Nutrition During Cancer Treatment: Why What You Eat Matters Alongside Medical Care
When someone receives a cancer diagnosis, attention naturally turns to medical treatments such as chemotherapy, radiation, immunotherapy and surgery.
But there is another important aspect of cancer care that also deserves attention: nutrition.
While food cannot replace conventional cancer treatment, research increasingly recognises the importance of nutritional support in helping patients maintain their strength, manage symptoms and cope with the physical demands of treatment.
Why nutrition matters during treatment
Chemotherapy and radiation can affect appetite, digestion, taste and the ability to eat normally.
For some patients, this leads to unintentional weight loss and reduced muscle mass.
These changes are important because malnutrition and muscle loss have been associated with poorer treatment tolerance, reduced physical functioning and worse clinical outcomes.
Maintaining adequate nutrition is therefore not simply about eating healthily. During cancer treatment, it can be an important part of supportive medical care.
What does the research show?
A 2024 systematic review examined dietary counselling interventions during radiation therapy.
Researchers found that individualised nutritional counselling tended to improve nutritional status, help maintain body weight, improve quality of life and reduce some radiation-related symptoms.
Another systematic review published in 2023, reported that nutritional interventions in head and neck cancer patients produced benefits in areas including weight maintenance, quality of life and treatment tolerance.
These findings suggest that personalised nutritional care can make a meaningful difference to patients' experiences during treatment.
Can nutrition improve cancer survival?
This is where the evidence requires careful interpretation.
Poor nutritional status is associated with worse outcomes, but this does not necessarily mean that changing someone's diet will directly improve their cancer survival.
A 2024 systematic review of 252 randomised controlled trials involving more than 31,000 patients found that relatively few studies directly measured cancer progression or overall survival. The larger trials had not demonstrated improvements in cancer outcomes from dietary interventions.
More research is needed to establish whether particular nutritional strategies can improve long-term survival.
What should people focus on?
For someone undergoing cancer treatment, nutritional priorities may be different from those of a generally healthy person.
Rather than pursuing restrictive diets or trying to eliminate entire food groups, the immediate priority may be maintaining adequate energy and protein intake.
For people who have completed treatment, a balanced dietary pattern rich in vegetables, fruit, protein and other nutritious foods can support long-term health.
The best approach depends on the person's diagnosis, treatment, nutritional status and individual needs.
The bigger picture
Cancer care involves more than targeting the disease. It also involves supporting the person living with it.
Nutrition is one important part of that process.
The goal is not to choose between medical treatment and nutrition. It is to recognise the value of both within comprehensive, evidence-based cancer care.
This article is for general education and is not a substitute for personalised advice from an oncology team or accredited practising dietitian.
References
James, S., Oppermann, A., Schotz, K. M., Minotti, M. M., Rao, G. G., Kleckner, I. R., Baguley, B. J., & Kleckner, A. S. (2024). Nutritional Counseling During Chemotherapy Treatment: A Systematic Review of Feasibility, Safety, and Efficacy. Current oncology (Toronto, Ont.), 32(1), 3. https://doi.org/10.3390/curroncol32010003
Ilerhunmwuwa, N. P., Abdul Khader, A. H. S., Smith, C., Cliff, E. R. S., Booth, C. M., Hottel, E., Aziz, M., Lee-Smith, W., Goodman, A., Chakraborty, R., & Mohyuddin, G. R. (2024). Dietary interventions in cancer: a systematic review of all randomized controlled trials. Journal of the National Cancer Institute, 116(7), 1026–1034. https://doi.org/10.1093/jnci/djae051
Leis, C., Arthur, A. E., Chen, X., Greene, M. W., & Frugé, A. D. (2023). Systematic Review of Nutrition Interventions to Improve Short Term Outcomes in Head and Neck Cancer Patients. Cancers, 15(3), 822. https://doi.org/10.3390/cancers15030822
Ligibel, J. A., Bohlke, K., May, A. M., Clinton, S. K., Demark-Wahnefried, W., Gilchrist, S. C., Irwin, M. L., Late, M., Mansfield, S., Marshall, T. F., Meyerhardt, J. A., Thomson, C. A., Wood, W. A., & Alfano, C. M. (2022). Exercise, Diet, and Weight Management During Cancer Treatment: ASCO Guideline. Journal of clinical oncology : official journal of the American Society of Clinical Oncology, 40(22), 2491–2507. https://doi.org/10.1200/JCO.22.00687