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Nutritional Management of Side Effects in Cancer Treatment

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Nutritional Management of Side Effects in Cancer Treatment

A cancer diagnosis can sometimes feel like an ambush. In an instant, a life is transformed as patients brace themselves for a battle with a formidable foe.

Cancer treatments such as chemotherapy, radiation therapy, surgery, immunotherapy, and others can be lifesaving, but they often come with difficult side effects that impact quality of life. However, a powerful tool lies ready to aid in the battle – one too often left unused and underestimated. It's not a new chemotherapy concoction, radiotherapy protocol, or biological therapy breakthrough. Rather, it’s helping to support the body’s many modes of healing through proper diet and nutrition.

It goes without saying that patients experience side effects from cancer therapy. Fatigue, nausea, vomiting, loss of appetite, taste changes, diarrhea, and constipation are common for many cancer patients. And it is here, reducing side effects, where nutrition can really make a difference.

Managing side effects is an important part of overall cancer care that can help patients better tolerate treatments and improve outcomes, all while maintaining strength and weight. Proper nutritional management can make a difference in cancer patients' well-being during this challenging time.

This article will explore the use of nutrition in managing cancer treatment side effects. With a focus on evidence-based nutritional strategies to minimize symptoms of side effects and empower patients to take an active role in their care. The goal is to provide practical advice patients and caregivers can use to improve comfort, nutritional status, and quality of life for those undergoing cancer treatment.


Common Side Effects of Cancer Treatments

Cancer treatments, while lifesaving or life-extending, frequently come with challenging side effects. The most common side effects of cancer treatments cluster around the gastrointestinal system and energy levels.

Chemotherapy, in particular, often affects the cells that line the digestive tract, causing many common side effects like nausea, vomiting, diarrhea, constipation, and appetite changes. Radiation therapy can also irritate parts of the GI tract, leading to similar issues.

Here are some of the more common side effects:

  • Nausea and Vomiting are among the most feared chemotherapy side effects. Nausea can last for hours, or even days, after treatment. Vomiting is a problem because it prevents the intake of food and fluids, sometimes leading to dehydration and reduced nutritional intake.
  • Appetite Loss/Weight Changes arise from chemotherapy, radiation therapy, immunotherapy, and even cancer itself. Many patients have decreased appetite during treatment, leading to unwanted weight loss. Unintended weight gain can occur due to fluid retention (holding on to water), corticosteroid (steroid) treatments, and other factors.
  • Fatigue is a very common side effect of cancer treatment. Fatigue can zap motivation and make daily functioning difficult. The loss of energy can arise directly from anti-cancer drugs or radiation therapy. Anemia, which is a loss of red blood cells that carry oxygen to your body, is another common side effect of some cancer treatments that lead to fatigue.
  • Diarrhea and Constipation are common complaints of cancer patients. Cancer treatments often damage digestive tract tissue, leading to diarrhea, while some medications or dehydration can lead to constipation. Patients frequently alternate between constipation and diarrhea during different treatment phases.

Role of Nutrition in Cancer Care

Proper nutrition is critically important for cancer patients undergoing treatment. Research shows that nutrition’s role in cancer care can make the difference between merely surviving cancer and thriving in recovery. Maintaining good nutritional status minimizes treatment side effects, speeds healing, boosts immunity and energy and improves response to medical therapy.

The importance of diet in cancer treatment cannot be underestimated. Research indicates that 30–60% of the basic energy needs of a cancer patient may go unmet during cancer therapy. This means people are not consuming enough food and nutrients to satisfy their body’s needs. This is at a time when they need it most. Staying well-nourished can also minimize nutritional deficiencies that exacerbate treatment side effects like fatigue, infection, nausea, diarrhea, and mouth sores.

Start with a diet focused on whole foods, and not processed foods. The diet should be rich in fruits, vegetables, lean proteins, and healthy fats to provide the nutrients needed to meet increased needs during this metabolically stressful time.

The right balance of macronutrients (proteins, fats, and carbohydrates) along with micronutrients (vitamins and minerals) supply the raw materials to maintain weight, rebuild tissue damaged by radiation, chemotherapy, and surgery, and help regenerate cells damaged during chemotherapy.

Finally, specific nutrients like antioxidants and phytochemicals found abundantly in fruits, veggies, legumes, nuts, and teas have immune-enhancing and cancer-fighting properties. Eating for health during cancer not only supports the patient today but may help prevent a recurrence tomorrow. 

Nutritional Strategies for Managing Nausea and Vomiting

Nausea and vomiting are miserable, but common side effects impacting over 40% of chemotherapy patients. Fortunately, dietary strategies can help control nausea and decrease vomiting episodes.

Dietary management of chemotherapy nausea doesn’t have to be difficult.

Eating small, frequent meals instead of larger ones prevents the stomach from overfilling, which can trigger nausea. Meals that combine a mixture of nutritious carbs, protein, and fat can alleviate nausea better than eating a single nutrient alone. Easy-to-digest foods like soup, yogurt, smoothies, and soft fruits and vegetables are good options when nausea is severe.

Many cancer patients find that they can only eat one or two particular foods following a round of chemotherapy. There is nothing wrong with eating only, say, eating only saltine crackers or peanut butter for a day or so, as long as it is only temporary.

Certain smells, textures, foods, or beverages can become linked with past nausea. It helps to avoid these “nausea triggers” following chemotherapy. These triggers often fade with time.

Staying hydrated is also key - sucking on ice chips, sipping clear broth, and using electrolyte replacement drinks, or water between meals prevents dehydration and electrolyte imbalances caused by vomiting. Herbal teas like ginger or peppermint can soothe the gut as well.

What not to eat can be as important as what to consume during this time. Greasy, fatty, overly sweet, or spicy dishes can trigger stomach upset in some patients undergoing chemotherapy. 

Addressing Appetite Loss and Weight Changes

Both unintended weight loss and unintended weight gain are common issues for those undergoing cancer treatment. The key concerns here are “unintended” weight loss or gain.

While many cancer patients are overjoyed when they lose weight after starting chemotherapy, this is not necessarily a good thing. Losing weight can mean the patient is not consuming enough nutrients to support their basic body needs. While the scale may be moving in the right direction, this could be a sign of sarcopenia (a loss of vital muscle mass).  

Appetite can fluctuate greatly when battling cancer, in part due to nausea and in part due to a change in taste buds. Nutrition for appetite loss in cancer means following a nutrient-dense diet, exercising caution before limiting calories, and tracking weight routinely can help manage changes.

If unwanted weight loss persists, speak to your care team about a referral to an oncology dietitian or nutritionist.

On the other hand, some patients gain weight during treatment due to medications like steroids or changes in hormone levels due to the cancer or the treatment. Weight gain is often a combination of increased fat and lowered muscle mass (so-called sarcopenic obesity). This points to the importance of maintaining good muscle mass throughout cancer therapy. Exercise and good nutrition are the keys to keeping muscle mass.

Both unintended weight loss and weight gain have the same solution: focus on eating whole foods over less nutritious foods, such as processed foods.

Nutrient-rich smoothies blended with avocado, nut butter, and protein powder supplement the diet nicely. Full-fat Greek yogurt, eggs, soups made with whole milk and protein, hummus, and nuts/seeds also deliver concentrated nutrition in small servings.

Many hospitals and doctor’s offices employ dietitians who can help you manage your weight while still promoting adequate nutritional intake to support treatment response. 

Coping with Fatigue Through Diet

It’s estimated that up to 90 percent of cancer patients experience exhaustion and fatigue during their treatment. This cancer-related fatigue impairs quality of life and the ability to tolerate some cancer regimens.

Dietary management of cancer fatigue includes balancing protein, fat, and carbohydrate intake over the course of daily meals and snacks. The key is to prevent nutrient deficiencies and fight oxidative stress, both of which can lead to feeling tired.

Some examples are apples with peanut butter, carrots, and hummus, oatmeal with nuts and berries, or Greek yogurt topped with mixed fruit and chia seeds. Staying adequately hydrated is also key to delivering nutrients to tissues and preventing fatigue - herbal teas, broths, and water or diluted juices supplement meals nicely.

Certain nutrients also combat fatigue directly: B vitamins, vitamin C, iron, magnesium, and zinc, in particular, seem beneficial, especially if someone is deficient. Iron-rich foods are critical for preventing and treating fatigue-causing anemia too - red meats, spinach, pumpkin seeds, lentils, and raisins are all good sources. Omega-3s from fatty fish, walnuts, and flax help reduce inflammation, causing fatigue as well. Ginseng, Rhodiola, Cordyceps, and other traditional herbs and mushrooms have a place as well.

Balancing nutrition needs with calorie-dense, nutrient-boosting choices ensures energy is there to sustain cancer healing without excess weight gain. 

Nutritional Support for Specific Cancer Types

While proper nutrition is essential for all cancer patients, there is nutrition for specific cancers that may be adapted based on the type of cancer and prescribed treatments.

Here are some ideas for tailored dietary approaches in cancer treatment:

  • Breast cancer: Consume more fruits, vegetables, fiber, soy foods, and green tea. Avoid alcohol, processed meats, refined carbs, and added sugars.
  • Prostate cancer: Increase intake of tomatoes, cruciferous vegetables, fish, and pomegranate juice. Supplement with green tea, curcumin, and selenium.
  • Colorectal cancer: Eat more vegetables, fruits, whole grains, legumes. Get adequate folate, calcium, and vitamin D.
  • Lung cancer: Increase fruits and vegetables high in carotenoids (carrots, sweet potatoes, spinach). Supplement with beta-carotene and vitamin E.
  • Pancreatic cancer: Consume more fruits, vegetables, tea, carotenoids. Use the spice turmeric or try curcumin supplements.
  • Stomach cancer: Eat more fruits and vegetables. Reduce intake of processed meats, salt, and alcohol.
  • Liver cancer: Drink coffee and green tea.

This is by no means an exhaustive list, and all cancer patients can benefit from eating a more whole-food diet with plenty of vegetables and good-quality proteins. 

The Role of Nutrition Professionals in Cancer Care

Nutritional support from healthcare professionals can come in many forms. The most common are dietitians and nutritionists. These professionals play a critical role in the multidisciplinary cancer care team. As food and nutrition experts, they provide personalized dietary strategies and counseling to help patients prevent and manage treatment-related side effects, maintain strength and muscle mass, and meet increased nutritional needs.

These specialists stay up-to-date on the latest evidence-based nutrition recommendations for cancer populations to best advise patients. They develop individualized meal plans and make specific food suggestions to manage symptoms and weight changes while providing optimal nourishment to heal. They can provide education on nutrition supplement drinks, tube feeding support, or vitamin injections, which may be warranted.

Dietitians also monitor patients' nutritional status over the course of treatment, making diet adjustments for altered needs, abilities, or appetites. Ongoing support provides accountability as well as physical and emotional encouragement during an extremely challenging illness.

In addition to offering their own expertise, oncology dietitians in cancer care collaborate with doctors, nurses, social workers, and others to provide comprehensive patient care. They help the cancer care team identify high-risk patients for malnutrition, relay relevant intake and weight changes, assist with treatment decisions based on nutritional status, and communicate across disciplines to enhance quality of life during cancer therapy and recovery. Their skillset is invaluable for optimal patient outcomes.


Nutritional Management of Side Effects in Cancer Treatments

Proper nutrition is a powerful yet underutilized tool that should be integrated into every cancer patient's treatment plan. With guidance from a dietitian or qualified nutrition professional tailored to meet their increased nutritional needs, proper nutrition can help cancer patients better manage treatment side effects, maintain strength and muscle mass, support immunity, and improve quality of life. 

Ultimately, integrating nutritional support enables patients to optimize their response to conventional treatments like chemotherapy and radiation while equipping them to fully engage in their recovery. 

The metabolic demands of cancer and its treatments make nutrition a key component of care. By augmenting conventional therapies with nutritional support, patients can potentially reduce challenging side effects, speed healing, and improve their chances of overcoming cancer.

The information provided is not intended to be a substitute for professional medical advice. Always consult with your doctor or other qualified healthcare provider before taking any dietary supplement or making any changes to your diet or exercise routine.
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  1. Barnish, M., Sheikh, M., & Scholey, A. (2023). Nutrient Therapy for the Improvement of Fatigue Symptoms. Nutrients, 15(9), 2154–2154.
  2. Benefits of Good Nutrition During Cancer Treatment. (n.d.).
  3. Caccialanza, R., Goldwasser, F., Marschal, O., Ottery, F., Schiefke, I., Tilleul, P., Zalcman, G., & Pedrazzoli, P. (2020). Unmet needs in clinical nutrition in oncology: a multinational analysis of real-world evidence. Therapeutic Advances in Medical Oncology, 12, 175883591989985.
  4. Chen, G., Han, Y., Zhang, H., Tu, W., & Zhang, S. (2021). Radiotherapy-Induced Digestive Injury: Diagnosis, Treatment and Mechanisms. Frontiers in Oncology, 11, 757973.
  5. Christie ND, CNS, Dr. J. (2022, March 8). Weakness, Pale Skin, And Headache Are Signs Of This Mineral Deficiency. Rupa Health.
  6. Christie ND, CNS, Dr. J. (2024, January 8). Can B Vitamins Supercharge Your Energy Levels? Rupa Health.
  7. Cloyd ND, Dr. J. (2023a, April 14). A Functional Medicine Clinical Protocol To Support Patients With Sarcopenia. Rupa Health.
  8. Cloyd ND, Dr. J. (2023b, October 18). The Top 6 Essential Health Benefits of Magnesium That You Should Know. Rupa Health.
  9. Cloyd ND, Dr. J. (2023c, October 27). Macro and Micronutrients Uncovered: Understanding Their Role, Deficiencies, and Clinical Relevance. Rupa Health.
  10. Di Fiore, F., & Van Cutsem, E. (2009). Acute and long-term gastrointestinal consequences of chemotherapy. Best Practice & Research Clinical Gastroenterology, 23(1), 113–124.
  11. Fukuda, S., Nojima, J., Motoki, Y., Yamaguti, K., Nakatomi, Y., Okawa, N., Fujiwara, K., Watanabe, Y., & Kuratsune, H. (2016). A potential biomarker for fatigue: Oxidative stress and anti-oxidative activity. Biological Psychology, 118, 88–93.
  12. Gupta, K., Walton, R., & Kataria, S. P. (2021). Chemotherapy-Induced Nausea and Vomiting: Pathogenesis, Recommendations, and New Trends. Cancer Treatment and Research Communications, 26(100278), 100278.
  13. Hofman, M., Ryan, J. L., Figueroa‐Moseley, C. D., Jean‐Pierre, P., & Morrow, G. R. (2007). Cancer‐Related Fatigue: The Scale of the Problem. The Oncologist, 12(S1), 4–10.
  14. Kleckner, A. S., Culakova, E., Kleckner, I. R., Belcher, E. K., Demark-Wahnefried, W., Parker, E. A., Padula, G. D. A., Ontko, M., Janelsins, M. C., Mustian, K. M., & Peppone, L. J. (2022). Nutritional Status Predicts Fatty Acid Uptake from Fish and Soybean Oil Supplements for Treatment of Cancer-Related Fatigue: Results from a Phase II Nationwide Study. Nutrients, 14(1), 184.
  15. Luo, C., Xu, X., Wei, X., Feng, W., Huang, H., Liu, H., Xu, R., Lin, J., Han, L., & Zhang, D. (2019). Natural medicines for the treatment of fatigue: Bioactive components, pharmacology, and mechanisms. Pharmacological Research, 148, 104409.
  16. Makari-Judson, G. (2014). Weight gain following breast cancer diagnosis: Implication and proposed mechanisms. World Journal of Clinical Oncology, 5(3), 272.
  17. Mariani, L., Lo Vullo, S., & Bozzetti, F. (2011). Weight loss in cancer patients: a plea for a better awareness of the issue. Supportive Care in Cancer, 20(2), 301–309.
  18. National Cancer Institute. (2022, August 23). Chemotherapy. National Cancer Institute;
  19. Rajabalizadeh, R., Ghasemzadeh Rahbardar, M., & Hosseinzadeh, H. (2022). Medicinal herbs in treating chemotherapy‐induced nausea and vomiting: A review. Phytotherapy Research.
  20. Sweetnich ND, Dr. J. (2023a, April 5). Health Benefits of Zinc. Rupa Health.
  21. Sweetnich ND, Dr. J. (2023b, May 9). How to Make Sure Your Patients Are Getting Enough Vitamin C in Their Diet: Understanding Testing, RDAs, and The Benefits of Supplementation. Rupa Health.
  22. Tardy, A.-L., Pouteau, E., Marquez, D., Yilmaz, C., & Scholey, A. (2020). Vitamins and minerals for energy, fatigue and cognition: A narrative review of the biochemical and clinical evidence. Nutrients, 12(1), 228.
  23. Weinberg, J. (2022, November 16). 4 Science Backed Health Benefits of The Mediterranean Diet. Rupa Health.
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