Ultra-processed foods and dietary habits of oncology patients: Risk factor or survival strategy

Abstract

The consumption of ultra-processed foods (UPFs) is continuously increasing, and there is growing evidence that these foods contribute to the development and progression of cancer. For oncology patients alone, maintaining nutritional status is crucial for tolerating treatments and improving survival. The aim of this paper is to review the role of UPFs in the diet of oncology patients, highlighting their potential health-damaging effects (e.g., increased inflammation, microbiome disruption, nutrient deficiencies) and potential benefits (e.g., easy accessibility, high energy content, specially formulated nutritional supplements) particularly in the context of addressing the energy and nutrient needs and nutritional challenges of patients experiencing cancer-related cachexia or anorexia. Using a literature review, we examine how the UPFs can impact oncology patients’ health, supporting the quality of life and clinical outcomes of oncology patients.

Key Words: Ultra-processed foods; Oncology patients; Cancer nutrition; Nutritional status; Quality of life; Processed food and cancer

Core Tip: Ultra-processed foods (UPFs) are increasingly consumed and may significantly impact the health of oncology patients. This review explores the dual role of UPFs - highlighting potential harms such as inflammation, microbiome disruption, and nutrient deficiencies, as well as potential benefits like energy density and accessibility for patients with cancer-related cachexia or anorexia. By examining current literature, the paper underscores the importance of carefully evaluating UPFs in the dietary management of cancer patients to support treatment tolerance, nutritional status, and quality of life.

INTRODUCTION

Ultra-processed foods (UPFs) are industrially produced food products that have undergone extensive industrial processing and contain ingredients not commonly used in home cooking[1]. They are also characterized by undergoing a multi-stage industrial processing process. The aim is to produce products that are as tasty as possible, ready for immediate consumption, and have a long shelf life. In past decades, the UPF consumption has shown an increasing tendency, especially in countries where the Western-type diet is mainly followed[2]. To maintain an ideal body composition, having a balanced, varied diet, practicing an active lifestyle, and avoiding harmful habits are essential not just in the general, healthy population for prevention, but for patients too who are undergoing active oncology treatment and those receiving care. These factors can not only improve the effectiveness of treatments and the tolerability of side effects, but can also significantly influence (patients') quality of life and have an impact on patients' relapse-free survival[3,4].

CLASSIFICATION OF UPFS (E.G., ACCORDING TO NOVA CLASSIFICATION)

The different food products since 2010 are classified by the NOVA system[5]. The NOVA classification (the name is not an acronym, but refers to the novelty of the classification, and is derived from the Portuguese term “NOVA classification”, new classification) is a new, widely accepted and widely used framework for the study of food processing, developed by Monteiro and his research group at the University of São Paulo and later they have extended it for more precise classification[5,6]. NOVA provides a specific, coherent and comprehensive framework for assessing the levels of processing of foods, thereby allowing the assessment of their impact on nutritional quality and health[6] It is important to emphasize that this classification system focuses on the physical, chemical and biological methods used during the food production process rather than on the nutritional composition of the diet[5]. The NOVA classification classifies foods into four main groups based on the extent, purpose, and nature of industrial processing. The classification is summarized in Table 1.

Table 1 The NOVA classification as presented.

NOVA food classification, Monteiro et al[6], 2019
Categories	Short definition	Examples
Group 1: Unprocessed or minimally processed foods	Natural or slightly changed foods; processes like freezing, drying, or pasteurizing may be used, but no added salt, sugar, oils, or fats; aimed at preservation or ease of use	Fresh or frozen fruits, vegetables, grains (such as rice, oats), legumes, tubers (like potatoes), fresh meat, fish, eggs, milk, plain yogurt, coffee, tea, water, unsweetened juices, and plain flours
Group 2: Processed culinary ingredients	Substances extracted from group 1 foods or nature, used in cooking; often refined or purified	Vegetable oils, butter, lard, sugar, molasses, honey, starches, salt, and combinations like salted butter or iodized salt
Group 3: Processed foods	Group 1 foods with added salt, oil, or sugar; preserved or enhanced for taste and shelf life	Canned vegetables, beans, salted nuts, smoked meats, canned fish, fruits in syrup, simple breads, and cheeses
Group 4: Ultra-processed foods (UPFs)	Industrial products are made from many ingredients, often modified or artificial, designed to be tasty, cheap, long-lasting, and ready-to-eat	Soft drinks, packaged snacks, candy, ice cream, processed bread, cookies, breakfast cereals, flavored yogurts, instant noodles, frozen meals, chicken nuggets, sausages, powdered soups, baby formulas, and meal replacements

UPFs: Ultra-processed foods.

This classification helps to understand from a nutritional perspective how different forms of food processing influence eating habits. However, it should be taken into account when using the NOVA classification that some foods may not always be clearly classified, as in some cases it is not easy to clearly assign them to a single group[7]. Given that the NOVA system is primarily based on the degree and nature of industrial processing rather than nutritional composition, it is crucial to emphasize that foods within the same classification group can vary significantly in their nutritional profiles. While many UPFs are energy-dense and nutrient-poor, not all products in this category are nutritionally equivalent. Notably, some UPFs, particularly those developed for clinical or therapeutic use, are deliberately formulated to provide balanced macronutrients and essential micronutrients. These exceptions highlight the need for nuance when interpreting and applying the NOVA classification, particularly in nutrition research and public health policy[8].

CHARACTERISTICS OF UPFS

These foods typically consist of a variety of ingredients, including processed culinary ingredients used to make processed foods, as well as artificial additives, primarily found in UPF, and other substances that enhance the enjoyment value, while they contain no or minimal amounts of whole foods, such as dietary fiber, vegetables, fruits, and natural sources of vitamins and minerals[6]. Artificial additives include, for example, emulsifiers, dyes, sweeteners, flavor enhancers, color stabilizers, aromas, anti-caking and anti-foaming agents, and bulking agents[9]. Other appetizing enhancers include various sugars (lactose, dextrose, maltodextrin, fructose, high fructose corn syrup, fruit juice concentrates, invert sugar), modified oils (hydrogenated or transesterified oils), and proteins (gluten, casein, whey protein, hydrolyzed proteins, soy protein isolate, and mechanically separated meats)[6,9].

UPFs are nutritionally unbalanced and generally have poor overall nutritional value. Although they are high in energy density, they do not provide satiety, meaning that despite their high calorie content, they do not effectively satisfy hunger, which is further exacerbated by their extremely low dietary fiber content. In addition, they are high in added salt, sugar, free fructose, fat, saturated and trans fats, and other artificial additives, and are low in protein, dietary fiber, vitamins, minerals, and other micronutrients[9]. During processing, the physical structure of the food matrix changes, which can consequently alter the bioavailability of nutrients, absorption kinetics, and composition of the gut microbiome[10,11].

UPF-CONSUMPTION INCREASES WORLDWIDE

In today’s modern society, there is an increasing demand for foods that are ready for immediate consumption, easy and quick to prepare, and have a long shelf life. Adapting to the growing needs has also been made possible by the rapid development of food production and processing technologies[12]. As a result, it is not surprising that UPFs have penetrated into the dietary habits all over the world and achieved a significant share of the global food market, where they have now taken over the leading role. Previously, they were mainly dominant in high-income countries, but they are increasingly spreading in low- and middle-income ones, and in fact, the growth rate is the highest here[6,9,13] In high-income countries, they account for more than half of energy intake, while in middle-income ones, they account for up to 30% and it’s growing[2]. UPF consumption is expected to increase worldwide[14,15]. Since the majority of the world’s population lives in middle-income countries, it is particularly important to be aware of the health consequences of UPF consumption[2].

SPECIAL NUTRITIONAL NEEDS OF ONCOLOGY PATIENTS

The nutritional needs of cancer patients differ significantly from the healthy population. Oncological treatments - such as chemotherapy, radiotherapy, immunotherapy, or surgery - often have a serious impact on the body’s metabolism, appetite, digestion, and nutrient absorption[16]. Targeted, personalized nutritional support is particularly important for this patient group, as malnutrition, or its more severe form, cancer cachexia, can significantly impair the patient’s quality of life, the effectiveness of treatments, and the chances of survival[17]. Cancer often increases metabolism, while the patient may suffer from loss of appetite, nausea, vomiting, or taste disturbances[18]. As a result, the body’s energy and protein needs increase, while nutrient intake decreases. Ensuring the right amount and quality of protein is vital, as it is essential for maintaining muscle mass and regeneration[19]. If the increased need is not met, rapid weight and muscle loss may occur. This can lead to the development of sarcopenic conditions, which may sometimes present in a concealed form known as sarcopenic obesity. Such conditions can increase the risk of adverse events and treatment-related side effects[20].

Although weight loss and malnutrition are often the focus of attention in cancer patients, sarcopenic obesity is becoming increasingly common, which refers to a dual condition: The patient is both overweight or obese (high body fat percentage) and suffers from a lack of muscle mass (sarcopenia)[21]. This condition is particularly dangerous because it occurs invisibly - body weight or body mass index alone does not indicate that the patient’s muscle mass has significantly decreased, while their fat mass has remained or increased. Excessive consumption of UPFs can contribute to this condition[22]. These foods are often high in energy but low in protein and micronutrients. If the patient uses these foods to replace energy intake - for example, in the case of loss of appetite, because it is easier to swallow a sweet drink or pastry - they increase adipose tissue but do not support the maintenance of muscle mass. In parallel, protein deficiency and lack of exercise (which is common due to side effects of treatments) accelerate muscle loss[23].

Sarcopenic obesity seriously worsens the general condition of the patient: It weakens physical performance, increases the risk of falls and hospital complications, and - which is of utmost importance from the point of view of oncological treatment - reduces the tolerance and effectiveness of therapy[22]. According to research, sarcopenic obesity is associated with worse survival, more frequent dose reductions during treatment, and more side effects[22]. Moreover, this condition may also be a predisposing factor for chronic inflammation, since adipose tissue produces inflammatory substances, and the lack of muscle mass reduces anti-inflammatory mediators[24]. Therefore, it is vital that not only body weight, but also body composition be taken into account when assessing the nutritional status of oncological patients[25]. Dietary interventions should pay special attention to the adequate quantity and quality of protein intake and the replacement of micronutrients, while avoiding the disproportionate intake of “empty calories”[23].

Unfortunately, sarcopenic obesity often remains hidden, but it is a serious risk factor in the treatment of cancer patients[23]. The nutritional deficiency state associated with UPFs supports its development; therefore, a qualitatively balanced diet rich in protein and micronutrients is not only desirable but also therapeutically important in oncology patients. The side effects of the treatment should also be taken into account when feeding. Stomatitis, difficulty swallowing, constipation, diarrhea, or excessive fatigue can all affect the patient’s food intake[26]. In addition, reduced appetite may not only result from these treatment side effects but can also be caused by anorexigenic substances produced by the tumor itself[27]. In such cases, the diet should be adjusted individually: For example, in the case of stomatitis, soft, mushy, non-irritating foods are recommended, while in the case of nausea, frequent, small amounts of dry food may be more beneficial[26]. Supporting the immune system is also an important aspect.

As part of oncological rehabilitation, individualized dietary interventions are essential for maintaining nutritional balance, enhancing recovery, and supporting immune function. Regular monitoring using e.g., bioelectrical impedance analysis tools - such as the InBody device - provides detailed information on body composition, including skeletal muscle mass, fat mass, body water, and segmental lean mass[28]. This allows for the early detection of muscle loss or fluid imbalances, enabling timely adjustments in nutrition and physical activity to prevent complications such as cachexia and improve overall outcomes in cancer patients[28].

An adequate supply of vitamins and minerals - especially vitamins C and D, as well as zinc - can play a role in preventing infections and maintaining the body’s general resistance[29]. However, the use of dietary supplements should only be done under medical supervision, because certain active ingredients can affect the effectiveness of anti-cancer treatments. If oral nutrition is not sufficient, special nutritional supplements may be needed, or in more severe cases, enteral (through a tube) or parenteral (intravenous) nutrition[19]. There are many artificial medical foods available that are high in protein, enriched with omega-3 fatty acids and antioxidants, and provide essential nutrients in an easily digestible form.

Psychological and social factors should not be forgotten either. Cancer patients often struggle with anxiety, depression, or isolation, which can further reduce appetite. Eating is not only a biological need, but also a spiritual and social event, so family support, an empathetic attitude, and close cooperation with a dietitian or nutrition therapist are important. Overall, nutrition for cancer patients requires a complex and individualized approach. Maintaining proper nutritional status is not only important for improving quality of life, but it has also been proven to support treatment success, aid in recovery, and reduce the risk of tumor recurrence[26].

POTENTIALLY HARMFUL EFFECTS OF UPFS

Inflammatory effect

One of the most concerning features of UPFs is that they are associated with an increase in supporting chronic, low-level inflammation in the body[30,31]. This is particularly important for oncology patients, as inflammation has been shown to play a role in the development and progression of tumors[32]. UPFs often contain high levels of refined sugars, trans-fatty acids, and artificial additives such as emulsifiers, preservatives, flavor enhancers, or colorings[6]. In addition, harmful additives, the formation of carcinogenic compounds during high-temperature processing (e.g., heterocyclic amines, polycyclic aromatic hydrocarbons, acrylamide, nitrosamines), and chemical contaminants from packaging materials like bisphenol A and phthalates contribute to the potential health risks associated with UPFs. The carcinogenic potential of these substances depends on factors such as their concentration, frequency of exposure, and specific biological effects, highlighting the need for stricter regulation and continued research[33]. These compounds can damage DNA, disrupt hormonal balance, impair immune function, and contribute to the development of various cancers, particularly in the liver, thyroid, and gastrointestinal tract[33].

Several studies have shown that regular consumption of UPFs increases the body’s levels of inflammatory biomarkers, such as C-reactive protein, as well as inflammatory cytokines such as interleukin-6 and tumor necrosis factor-alpha[30]. These inflammatory mediators are not only associated with tumor progression, but also contribute to the development of side effects experienced during treatment, such as fatigue, muscle loss, loss of appetite, or depression[34-36]. It is important to emphasize that the pro-inflammatory effect does not only stem from the degree of “industrial processing” of foods, but also from their composition. For example, products that contain added sugar and trans fats may be more pro-inflammatory than UPFs that are processed but have a more balanced nutritional profile (e.g., fortified foods for medical purposes)[37]. Based on all this, it can be said that excessive consumption of UPFs may contribute to the maintenance of chronic inflammation, which is particularly unfavorable for oncology patients. Therefore, it is recommended to limit the consumption of these types of foods and strive to develop a complete, nutrient-rich, anti-inflammatory diet - for example, in the form of a Mediterranean-type or plant-based diet, tailored to the individual[38-40].

Microbiome disruption

One of the key problems with UPFs is that they are low in dietary fiber and high in emulsifiers, artificial additives, and refined ingredients. This composition can influence the microbial community in the gut, which is linked to the functioning of the immune system[41]. A growing body of research suggests that such disruption to the microbial community can inadvertently negatively influence the effectiveness of cancer therapies, highlighting the broader health implications of regular UPF consumption[42]. Dietary fiber is a prebiotic nutrient that helps the growth of beneficial bacteria in the gut and contributes to maintaining microbial balance[43]. The low fiber content of UPFs does not provide an adequate nutrient medium for these microorganisms, while the emulsifiers (e.g., carboxymethyl cellulose, polysorbate 80) and other additives they contain can adversely affect the composition of the gut flora[44]. Several animal and human studies suggest that these additives may reduce microbial diversity, promote the proliferation of inflammatory bacterial strains, and damage the intestinal mucosa[45].

A decrease in microbial diversity, i.e., a reduction in the number and proportion of different bacterial strains, is associated with impaired immune function[46]. The gut microbiota is directly involved in regulating T-cell immune responses, modulating inflammatory processes, and the development of responses to immunotherapeutic agents[46]. For example, the presence of certain bacterial strains (e.g., Akkermansia muciniphila, Bifidobacterium species) in the gut has been associated with improved efficacy of immune checkpoint inhibitors (e.g., anti-programmed cell death 1 therapy) in some oncological diseases[46]. The prevalence of UPFs in the diet may indirectly reduce the effectiveness of the antitumor immune response and impair the success of therapy through the destruction of the microbiome[46]. Although many questions remain to be clarified in this area, based on current evidence, it is worth emphasizing how important the development of a microbiome-friendly diet is, that is, high in fiber, natural, minimally processed foods, and avoiding products containing unnecessary additives.

Nutrient deficiencies

Oncology patients often present deficiencies in protein, vitamins (such as D, B12, and folate), minerals (including iron, zinc, and magnesium), and electrolytes, which can be influenced by tumor-related metabolic alterations, treatment effects, and reduced nutritional intake, frequently contributing to a calorie deficit that may further impact their overall nutritional status[47]. One of the most important nutritional problems of UPFs is that they largely contain so-called “empty calories”. This means that although their energy content is often high - thanks to the large amounts of refined sugars and fats - their nutrient density is low: They are low in essential vitamins, minerals, and other biologically active components that are essential for maintaining health[13]. As a result, this type of diet can contribute to the development of micronutrient deficiencies, especially if the patient is inappetent, has a reduced food intake, or has difficulty chewing and swallowing. This is particularly worrying in the case of oncology patients, since cancer and the therapies used during their treatment (e.g., chemotherapy, radiotherapy, immunotherapy) increase the body’s nutrient requirements, but at the same time can reduce its ability to absorb and utilize nutrients[19]. It is also important to consider the phase of treatment the patient is in, as well as the specific type of therapy being administered. In such circumstances, a diet that is poor in nutrients but rich in calories is not only ineffective but can also be downright harmful. Inadequate micronutrient supply impairs the regeneration capacity of cells, weakens the immune response, increases the risk of infections, and slows down recovery after treatments[29].

Ensuring adequate protein intake is particularly important, as protein is essential for maintaining muscle mass, immune system function, and wound healing. Weight loss and muscle loss (sarcopenia) are common in oncology patients, even in cases of normal body weight. Insufficient protein consumption can accelerate this process and significantly worsen the patient’s physical condition, quality of life, and treatment tolerability[48]. Regular consumption of proteins with high biological value - such as eggs, dairy products, fish, lean meat, and legumes - has key importance, and if necessary, the use of special nutritional supplements and protein-enriched preparations may also be essential[48].

Micronutrients such as iron, zinc, selenium, vitamin D, B vitamins, and antioxidants (e.g., vitamins C and E) also play a key role in cellular defense, regulating inflammatory processes, maintaining immune function, and reducing fatigue[29]. Therefore, when designing the diet of oncology patients, one should strive for a nutrient-rich, varied, balanced diet that covers the body's needs not only in calories but also in protein and micronutrients. This can help maintain the patient's physical condition, improve quality of life, and contribute to better efficiency and effectiveness of therapies. Figure 1 summarizes the potential carcinogenic pathways and harms from food sources.

Figure 1 Summary of the potential carcinogenic pathways and harms from food sources, (adapted from Menegassi et al[33], 2025). Citation: Menegassi B, Vinciguerra M. Ultraprocessed Food and Risk of Cancer: Mechanistic Pathways and Public Health Implications. Cancers (Basel) 2025; 17: 2064. Copyright© 2025 by the authors. Published by MDPI, Basel, Switzerland (https://creativecommons.org/Licenses/by/4.0/).

POTENTIAL BENEFITS FROM A PRACTICAL CLINICAL PERSPECTIVE

Easy accessibility and consumption

Although we have discussed the potential disadvantages of UPFs so far, it cannot be denied that they can actually be useful in some cases. The UPFs offer several practical advantages that can be highly relevant in clinical settings, especially for patients experiencing low energy or compromised health status, such as oncology patients undergoing treatment. One of the key benefits of UPFs is their stable storage characteristics. These products are often designed to have a long shelf life without the need for refrigeration, thanks to advanced preservation methods such as dehydration, canning, vacuum sealing, or the addition of preservatives[5]. This stability ensures that UPFs remain safe and edible over extended periods, making them convenient for patients who may not have frequent access to fresh foods or who struggle with preparing meals regularly. Additionally, UPFs are typically easy to transport and store, as they often come in lightweight, compact packaging. This feature is particularly advantageous for patients who may have limited mobility, live alone, or are frequently transitioning between home and healthcare facilities[49]. For example, a patient receiving outpatient chemotherapy might find it difficult to shop for and prepare fresh meals due to fatigue or treatment side effects. Having access to shelf-stable, ready-to-eat, or minimally prepared UPFs can provide an important source of nutrition without adding burden. Moreover, these foods are generally easy to consume, requiring minimal preparation - sometimes none at all - making them accessible for patients with swallowing difficulties (dysphagia), oral mucositis, or other treatment-related side effects[50]. Nutritionally fortified UPFs, such as specialized oral nutritional supplements (ONS) or high-protein energy bars, can help maintain adequate caloric and nutrient intake during periods when appetite and intake are compromised[50]. In summary, despite concerns about their long-term health effects, the practical advantages of UPFs in clinical nutrition - including stable storage, ease of transport, and low preparation requirements - make them valuable tools to support vulnerable patients in maintaining energy intake and nutritional status during challenging treatment phases.

High energy content

In patients with cachexia or anorexia, increasing energy intake is often a priority goal in nutritional therapy. Cachexia and anorexia, although different concepts, are common in cancer patients and both pose significant challenges in terms of treatment and recovery. Cachexia is a complex metabolic disorder characterized by progressive loss of muscle mass and body fat, regardless of the amount of food consumed, and is usually associated with inflammatory processes[51]. Anorexia, on the other hand, is a decrease in appetite and food intake, which may be due to the disease itself, therapeutic side effects (such as nausea, mouth and throat pain), or psychological factors[51]. As a result of both conditions, the body’s energy and nutrient supply are unable to cover the increased needs, which further worsens the patient's general condition, weakens the immune system, slows wound healing, and reduces the effectiveness of therapies. Therefore, increasing energy intake is essential, especially when the patient’s body weight and muscle mass are decreasing and the physical condition is deteriorating[51].

When increasing energy intake, it is not only the quantity of calories that matters, but also their quality. The aim of nutrition is to provide calorie-dense but nutrient-rich foods or nutritional supplements that help maintain muscle mass and promote body regeneration. For example, high-protein, energy-dense foods or food preparations that are easy to consume but have a concentrated nutrient content are often used. Certain types of UPFs may be beneficial in this situation, as they are easily accessible, have a long shelf life, and are often high in calories, thus contributing to covering energy needs, especially if the patient is unable or unwilling to consume fresh foods regularly[50]. In conclusion, increasing energy intake is a key element of therapy in cachectic or anorexic oncology patients, which may contribute to improved quality of life, tolerability of therapy, and improved survival.

Specially formulated UPFs

UPFs are generally viewed negatively, as many of them are low in nutrients and high in sugar or additives. However, there is a special group of them, medical formulas and enteral formulas, which are also considered UPFs, but play a vital role in patient care, especially for oncology patients[50]. While medical UPFs can be classified into multiple subgroups, we will focus on two primary categories in this context: ONS and enteral nutrition formulas (Tube feeding). These specially formulated, targeted products are designed to provide the body with the right amount and quality of nutrients in situations where conventional nutrition is insufficient or impossible. Medical formulas contain concentrated protein, essential fatty acids, vitamins, minerals, and other micronutrients in precisely defined proportions[50].

ONS are specially formulated for individuals who have difficulty meeting their nutritional needs through regular meals, particularly during cancer treatment and rehabilitation[52]. Often used to address malnutrition and support recovery, ONS provides a concentrated source of essential nutrients, including proteins, fats, carbohydrates, vitamins, and minerals in precise ratios[52]. Available as drinks, powders, or dessert-style options, they can be tailored to meet the unique dietary demands of cancer patients, such as higher protein or calorie needs, or to manage complications related to specific conditions like chemotherapy-induced weight loss or treatment-related metabolic changes[52]. The Enteral formulas, which are usually delivered via tube feeding into the stomach or small intestine, are particularly important for patients who are unable to eat orally, for example, due to nausea, difficulty swallowing, or damage to the digestive tract[53]. These special UPFs have several advantages: Their precisely adjustable nutrient profile allows for individual dosing, they are manufactured in a sterile, medical-grade manner, thus reducing the risk of infection, and their liquid, easy-to-administer form facilitates treatment[53].

For all these reasons, these medical formulas play a life-saving role in cases of severe malnutrition, cachexia, or nutritional barriers, supporting the stabilization of the patient’s condition, better tolerability of therapy, and improving the chances of survival. However, it is important to emphasize that these products are used only on medical indication and are not a substitute for balanced, fresh foods, nor are they comparable to commercially available, nutrient-poor UPFs.

CONSIDERATIONS IN CLINICAL PRACTICE

While minimizing the consumption of UPFs, it may be important to take advantage of their practical benefits, especially in situations where the patient’s physical condition or living conditions make it difficult to regularly consume fresh, home-cooked meals. To this end, conscious choice and a balanced diet are key[54]. One of the most important steps is to integrate nutrient-rich, less processed foods into the diet, which, thanks to their high fiber, vitamin, and mineral content, contribute to the optimal functioning of the body and reduce inflammatory processes. These foods help to counteract the possible negative effects caused by UPFs, such as disruption of the microbiome balance[6,45]. In parallel, especially for oncology patients, it can be recommended to include probiotics in the diet, as they support the health of the intestinal flora and promote the proper functioning of the immune system[55]. Probiotics are live microorganisms that provide beneficial bacteria to the intestinal tract, while prebiotics are fibers that promote the growth and activity of these bacteria. Maintaining adequate microbial diversity can improve the effectiveness of cancer therapies and reduce side effects[43,45].

To achieve all this, close collaboration with a qualified dietitian is essential, who will create a personalized diet plan, taking into account the patient’s condition, nutritional needs, living conditions, and preferences[19]. The dietitian will help find a balance that allows you to take advantage of the practical benefits of UPFs - such as easy storage, quick preparation, or high energy content - while minimizing long-term negative consequences by incorporating fresh, nutrient-rich foods and appropriate dietary supplements. This holistic approach supports patients in maintaining their nutritional status, improving their quality of life, and contributing to the success of their treatment[19].

To advance the understanding of the relationship between UPF consumption and cancer outcomes, future research should include longitudinal cohort studies that track dietary patterns, treatment response, and disease progression in cancer populations over time. In addition, well-designed intervention trials are needed to test the effects of dietary modifications - such as reducing UPF intake or promoting whole and minimally processed foods - on recurrence rates, survival, treatment tolerance, and quality of life. A comparative analysis of UPFs and whole or minimally processed foods is also essential, particularly in terms of their nutritional adequacy for cancer patients. Understanding these differences will be key to developing evidence-based dietary guidelines tailored to oncology care.

CONCLUSION

UPFs cannot be universally considered “bad” or unhealthy, but their excessive or exclusive consumption can be a serious problem for cancer patients. These foods are often high in energy but low in nutrients, and their ingredients often contain additives, artificial flavor enhancers, emulsifiers, and other substances that may have adverse long-term health effects. However, in certain situations - such as reduced appetite, difficulty chewing or swallowing - some UPFs may be useful in helping to provide calories and protein. It is essential to find a balance: Meeting nutritional needs in the short term cannot be done without considering long-term health risks. By making thoughtful dietary choices tailored to the patient’s condition, nutrition can support recovery while minimizing unnecessary risks. However, further research is needed, especially to better understand the different health effects of different UPF types, and to develop patient-centered nutritional strategies that take into account the specific needs of cancer patients, treatment side effects, and long-term quality of life. Prevention can play a major role in reducing the consumption of UPFs. It is important to emphasize that the health risks associated with UPF consumption can vary depending on the stage of the disease and the type of oncological therapy. Therefore, personalized nutrition plans can be essential to balancing immediate dietary needs with long-term health outcomes in cancer care.