Nutrition During Cancer Treatment

Nutrition is what you eat and drink, and how your body uses it. A healthy diet includes a range of foods and liquids. They provide the nutrients your body needs: vitamins, minerals, proteins, carbohydrates, fats and water.

Good nutrition for people with cancer may look different from what we usually call healthy. When you have cancer, you may need extra protein and calories. So your diet may include more meat, fish, eggs, dairy, fats and plant-based proteins. The extra protein and calories help you keep your strength up. That helps you cope with side effects, avoid malnutrition, and hold on to the best quality of life you can. A registered dietitian can help you get the right amounts.

During treatment, you may be tired and unwell. That can make it harder to shop, cook and eat. Planning before treatment makes eating easier. Fill your kitchen with high-protein, high-calorie foods. Stock up on items that need little cooking. Keep easy-to-digest snacks like crackers on hand. Cook and freeze meals in advance. It's also fine to accept help. Let friends and family shop and cook, and give them a grocery list.

Cancer and cancer treatments can both cause side effects that affect eating. They can change taste, smell and appetite. They can also affect your ability to eat or to absorb nutrients. Each treatment causes different problems:

• Chemotherapy can cause loss of appetite, nausea and vomiting, constipation, diarrhea, dry mouth, mouth or throat sores, taste changes, trouble swallowing, and feeling full quickly.
• Hormone therapy can cause weight gain, fluid retention, nausea, high blood sugar, and fatigue.
• Immunotherapy can cause fatigue, fever, nausea and vomiting, and diarrhea.
• Radiation therapy to the digestive system can cause eating problems. Which ones depend on the area treated.
• Stem cell transplant can cause mouth and throat sores and diarrhea. It also brings a high infection risk.
• Surgery can cause loss of appetite, trouble chewing or swallowing, and early satiety (feeling full very quickly).
• Targeted therapy can cause constipation, diarrhea, nausea, abdominal pain, taste changes, and a dry or sore mouth.

Some cancer treatments weaken your immune system. That makes it harder to fight infections, including illness from food. So take special care with how you handle and prepare food. Keep foods at safe temperatures. Scrub raw vegetables and fruits. Use separate utensils, plates and cutting boards for meats and produce.

There are practical ways to manage each problem:

• Appetite loss and early satiety: eat high-protein, high-calorie foods, and eat those first. Drink fluids mostly between meals. Aim for 5 to 6 small meals a day.
• Nausea and vomiting: medicines can prevent or relieve these. Sip fluids to avoid dehydration and to replace lost electrolytes.
• Dry mouth: moisten food with sauces, sip water often, try tart foods to make saliva, and avoid tobacco and alcohol.
• Mouth sores: eat soft foods, cut food small, and eat cold or room-temperature foods. Avoid citrus, spicy, salty and crunchy foods.
• Sore throat and trouble swallowing: eat soft, moist foods, and sit upright when eating. Stay away from hot, spicy, acidic or crunchy foods.
• Taste and smell changes: use herbs, spices and marinades. Try plastic or bamboo utensils if food tastes metallic. Keep foods covered to reduce smells.

Many of these problems get better after treatment ends.

You may have trouble eating and keeping your weight up. If so, your team may ask questions to check whether you are malnourished, or at risk of it. A registered dietitian can then do a full assessment and build a nutrition care plan.

Sometimes you cannot eat enough to stay strong, despite your best efforts. Then nutrition support may help:

• Enteral nutrition gives nutrients in liquid form through a feeding tube. The tube goes into the stomach or small intestine.
• Parenteral nutrition gives nutrients straight into a vein through a catheter. It is used when the stomach and intestines cannot be used.

Your doctor or dietitian will discuss these options with you if they think they will help.

Near the end of life, the goal shifts. Comfort and quality of life matter more than getting enough nutrients. People often feel little hunger. Sips of water, ice chips and mouth care can help with thirst. Food and fluids should not be forced. You and your loved ones have the right to make informed decisions. Your care team and dietitian can explain the benefits and risks of nutrition support.

• Call 911 or go to an emergency department if you faint, or become confused or hard to wake after days of drinking very little.
• Telephone your care team right away if your temperature reaches 100.4°F (38°C) while you are having treatment. CDC calls this a medical emergency, because a fever may be the only warning of an infection at a point when your body cannot fight one. Do not wait to see whether it settles overnight. If nobody answers quickly, go to an emergency department and tell them you are having cancer treatment.
• Call your care team the same day if nothing you drink stays down, you have stopped passing urine, or your urine turns dark amber.
• Call your care team within a day or two if eating keeps getting harder, the weight keeps coming off, or mouth sores stop you finishing meals.

Sources for these signs: MedlinePlus on dehydration, CDC on fever during cancer treatment, and NCI on infection during cancer treatment.