitrite-nitric oxide pathway in the gut

Dietary polyphenols are redox active compounds endowed with recognized health benefits. Their in vivo impact needs to be addressed in connection with a sequence of reactions intrinsically related to the biological compartments that, after consumption in the diet, the alimentary bolus travels through. In this regard, it has been recognized that the structural modifications suffered in the gut and during absorption alter the kinetic and thermodynamic properties supportive of the well-known antioxidant properties in vitro. The chemical, biophysical and biological properties of their metabolites are, in most cases, quite different from the ones of the parent molecules. Thus, the current view for the wide-range effects of dietary polyphenols considers their bioavailability and the potential effects of metabolites derived from the original structures consumed in the diet. Few years ago we have shown that dietary polyphenols and dietary nitrite interact in the human stomach yielding a burst of nitric oxide (NO) in a process encompassing the one electron reduction of nitrite by polyphenols [1]. In turn, NO, a ubiquitous cell messenger, exert not only local but more widespread effects. In fact, at acidic gastric pH, dietary polyphenols, in the form they are conveyed in foods and at high concentration, promote nitrite reduction to NO but also embark in a complex network of chemical reactions to produce higher nitrogen oxides with signaling functions, namely by inducing post-translational modifications. Modified endogenous molecules, such as nitrated proteins and lipids, acquire important physiological functions via the modulation of redox signaling pathways. Systemic effects of NO such as modulation of vascular tone, mucus production in the gut and protection against ischemia-reperfusion injury might, in this sense, triggered by dietary polyphenols. This rises the notion that bypassing gut metabolization and absorption, the redox and kinetic properties of original polyphenolic structures trigger wide-spread biological effects via the nitrate:nitrite:nitric oxide pathway. This notion will be herein experimentally supported and discussed.

Challenges in providing credible scientific evidence of health benefits of dietary polyphenols

► Credible scientific evidence of health benefits of dietary polyphenols is needed. ► Bioavailability of bioactive compounds must be known. ► Bioavailability includes absorption, distribution, metabolism, and excretion. ► Metabolites must be included in vitro and in vivo studies. ► Physiological concentrations of bioactive compounds must be used.

Dihydroxylated phenolic acids derived from microbial metabolism reduce lipopolysaccharide-stimulated cytokine secretion by human peripheral blood mononuclear cells

Oligomers and polymers of flavan-3-ols (proanthocyanidins) are very abundant in the Mediterranean diet, but are poorly absorbed. However, when these polyphenols reach the colon, they are metabolised by the intestinal microbiota into various phenolic acids, including phenylpropionic, phenylacetic and benzoic acid derivatives. Since the biological properties of these metabolites are not completely known, in the present study, we investigated the effect of the following microbial phenolic metabolites: 3,4-dihydroxyphenylpropionic acid (3,4-DHPPA), 3-hydroxyphenylpropionic acid, 3,4-dihydroxyphenylacetic acid (3,4-DHPAA), 3-hydroxyphenylacetic acid, 4-hydroxybenzoic acid and 4-hydroxyhippuric acid (4-HHA), on modulation of the production of the main pro-inflammatory cytokines (TNF-alpha, IL-1beta and IL-6). The production of these cytokines by lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMC) pre-treated with the phenolic metabolites was studied in six healthy volunteers. With the exception of 4-HHA for TNF-alpha secretion, only the dihydroxylated compounds, 3,4-DHPPA and 3,4-DHPAA, significantly inhibited the secretion of these pro-inflammatory cytokines in LPS-stimulated PBMC. Mean inhibition of the secretion of TNF-alpha by 3,4-DHPPA and 3,4-DHPAA was 84.9 and 86.4 %, respectively. The concentrations of IL-6 in the culture supernatant were reduced by 88.8 and 92.3 % with 3,4-DHPPA and 3,4-DHPAA pre-treatment, respectively. Finally, inhibition was slightly higher for IL-1beta, 93.1 % by 3,4-DHPPA and 97.9 % by 3,4-DHPAA. These results indicate that dihydroxylated phenolic acids derived from microbial metabolism present marked anti-inflammatory properties, providing additional information about the health benefits of dietary polyphenols and their potential value as therapeutic agents.

Bioavailability issues in studying the health effects of plant polyphenolic compounds

Polyphenolic compounds are common in the diet and have been suggested to have a number of beneficial health effects including prevention of cancer, cardiovascular disease, diabetes, and others. For some dietary polyphenols, certain benficial effects are suggested by epidemiological studies, some are supported by studies in animal models, and still others are extrapolated from studies in vitro. Because of the relatively poor bioavailability of many of these compounds, the molecular basis of these beneficial effects is not clear. In the present review, we discuss the potential health benefits of dietary polyphenols from the point of view of bioavailability. Tea catechins, curcumin, and proanthocyanidins are used as examples to illustrate some of the problems that need to be resolved. Further research on both the biological activity and bioavailability of dietary polyphenols is needed to properly assess their usefulness for the prevention and treatment of disease.

Cocoa Procyanidins and Human Cytokine Transcription and Secretion

We examined whether cocoa, in its isolated procyanidin fractions (monomer through decamer), would modulate cytokine production at the levels of transcription and protein secretion in both resting and phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMC). In resting cells, interleukin (IL)-1beta and IL-4 gene expression from cocoa-treated cells varied markedly among the subjects tested. However, at the protein level, the larger fractions (pentamer through decamer) stimulated a dramatic increase in IL-1beta concentration (up to ninefold) with increasing degree of polymerization. Similarly, these larger fractions augmented IL-4 concentration by as much as 2 pg/ml, whereas the control displayed levels nearly undetectable. In the presence of PHA, gene expression also seemed to be most affected by the larger procyanidin fractions. The pentameric through decameric fractions increased IL-1 beta expression by 7-19% compared with PHA control, whereas the hexameric through decameric fractions significantly inhibited PHA-induced IL-4 transcription in the range of 71-86%. This observation at the transcription level for IL-1 beta was reflected at the protein level in PHA-stimulated PBMC. Significant reductions in mitogen-induced IL-4 production were also seen at the protein level with the hexamer, heptamer and octamer. Individual oligomeric cocoa fractions were unstimulatory for IL-2 in resting PBMC. However, when induced with PHA, the pentamer, hexamer and heptamer fractions caused a 61-73% inhibition in IL-2 gene expression. This study offers additional data for the consideration of the health benefits of dietary polyphenols from a wide variety of foods, including those benefits associated specifically with cocoa and chocolate consumption.

Effect of Cocoa Procyanidins on the Secretion of Interleukin-4 in Peripheral Blood Mononuclear Cells

Given the widespread ingestion of cocoa in many cultures, we investigated whether cocoa, in its isolated procyanidin fractions (monomer through decamer), would modulate synthesis of the antiinflammatory cytokine, interleukin-4 (IL-4). Both resting and phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMC) were investigated at the protein secretion level. The smaller-sized cocoa fractions (tetramer or less) were unable to induce an IL-4 response (i.e., values fell below the detection limit of 0.25 pg/ml). The larger oligomeric procyanidins (pentamer or greater) stimulated secretion of IL-4 in resting PBMC by as much as 1.42 pg/ml, as shown by the nonamer. However, only the hexameric, heptameric, and decameric fractions proved to be statistically significant. Cells coincubated with PHA showed an immense increase in secretory IL-4 (21.1 ± 1.1 pg/ml). Only the monomeric fraction was able to enhance PHA-induced secretion by 48%. The other procyanidin oligomers suppressed IL-4 production; in particular, the hexameric, heptameric, and octameric fractions significantly inhibited mitogen-stimulated secretion of IL-4, by 55%, 61%, and 71% respectively. This study offers additional data for consideration of the health benefits of dietary polyphenols from a wide variety of foods, including those benefits associated specifically with cocoa and chocolate consumption.