Jul 2026· Kybele Medical Journal· Vol 1· 0 citations
TL;DR
Although the overall findings are encouraging, dose-response patterns, sustained effects, and causal mechanisms still require stronger clinical investigation and should therefore be viewed as potentially valuable components of preventive and personalized nutrition rather than as uniformly acting compounds.
Abstract
Flavonoids comprise a broad range of plant polyphenols present in many foods, particularly fruits, vegetables, pulses, cereals, tea, and cocoa. Their relevance to human health has been linked to several complementary actions, including modulation of oxidative balance, inflammation, immune responses, vascular function, and metabolic control. This narrative review integrates evidence on flavonoid chemistry and classification with information on food sources, absorption, biotransformation, and health-related outcomes. It considers the principal dietary groups - flavonols, flavones, flavanones, flavan-3-ols, isoflavones, and anthocyanins - together with the foods in which they commonly occur. Particular attention is given to the processes that determine systemic exposure, such as digestion, microbial conversion, interactions within the food matrix, and person-to-person metabolic variation. Population and intervention studies generally support favorable associations with cardiovascular and metabolic health, whereas conclusions concerning neurodegeneration and cancer remain less certain. The gut microbiome is increasingly recognized as both a converter of flavonoids and a target of their activity, making this reciprocal relationship relevant to individual responses. Although the overall findings are encouraging, dose-response patterns, sustained effects, and causal mechanisms still require stronger clinical investigation. Flavonoids should therefore be viewed as potentially valuable components of preventive and personalized nutrition rather than as uniformly acting compounds.
Background/Objectives: Flavonoids are a diverse group of dietary polyphenolic compounds associated with a range of important biological activities. However, their low systemic bioavailability and extensive metabolism raise questions about how they exert their purported benefits. Methods: A comprehensive survey of literature published over the past 10 years was conducted, focusing on human, animal, and in vitro studies addressing the metabolic fate of major flavonoid subclasses. Results: Original research articles (n = 159) were selected following predetermined inclusion criteria. Data from diverse experimental models—including intestinal and hepatic systems—demonstrate that flavonoids undergo substantial transformation by Phase I and Phase II enzymes, alongside extensive biotransformation by the gut microbiota. In this critical narrative review we summarize dietary sources, bioavailability patterns, metabolic pathways, and analytical strategies, emphasizing advances enabled by high-resolution mass spectrometry. Recent findings indicate that enterohepatic recirculation and the biological activities of circulating and tissue-associated metabolites contribute significantly to the observed health effects, despite limited levels of parent compounds. Conclusions: Flavonoids exhibit limited oral bioavailability and undergo complex metabolic processing, yet growing evidence indicates that their metabolites play key roles in mediating beneficial effects. Understanding these metabolic pathways is essential for interpreting epidemiological associations and designing more effective intervention studies.
Eduardo de Jesus Oliveira, C. Grael, Valéria Moreira da Costa et al.· Nutraceuticals· 1 citation
Dietary bioactive compounds, particularly polyphenols and glucosinolates, are widely associated with reduced risk of chronic disease, yet fewer than 10% of most ingested polyphenols reach systemic circulation in their active form, a figure that varies markedly by compound class; resveratrol bioavailability is below 1%, whereas some simple phenolic acids may reach 30%–50%. The gut microbiota is the primary site where these compounds are chemically transformed into absorbable metabolites, but individuals vary enormously in their capacity to carry out this transformation. This review examines how gut microbiota-mediated biotransformation of dietary bioactive compounds is determined by three interacting factors: baseline microbiota composition, fermented food consumption, and probiotic or prebiotic supplementation. The review covers polyphenols, isoflavones, ellagitannins, glucosinolates, and alkaloids. Synthetic drugs and non-dietary administration routes are excluded. The three-factor framework collectively determines an individual’s biotransformation phenotype, which governs how much of a given dietary bioactive reaches the bloodstream as an active metabolite. Documented examples include equol production from daidzein (present in only around 30% of Western adults), urolithin generation from ellagitannins (three distinct metabotypes in the population), and dihydroberberine production from berberine. Each of these variations produces measurable differences in health outcomes, including cardiovascular markers, glycaemic control, and muscle function. Biotransformation phenotyping is technically feasible through urine metabolomics and faecal enzyme assays. Personalised dietary guidance that accounts for an individual’s biotransformation capacity has the potential to resolve the inconsistency that has characterised polyphenol intervention trials. Standardised phenotyping protocols, re-analysis of existing trial datasets, and updated regulatory frameworks represent the most urgent research priorities.
Tapash Chakraborty, Shashanka Jyoti Kashyap, Pragyan Deep Chetia et al.· Frontiers in Systems Biology· 0 citations
Modern nutritional science places increasing emphasis not only on absolute nutrient content, but primarily on bioavailability and interactions with the food matrix. This paper presents a comprehensive comparison of the bioavailability of protein, vitamins (A, D, and B12), and key minerals (iron, zinc, and calcium) from animal-source foods (ASF) and plant-based alternatives. Based on the literature indexed in the Web of Science, Scopus, PubMed, and ScienceDirect databases, this review assessed nutrient absorption and matrix effects, including both antinutritional factors and health-promoting compounds. The analysis shows that while ASF generally exhibit higher baseline bioavailability of several essential micronutrients and protein (measured by PDCAAS and DIAAS) due to the absence of phytates and oxalates, plant-based matrices offer distinct physiological benefits, including dietary fiber and phytonutrients. Moreover, the lower bioavailability in plant sources can be significantly improved through food processing techniques (e.g., fermentation, germination, thermal treatment) and strategic dietary combinations. Therefore, adequate nutrient intake depends not only on the food’s origin but also on its preparation methods and the overall dietary pattern. It is also important that the best diet is both nutritionally adequate and sustainable for the individual and the environment.
Nutraceuticals, defined broadly as food-derived products that deliver physiological benefits beyond basic nutrition, have moved from a niche wellness category into a central pillar of preventive medicine. Rising rates of cardiovascular disease, type 2 diabetes, obesity and certain cancers, combined with an ageing global population, have driven sustained interest in dietary bioactives such as polyphenols, omega-3 fatty acids, curcuminoids, probiotics, prebiotics and vitamin D as adjuncts to conventional pharmacotherapy. This review synthesises contemporary evidence on the mechanisms through which nutraceuticals act, the clinical settings in which they show measurable benefit, and the regulatory, technological and safety considerations that shape their responsible use. Particular attention is given to antioxidant and anti-inflammatory pathways, gut microbiome modulation, immune regulation and glycaemic control, alongside emerging delivery technologies such as nanoencapsulation that address the poor bioavailability of many plant-derived compounds. The regulatory patchwork spanning the United States, the European Union, India and other jurisdictions is examined as a major barrier to harmonised quality assurance and consumer protection. The review also considers the trajectory toward personalised and precision nutrition, in which genetic, metabolic and microbiome data are used to tailor nutraceutical recommendations to the individual. Taken together, the evidence indicates that nutraceuticals occupy a genuine, if carefully bounded, role in health promotion and chronic disease prevention, provided that product quality, dosing and regulatory oversight keep pace with scientific advancement.
Tawanda Tasiyana, Suvigya Bhardwaj, Smrutiranjan Dash· Journal of international res...· 0 citations
Saccharin is one of the oldest and most extensively used nonnutritive sweeteners, valued for its intense sweetness, chemical stability and negligible caloric contribution. Since its discovery in 1879, it has been widely incorporated into foods, beverages, pharmaceuticals and personal care products, while its safety has remained the subject of considerable scientific and regulatory debate. Early experimental studies linking saccharin to bladder tumour formation in rodents raised concerns regarding its carcinogenic potential; however, subsequent mechanistic investigations, epidemiological evidence and comprehensive risk assessments have demonstrated that these findings are species-specific and not directly applicable to humans. This review provides a comprehensive and critical synthesis of current knowledge on saccharin, encompassing its chemical characteristics, physicochemical properties, industrial and pharmaceutical applications, absorption, metabolism, excretion and toxicological profile. Particular emphasis is placed on evaluating evidence related to carcinogenicity, genotoxicity, metabolic effects, oxidative stress, gut microbiota interactions and other emerging health concerns through the integration of experimental, clinical and population-based studies. In addition, the review examines the scientific basis of international regulatory decisions, discusses the challenges of translating animal toxicology findings into human health risk assessment and identifies persistent knowledge gaps requiring further investigation. Current evidence consistently supports the safety of saccharin when consumed within established acceptable daily intake limits established by international regulatory agencies. Nevertheless, well-designed long-term human studies and mechanistic investigations remain necessary to better define its potential effects on metabolic health, the gut microbiome and susceptible populations. By integrating historical evidence with contemporary advances in toxicology and regulatory science, this review provides an updated framework for understanding the safety, biological effects and public health implications of saccharin consumption.
A. Qadir, A. Ahmed, Musa M. Zorab et al.· Journal of Applied Toxicolog...· 0 citations
This review combines the chemistry, processing and health-related aspects of anthocyanins in a single structure-processing function paradigm, limited to wheat, rice and maize, and evaluates the in vitro to human evidence in a logical framework. These compounds exhibit cereal-specific structural signatures: cyanidin-3-glucoside predominates across cereals like wheat, while maize displays the most complex glycosylation and acylation patterns. Preclinical and limited human evidence link pigmented cereal consumption to improved glycemic modulation (via inhibition of carbohydrate-digesting enzymes), enhanced insulin sensitivity, attenuation of NF-κB-mediated inflammation, and activation of Nrf2 antioxidant pathways; neuroprotective associations are so far supported almost exclusively by cell and animal models. However, the inherent instability of anthocyanins during milling, thermal processing, and cooking substantially compromises bioactivity. Emerging strategies, including encapsulation, superheated steam treatment, and fermentation, offer promising routes to enhance pigment stability and bioaccessibility. Addressing critical gaps in methodological standardization, human intervention studies, and microbiome-mediated metabolism is essential to advance pigmented cereals as functional food ingredients. Future research should prioritize integrated multi-omics approaches and personalized nutrition strategies to fully elucidate the health potential of these cereals across diverse populations.
Muhammad Bilal, Zain Ul Abideen, Nabila Murtaza et al.· Food Chemistry· 0 citations
We use cookies to run the site and, with your consent, for analytics and to show ads.
See our Cookie Policy.
