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BMC Endocrine Disorders Mar 2024Accumulating evidence has suggested that dietary polyphenols may be protective against metabolic syndrome (MetS); however, the available evidence is contradictory. The... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Accumulating evidence has suggested that dietary polyphenols may be protective against metabolic syndrome (MetS); however, the available evidence is contradictory. The aim of this meta-analysis was to assess the association between dietary intake of polyphenols and the odds of MetS.
METHODS
The PubMed and Scopus databases were systematically searched to obtain eligible studies. The risk of MetS for the highest versus the lowest intakes of total, subclasses and individual polyphenols were examined by pooling odds ratios (OR) and 95% confidence intervals (95%CI) using the random effects model.
RESULTS
A total of 14 studies (6 cohort and 8 cross-sectional studies) involving a total of 50,366 participants with 10,879 cases of MetS were included. When various polyphenol compounds were pooled, they were significantly related to a 22% decreased odds of MetS (([5 studies]; OR: 0.78; 95%CI: 0.72-0.85). Higher intakes of total flavonoids (([9 studies]; OR: 0.78; 95%CI: 0.72-0.85), flavan-3-ols (([2 studies]; OR: 0.64; 95%CI: 0.43-0.94), isoflavones (([3 studies]; OR: 0.84; 95%CI: 0.75-0.93), stilbenes (([4 studies]; OR: 0.86; 95%CI: 0.76-0.97), flavones (([2 studies]; OR: 0.79; 95%CI: 0.71-0.89), and quercetin (([2 studies]; OR: 0.63; 95%CI: 0.43-0.93) were also significantly associated with a decreased risk of MetS. The associations were not modified by the age of the participants. No association was found for total polyphenols, phenolic acids, lignans, anthocyanins, and flavonols.
CONCLUSION
The results of this meta-analysis supported that higher polyphenol intake can lower the risk of MetS.
Topics: Humans; Anthocyanins; Diet; Metabolic Syndrome; Polyphenols
PubMed: 38429765
DOI: 10.1186/s12902-024-01556-x -
Redox Biology May 2024This systematic review provides an overview of the available evidence on the inter-individual variability (IIV) in the absorption, distribution, metabolism, and... (Review)
Review
This systematic review provides an overview of the available evidence on the inter-individual variability (IIV) in the absorption, distribution, metabolism, and excretion (ADME) of phenolic metabolites and its determinants. Human studies were included investigating the metabolism and bioavailability of (poly)phenols and reporting IIV. One hundred fifty-three studies met the inclusion criteria. Inter-individual differences were mainly related to gut microbiota composition and activity but also to genetic polymorphisms, age, sex, ethnicity, BMI, (patho)physiological status, and physical activity, depending on the (poly)phenol sub-class considered. Most of the IIV has been poorly characterised. Two major types of IIV were observed. One resulted in metabolite gradients that can be further classified into high and low excretors, as seen for all flavonoids, phenolic acids, prenylflavonoids, alkylresorcinols, and hydroxytyrosol. The other type of IIV is based on clusters of individuals defined by qualitative differences (producers vs. non-producers), as for ellagitannins (urolithins), isoflavones (equol and O-DMA), resveratrol (lunularin), and preliminarily for avenanthramides (dihydro-avenanthramides), or by quali-quantitative metabotypes characterized by different proportions of specific metabolites, as for flavan-3-ols, flavanones, and even isoflavones. Future works are needed to shed light on current open issues limiting our understanding of this phenomenon that likely conditions the health effects of dietary (poly)phenols.
Topics: Humans; Biological Availability; Phenols; Flavonoids; Isoflavones; Diet
PubMed: 38428187
DOI: 10.1016/j.redox.2024.103095 -
Nutrients Feb 2024Negative health consequences of obesity include impaired neuronal functioning and cell death, thus bringing the risk of impaired cognitive functioning. Antioxidant... (Meta-Analysis)
Meta-Analysis Review
Negative health consequences of obesity include impaired neuronal functioning and cell death, thus bringing the risk of impaired cognitive functioning. Antioxidant properties of polyphenols offer a possible intervention for overweight people, but evidence for their effectiveness in supporting cognitive functioning is mixed. This review examined evidence from randomized controlled trials concerning the effect of polyphenols on tasks requiring either immediate or delayed retrieval of learned information, respectively, thus controlling for differences in cognitive processes and related neural substrates supporting respective task demands. Searches of the PubMed/Medline, PsycInfo, and Scopus databases identified 24 relevant primary studies with N = 2336 participants having a BMI ≥ 25.0 kg/m. The participants' mean age for the 24 studies exceeded 60 years. Respective meta-analyses produced a significant summary effect for immediate retrieval but not for delayed retrieval. The present findings support a potential positive effect of chronic supplementation with polyphenols, most notably flavonoids, on immediate retrieval in participants aged over 60 years with obesity being a risk factor for cognitive impairment. We recommend further investigation of this potential positive effect in participants with such risk factors. Future research on all populations should report the phenolic content of the supplementation administered and be specific regarding the cognitive processes tested.
Topics: Adult; Humans; Middle Aged; Aged; Overweight; Polyphenols; Obesity; Memory; Dietary Supplements
PubMed: 38398799
DOI: 10.3390/nu16040474 -
Food & Function Mar 2024Common buckwheat (CBW) is grown and consumed worldwide. In addition to its already established reputation as an excellent source of nutrients, CBW is gaining popularity... (Review)
Review
Common buckwheat (CBW) is grown and consumed worldwide. In addition to its already established reputation as an excellent source of nutrients, CBW is gaining popularity as a possible component of functional foods. Whereas human studies remain the gold standard for evaluating the relationship between nutrition and health, the development of reliable or models has made it possible to investigate the cellular and molecular mechanisms of CBW effects on human health. Herein is a systematic review of studies on the biological effect of CBW supplementation, as assessed on various types of cellular models. Although the studies reported here have been conducted in very different experimental conditions, the overall effects of CBW supplementation were found to involve a decrease in cytokine secretion and oxidation products, related mainly to CBW polyphenols and protein or peptide fractions. These chemical species also appeared to be involved in the modulation of cell signaling and hormone secretion. Although further studies are undoubtedly necessary, as is their extension to systems, these reports suggest that CBW-based foods could be relevant to maintaining and/or improving human health and the quality of life.
Topics: Humans; Fagopyrum; Quality of Life; Cell Culture Techniques; Functional Food; Nutrients
PubMed: 38390666
DOI: 10.1039/d4fo00202d -
Journal of Ovarian Research Feb 2024This study aims to investigate the effects of natural products on animal models of premature ovarian failure (POF). (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
This study aims to investigate the effects of natural products on animal models of premature ovarian failure (POF).
METHODS
We conducted comprehensive literature searches and identified relevant studies that examined the protective effects of natural products on experimental POF. We extracted quantitative data on various aspects such as follicular development, ovarian function, physical indicators, oxidative stress markers, inflammatory factors, and protein changes. The data was analyzed using random-effects meta-analyses, calculating pooled standardized mean differences and 95% confidence intervals. Heterogeneity was assessed using the I statistic, and bias was estimated using the SYRCLE tool.
RESULTS
Among the 879 reviewed records, 25 articles met our inclusion criteria. These findings demonstrate that treatment with different phytochemicals and marine natural products (flavonoids, phenols, peptides, and alkaloids, etc.) significantly improved various aspects of ovarian function compared to control groups. The treatment led to an increase in follicle count at different stages, elevated levels of key hormones, and a decrease in atretic follicles and hormone levels associated with POF. This therapy also reduced oxidative stress (specifically polyphenols, resveratrol) and apoptotic cell death (particularly flavonoids, chrysin) in ovarian granulosa cells, although it showed no significant impact on inflammatory responses. The certainty of evidence supporting these findings ranged from low to moderate.
CONCLUSIONS
Phytochemicals and marine natural product therapy (explicitly flavonoids, phenols, peptides, and alkaloids) has shown potential in enhancing folliculogenesis and improving ovarian function in animal models of POF. These findings provide promising strategies to protect ovarian reserve and reproductive health. Targeting oxidative stress and apoptosis pathways may be the underlying mechanism.
Topics: Female; Humans; Animals; Primary Ovarian Insufficiency; Menopause, Premature; Flavonoids; Phenols; Peptides; Alkaloids
PubMed: 38378652
DOI: 10.1186/s13048-024-01369-5 -
Cureus Jan 2024Periodontitis is a chronic, infectious, and inflammatory oral disease with a high prevalence in developing countries, where limited access to modern dental care curtails... (Review)
Review
Periodontitis is a chronic, infectious, and inflammatory oral disease with a high prevalence in developing countries, where limited access to modern dental care curtails its treatment. This review is dedicated to examining three indigenous botanical species frequently recommended by traditional therapists for the treatment of periodontal disease, namely, , with the aim of elucidating their chemical constituents and pharmacological properties that may support their empirical use. This review adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines extension for scoping reviews. An electronic search was conducted in three databases (PubMed, Science Direct, and Google Scholar) up to July 2022. Out of 700 articles initially identified, only 11 were deemed eligible for inclusion; a substantial majority (80%) of these comprised in vitro studies. Among the trio of botanicals considered, emerged as the most extensively investigated (65% of the studies). The administration of these plants was predominantly in the form of decoctions or macerations, with extraction methods employing alcoholic agents (ethanolic and methanolic), hydroalcoholic solutions, or aqueous solvents. The selected plants exhibited notable richness in polyphenolic compounds, particularly flavonoids, and demonstrated anti-inflammatory effects, as indicated in 60% of the studies, along with antibacterial properties (against ). None of the studies reported antibacterial activity against periodontal pathogens. The pharmacological properties of these plants may hold promise for the management of oral inflammatory and infectious conditions. Nevertheless, further comprehensive investigations are imperative to establish their safety and efficacy for periodontitis treatment before conclusive recommendations can be formulated.
PubMed: 38371022
DOI: 10.7759/cureus.52471 -
Food Science & Nutrition Feb 2024Evidence supports the potential application of polyphenols as agents against obesity. Pomegranate is one of the fruits that possess a high content of polyphenols. This... (Review)
Review
Evidence supports the potential application of polyphenols as agents against obesity. Pomegranate is one of the fruits that possess a high content of polyphenols. This systematic review and meta-analysis of randomized controlled trials (RCTs) sought to evaluate the effects of pomegranate consumption on obesity indices, including body mass index (BMI), body weight, waist circumference (WC), fat mass (FM), body fat percentage (BFP), and fat-free mass (FFM) in adults. Relevant RCTs were obtained by searching databases, including PubMed, SCOPUS, and Web of Science, up to May 2023. Heterogeneity tests of the included trials were performed using the statistic. Random effects models were assessed based on the heterogeneity tests, and pooled data were determined as the weighted mean difference with a 95% confidence interval. Pooled analysis of 28 trials revealed that pomegranate consumption led to a significant reduction in body weight (WMD: -1.97, 95% CI: -2.91, -1.03, < .05), and a significant decrease in BMI (WMD: -0.48, 95% CI: -0.76, -0.20, < .05) in comparison with the control group. However, there were no significant effects on WC, FM, FFM, and BFP in comparison with the control group. Pomegranate consumption may yield a beneficial effect on body weight and BMI in adults. However, there were no significant effects on WC, FM, FFM, and BFP, by pomegranate consumption. Also, pomegranate consumption can reduce body weight, BMI, WC, and BFP in obese adults. Long-term trials with different doses of pomegranate are needed.
PubMed: 38370057
DOI: 10.1002/fsn3.3739 -
Journal of Dairy Science Jan 2024A systematic literature review of in vitro studies was performed to identify methane (CH) mitigation interventions with a potential to reduce CH emission in vivo. Data... (Meta-Analysis)
Meta-Analysis
A systematic literature review of in vitro studies was performed to identify methane (CH) mitigation interventions with a potential to reduce CH emission in vivo. Data from 277 peer-reviewed studies published between 1979 and 2018 were reviewed. Individual CH mitigation interventions were classified into 14 categories of feed additives based on their type, chemical composition, and mode of action. Response variables evaluated were absolute CH emission (number of treatment means comparisons = 1,325); total volatile fatty acids (n = 1,007), acetate (n = 783), propionate (n = 792), and butyrate (n = 776) concentrations; acetate to propionate ratio (n = 675); digestibility of dry matter (n = 489), organic matter (n = 277), and neutral detergent fiber (n = 177). Total gas production was used as an explanatory variable in the model for CH production. Relative mean difference between treatment and control means reported in the studies was calculated and used for statistical analysis. The robust variance estimation method was used to analyze the effects of CH mitigation interventions. In vitro CH production was decreased by antibodies (-38.9%), chemical inhibitors (-29.2%), electron sinks (-18.9%), essential oils (-18.2%), plant extracts (-14.5%), plant inclusion (-11.7%), saponins (-14.8%), and tannins (-14.5%). Overall effects of direct-fed microbials, enzymes, macroalgae, and organic acids supplementation did not affect CH production in the current meta-analysis. When considering the effects of individual mitigation interventions containing a minimum number of 4 degrees of freedom within feed additives categories, Enterococcus spp. (i.e., direct-fed microbial), nitrophenol (i.e., electron sink), and Leucaena spp. (i.e., tannins) decreased CH production by 20.3%, 27.1%, and 23.5%, respectively, without extensively, or only slightly, affecting ruminal fermentation and digestibility of nutrients. It should be noted, however, that although the total number of publications (n = 277) and treatment means comparisons (n = 1,325 for CH production) in the current analysis were high, data for most mitigation interventions were obtained from less than 5 observations (e.g., maximum number of observations was 4, 7, and 22 for nitrophenol, Enterococcus spp., and Leucaena spp., respectively), because of limited data available in the literature. These should be further evaluated in vitro and in vivo to determine their true potential to decrease enteric CH production, yield, and intensity. Some mitigation interventions (e.g., magnesium, Heracleum spp., nitroglycerin, β-cyclodextrin, Leptospermum pattersoni, Fructulus Ligustri, Salix caprea, and Sesbania grandiflora) decreased in vitro CH production by over 50% but did not have enough observations in the database. These should be more extensively investigated in vitro, and the dose effect must be considered before adoption of mitigation interventions in vivo.
Topics: Female; Animals; Diet; Milk; Lactation; Propionates; Methane; Tannins; Rumen; Acetates; Nitrophenols; Fermentation; Digestion; Animal Feed
PubMed: 38353472
DOI: 10.1016/S0022-0302(23)00819-6 -
Journal of Orthopaedic Surgery and... Feb 2024There is still a lack of sufficient evidence-based medical data on the effect of resveratrol (Res) on primary osteoporosis (OP). This meta-analysis aimed to... (Meta-Analysis)
Meta-Analysis
BACKGROUND
There is still a lack of sufficient evidence-based medical data on the effect of resveratrol (Res) on primary osteoporosis (OP). This meta-analysis aimed to comprehensively evaluate the role of Res in animal models of primary OP.
METHODS
The PubMed, Cochrane Library, Web of Science and Embase databases were searched up to August 2023. The risk of bias was assessed by the SYRCLE RoB tool. Random- or fixed-effects models were used to determine the 90% confidence interval (CI) or standardized mean difference (SMD). Statistical analysis was performed with RevMan 5.4 and Stata 14.0.
RESULTS
A total of 24 studies containing 714 individuals were included. Compared with those in the control group, the bone mineral density (BMD) (P < 0.00001), bone volume/total volume (BV/TV) (P < 0.001), trabecular thickness (Tb.Th) (P < 0.00001), and trabecular number (Tb.N) (P < 0.00001) were markedly greater, and the trabecular separation (Tb.Sp) (P < 0.00001) was significantly greater. Compared with the control group, the Res group also exhibited marked decreases in alkaline phosphatase (ALP) (P < 0.05), tartrate-resistant acid phosphatase 5b (TRAP5b) (P < 0.01), and type I collagen strong carboxyl peptide (CTX-1) (P < 0.00001) and a marked increase in osteoprotegerin (OPG) (P < 0.00001).
CONCLUSION
In summary, we concluded that Res can markedly increase BMD, improve morphometric indices of trabecular microstructure and serum bone turnover markers (BTMs), and exert a protective effect in animal models of primary osteoporosis. This study can supply experimental reference for Res in primary osteoporosis treatment.
Topics: Animals; Humans; Osteoporosis; Resveratrol; Bone Density; Alkaline Phosphatase; Models, Animal
PubMed: 38350991
DOI: 10.1186/s13018-024-04595-1 -
International Journal of Molecular... Jan 2024Polyphenols are natural compounds also contained in daily consumed foods that show their efficacy in different clinical fields. Both pre-clinical and clinical studies... (Review)
Review
Polyphenols are natural compounds also contained in daily consumed foods that show their efficacy in different clinical fields. Both pre-clinical and clinical studies demonstrated that polyphenols may manage neuroinflammation and oxidative stress processes tightly connected to neurodegenerative diseases and mental disorders. Thus, a neuroinflammatory state may influence the neurotransmitters pathways, such as the noradrenergic, glutamatergic, serotoninergic, and, in particular, dopaminergic ones, whose impairment is strongly associated with attention deficit hyperactivity disorder (ADHD). Therefore, the aim of the present systematic review is to provide an overview of the clinical outcomes' changes following ADHD treatment with polyphenols alone and in combination with the traditional drugs. This review was conducted according to PRISMA guidelines and recorded on PROSPERO with the number CRD42023438491; PubMed, Scopus, and Web of Science were used as search-engines to lead our research until June 2023. The inclusion criteria were articles written in English, including clinical, placebo-controlled, and case-control trials. We excluded reviews, metanalyses, background articles, and papers published in other languages. To avoid any bias, Rayyan software (COPYRIGHT © 2022 RAYYAN) was used to organize the work and manage the literature review. After screening, 10 studies were included, with a total of 556 patients that met the established inclusion criteria. The data obtained from these studies showed that polyphenols rebalanced oxidative stress pathways through different mechanisms, are effective for the treatment of ADHD both alone and in combination with traditional drugs, and are able to reduce symptoms as well as the side effects related to the use of conventional therapies. Finally, a positive effect of using polyphenols for ADHD prevention could be hypothesized.
Topics: Humans; Attention Deficit Disorder with Hyperactivity; Polyphenols; Food; Software
PubMed: 38338814
DOI: 10.3390/ijms25031536