Immunotherapy harnesses the body’s immune system to combat cancer. Proper nutrition supports the body throughout this process. A well-considered diet can help manage treatment side effects, preserve immune function, and contribute to overall well-being. Careful dietary choices can optimize therapy effectiveness and minimize complications.
Infection Risk Foods
Patients undergoing immunotherapy often have a compromised immune system, which increases their vulnerability to infections from foodborne pathogens. Raw or undercooked meats, poultry, and seafood, such as sushi or raw oysters, can harbor harmful bacteria like Salmonella or Listeria. Similarly, unpasteurized dairy products, including certain milks and cheeses, may contain bacteria that a weakened immune system struggles to fight.
Unwashed fruits and vegetables can also pose a risk, as they may carry pathogens from soil or handling, emphasizing the need for thorough washing. Deli meats and soft cheeses are sometimes associated with Listeria contamination. Foods containing raw eggs, such as homemade mayonnaise or certain dessert batters, present a risk of Salmonella infection. Additionally, items from buffets or open salad bars, where food may sit at unsafe temperatures for extended periods, can increase the chance of contamination.
Foods and Supplements Affecting Treatment
Certain foods, beverages, and supplements can potentially interfere with immunotherapy’s effectiveness or lead to adverse interactions. Grapefruit and its juice are known to interact with many medications by affecting enzymes in the liver that metabolize drugs, which can alter drug levels in the bloodstream. Some herbal supplements, including St. John’s Wort, echinacea, or ginseng, can also influence drug metabolism or modulate the immune system in ways that might counteract immunotherapy. Many supplements lack robust safety data in cancer treatment.
High-dose antioxidant supplements, like Vitamins C or E, may interfere with immunotherapies that rely on oxidative stress to eliminate cancer cells, though more research is needed. Alcohol is generally discouraged during immunotherapy as it can exacerbate common side effects like nausea, dehydration, and fatigue. Alcohol also places additional strain on the liver, which processes some immunotherapy drugs, and studies suggest it may reduce the efficacy of certain immunotherapies. Highly processed foods, often rich in sugar or unhealthy fats, can contribute to systemic inflammation, which might indirectly affect the body’s overall tolerance to treatment.
Dietary Choices for Side Effect Management
Dietary adjustments can play a role in managing common side effects experienced during immunotherapy. For patients experiencing diarrhea or nausea, it is often advisable to avoid spicy foods, high-fiber foods (temporarily), and fatty or greasy items, as these can irritate the digestive system. Excessive caffeine and very sugary drinks may also worsen these symptoms. When fatigue is a prominent side effect, limiting foods that cause rapid energy fluctuations, such as refined sugars and large amounts of simple carbohydrates, can help maintain more stable energy levels.
Oral mucositis or a sore mouth can make eating challenging, so it is beneficial to avoid acidic foods like citrus fruits and tomatoes, which can irritate sensitive tissues. Spicy, rough, crunchy, very hot, or very cold foods should also be limited. While less direct, managing skin reactions may involve considering a reduction in highly inflammatory foods to support overall skin health and reduce systemic inflammation.
When to Seek Expert Advice
Consulting with the oncology care team, particularly a registered dietitian specializing in oncology, is important before making any significant dietary changes or taking supplements during immunotherapy. Personalized dietary advice is important because individual needs vary based on the specific immunotherapy drugs, cancer type and stage, and co-existing health conditions. These professionals can assess individual nutritional status and help manage treatment side effects through tailored dietary plans.
Patients should avoid self-prescribing supplements or making drastic dietary changes based on anecdotal information. Open communication with doctors and dietitians about all food and supplement intake ensures that dietary choices support treatment goals and patient well-being.