A healthy diet is beneficial for everyone, but it can be especially important for people who are being treated for kidney cancer. Eating nutritious and healthy foods before, during, and after treatment can play an important role in helping you feel better and maintaining your strength.
Unfortunately, many kidney cancer treatments, particularly systemic treatments — prescription pills or intravenous infusions, such as targeted therapy, designed to reach cancer cells throughout the body — can lead to nausea or gastrointestinal problems. These side effects can interfere with your ability to eat and process food normally.
“Some people may experience diarrhoea or constipation from the treatments and may also experience gas and bloating,” says Melissa Prest, DCN, RDN, who provides medical and nutritional therapy at the National Kidney Foundation of Illinois in Chicago and is a national spokesperson for the Academy of Nutrition and Dietetics. Patients often lose their appetites completely or experience mouth sores that can make it difficult to eat anything, according to the American Cancer Society (ACS).
Because there can be a variety of eating issues associated with kidney cancer treatments, it’s a good idea to work with a registered dietitian or nutritionist to create a plan that’s best for you. A nutrition expert can help you identify strategies to avoid malnutrition or excessive weight loss and find the right diet to maintain your strength, keep your bones and body healthy, and decrease the side effects of your treatment. If your cancer care facility doesn’t include a dietitian or nutritionist who can be part of your care team, you can find an expert in your area at eatright.org.
What You Should Eat
A kidney cancer diet should include many of the same things found in any healthy diet, with some nutritional tweaks to combat the specific effects of cancer treatment. Unless your doctor or dietitian tells you otherwise, your daily nutrition should include:
- Plenty of fruits and vegetables “Chronic inflammation plays a role in many chronic diseases like chronic kidney disease and cancer,” says Prest. “Fruits and vegetables are important for their anti-inflammatory properties.” A review published in January 2018 in the journal Current Opinion in Urology examined 76 studies on kidney cancer risk factors related to lifestyle, medication, and nutrition. They found that research suggests fruits and fibre-rich vegetables may have a protective effect against kidney cancer and its recurrence. (The review notes that there isn’t enough evidence yet to say that a healthy diet can definitely help prevent kidney cancer.
- A good amount of whole grains “Whole grains may reduce cancer risk because of their high amounts of fibre, antioxidants from vitamins and minerals like vitamin E and selenium, and phytochemicals,” Prest says. Look for whole wheat, oatmeal, whole grain cornmeal, or whole rye as the first ingredient on the food label to ensure you are choosing a whole grain food.
- Lots of calories Here’s where a cancer diet differs from a typical diet. “High-calorie foods are important to include, because people may find it difficult to maintain weight when undergoing treatment for cancer,” Prest says. People with cancer are often urged to eat high-calorie foods, such as peanut butter, milkshakes, sauces, gravies, and meats. And the National Cancer Institute suggests using whole milk instead of low-fat, adding cheese to dishes, and eating plenty of granola, eggs, and dried fruit.
- The right amount of protein Kidney function may decrease as a result of cancer treatment, particularly if surgeons have to remove a kidney. High-protein diets filled with meat, dairy, and nuts may cause the kidneys to work harder to remove urea, a waste product created as your body breaks protein down for use. People undergoing kidney cancer treatment need to keep their weight up but should discuss their protein intake with medical experts. “Current guidelines recommend reducing the amount of protein in your diet when kidney function has declined and you are not being treated with a renal replacement therapy,” Prest notes.
How You Should Eat
The side effects of your cancer treatment will have a lot to do with your diet. Here are some problems you may face, along with potential solutions.
Poor appetite Cancer treatment can wipe out your appetite, but you still need to eat. To make sure you get the nutrition you need, try to:
- Have five or six small meals during the day instead of three large ones.
- Keep small snacks handy for when you feel like eating.
- Eat as much as you can when your appetite is strongest, usually early in the morning.
- Focus on the foods you can eat without difficulty, even if there are only a couple of them.
- Drink a shake or a smoothie if a full meal is unappealing.
Nausea Lots of different things can nauseate you during kidney cancer treatment. To avoid it, you might:
- Choose bland foods, such as white toast, plain yoghurt, and clear broth, and avoid spicy, sour, or acidic foods.
- Eat foods that are room temperature, rather than cold or hot.
- Limit the number of beverages you consume with meals and instead get your fluids in between meals — and take smaller sips.
- Make sure you don’t skip meals and snacks. An empty stomach is more likely to make you feel nauseous.
- Avoid your most loved foods while you are nauseated. Although it may seem counterintuitive, if you try to eat your favourite foods when you are sick, you may develop an aversion to them.
Weakness Kidney cancer treatment can rob you of energy. To make sure you eat enough despite fatigue and weakness, you should:
- Stock up on foods that are easily prepared, such as canned soups — your doctor may prefer that you purchase low-sodium varieties — frozen dinners, and precooked meals.
- Cook meals ahead of time, when you’re feeling well, and freeze them for later.
- Ask friends, prior to treatment, to help you shop and cook when you’re not feeling well later on.
- Plan for foods that come in thick liquid (milkshakes) or semisolid (mashed potatoes) form for when you are too weak to chew properly.
- Get groceries delivered to your home if going shopping is not feasible.
Mouth sores It’s common for kidney cancer patients who are being treated with targeted drugs and immunotherapy to experience inflammation, irritation, and ulceration of the mouth, oesophagus, and other parts of the gastrointestinal tract. If you’re having trouble eating due to these issues, Prest suggests the following:
- Choose nutrient-dense, soft, moist, easy-to-chew foods.
- Avoid acidic foods, alcohol, and spicy foods.
- Choose foods that are not too cold or too hot.
- Practice good oral hygiene with a soft toothbrush.
- Talk to your doctor about using pain meds or a topical analgesic mouth rinse before meals.
Increased risk of infection Certain cancer treatments, such as radiation therapy, or even the cancer itself can ravage the immune system and leave you open to infection, according to the ACS. “Pay attention to the four principles of food safety: Clean, separate, cook, and chill,” Prest says. You — or the person preparing your meals — should:
- Thoroughly wash and scrub fruits and vegetables.
- Wash your hands, clean knives, and scrub down countertops before and after you prepare food, especially raw meat.
- Keep cooked and raw foods separate to avoid cross-contamination.
- Use a different cutting board and utensils for raw and cooked foods.
- Fully cook meats, poultry, and eggs. Meat should have no pink; eggs should not be runny.
- Store leftovers in the refrigerator immediately after eating.
- Drink only pasteurised milk or fruit juice.
- Avoid uncooked shellfish or raw fish.
- Pass on any foods that show signs of mould, including mouldy cheeses such as blue cheese.
- Pay attention to freshness dates and don’t eat expired foods.
Other tips to keep in mind:
- If you’re experiencing vomiting or diarrhoea, be sure to sip small amounts of water or broth (per your doctor’s recommendations) throughout the day to replenish lost fluid.
Kidney cancer treatments such as immunotherapy medications and targeted therapy drugs can increase your risk of high blood pressure and cholesterol. By working with your dietitian, you can make a healthy eating plan that can keep this risk in mind and still give you the calories and nutrition you need.
