Nutritional dynamics of weeds in agroecosystem and their utilization in the agro-food industry within a circular economy framework

1 Introduction

Global food systems are facing unprecedented challenges driven by rapid population growth, climate change, declining biodiversity, land degradation and increasing pressure on natural resources. According to recent estimates, the global population is projected to approach 9.7 billion by 2050, placing considerable demands on agricultural production and food supply systems (Iasmin et al., 2025). Simultaneously, conventional agricultural practices are increasingly constrained by shrinking arable land, water scarcity, environmental degradation and rising production costs (Wijerathna-Yapa and Pathirana, 2022). These challenges highlight the urgent need to identify sustainable, resource-efficient and nutritionally diverse food sources that can complement existing agricultural systems while minimising environmental impacts (Aćimović et al., 2020; Altyar et al., 2022; Blassioli-Moraes et al., 2022; Ali et al., 2024).

The concept of the circular bio-economy has emerged as an important framework for addressing these challenges by promoting the efficient utilisation of renewable biological resources, reducing waste generation and creating value-added products from agricultural biomass (Jaroenkietkajorn et al., 2024). Rather than following the traditional linear model of resource extraction, consumption and disposal, circular agricultural systems emphasise recycling, reuse and valorisation of biological materials to improve sustainability and resource-use efficiency (Coannouer, 2015; Chen and Zhang, 2015; Cong et al., 2017; Chandrasena, 2021). Within this context, several underutilised plant resources have attracted increasing scientific attention because of their potential contributions to food security, environmental sustainability and rural livelihoods (Cornelis et al., 2019; Ghosh et al., 2019; Edwards et al., 2022; El-Ramady et al., 2022; Fan et al., 2023). Among these underutilised resources, edible weeds represent an important yet largely overlooked component of agricultural biodiversity. Traditionally, weeds have been regarded primarily as undesirable plants that compete with cultivated crops for water, nutrients, light and space, thereby reducing crop productivity and increasing production costs (Glaspie et al., 2021; Hartady et al., 2021; Idris Ahmed, 2021; Ilkow, 2021; Greer, 2022; Gupta et al., 2023). Consequently, weed management has historically focused on their complete eradication through mechanical, chemical, or cultural control measures. However, this conventional perspective has gradually evolved as increasing evidence demonstrates that numerous weed species possess considerable nutritional, medicinal, ecological and economic value.

The term edible weed refers to plant species that commonly occur in agricultural or disturbed environments and can be safely consumed following appropriate identification and preparation (Turner et al., 2011). Importantly, weed status is not an inherent botanical characteristic but is determined by ecological context and agricultural management practices. A plant considered a weed in one cropping system or geographical region may be intentionally cultivated elsewhere for food, fodder, or medicinal purposes. For example, several species of Amaranthus, Chenopodium and Portulaca occur naturally as weeds in many agricultural ecosystems while also being cultivated as leafy vegetables or grain crops in other regions. Consequently, their inclusion in this review is based on their documented occurrence as agricultural weeds together with evidence supporting their nutritional and agro-food relevance (Baddeley et al., 2017; Jan et al., 2017; Kakraliya et al., 2018; Kara et al., 2022).

Many edible weeds have been consumed for centuries as traditional foods by indigenous and rural communities across Asia, Africa, Europe and the Mediterranean region. Young leaves, tender shoots, flowers, seeds, roots and fruits of these plants are incorporated into salads, soups, cooked vegetables, herbal teas, fermented foods and traditional medicinal preparations (Lorenz and Dewey, 2019; Anwar et al., 2021; Malik et al., 2020; Martin et al., 2017; Masłowski et al., 2021). Their long history of consumption demonstrates that several weed species possess substantial cultural as well as nutritional importance (Kumar et al., 2015; Kumar, 2017; Lenka et al., 2017; Kregiel et al., 2018; Kianitalaei et al., 2019). Scientific interest in edible weeds has increased considerably during the past decade owing to growing recognition of their exceptional nutritional composition. Numerous studies have reported that species such as Portulaca oleracea, Taraxacum officinale, Urtica dioica, Chenopodium album, Stellaria media and Plantago major contain appreciable concentrations of dietary fibre, essential amino acids, vitamins, minerals, carotenoids, phenolic acids, flavonoids, betalains and essential fatty acids (Stegmann et al., 2020). These phytochemicals contribute not only to plant defence mechanisms but also to biological activities that have attracted considerable attention in nutrition and food science research (Abbas et al., 2024).

Research suggest that extracts or dietary preparations derived from several edible weeds exhibit antioxidant, anti-inflammatory, antimicrobial, hepatoprotective, hypoglycaemic, cardioprotective and immunomodulatory activities (McKenna et al., 2018; Milovanovic et al., 2022; Monteiro and Santos, 2022; Matías et al., 2024). These biological effects are primarily attributed to their diverse phytochemical constituents, which may modulate oxidative stress, inflammatory signalling pathways, glucose metabolism and lipid metabolism (Molina et al., 2014). However, although laboratory and animal studies provide encouraging evidence, relatively few well-designed clinical trials have evaluated these effects in humans. Therefore, many proposed health benefits should be interpreted cautiously until stronger clinical evidence becomes available. Beyond their nutritional and medicinal properties, edible weeds also present significant opportunities for sustainable agricultural development. Their ability to thrive under low-input conditions, tolerate environmental stress and produce considerable biomass makes them attractive candidates for climate-resilient agriculture and circular bio-economy initiatives. Weed biomass can potentially be utilised for human food, livestock feed, compost production, biofertilizers, nutraceuticals, natural food preservatives, pharmaceuticals, cosmetics, biodegradable biomaterials and other value-added products. Such diversified utilisation not only reduces agricultural waste but also contributes to resource recovery and improved sustainability within agroecosystems.

Despite increasing research interest, current knowledge regarding edible weeds remains fragmented across several scientific disciplines, including agronomy, food science, nutrition, pharmacology, veterinary science and environmental sustainability (Borsari and Vidrine, 2024). Most published studies focus on individual species or isolated applications, while comparatively few reviews critically integrate nutritional composition, functional properties, agro-food utilisation, livestock feeding potential and circular bio-economy perspectives within a single framework. Furthermore, considerable variation exists among studies with respect to species selection, phytochemical characterisation, analytical methodologies and reported biological activities, making direct comparisons difficult (Uusiku et al., 2010; Shaw and Charters, 2016; Singh et al., 2022; Wang, 2022; Sun et al., 2023).

Therefore, this narrative review critically evaluates the nutritional composition, phytochemical diversity, functional properties, agro-food applications, livestock feed potential and sustainability implications of selected edible weed species occurring in agricultural ecosystems. Particular emphasis is placed on evaluating the quality of available evidence, identifying current knowledge gaps, discussing food safety considerations and anti-nutritional factors and highlighting future research priorities required for the responsible utilisation of edible weeds within sustainable and circular agricultural systems.

2 Methodology

This study was conducted as a narrative literature review to critically synthesise current knowledge regarding the nutritional composition, phytochemical diversity, functional properties, agro-food applications, livestock feed potential and sustainability implications of edible weed species within the framework of the circular bio-economy. A comprehensive literature search was conducted using the electronic databases Scopus, Web of Science, PubMed, ScienceDirect and Google Scholar. Publications published between 2010 and 2026 were primarily considered, while earlier landmark studies were included where necessary to provide historical background or explain the development of current knowledge.

The literature search employed combinations of the keywords, and Boolean operators (AND, OR) were used to refine the search strategy and retrieve relevant publications from multiple disciplines. Studies were included in the review if they fulfilled one or more of the following criteria: investigated plant species that commonly occur as weeds in agricultural ecosystems, recognising that weed status is context-dependent and that some species may also be cultivated under specific regional conditions; reported nutritional composition, phytochemical constituents, or bioactive compounds; evaluated food, medicinal, livestock feed, industrial, or environmental applications of edible weeds; were published in peer-reviewed scientific journals; provided original research findings or comprehensive review articles relevant to the objectives of this review. The present review focuses on edible weed species that have been widely reported in agricultural landscapes and for which sufficient scientific information regarding nutritional composition and potential applications is available (Grivetti and Ogle, 2000). Representative species include P. oleracea, T. officinale, U. dioica, C. album, S. media, P. major and selected Amaranthus species. Although some Amaranthus species are intentionally cultivated as leafy vegetables or pseudocereals, others frequently occur as agricultural weeds in cropping systems worldwide. Their inclusion in this review reflects this dual ecological role and the availability of substantial literature concerning their nutritional and functional characteristics.

3 Edible weeds in agroecosystems: Ecological and agro-food relevance

Edible weeds constitute an important yet underutilised component of agricultural biodiversity. Traditionally, weeds have been viewed primarily as undesirable plants because they compete with cultivated crops for water, nutrients, light and space, thereby reducing agricultural productivity (Rana and Rana, 2016). Consequently, conventional weed management has largely focused on their suppression or eradication. However, growing interest in sustainable agriculture and circular bio-economy approaches has led to a reassessment of this perspective, with increasing recognition that many weed species possess considerable nutritional, medicinal, ecological and economic value.

The term edible weed refers to plant species that commonly occur in agricultural or disturbed environments and can be safely consumed following appropriate identification and preparation. Importantly, weed status is context-dependent rather than an inherent botanical characteristic. Several species discussed in this review, including selected Amaranthus species, may function as weeds in some cropping systems while being intentionally cultivated elsewhere for food, fodder, or medicinal purposes. Their inclusion in this review is therefore based on their documented occurrence in agricultural ecosystems together with evidence supporting their nutritional and agro-food relevance (Wijerathna-Yapa and Pathirana, 2022).

Many edible weeds exhibit remarkable ecological adaptability and can thrive under low-input conditions with minimal irrigation, fertiliser application, or pesticide use. Such resilience makes them attractive candidates for climate-resilient agriculture and resource-efficient food production. Their ability to establish naturally on marginal lands further reduces cultivation costs while creating opportunities for biomass utilisation within circular agricultural systems (Panoutsou et al., 2022).

Beyond their ecological adaptability, edible weeds frequently contain substantial concentrations of vitamins, minerals, dietary fibre, essential fatty acids and diverse phytochemicals. Increasing evidence suggests that several species possess antioxidant, anti-inflammatory, antimicrobial and metabolic regulatory properties, which have stimulated interest in their use as functional foods, nutraceutical ingredients, livestock feed resources and raw materials for value-added products. Nevertheless, the strength of evidence varies considerably among species, and many reported health benefits remain supported primarily by laboratory and animal studies rather than robust clinical trials (Knight, 2007).

Edible weeds also contribute to agroecosystem functioning through multiple ecological services, including soil stabilisation, nutrient cycling, organic matter accumulation and support for pollinators and beneficial insects. Weed biomass can be converted into compost, green manure, biofertilizers, biochar, livestock feed and other bio-based products, thereby supporting circular resource utilisation and reducing agricultural waste (Priya et al., 2023) (Figures 1–4).

Despite these advantages, widespread utilisation of edible weeds remains constrained by several challenges. Correct botanical identification is essential because some morphologically similar species may contain toxic compounds. Nutritional composition can vary substantially with environmental conditions, soil characteristics, growth stage and post-harvest handling. In addition, certain species accumulate anti-nutritional factors such as oxalates, phytates, tannins, nitrates and alkaloids that may reduce nutrient bioavailability or pose health concerns when consumed excessively. Appropriate processing methods, including boiling, blanching, drying and fermentation, can substantially reduce many of these compounds, although standardised processing protocols are still limited for commercial applications (Fellows, 2022).

Consumer perception represents another important barrier. In many societies, weeds continue to be associated with poor-quality foods or agricultural pests, which limits market acceptance despite their documented nutritional value. Future research should therefore focus on food safety assessment, standardisation of cultivation and processing practices, nutritional characterisation, toxicity evaluation and consumer education to facilitate the responsible utilisation of edible weeds within sustainable agro-food systems (Tables 1–6 and Figures 1, 2).

TABLE 1. Sustainable uses of weeds for product development and culinary applications.

TABLE 2. Study of different weeds: Habitat, uses and challenges.

TABLE 3. Nutritional and health benefits of edible weeds.

TABLE 4. Sustainable uses of weeds for product development and culinary applications.

TABLE 5. Biochemical constituents of weeds value in percent.

TABLE 6. Comparative nutritional composition of common weed species.

4 Nutritional composition of edible weeds

Edible weeds are increasingly recognised as valuable sources of macro- and micronutrients that can complement conventional diets and contribute to dietary diversity. Although their nutritional composition varies among species, geographical regions, environmental conditions and stages of plant development, several common characteristics have been consistently reported across the literature (Tables 1–6 and Figures 2–7).

4.1 Macronutrients

Species such as C. album, Amaranthus spp. And U. dioica are particularly noted for their relatively high protein content, although values vary according to growing conditions and maturity stage (Table 5).

4.2 Vitamins and minerals

Edible weeds frequently provide substantial quantities of vitamins A, C, E and K, together with essential minerals including calcium, iron, magnesium, potassium, zinc and manganese. For example, T. officinale and U. dioica have been reported to contain high concentrations of calcium and iron, whereas P. oleracea is recognised for its vitamin C content and mineral diversity. These nutrients play important roles in bone health, immune function, antioxidant defence and energy metabolism (Ghosh and Ghoshal, 2026).

4.3 Phytochemicals and bioactive compounds

One of the most distinctive features of edible weeds is their rich phytochemical composition. Numerous species contain phenolic acids, flavonoids, carotenoids, betalains, terpenoids, alkaloids, glucosinolates and essential fatty acids. These compounds contribute to plant defence mechanisms and are also associated with potential health-promoting properties in humans.

Portulaca oleracea is particularly notable for its content of alpha-linolenic acid (ALA), an omega-3 fatty acid that is relatively uncommon in terrestrial leafy vegetables. Taraxacum officinale contains phenolic acids such as chicoric and chlorogenic acids, while U. dioica is rich in flavonoids and caffeic acid derivatives. Such phytochemicals have been widely investigated for their antioxidant, anti-inflammatory and antimicrobial activities (Ghosh and Ghoshal, 2026).

4.4 Factors affecting nutritional composition

The nutritional quality of edible weeds is influenced by multiple factors, including species, genotype, soil fertility, climate, irrigation, harvesting stage and post-harvest processing (Polyzos et al., 2025). Young leaves often contain higher concentrations of certain vitamins and bioactive compounds than mature tissues, whereas mineral accumulation may increase with plant age. Consequently, direct comparisons among studies should be interpreted cautiously because differences in methodology and environmental conditions can substantially affect reported values.

4.5 Anti-nutritional factors

Despite their nutritional advantages, several edible weeds contain anti-nutritional compounds such as oxalates, phytates, tannins, nitrates and saponins. Excessive intake of these compounds may reduce mineral bioavailability or cause adverse effects in susceptible individuals. However, traditional processing methods, including boiling, blanching, soaking, drying and fermentation, have been shown to significantly reduce many anti-nutritional factors and improve the safety and nutritional quality of edible weeds (Soetan and Oyewole, 2009).

4.6 Nutritional significance

Overall, available evidence indicates that edible weeds can serve as nutrient-dense complementary foods capable of enhancing dietary diversity and providing valuable micronutrients and phytochemicals. Nevertheless, considerable variability exists among species and studies, underscoring the need for standardised nutritional evaluation and further research on bioavailability, safety and long-term dietary effects (Xiaoying et al., 2025).

5 Nutritional and functional potential of major edible weed species

The nutritional value and biological activities of edible weeds differ considerably among species owing to variations in their phytochemical composition, ecological adaptation and environmental conditions. While many edible weeds share common nutritional characteristics, individual species exhibit unique profiles that influence their potential applications in human nutrition, livestock feeding and functional food development. This section critically evaluates representative edible weed species with emphasis on their nutritional composition, bioactive constituents, mechanisms underlying reported biological activities, available experimental and clinical evidence and agro-food applications (Minteguiaga et al., 2023).

5.1 Portulaca oleracea L (Purslane)

5.1.1 Nutritional composition

Portulaca oleracea is one of the most extensively investigated edible weeds because of its exceptional nutritional profile. The leaves and young shoots contain appreciable quantities of dietary fibre, proteins, vitamins A, C and E, carotenoids, potassium, magnesium, calcium and iron. A distinguishing characteristic of purslane is its relatively high concentration of α-linolenic acid (ALA), making it one of the richest terrestrial plant sources of omega-3 fatty acids.

In addition to essential nutrients, purslane contains numerous phytochemicals, including flavonoids, phenolic acids, betalains, alkaloids and polysaccharides, which contribute to its biological activities (Kumar et al., 2022).

5.1.2 Bioactive compounds and mechanisms

The health-promoting properties of P. oleracea are largely attributed to its diverse phytochemical composition. Phenolic compounds and betalains act as potent antioxidants by scavenging reactive oxygen species (ROS) and enhancing endogenous antioxidant enzymes such as superoxide dismutase, catalase and glutathione peroxidase. Omega-3 fatty acids may reduce inflammatory responses through modulation of eicosanoid synthesis and suppression of pro-inflammatory cytokines, including tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6).

Experimental studies further suggest that polysaccharides isolated from purslane may improve glucose metabolism through enhanced insulin sensitivity and reduced oxidative stress, although these mechanisms require further clinical validation (Wang et al., 2023).

5.1.3 Evidence of biological activity

Numerous in vitro and animal studies have demonstrated antioxidant, anti-inflammatory, antimicrobial, hepatoprotective, hypoglycaemic and cardioprotective activities of purslane extracts. Dietary supplementation has been associated with improvements in serum lipid profiles, antioxidant status and glucose metabolism in experimental models. Although several small-scale clinical studies have reported favourable metabolic effects, the available evidence remains limited by modest sample sizes and methodological heterogeneity. Larger randomised controlled trials are therefore required before definitive health claims can be established.

5.1.4 Agro-food applications

Young leaves and stems are widely consumed as salads, cooked vegetables, soups and pickles. Owing to its high antioxidant capacity and omega-3 fatty acid content, purslane is increasingly being explored for incorporation into functional foods, fortified bakery products, beverages and nutraceutical formulations. Its adaptability to low-input agricultural systems further enhances its potential as a sustainable food resource.

5.2 Taraxacum officinale F.H. Wigg (Dandelion)

5.2.1 Nutritional composition

Taraxacum officinale is a nutrient-rich edible weed traditionally consumed in many parts of Europe and Asia. Its leaves contain considerable amounts of vitamins A, C and K, together with calcium, potassium, iron and dietary fibre. The plant is also rich in carotenoids, phenolic acids, flavonoids and sesquiterpene lactones, contributing to its high antioxidant capacity (Mars, 2016).

5.2.2 Bioactive compounds and mechanisms

Major bioactive constituents include chicoric acid, chlorogenic acid, luteolin derivatives and taraxasterol. These compounds have been shown to reduce oxidative stress through free radical scavenging and activation of endogenous antioxidant defence systems. Experimental evidence also suggests inhibition of NF-κB signalling pathways and decreased production of inflammatory mediators such as TNF-α and IL-1β, thereby providing a mechanistic basis for the anti-inflammatory properties traditionally attributed to dandelion.

5.2.3 Evidence of biological activity

Laboratory studies have demonstrated antioxidant, antimicrobial, anti-inflammatory and hepatoprotective activities of T. officinale. Animal studies indicate improvements in liver enzyme profiles and protection against oxidative damage. However, clinical investigations remain limited and further well-designed human studies are required to confirm these biological effects and establish effective dietary intake levels.

5.2.4 Agro-food applications

Young leaves are consumed as salads or cooked vegetables, while roasted roots are traditionally used as caffeine-free coffee substitutes. Taraxacum officinale is also incorporated into herbal teas, dietary supplements and functional beverages because of its antioxidant properties (Shaw and Charters, 2016).

5.3 Urtica dioica L (Stinging nettle)

5.3.1 Nutritional composition

Urtica dioica is widely recognised as one of the most nutritious wild leafy plants. The leaves contain substantial amounts of proteins, dietary fibre, chlorophyll, carotenoids, vitamins A, C and K, together with calcium, magnesium, iron and other essential minerals. Nettle is also a rich source of flavonoids, lignans, caffeic acid derivatives and chlorogenic acid (Jan et al., 2017).

5.3.2 Bioactive compounds and mechanisms

The anti-inflammatory properties of U. dioica are attributed primarily to flavonoids, caffeic acid derivatives and lignans, which inhibit cyclooxygenase (COX) and lipoxygenase (LOX) pathways involved in inflammatory mediator synthesis. Experimental studies further demonstrate suppression of NF-κB activation and reduced production of pro-inflammatory cytokines, including TNF-α, IL-1β and IL-6. The high antioxidant capacity of nettle additionally contributes to protection against oxidative stress (Taheri et al., 2022).

5.3.3 Evidence of biological activity

Extensive experimental evidence supports antioxidant, antimicrobial and anti-inflammatory activities of nettle extracts. Clinical investigations have reported symptomatic improvements in certain inflammatory conditions, including osteoarthritis and benign prostatic hyperplasia; however, available studies remain relatively small and vary considerably in design. Consequently, additional large-scale clinical trials are required before therapeutic recommendations can be made.

5.3.4 Agro-food applications

Following appropriate processing to remove stinging hairs, nettle leaves are widely consumed in soups, herbal teas, vegetable dishes and functional food products. The plant is also utilised in nutraceuticals, cosmetic formulations and livestock feed owing to its high nutritional value and bioactive compound content.

5.4 Chenopodium album L (Lamb’s quarters/bathua)

5.4.1 Nutritional composition

Chenopodium album is among the most nutritionally valuable edible weeds and has been traditionally consumed throughout South Asia, Europe and parts of Africa. The young leaves are rich in proteins, dietary fibre, essential amino acids, calcium, iron, magnesium, phosphorus, potassium and vitamins A. Compared with many commonly consumed leafy vegetables, C. album provides a balanced micronutrient profile, making it an important seasonal dietary resource in rural communities.

In addition to its nutritional constituents, the plant contains significant quantities of phenolic acids, flavonoids, carotenoids and chlorophyll pigments that contribute to its antioxidant properties (Nwozo et al., 2023).

5.4.2 Bioactive compounds and mechanisms

The principal bioactive compounds identified in C. album include quercetin, kaempferol, rutin, ferulic acid, chlorogenic acid and various carotenoids. These compounds neutralise reactive oxygen species, reduce lipid peroxidation and modulate inflammatory signalling pathways through suppression of NF-κB activation and reduced expression of pro-inflammatory cytokines (Majumdar et al., 2025; Minteguiaga et al., 2026).

Dietary fibre present in the leaves may also contribute to improved glycaemic control by slowing glucose absorption and promoting beneficial gut microbiota. However, these mechanisms have primarily been demonstrated under experimental conditions.

5.4.3 Evidence of biological activity

Experimental investigations have demonstrated antioxidant, antimicrobial, anti-inflammatory and hepatoprotective activities of C. album extracts. Animal studies further suggest beneficial effects on glucose metabolism and lipid regulation. Nevertheless, evidence from well-designed human clinical trials remains limited, preventing definitive conclusions regarding therapeutic efficacy.

5.4.4 Food and agro-food applications

Young leaves are widely consumed as cooked vegetables, soups, flatbread fillings and traditional dishes. Owing to its high nutritional value, C. album has potential applications in dehydrated vegetable powders, fortified foods and nutrient-enriched formulations. The plant also represents a valuable supplementary forage resource for livestock because of its favourable protein and mineral composition.

5.4.5 Limitations

Like several leafy weeds, C. album contains oxalates and saponins that may reduce mineral bioavailability if consumed in excessive quantities. Traditional cooking and blanching substantially reduce these compounds and improve nutritional quality.

5.5 Amaranthus spp

5.5.1 Nutritional composition

Due to their dual ecological role, species in the genus ecological role, species in the genus Amaranthus hold a special place in this review. Some species occur naturally as agricultural weeds in various cropping systems, while others are purposefully grown as leafy vegetables or pseudocereals. Their inclusion in this review thus reflects both their acknowledged nutritional significance and their reported presence as weeds in numerous agroecosystems (Ilkow, 2021).

Significant amounts of proteins, dietary fibre, calcium, iron, magnesium, potassium, folates, and vitamins A and C can be found in the leaves of Amaranthus species. Their more favourable amino acid content, which includes higher amounts than many cereal grains, makes them very valuable (Majumdar et al., 2025).

5.5.2 Bioactive compounds and mechanisms

Betalains, phenolic acids, flavonoids, carotenoids, and tocopherols are important phytochemicals. By lowering oxidative stress and shielding biological components from free radical damage, these substances demonstrate antioxidant activity. Additionally, experimental evidence suggests anti-inflammatory benefits through suppression of oxidative pathways linked to chronic illness and control of cytokine production.

5.5.3 Evidence of biological activity

Amaranthus species extracts have been shown to have antibacterial and antioxidant properties in numerous laboratory experiments, and research on animals indicates that they may have positive effects on oxidative state and lipid metabolism. There is still very little human evidence, and it frequently comes from nutritional studies that assess cultivated Amaranthus vegetables rather than weedy populations. Therefore, it is important to exercise caution when extrapolating to all A. species.

5.5.4 Food and industrial applications

In many tropical and subtropical climates, leaves are eaten as cooked vegetables, soups, curries, and traditional cuisines. While leafy biomass has potential uses in functional meals, livestock feed, and nutraceutical goods, the seeds of cultivated species are commonly used as pseudocereals. The usefulness of Amaranthus species in circular agricultural approaches is further supported by their ability to adapt to low-input production methods.

5.5.5 Limitations

There have been reports of nitrate buildup in some Amaranthus species under particular environmental circumstances. Therefore, it is crucial to use proper growth techniques, harvesting plans, and processing techniques to guarantee food safety.

5.6 Plantago major L (Broadleaf plantain)

5.6.1 Nutritional composition

Plantago major has long been utilised as both a food and a medicinal plant in many traditional cultures. The young leaves contain dietary fibre, calcium, potassium, magnesium, vitamins A and C, together with numerous secondary metabolites that contribute to their biological activity.

A distinguishing characteristic of P. major is the presence of mucilage polysaccharides, which influence both its nutritional and functional properties (Behbahani et al., 2017).

5.6.2 Bioactive compounds and mechanisms

Important bioactive constituents include acteoside, aucubin, catalpol, flavonoids, tannins and phenolic acids. These compounds exhibit antioxidant and anti-inflammatory activities through scavenging reactive oxygen species, inhibition of inflammatory mediators and modulation of immune responses.

The soluble mucilage present in the leaves and seeds may contribute to improved glycaemic regulation by delaying gastric emptying and reducing glucose absorption following meals (Chand et al., 2024).

5.6.3 Evidence of biological activity

Experimental studies consistently demonstrate antimicrobial, wound-healing, antioxidant and anti-inflammatory activities. Traditional medicinal applications have been documented extensively; however, relatively few controlled clinical studies have confirmed these therapeutic effects. Consequently, further clinical investigation is required before specific health claims can be substantiated.

5.6.4 Food and industrial applications

Young leaves are consumed in salads, soups and cooked vegetable preparations. Owing to their mucilage content, Plantago species are also used in dietary fibre supplements and functional food formulations (Strkalj et al., 2025). Extracts have potential applications in cosmetic products, pharmaceutical preparations and natural preservatives.

5.6.5 Limitations

The nutritional composition of P. major varies considerably with environmental conditions and harvesting stage. Standardization of cultivation and processing practices remains necessary to support wider commercial utilization (Bano et al., 1988).

5.7 Stellaria media (L.) vill (Common chickweed)

5.7.1 Nutritional composition

Stellaria media is traditionally used in North America, Europe, and Asia. Stellaria media is a widely distributed edible weed. Young leaves and young shoots include significant amounts of vitamin C, provitamin A carotenoids, calcium, magnesium, potassium, and nutritional fibre. They can be consumed fresh in salads or mildly cooked. Despite having less protein than C. album and U. dioica, it is nonetheless a useful seasonal source of minerals. The plant’s antioxidant potential is further enhanced by the presence of flavonoids, phenolic acids, saponins, triterpenoids, and chlorophyll pigments.

5.7.2 Bioactive compounds and mechanisms

The principal bioactive constituents include apigenin, luteolin derivatives, rutin, chlorogenic acid and triterpenoid saponins. These compounds reduce oxidative stress by scavenging reactive oxygen species and may suppress inflammatory signalling through inhibition of NF-κB activation and reduced cytokine production (Chagas et al., 2022).

Experimental studies also suggest that certain phytochemicals may contribute to antimicrobial activity by disrupting microbial cell membranes and inhibiting bacterial growth.

5.7.3 Evidence of biological activity

Laboratory investigations have demonstrated antioxidant, antimicrobial, anti-inflammatory and wound-healing activities. Animal studies indicate possible hepatoprotective and metabolic benefits; however, robust human clinical evidence remains scarce. Consequently, the medicinal potential of S. media should currently be regarded as promising rather than clinically established.

5.7.4 Food and agro-food applications

Young shoots are consumed in salads, soups, vegetable preparations and herbal teas. Because of its mild flavour and nutritional composition, S. media has potential for incorporation into fresh salad mixes, dehydrated vegetable powders and functional food products. The plant may also serve as supplementary forage for small livestock under appropriate management conditions.

5.7.5 Limitations

The phytochemical composition of S. media varies considerably with environmental conditions and growth stage. Additional research is required to standardise processing methods and evaluate long-term dietary safety.

5.8 Oxalis spp

5.8.1 Nutritional composition

Oxalis Species are traditionally consumed in several regions as leafy vegetables, condiments, or flavouring agents because of their characteristic sour taste. The leaves contain vitamin C, potassium, magnesium, dietary fibre and several phenolic compounds. Their pleasant acidity is primarily attributable to naturally occurring organic acids.

5.8.2 Bioactive compounds and mechanisms

The antioxidant activity of Oxalis species has been associated with flavonoids, anthocyanins, phenolic acids and vitamin C. These compounds contribute to the neutralisation of reactive oxygen species and protection against oxidative damage (Zhong et al., 2025).

Experimental evidence also suggests anti-inflammatory and antimicrobial activities, although the underlying molecular mechanisms remain less extensively investigated than for species such as purslane or nettle.

5.8.3 Evidence of biological activity

Most available evidence derives from phytochemical analyses and laboratory investigations. Human clinical studies evaluating the nutritional or therapeutic effects of O. species remain extremely limited (Majumdar et al., 2026). Therefore, current evidence primarily supports their nutritional rather than medicinal significance.

5.8.4 Food and agro-food applications

Leaves are consumed fresh in salads, chutneys, soups and traditional culinary preparations. Their characteristic acidic flavour also makes them suitable as natural flavouring ingredients in selected food products.

5.8.5 Limitation

A major nutritional limitation of O. species is their relatively high oxalic acid content. Excessive consumption may reduce calcium bioavailability and increase the risk of kidney stone formation in susceptible individuals. Moderate consumption together with appropriate culinary processing is therefore recommended.

6 Functional properties and health-promoting potential of edible weeds

6.1 Functional foods and bioactive phytochemicals

Edible weeds have drawn more scientific attention as valuable sources of bioactive phytochemicals that offer health advantages beyond basic nutrition due to the growing interest in functional meals. As adaptive reactions to environmental stresses like drought, UV radiation, herbivory, and pathogen attack, edible weeds frequently accumulate higher concentrations of phenolic compounds, flavonoids, carotenoids, glucosinolates, alkaloids, terpenoids, and polysaccharides than many cultivated vegetables. Edible weeds are intriguing components of functional foods and nutraceuticals because their phytochemicals have been linked to antioxidant, anti-inflammatory, antibacterial, and metabolic-regulating effects (Petropoulos et al., 2018; Shakya, 2016).

One of the best plant sources of α-linolenic acid (omega-3 fatty acid) among edible weeds, P. oleracea also has significant levels of phenolic compounds, flavonoids, vitamin A, C and E, which contribute to its great antioxidant potential. In a similar vein, phenolic chemicals are abundant in U. dioica (up to 129.5 129.5 mg gallic acid equivalents g^-1 extract) and exhibit strong free radical scavenging activity with reported DPPH IC₅₀ values ranging from approximately 30–70 μg mL^-1, based on the plant portion and extraction solvent (Bhusal et al., 2022; Kureshi et al., 2025).

However, as many phytochemicals’ absorption, metabolism and pharmacokinetics are still poorly understood, antioxidant activity determined in vitro should not be taken as direct proof of therapeutic benefit. Therefore, before these bioactive substances may be suggested for regular dietary or pharmaceutical usage, more human clinical research is needed to determine effective doses, long-term safety and therapeutic relevance (Shakya, 2016; Kureshi et al., 2025).

6.2 Antioxidant properties

An imbalance between the production of reactive oxygen species (ROS) and endogenous antioxidant defence systems causes oxidative stress, which damages cells and is linked to cancer, diabetes mellitus, neurodegenerative diseases, chronic inflammation and cardiovascular diseases (Lobo et al., 2010). The phenolic compounds, flavonoids, carotenoids, and vitamins C and E found in many edible weeds can scavenge free radicals, chelate transition metals, and boost endogenous antioxidant enzymes like glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD) (Bhusal et al., 2022; Kureshi et al., 2025).

Strong antioxidant activity has been shown by edible weeds such as has been shown by edible weeds such as P. oleracea, T. officinale, U. dioica, C. album, and Amaranthus spp. For example, DPPH radical scavenging action has been demonstrated by U. dioica extracts, with reported IC50 values ranging from around 30–70 μg mL^-1. However, because of its high phenolic and flavonoid content, P. oleracea shows strong antioxidant potential (Bhusal et al., 2022; Kureshi et al., 2025). However, there are still few well-designed human clinical investigations, and the majority of the evidence comes from in vitro testing. Therefore, before these antioxidant qualities may be translated into therapeutic recommendations, more study is needed to determine appropriate doses, bioavailability and clinical efficacy (Shakya, 2016; Kureshi et al., 2025).

6.3 Anti-inflammatory activity

Several non-communicable diseases, including obesity, cardiovascular disease, type 2 diabetes, arthritis and several types of cancer, are significantly increased by chronic low-grade inflammation. According to experimental research, several edible weeds reduce inflammation by blocking nuclear factor-kappa B (NF-κB) signalling, inhibiting pro-inflammatory cytokines and the cyclooxygenase (COX) and lipoxygenase (LOX) pathways (TNF-α, IL-1β, and IL-6), and modulating nitric oxide production (Shakya, 2016; Bhusal et al., 2022).

Among edible weeds, U. dioica has demonstrated significant inhibition of NF-κB activation and the generation of pro-inflammatory cytokines in both animal and in vitro research. While P. oleracea demonstrates anti-inflammatory activity through its omega-3 fatty acids, flavonoids and phenolic compounds, T. officinale contains bioactive components including taraxasterol and chicoric acid that decrease inflammatory mediators. Although there is still little data from carefully planned human treatment trials, P. oleracea extract given at doses of 100–400 mg kg^-1 body weight considerably reduced inflammatory responses in experimental models (Kureshi et al., 2025; Schütz et al., 2006; Bhusal et al., 2022).

6.4 Antidiabetic potential

Growing evidence of research indicates that a number of edible weeds may enhance glucose homeostasis through a variety of mechanisms, such as inhibiting α-amylase and α-glucosidase, delaying the digestion of carbohydrates, improving insulin sensitivity, lowering oxidative stress and increasing peripheral glucose uptake (Shakya, 2016; Kureshi et al., 2025).

Several of the evaluated species, P. oleracea, P. major, and C. album, have shown encouraging hypoglycemic action in tests. While P. major and C. album have demonstrated inhibitory effects against α-amylase and α-glucosidase enzymes, suggesting their potential role in glycaemic control, P. oleracea extract administered at doses of 100–400 mg kg^-1 body weight significantly reduced fasting blood glucose and improved insulin sensitivity in diabetic animal models (Kureshi et al., 2025; Samuelsen, 2000; Shakya, 2016).

However, depending on the extraction technique, dosage, length of therapy and experimental animal, the observed antidiabetic effects differ significantly. Therefore, before these edible weeds can be suggested for the control of diabetes, carefully planned human clinical trials are needed.

6.5 Cardiovascular benefits

Bioactive substances linked to cardiovascular health can be found in a number of edible weeds, such as dietary fibre, potassium, magnesium, omega-3 fatty acids, flavonoids and phenolic compounds. Through their antioxidant and anti-inflammatory qualities, these components may boost endothelial function, lower low-density lipoprotein (LDL) oxidation, improve lipid metabolism, and help regulate blood pressure (Lobo et al., 2010; Kureshi et al., 2025).

Urtica dioica and T. officinale offer significant amounts of potassium, magnesium, and phenolic compounds that promote cardiovascular health, while P. oleracea is one of the richest plant sources of α-linolenic acid (omega-3 fatty acid), with about 300–400 mg per 100 g fresh weight (Kureshi et al., 2025; Bhusal et al., 2022; Schütz et al., 2006). However, before edible weeds may be suggested as therapeutic interventions for cardiovascular disorders, well-designed human clinical trials are still needed, as the majority of the evidence currently available comes from experimental and observational studies.

6.6 Antimicrobial activity

Several edible weed extracts show inhibitory efficacy against certain fungal diseases and both Gram-positive and Gram-negative bacteria. Phenolic compounds, flavonoids, alkaloids, terpenoids, and organic acids have all been linked to these antimicrobial effects. These compounds cause oxidative damage, interfere with nucleic acid synthesis, disrupt microbial cell membranes, and inhibit vital enzymes (Kureshi et al., 2025; Bhusal et al., 2022).

Significant antibacterial activity has been shown by P. oleracea, U. dioica, and Plantago spp. Major among the examined species. Depending on the extract type and test organism, published studies have revealed minimum inhibitory concentration (MIC) values against common pathogens, such as Escherichia coli and Staphylococcus aureus, ranging from about 0.5 to 4.0 mg mL^-1 (Kureshi et al., 2025; Samuelsen, 2000). These concentrations, however, are typically higher than those attained by regular dietary consumption. Therefore, rather than being used as direct medicinal agents, the evidence now available supports their use mainly as natural food preservatives or sources of antibacterial chemicals.

6.7 Other functional properties

Additional biological actions of edible weeds, including hepatoprotective, gastroprotective, neuroprotective, immunomodulatory, wound-healing and anticancer effects, have been reported in experimental research. Phenolic compounds, flavonoids, polysaccharides, terpenoids, and other bioactive metabolites that control oxidative stress, inflammation, apoptosis, and immunological responses have been linked to these activities (Kureshi et al., 2025; Bhusal et al., 2022; Shakya, 2016).

For instance, in experimental animal models, P. oleracea extract at doses of 100–400 mg kg^-1 body weight has demonstrated hepatoprotective and gastroprotective effects, while U. dioica has shown wound-healing and immunomodulatory mediators and antioxidant enzymes (Kureshi et al., 2025; Bhusal et al., 2022). These conclusions, however, are mostly based on preclinical research employing concentrated extracts, and direct comparison between studies is limited by differences in extraction techniques, experimental models and phytochemical composition. Therefore, before these functional features can be converted into therapeutic applications, future research should focus on standardised extraction techniques, pharmacokinetic evaluation, dose-response relationships, and well-designed randomised clinical trials.

6.8 Critical evaluation of current evidence

The overall quality of the evidence is still low, despite the increasing number of studies detailing the biological activity of edible weeds. While well-designed randomised human clinical trials assessing efficacy, appropriate dosage, and long-term safety are rare, the majority of published findings are based on in vitro assays and animal investigations (Shakya, 2016; Kureshi et al., 2025). Furthermore, it is challenging to compare studies because claimed biological activities frequently vary with extraction techniques, plant origin, phytochemical composition, and experimental settings (Bhusal et al., 2022).

While several edible weeds, including P. oleracea and U. dioica in particular, have shown promising antioxidant, anti-inflammatory, antimicrobial and antidiabetic activities in experimental models, these effects have typically been observed at extract doses of 100–400 mg kg^-1 body weight or under laboratory conditions that are unlikely to be achieved through normal dietary intake (Kureshi et al., 2025; Bhusal et al., 2022). As a result, current research emphasises the need for standardised extraction techniques, pharmacokinetic analyses, and extensive clinical trials in order to support the inclusion of edible weeds as nutritionally beneficial elements of varied diets rather than as alternatives to proven medicinal treatments.

7 Industrial and commercial applications of edible weeds in the circular bio-economy

7.1 Edible weeds as resources for sustainable agro-food systems

Finding and utilizing underutilized biological resources that can improve food security, nutritional variety, and resource-use efficiency is necessary for the shift to sustainable food systems. In this regard, edible weeds are important biomass resources that can support several bioeconomic sectors. They are appealing candidates for the production of value-added goods because of their nutritional richness, tolerance to a variety of environmental circumstances, and capacity to flourish under low-input agricultural systems (Sharma et al., 2021). The potential applications of selected edible weeds in product development, culinary uses, and sustainability are summarized in Table 1.

Many edible weeds grow spontaneously in agroecosystems and provide significant biomass with little assistance from outside sources, in contrast to conventional agricultural commodities that are frequently linked to intense cultivation requirements. As a result, their use is in line with the circular bio-economy’s emphasis on sustainable production, resource recovery, and waste reduction.

7.2 Functional foods and nutraceutical development

The use of edible weeds in functional food composition has expanded due to growing consumer interest in health-promoting foods. They are appropriate foods. Components for nutrient-enriched diets due to their high concentrations of vitamins, minerals dietary fibre, phenolic compounds, flavonoids, carotenoids, and essential fatty acids (Petropoulos et al., 2018; Bhusal et al., 2022; Kureshi et al., 2025). Because of their nutritional and bioactive makeup, several edible weeds, such as and bioactive makeup, P. oleracea, U. dioica, and C. album, have demonstrated potential for use in baked goods, drinks, dietary supplements, and fortified foods (Kureshi et al., 2025; Petropoulos et al., 2018; Bhusal et al., 2022). To standardize processing techniques and clinically prove their nutraceutical advantages (Shakya, 2016).

7.3 Natural food preservatives and food additives

Research in plant-derived substitutes for artificial preservatives has grown due to consumer demand for natural ingredients. Many edible weeds, including P. oleracea, contain Phenolic chemicals, flavonoids, essential oils, and other bioactive metabolites with antibacterial and antioxidant qualities, which are found in many edible weeds and may improve food stability and increase shelf life (Kureshi et al., 2025; Bhusal et al., 2022). Preventing lipid oxidation, lowering microbial spoiling, improving colour stability, and enhancing overall product quality during storage are some possible uses. Despite encouraging preservation potential in laboratory investigations, commercial application is still restricted because of issues with extraction efficiency, standardization, sensory qualities and regulatory approval (Bingol et al., 2021).

Future studies should concentrate on determining customer acceptance of goods containing compounds derived from marijuana and examining the effectiveness of preservatives under practical food processing circumstances.

7.4 Pharmaceutical and nutraceutical applications

In the past, traditional medical systems in Asia, Europe, Africa and the Americas have used a variety of edible weeds. Numerous bioactive substances, such as phenolics, flavonoids, alkaloids, terpenoids and carotenoids have been discovered by contemporary phytochemical research and may support their traditional medicinal uses (Shakya, 2016; Kumar et al., 2021). Numerous in vitro and animal investigations have shown the reported biological activities, which include antioxidant, anti-inflammatory, antibacterial, hepatoprotective, wound-healing and metabolic regulating actions (Shakya, 2016; Bhusal et al., 2022).

Research in creating therapeutic and nutraceutical products from edible weed biomass has increased as a result of these findings. However, because the majority of the evidence is obtained from laboratory and preclinical investigations, clinical translation is still restricted. Standardised dosage, bioavailability, toxicity profiles, and long-term safety must be established by well-planned human clinical trials (Kureshi et al., 2025; Shakya, 2016; Kumar et al., 2021). Therefore, rather than being recognised as pharmaceutical treatments, edible weeds should now be viewed as possible sources of bioactive chemicals.

7.5 Cosmetic and personal care applications

Plant-based compounds with anti-inflammatory, moisturising, antioxidant and skin-protective qualities are becoming more and more sought after by the cosmetics industry. Flavonoids, phenolic acids, carotenoids, and other bioactive substances found in extracts from a variety of edible weeds help shield the skin from oxidative stress and environmental harm.

(Bhusal et al., 2022; Shakya, 2016). Anti-ageing formulas, moisturisers, skin-soothing products, hair care products, and natural cosmetics preservatives are examples of potential uses. Because of their antioxidant and anti-inflammatory qualities, U. dioica, T. officinale, and P. spp. Are particularly well-known for their phytochemical composition and potential application in skin-care and cosmetic formulations (Bhusal et al., 2022). Before large-scale cosmetic uses may be realised, further research is required to show efficacy, safety, formulation stability and regulatory compliance, despite increased commercial interest.

7.6 Livestock feed and animal nutrition

The use of edible weeds as animal feed is one of their many practical uses. Proteins, minerals, vitamins, and bioactive substances found in many edible weed species can enhance animal nutrition while lowering dependency on traditional feed sources (Bhusal et al., 2022; Mavengahama et al., 2013). Because of their advantageous nutritional composition, species like U. dioica, C. album, A. spp., and P. oleracea have shown promise as supplemental feed ingredients for ruminants, poultry, rabbits, and other livestock (Kureshi et al., 2025; Mavengahama et al., 2013; Bhusal et al., 2022).

Improved nutrient intake, improved growth performance, better feed utilisation, higher antioxidant status and possible improvements in animal health are among the benefits that have been reported. However, it is important to carefully consider elements like digestibility, palatability, anti-nutritional chemicals, and species-specific safety. Further research is required to determine optimal inclusion levels and evaluate long-term effects on animal productivity (Kureshi et al., 2025; Mavengahama et al., 2013).

7.7 Biofertilizers, compost and biomass valorisation

Instead of disposing of biological materials as waste, the circular bio-economy focuses on turning them into products with additional value. In this regard, edible weeds present substantial chances for sustainable resource use and biomass valorisation (Stegmann et al., 2020). Weed biomass can be used to make compost, green manure, biofertilizers, vermicomposting, charcoal, and biogas. These uses improve soil fertility, increase organic matter content, recycle nutrients, and lessen reliance on artificial agricultural inputs (Stegmann et al., 2020; Bote et al., 2020). Therefore, including weed biomass into circular agricultural systems promotes environmental sustainability while producing revenue from materials that are typically thought of as waste.

7.8 Commercialisation challenges and future prospects

The widespread commercialisation of edible weeds is still constrained by a number of obstacles, despite their significant potential. Variability in phytochemical composition, the absence of standardised harvesting and processing procedures and food safety issues like pesticide contamination, heavy metal accumulation, anti-nutritional factors and species misidentification are major obstacles (Shakya, 2016).

Regulations about novel foods, quality control standards, labelling laws and low consumer acceptance because of unfavourable opinions about the name “weed” and ignorance of its nutritional worth are further limitations.

Agronomists, food scientists, nutritionists, toxicologists, legislators and business stakeholders must work together across academic boundaries to address these issues. Standardised cultivation procedures, food safety evaluations, clinical validation of health claims, economic viability analyses, consumer acceptability studies and commercialisation paths should be the top priorities for future research (Stegmann et al., 2020).

7.9 Synthesis: edible weeds within the circular bio-economy

Collectively, the evidence reviewed suggests that edible weeds possess considerable potential to contribute to sustainable agro-food systems through multiple pathways. Their value extends beyond direct human consumption to include livestock feeding, functional food development, nutraceutical production, natural preservatives, cosmetics, composting and biomass valorisation.

However, their contribution should not be viewed as a replacement for conventional crops. Rather, edible weeds represent complementary biological resources capable of enhancing dietary diversity, improving resource-use efficiency, reducing waste and supporting circular agricultural systems. Realising this potential will require rigorous scientific validation, improved processing technologies, supportive regulatory frameworks and increased public awareness.

8 Discussion

The findings synthesised in this review demonstrate that edible weeds represent an important yet underutilised component of agricultural biodiversity with considerable potential to contribute to sustainable food systems and circular bio-economy initiatives. Traditionally regarded as undesirable plants that compete with cultivated crops for essential resources, many edible weeds possess nutritional characteristics comparable with and in some cases superior to those of several commonly cultivated leafy vegetables. Their ability to thrive under low-input agricultural conditions, adapt to diverse environmental stresses and produce substantial biomass without intensive cultivation further strengthens their relevance within sustainable agricultural systems. Nevertheless, the available evidence suggests that edible weeds should not be viewed as replacements for conventional crops but rather as complementary resources capable of enhancing dietary diversity, improving resource-use efficiency and supporting resilient food systems. This distinction is particularly important because the current body of evidence does not justify broad claims that edible weeds alone can substantially resolve global food security challenges.

A consistent observation across the reviewed literature is the considerable variability in the nutritional composition and phytochemical profiles of edible weeds. Differences among species are influenced by genotype, geographical location, soil characteristics, climatic conditions, harvesting stage and post-harvest handling, as well as by differences in analytical methodologies employed across studies. Consequently, nutrient concentrations reported for species such as C. album, U. dioica and Amaranthus spp. Often vary substantially among investigations, making direct comparisons difficult. These inconsistencies highlight the need for standardised sampling procedures, analytical protocols and reporting practices that would facilitate meaningful comparisons and improve the reliability of future nutritional assessments.

Another important finding emerging from this review is the imbalance between experimental and clinical evidence supporting the proposed health benefits of edible weeds. Numerous investigations have demonstrated antioxidant, anti-inflammatory, antimicrobial, hepatoprotective, hypoglycaemic and cardioprotective activities using in vitro assays and animal models. Mechanistically, these biological activities are largely attributed to the presence of phenolic compounds, flavonoids, carotenoids, betalains and other bioactive metabolites capable of reducing oxidative stress, modulating inflammatory signalling pathways and influencing glucose and lipid metabolism. However, relatively few well-designed randomised controlled clinical trials have evaluated these effects in humans. Consequently, although the available experimental evidence is encouraging, many proposed health benefits should currently be interpreted with caution until stronger clinical validation becomes available. Future investigations should therefore prioritise human intervention studies that evaluate not only efficacy but also bioavailability, optimal dietary intake, long-term safety and interactions with conventional therapies.

Food safety remains another critical consideration for the wider utilization of edible weeds. While these plants offer significant nutritional advantages, several species possess the capacity to accumulate heavy metals, pesticide residues, nitrates, oxalates, phytates and other anti-nutritional compounds depending upon environmental conditions and cultivation practices. Furthermore, the possibility of incorrect botanical identification may increase the risk of accidental consumption of toxic species with similar morphological characteristics. These challenges emphasise the importance of developing standardised cultivation protocols, quality assurance systems, contaminant monitoring programmes and evidence-based processing methods capable of reducing anti-nutritional factors while preserving nutritional quality. Appropriate consumer education and regulatory oversight will also be essential for ensuring the safe incorporation of edible weeds into mainstream food systems.

Beyond their direct nutritional value, edible weeds demonstrate considerable potential for diversified commercial utilization within circular agricultural systems. The literature reviewed indicates promising opportunities for incorporating edible weeds into functional foods, nutraceuticals, dietary supplements, natural food preservatives, cosmetics, livestock feed, compost, biofertilizers and renewable bioenergy production. Their multifunctional utilisation is particularly attractive because it enables agricultural biomass that is traditionally regarded as waste to be transformed into value-added products, thereby improving resource-use efficiency and reducing environmental impacts. However, despite increasing scientific interest, relatively few edible weed-based products have progressed beyond laboratory research or small-scale commercial production. The principal constraints include variability in raw material quality, insufficient clinical validation of health claims, lack of standardised processing technologies, regulatory uncertainty and limited consumer awareness. Addressing these barriers will require interdisciplinary collaboration among agronomists, food scientists, nutritionists, toxicologists, economists, policymakers and industry stakeholders.

The concept of the circular bio-economy provides an appropriate framework within which the future utilisation of edible weeds can be considered. Unlike conventional linear agricultural systems, circular bio-economy models emphasize the efficient use of renewable biological resources through recycling, reuse and value addition. Within this framework, edible weeds can simultaneously contribute to human nutrition, animal feeding, nutrient recycling, soil fertility improvement, compost production, biofertilizer development and renewable energy generation. Such multifunctionality distinguishes edible weeds from many conventional agricultural commodities and supports their integration into diversified farming systems. Nevertheless, successful implementation will require not only scientific validation but also economic feasibility analyses, life-cycle assessments, supportive regulatory policies and consumer acceptance studies to determine whether these resources can be integrated into sustainable commercial production systems.

Overall, this review demonstrates that edible weeds possess genuine nutritional, ecological and economic potential; however, the current evidence base remains characterized by considerable methodological heterogeneity and limited clinical validation. Future research should therefore move beyond descriptive phytochemical investigations towards multidisciplinary studies integrating agronomy, food science, nutrition, toxicology, clinical medicine, economics and sustainability assessment. Particular emphasis should be placed on standardised nutritional characterisation, large-scale clinical trials, food safety evaluation, processing optimisation, commercialisation strategies and life-cycle assessment. Such integrated research will provide a stronger scientific foundation for the responsible utilisation of edible weeds and facilitate their incorporation into sustainable agro-food systems and circular bio-economy initiatives (Damavandi et al., 2023).

9 Conclusion

Due to their nutritional value, bioactive phytochemical makeup, and several industrial uses, edible weeds are a diverse group of neglected plant species with significant potential to support sustainable food systems. Numerous edible weeds are important providers of vital vitamins, minerals, dietary fibre, proteins, and health-promoting secondary metabolites that may support metabolic, antibacterial, anti-inflammatory, and antioxidant processes, according to the reviewed literature. These species promote the circular bio-economy’s tenets by providing promising opportunities for integration into functional meals, nutraceuticals, livestock feed, natural food preservatives, cosmetics, and other value-added uses in addition to their nutritional worth.

Despite these encouraging qualities, the available data clearly highlights significant limits. While there is still a dearth of high-quality human clinical evidence, a large portion of the knowledge that is currently accessible comes from phytochemical analyses, laboratory research, and animal studies. Significant differences in species composition, environmental factors, harvesting procedures, processing techniques, and analytical methodologies all make it difficult to compare studies directly and restrict how broadly published results may be applied. Before large-scale commercialisation and widespread dietary acceptance can be advised, food safety concerns, such as the possible accumulation of heavy metals, pesticide residues, nitrates, and anti-nutritional chemicals, must also be thoroughly addressed.

The information that is now available supports the role as complementing biological resources that can increase food diversity, improve resource-use efficiency, and foster more resilient agricultural systems rather than portraying them as alternatives to traditional crops. Their incorporation into diverse farming systems can improve rural lives and environmental sustainability while promoting sustainable biomass consumption, decreased agricultural waste, and the creation of novel value-added products. Standardised farming methods, thorough food safety assessments, enhanced processing technology, encouraging legal frameworks, and raised consumer knowledge are necessary to achieve these advantages.

Comprehensive nutritional characterisation, standardised phytochemical analysis, carefully planned randomised clinical trials, bioavailability studies, toxicological evaluations, life-cycle analyses, and economic feasibility assessments should be the top priorities for future research. Transforming experimental results into useful applications would require interdisciplinary cooperation between agronomists, food scientists, nutritionists, toxicologists, economists, legislators, and industrial stakeholders. By filling in these knowledge gaps, edible weeds can be more successfully incorporated into circular bio-economy strategies and sustainable agro-food systems, improving resource efficiency and diversifying food production while enhancing rather than replacing traditional agricultural methods.

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Footnotes

Edited by: Nazimah Hamid, Auckland University of Technology, New Zealand

Reviewed by: Sharad Kumar Tripathi, Patanjali Research Institute, India

Francisco Valenzuela Zamudio, TecMilenio University, Mexico