The road ahead for functional foods: Promising opportunities amidst industry challenges

Functional foods, fortified with bioactive compounds, offer health benefits beyond basic nutrition. Despite their potential, challenges such as compound instability, scalability issues, and regulatory gaps exist. This commentary explores their role, market dynamics, and future trends, emphasizing the need for ongoing research and effective regulations. In the dynamic field of nutrition science, functional foods have carved a significant niche. These foods, which offer more than just basic nutrition, are fortified with bioactive compounds such as antioxidants (e.g., phenolic compounds, carotenoids, omega-3 fatty acids, some vitamins) that confer health-promoting and disease-preventing properties (Barik et al., 2022; Khan et al., 2013). The concept of functional foods amalgamates principles from food science, nutrition, and pharmacology, thereby offering a comprehensive approach to health and well-being (Granato et al., 2020). The rise in interest in functional foods is driven by a shift in consumer preference toward natural and health-enhancing products (Baker et al., 2022a; Topolska et al., 2021). As societies become increasingly health-conscious, there is a burgeoning demand for foods that can enhance health, boost performance, and mitigate the risk of disease. This trend is mirrored in the rapid expansion of the functional foods market, which is projected to witness substantial growth in the coming years (Vergari et al., 2010). However, the journey of functional foods from laboratory to market is laden with challenges. These encompass the technical issues related to the stability and bioavailability of bioactive compounds, regulatory hurdles, and consumer acceptance/trust. Despite these challenges, the potential of functional foods in the realm of nutrition (e.g., personalized nutrition) and the delivery of bioactive compounds (e.g., phenolic compounds) and bioactive microorganisms (e.g., probiotics) is vast (Ahluwalia, 2021; Gupta et al., 2020). Personalized nutrition, in particular, which customizes dietary recommendations to individual nutritional needs, holds the potential to revolutionize health and wellness in the near future (Gupta et al., 2020). Functional foods, with their capacity to deliver targeted health benefits, are ideally suited for this approach. However, harnessing this potential necessitates overcoming significant scientific, regulatory, and market challenges (Khan et al., 2013; Nazir et al., 2019). In the current landscape of scientific literature, there is an abundance of trending research and publications focusing on the topic of functional foods. However, despite the wealth of such information available, there is a noticeable void when it comes to a comprehensive and concise overview that captures the various facets of functional foods. This gap is particularly evident in the areas of personalized nutrition and applications within the food industry. Accordingly, this commentary aims to provide an exhaustive overview of the role of functional foods in future nutrition, the opportunities they present for both consumers and the food industry, and the challenges that exist on this exciting development road. It delves into the health-promoting effects of bioactives, the dynamics of the functional foods market, the decline of the supplements market, the rise of preventive strategies, and the increasing consumer awareness toward healthier and natural products. The paper also discusses the challenges in the space of functional foods and the corresponding nutrition, including issues related to the properties and stability of bioactives, scalability of the manufacturing process, potential toxicity, lack of clear regulations, limited data on clinical translation, limited interest from the food industry, and consumer skepticism/awareness. The commentary concludes with a discussion of the future trends in the functional foods market and their corresponding effect on nutrition in the future. Bioactive compounds are a diverse group of molecules with potential health benefits (Kamiloglu et al., 2022; Kumar et al., 2023). They exhibit a range of properties including antioxidant, anti-inflammatory, antimicrobial, antiatherogenic, antithrombotic, cardioprotective, and vasodilatory effects (Kamiloglu et al., 2022; Mohamed, 2015). Antioxidants, for instance, are known to combat free radicals, which are implicated in several different human diseases (Arshad & Ahmad, 2021). These compounds are found in a variety of foods, particularly fruits, herbs, spices, vegetables, cereals, legumes, chocolate, and beverages like tea, coffee, or wine (Mohamed, 2015). Bioactive compounds derived from plants, like biologically active proteins, polyphenols, phytosterols, biogenic amines, and carotenoids are known to have health benefits in conditions such as cancer, cardiovascular diseases, and diabetes (Samtiya et al., 2021). However, the efficacy of these compounds depends on their bioavailability, which can be influenced by factors such as food matrix, processing, storage, and individual differences (Berkel Kaşıkçı, 2023; de Freitas Queiroz Barros, Baú Betim Cazarin, & Maróstica Junior, 2022). Bioavailability denotes the degree and speed at which the active component (i.e., be it a drug or metabolite) is absorbed into the systemic circulation, thus reaching its action site. Unfortunately, the oral bioavailability of bioactive compounds is significantly impacted by factors such as the limited release of compounds from the plant matrix, their solubility in gastrointestinal fluid, the permeability through intestinal epithelial cells, and the enzymatic and chemical reactions taking place within the gastrointestinal tract (Berkel Kaşıkçı, 2023; de Freitas Queiroz Barros et al., 2022). Nonetheless, these compounds hold significant promise for promoting health and preventing chronic diseases. Further research is yet needed to fully understand the factors influencing their bioavailability and to optimize their delivery for maximum health benefits. Beyond plant-derived bioactives, it is important to acknowledge that bioactive compounds can also be derived from animal sources and microorganisms. For instance, omega-3 fatty acids, often derived from fish, have been widely recognized for their anti-inflammatory and cardioprotective effects. Similarly, probiotics, which are beneficial microorganisms, have been associated with improved gut health and immune function (Grand View Research, 2022). These examples underscore the vast diversity of bioactive compounds and their sources. As research progresses, it is anticipated that more bioactive compounds from various sources will be discovered and utilized for their health-promoting effects. This further emphasizes the need for comprehensive research to understand their bioavailability and safety profiles, as well as to develop effective delivery systems for these compounds. The global functional foods market, which was valued at USD 280.7 billion in 2021, is projected to expand at a compound annual growth rate of 8.5% from 2022 to 2030 (Grand View Research, 2022). This surge, which has been significantly noticeable in the US market as illustrated in Figure 1, is driven by a number of crucial elements. The present magnitude of the US functional food market and its projected growth in the upcoming years. One of the primary drivers is the rising demand for nutritional and fortifying food additives. As consumers become more aware of the impact of nutrition on physical and mental well-being, they are increasingly seeking out foods that not only satisfy hunger but also provide additional health benefits. This has led to a surge in the demand for functional foods, which are fortified with beneficial ingredients such as vitamins, minerals, fibers, and omega-3 fatty acids (Hilton, 2017). Another significant factor contributing to the growth of the functional foods market is the increasing health consciousness among consumers. With the prevalence of lifestyle-related diseases on the rise, more and more individuals are making dietary changes to improve their health and prevent disease (Daliri & Lee, 2015). Functional/fortified foods, with their added health benefits, are ideally suited to meet this growing demand. The aging population is another critical driver of the functional foods market. As people age, their nutritional needs change, and functional foods can play a crucial role in meeting these needs. For instance, functional foods fortified with calcium and vitamin D can help older adults maintain bone health, while those enriched with omega-3 fatty acids can support heart health of such individuals as well (van der Zanden, van Kleef, de Wijk, & van Trijp, 2014). The rising incidence of chronic diseases is also contributing to the growth of the functional foods market. Chronic conditions such as heart disease, diabetes, and cancer are increasingly prevalent, and diet plays a significant role in both the prevention and management of these diseases. Functional foods, with their disease-preventing properties, are therefore becoming an essential part of the dietary strategies to combat these health issues (Daliri & Lee, 2015; Essa et al., 2021). In summary, the market for such foods is experiencing rapid growth, driven by the rising demand for nutritional and fortifying food additives, increasing health consciousness among consumers, an aging population, and the rising incidence of chronic diseases. As these trends continue, the market for functional foods is expected to reach new heights in the coming years. While the functional foods market is experiencing a surge, the supplement market is witnessing a slowdown, with some categories even observing negative growth rates (Natarajan & GR, 2022; Wróbel et al., 2021). This trend suggests a shift in consumer preference from supplements to functional foods, which are perceived as more natural and holistic (Baker et al., 2022a; Kengpol et al., 2022). The supplement market, which saw astronomical sales gains over the past few years, is expected to see growth rates normalize. Despite seeing negative growth rates in some categories for the first time in a long while, the industry is still in a good place. For instance, despite a decline of 10% between 2020 and 2021, vitamin C sales in the cold-and-flu ingredient category were still a significant $586 million. Nevertheless, the shift in consumer preference does not spell doom for the supplement market. The shift indicates a growing consumer preference for functional foods. Preventive nutrition strategies, which focus on maintaining health and preventing disease through diet, are gaining popularity (Bhargava, 2010; Control & Prevention, 2022; Sharma, Luxita, Yadav, & Akanksha, 2022). Functional foods play a crucial role in these strategies due to their health-promoting properties (Sharma et al., 2022; Singh, 2021). They offer a practical and sustainable approach to disease prevention and health promotion, which is particularly important in the context of rising healthcare costs and the global burden of chronic diseases (Boone-Villa et al., 2019; Singh, 2021). Functional foods contain bioactive compounds that have significant health-promoting effects (Sharma et al., 2022). They can scavenge free radicals and also show effects contributing to anti-inflammatory, antimicrobial, anti-mutagenic, anti-tumor, and neuroprotective properties (Barik et al., 2022; Singh, 2021). These foods enhance a certain physiological response by reducing the risk of various diseases (Barik, Chowdhury, and Tewari), and can play a crucial role in preventive strategies, offering a practical and sustainable approach to disease prevention and health promotion. Consumers are becoming increasingly aware of their health and the impact of nutrition on their well-being. This heightened awareness is driving the demand for functional foods, which are perceived as natural and healthier alternatives to synthetic additives (Baker et al., 2022a; Bogue & Repar, 2023; Topolska et al., 2021). Functional foods, enriched with bioactive compounds like antioxidants, are seen as more natural and holistic, offering a comprehensive approach to health and wellness (Boone-Villa et al., 2019). The shift in consumer preference toward natural and health-enhancing products is a significant trend in the food industry. Consumers are not only interested in the nutritional content of their food but also the health benefits that these foods can provide (Baker et al., 2022a). This trend is reflected in the growing demand for functional foods, which are fortified with beneficial ingredients such as vitamins, minerals, phenolic compounds, fibers, omega-3 fatty acids, and probiotics. However, while consumer awareness is a driving force behind the growth of the functional foods market, it is equally important to ensure that consumers are well-informed and not misled by the corresponding health claims (Van Kleef et al., 2005; Williams & Ghosh, 2008). Misleading health claims can create false perceptions about the health benefits of certain foods and can lead to unhealthy dietary choices (Williams & Ghosh, 2008). Therefore, consumer education and communication are key to ensuring that consumers make informed choices about their diet. Educational programs and effective communication strategies can help increase consumers' health consciousness and their understanding of the health benefits of functional foods. These initiatives can also help consumers distinguish between scientifically substantiated health claims and those that are potentially misleading (Franco-Arellano et al., 2017; Williams & Ghosh, 2008). However, overall, it can be said that as consumers become more health-conscious and aware of the impact of nutrition on their well-being, the demand for functional foods is increasing. Bioactive compounds, while offering numerous health benefits, also pose certain challenges when used in the food industry. One of the key challenges is that their properties can change when the yield increases from small to large quantities (Bansal, Poonia, Kolluri, & Vasundhara, 2022; Sharma et al., 2021). This change can potentially affect the taste, texture, and nutritional content of the final product. For instance, the characteristics of products containing vegetable extracts or bioactives derived from such sources vary depending on the type of vegetable utilized (Aqilah et al., 2023). Moreover, these compounds are often unstable and can degrade during processing and storage. This instability can result in a loss of efficacy. For example, certain bioactive compounds are found susceptible to oxidative degradation, while some are known to be chemically unstable (Kandemir et al., 2022). This instability compromises their anticipated benefits, as it minimizes their health-promoting effects. The breakdown processes of these substances reveal that compounds like vitamin C, phenols, flavonoids, and glycosides interact with oxygen during the convective drying phase, especially at elevated temperatures. This interaction rate leads to a reduction in these bioactive compounds due to their high reducibility (Belwal et al., 2022; ElGamal et al., 2023). Thus, careful consideration and control of processing and storage conditions are crucial to maintain the efficacy of bioactive compounds incorporated into functional foods products. Scaling up food production, including functional foods, to meet the growing demand for functional foods is indeed a complex process that necessitates meticulous planning and execution. The process of scaling up functional foods fortified with bioactives is not as simple as multiplying the quantities. When the yield increases from small to large quantities, several factors change. The bioactive compounds that have been incorporated into the food product may not behave in the same way, so the corresponding delivery methods may need to be adjusted or changed to achieve the desired result. For instance, bioactive ingredients such as flavonoids, carotenoids, polyphenols, phytosterols, probiotics, bioactive peptides, and bioactive minerals, which can be incorporated into foodstuffs to improve their nutritional values, face challenges in terms of maintaining their original bioactivity under certain process and storage conditions (Hosseini et al., 2022). The stability of a specific bioactive compound may not meet the needs of the new process used for the food manufacture, and the finished functional product may have a different taste or texture. Changes in sourcing strategies, formula adjustments, and operational complexities are some of the challenges faced during scale-up of the functional foods containing bioactive compounds (Galanakis, 2021; Sutton et al., 2016). Sourcing larger quantities can impact the business in several ways. One may need to rewrite a formula to hit their price point, and the operational complexities of scale-up can lead to unnecessary costs and delays. Moreover, the use of novel technologies and ingredients in functional foods may require modifications to existing manufacturing processes, further complicating the scale-up process (Avelar et al., 2021; Galanakis, 2021). Thus, while scaling up the production of functional foods is necessary to meet growing demand, it presents several challenges. Overcoming these challenges requires careful planning, execution, and possibly the assistance of experts. Food safety encompasses multiple aspects, from the safe sourcing of ingredients to the implementation of hygienic manufacturing processes, proper storage, and safe preparation methods. In the context of functional foods, safety also extends to ensuring that the bioactive compounds used for fortification are safe for consumption in the quantities provided. In the pursuit of harnessing the potential of functional foods, it is essential not to overlook the basic principles of food safety. As the functional food industry continues to evolve, food safety must remain at the forefront of research, development, and regulation efforts. Additionally, although nanoparticles present a promising avenue for enhancing the stability and bioavailability of bioactive compounds, their potential toxicity is a significant concern (Kang et al., 2023; Rath et al., 2022; Sharma et al., 2022). These minute particles, due to their unique properties, can interact with biological systems in ways that larger particles cannot, potentially leading to harmful effects (Sukhanova et al., 2018). Therefore, rigorous safety evaluations are essential to ensure that these compounds do not pose a risk to human health. Similarly, extracts and isolated bioactive compounds, while beneficial in small amounts, can have toxic effects at high concentrations (Mlozi et al., 2020; Nana et al., 2011). Bioactive compounds, which are secondary metabolites produced by plants, while playing an important role in plant defense mechanisms, as well as in growth and reproduction systems, their effects on human health can vary widely depending on the concentration and conditions (Mlozi et al., 2020). At high concentrations, these compounds may lead to adverse effects, including oxidative stress, DNA damage, apoptosis, cell death, and induction of inflammatory responses (Mlozi et al., 2020; Sharma et al., 2022; Vilas-Boas et al., 2021). Therefore, rigorous safety evaluations and careful dosage control are crucial to ensure the safe use of bioactive compounds/ingredients in functional foods. Regulations in the functional foods market indeed vary significantly from country to country (Birch & Bonwick, 2019; Brown & Chan, 2010; Heller, 2001; Hoadley, 2011). The lack of clear, universal regulations can create uncertainty and pose challenges for manufacturers. For instance, so far, Japan is the only country with a specific regulatory definition and approval process for functional foods (Díaz et al., 2020). In contrast, the United States and Canada have attempted to define functional foods in the absence of a specific regulatory framework. In Europe, the European Union has adopted a working definition for functional foods, despite the lack of current Europe-wide regulations. This regulatory ambiguity can also lead to consumer confusion and skepticism, undermining the credibility of the functional foods market. On the other hand, misleading health claims can create false perceptions about the health benefits of certain foods and can lead to unhealthy dietary choices (Sato et al., 2023; Valls et al., 2013). Therefore, a well-defined regulatory framework is crucial for the successful market for functional foods. It not only ensures the safety and efficacy of these products but also builds consumer trust and acceptance. Such a framework would ensure the safety and efficacy of these products, foster consumer trust, and ultimately, enhance the credibility of the functional foods market. Several countries have excelled in the development of functional foods, setting benchmarks for the rest of the world. Japan, for instance, has been a pioneer in this field, introducing the term "FOSHU" (Foods for Specified Health Use) to classify functional foods. The Japanese government has implemented stringent regulations and standards for the production and marketing of these foods, ensuring their safety and efficacy. Similarly, Finland has made significant strides in this area, with the Finnish Food Authority actively promoting the consumption of functional foods as part of a balanced diet. In the United States, the FDA regulates functional foods under the same standards as conventional foods, but with additional requirements for health claims. The process involves rigorous scientific review to ensure that the functional food provides the claimed health benefits. These examples highlight the importance of government regulations and industry standards in the successful development and market acceptance of functional foods. They highlight the need for similar measures in other countries to harness the full potential of functional foods. There is enough valid evidence that functional foods show significant promise in disease prevention and health promotion (Mohanty & Singhal, 2018; Samtiya et al., 2021; Sharma et al., 2022). They contain bioactive compounds/ingredients that have been demonstrated to provide health benefits beyond meeting basic nutritional needs. However, there is limited data on their clinical translation. This refers to the process of applying discoveries gleaned from laboratory, clinical, or population studies into practical applications that improve human health (Homer-Vanniasinkam & Tsui, 2012; Mlozi et al., 2020). More research is needed to understand how these foods function in the human body and to validate their health claims. For instance, the precise mechanisms by which the bioactive compounds in functional foods exert their effects are not fully understood (de Freitas Queiroz Barros et al., 2022; Kang et al., 2023). Furthermore, the health benefits of functional foods often depend on the presence of specific bioactive compounds, which can vary widely in their concentration and bioavailability (Berkel Kaşıkçı, 2023; Wijesekara & Xu, 2023). This lack of clinical data can hinder the acceptance of functional foods by healthcare professionals and consumers. Healthcare professionals may be hesitant to recommend functional foods due to the lack of robust clinical evidence supporting their health benefits. Similarly, consumers may be skeptical of the health claims made by functional foods if they perceive that these claims are not backed by solid scientific evidence (Baker et al., 2022b). Therefore, while functional foods hold significant potential for disease prevention and health promotion, more research is needed to understand their mechanisms of action and to validate their health claims. This will not only enhance our understanding of functional foods but also increase their acceptance by healthcare professionals and consumers. While consumer awareness toward healthier and natural products is indeed growing (Baker et al., 2022a, Baker et al., 2022a; Topolska et al., 2021) and the market for functional foods is increasing rapidly, skepticism remains a significant factor when it comes to such foods containing certain bioactive ingredients with corresponding health claims. This doubt is often fueled by a lack of clear regulations and scientific evidence (Topolska et al., 2021; Van Kleef et al., 2005). Health claims suggest a correlation between the intake of functional foods and possible health advantages. Nonetheless, the absence of a globally accepted definition for functional foods influences the amount of proof required to validate health assertions across various nations. Therefore, health assertions in themselves do not provide adequate proof; it is crucial to comprehend the degree or significance of the scientific proof that underpins these assertions. Furthermore, there are differing views among consumers regarding the actual health benefits of functional foods. Some believe these foods are primarily promoted as part of a marketing strategy rather than for the health benefits of the customers/consumers (English, 2022; Vergari et al., 2010). Food labels that promote nutrition and health claims have also been criticized for containing misleading information (Siro et al., 2008; Valls et al., 2013). These observations suggest there is more to be done to better inform consumers of the potential health benefits linked with consuming functional foods. This underscores the need for rigorous scientific research and clear, transparent regulations to validate the health claims made by functional food manufacturers and to ensure consumers can make informed choices about their diet. Scaling up production: As mentioned earlier (Section 3.2), scaling up food production to meet the growing demand for functional foods is a complex process that requires careful planning and execution. Changes in sourcing strategies, formula adjustments, and operational complexities are some of the challenges faced during scale-up (Subramanian & Anandharamakrishnan, 2023). For instance, when the yield increases from small to large quantities, several factors change. The bioactive compounds of interest may not behave in the same way, so they may need to be adjusted or changed to achieve the desired result (Aqilah et al., 2023). Regulatory uncertainties: As stated in Section 3.4, regulations in the functional foods market vary significantly from country to country (Brown & Chan, 2010; Díaz et al., 2020; Heller, 2001). The lack of clear, universal regulations can create uncertainty and pose challenges for manufacturers. This regulatory ambiguity can also lead to consumer confusion and skepticism, undermining the credibility of the functional foods market (Baker et al., 2022a; Grand View Research, 2022). Need for substantial investment in research and development: The development of functional foods requires significant investment in research and development. This includes investment in understanding the health benefits of these foods, developing new manufacturing processes, and conducting clinical trials to validate health claims (Heller, 2001; Homer-Vanniasinkam & Tsui, 2012). Nonetheless, as the demand for functional foods continues to grow, more food companies will likely enter this market. To date, in various nations, corporations like BASF, Cargill, General Mills Inc., GFR Pharma, Nutri-Nation, Amway, and Arla Foods appear to be channeling resources into research and development endeavors related to functional foods. They are also undertaking ongoing strategic measures, such as introducing new products, to fortify their market standing (Grand View Research, 2022). The functional food market is on the edge of rapid expansion, propelled by a growing consumer awareness and an increasing demand for healthier and natural products. This growth is not merely a momentary trend, but a reflection of a broader shift in societal attitudes toward health and well-being. As consumers become more educated about the impact of diet on health, they are actively seeking out foods that offer specific health benefits, thereby driving the demand for functional foods. However, the path to harnessing the full potential of functional foods is laden with challenges. The instability of bioactive compounds, scalability issues in manufacturing, the potential toxicity of certain compounds, lack of clear regulations, limited clinical data, limited interest from the food industry, and consumer uncertainty are all significant hurdles that need to be overcome. These challenges underscore the need for a multidisciplinary approach that brings together researchers, industry, regulators, and consumers to ensure the safe and effective use of functional foods. Despite these challenges, the future of functional foods looks promising. Advancements in research and technology are paving the way for innovative solutions, from new methods of enhancing the stability and bioavailability of bioactive compounds to novel approaches for scaling up production. Simultaneously, the growing body of research on the health benefits of functional foods is helping to build a robust scientific foundation for this field. In the face of these opportunities and challenges, one thing is clear: functional foods have a crucial role to play in the future of nutrition. As we continue to explore the potential of functional foods, it is crucial to ensure that these foods are not only beneficial to health but also safe, sustainable, and accessible to all. This will require ongoing research, clear and effective regulations, and open dialogue between all stakeholders. With these concerted efforts, functional foods can truly live up to their promise as the future of nutrition. Ali Rashidinejad: Conceptualization; investigation; funding acquisition; writing - original draft; methodology; validation; writing - review & editing; software; project administration; resources. The author declares no competing financial interest. Data sharing is not applicable to this article as no new data were created or analyzed.