“Cancer is not always a purely localized process; many cancers and many cancer treatments have systemic effects that disrupt metabolism, immunity, and functional capacity.
While modern oncology has made remarkable advances through precision medicine, immunotherapy, and targeted treatments, nutrition remains an underrecognized yet essential component of comprehensive cancer care. Increasing evidence shows that nutritional status significantly influences treatment tolerance, clinical outcomes, and quality of life across the cancer continuum.
Malnutrition is common, particularly in advanced disease and in tumors affecting the GI tract or swallowing. Tumor-related inflammation, altered energy metabolism, reduced appetite, and treatment-associated side effects such as nausea, vomiting, mucositis, dysphagia, diarrhea, and taste alterations contribute to inadequate nutrient intake and progressive weight loss. Cancer-related malnutrition and cachexia are strongly associated with reduced physical function, increased treatment toxicity, higher infection rates, prolonged hospital stays, and poorer survival.
At the biological level, cancer induces profound metabolic dysregulation. Tumors exhibit increased glucose uptake and altered lipid and amino acid metabolism, while systemic inflammation accelerates muscle protein breakdown and suppresses synthesis. This leads to progressive loss of skeletal muscle mass, even in patients who may appear weight stable or overweight.
Importantly, this process cannot be reversed by increased caloric intake alone. Effective oncology nutrition requires a targeted and individualized approach, emphasizing adequate protein intake, appropriate energy provision, micronutrient sufficiency, and management of nutrition-impact symptoms.
The relationship between nutritional status and treatment outcomes is well established. Better nutritional status is consistently associated with improved treatment tolerance and fewer interruptions, and malnutrition is associated with higher toxicity and complications.
In surgical oncology, preoperative nutritional assessment and intervention are associated with reduced postoperative complications, shorter hospital stays, and improved recovery. As cancer treatments become increasingly complex, maintaining nutritional resilience is critical to maximizing therapeutic benefit.
Emerging research has expanded the role of nutrition beyond supportive care, particularly in the context of immunotherapy. The gut microbiota, shaped in part by diet, has been shown to influence immune function and response to immune checkpoint inhibitors. Although this field is still evolving, it highlights a promising intersection between nutrition, metabolism, and immuno-oncology that may inform future personalized interventions.
Nutrition is also integral across the full cancer trajectory. During active treatment, the primary goals are to prevent or minimize weight and muscle loss, manage treatment-related symptoms, and maintain functional capacity. In cancer survivorship, nutritional strategies shift toward reducing recurrence risk, addressing long-term treatment effects, and managing comorbid conditions such as cardiovascular disease, metabolic syndrome, and bone loss.
In palliative and end-of-life care, nutrition focuses on comfort, symptom relief, and respecting patient preferences rather than aggressive nutritional targets. This continuum underscores that oncology nutrition is dynamic, individualized, and deeply patient-centered.
Despite robust evidence, nutrition remains underintegrated into routine oncology practice. Late referrals for nutritional care, limited access to trained oncology nutrition professionals, and persistent misinformation, particularly around restrictive ‘anti-cancer’ diets and unregulated supplements, pose significant challenges. Such practices may worsen malnutrition, interfere with treatment efficacy, and increase patient anxiety during an already vulnerable period.
Integrating nutrition into standard oncology care is increasingly recommended to support tolerance, function, and quality of life. Early nutritional screening, individualized medical nutrition therapy, and multidisciplinary collaboration should be embedded within cancer care pathways. Ongoing research into cancer metabolism, nutrigenomics, inflammation, and dietary patterns will further refine evidence-based guidelines and enhance personalized care.
Nutrition may not cure cancer, but it fundamentally shapes how patients tolerate treatment, recover, and live with the disease. In modern oncology, where precision and personalization define progress, nutrition must be recognized not merely as supportive care, but as an essential pillar of effective, holistic cancer treatment.”
Written by Raisa Mehzabeen
BSc. (Honors), Food and Nutrition, DU
MPH ( Running), Public Health Nutrition, North South University
PGT on Nutrition and Fitness Training, Inspiron Fitness and Diet Consultancy Centre
Chief Executive Officer, Nutrition For Change
You can also read about Nutrition and Oncology on OncoDaily.