When you are diagnosed with cancer, you need to develop a practical plan to live and fight the disease. Paying close attention to what you eat is a very important part of that plan.

Your body needs enough calories and the right mixture of nutrients to stay strong and fight the disease. Good nutrition also can help cancer treatments work better. That’s why you need to choose what you eat wisely before, during and after treatments.

Here are a few things to remember as you adjust to life after cancer diagnosis.

Before treatment 

Many nutritionists suggest that you stick with healthy food before you begin your treatment. Concentrating on vegetables, fruits, nuts, applesauce, yogurt, brown rice, quinoa and easy-to-prepare essentials is the way to go.

It’s a good idea to make some batches of your favorite meals and freeze them because you may not have the energy to prepare your meals during the first days or weeks of therapy. Don’t be afraid of asking your friends and family to drop off healthy meals for you during those days either. Garlic, broccoli, tomatoes, strawberries, carrots, spinach and whole grains have all been proven to have cancer-fighting properties.

“Many patients ask for an ‘anti-cancer diet’, and unfortunately, as of yet, we don’t know what that is,” said Irene Kang, MD, breast oncologist at the USC Norris Comprehensive Cancer Center of Keck Medicine of USC. “We can use common sense/intuition to say eat whole and healthful foods.”

During Treatment

One of the side effects of cancer treatment is that you may suffer from a loss of appetite. On the days when you feel hungry, make sure to load up on high-protein foods, such as lean meats (chicken, turkey and fish), eggs, beans, nuts, seeds, cheese, milk and yogurt. You need to fortify your body and help repair any damage from the treatment.

  • Nutritionists recommend eating at least 2 ½ cups of fruits and vegetables each day. Colorful veggies (dark greens, such as kale and spinach, along with zucchini, cauliflower, and red and yellow peppers) and citrus fruits, such as oranges, lemons and grapefruits, all have plenty of cancer-fighting elements. Be sure to wash them thoroughly to protect your immune system.
  • Liquids are your friend. Drink plenty of water and fresh-squeezed juice. You need to keep your body hydrated and fortified with vitamins.
  • It’s crucial to eat when you’re hungry. Make breakfast your biggest meal, if that’s when you have the most appetite. If you have no appetite later in the day, resort to liquid meal replacements. If you are finding it difficult to eat bigger meals, go for five or six small ones throughout the day.
  • Healthy snacks can help your body throughout the day. Keep yogurt, cheese and crackers and organic soup close by. If you’re getting chemotherapy, a snack or small meal before the treatment may keep nausea at bay.
  • If you are suffering from side effects such as fatigue and digestive issues, try food that takes very little or no preparation, to ease your stomach. That means toast, crackers and pretzels; yogurt; sherbet; cream of wheat or oatmeal; boiled potatoes, rice or noodles; skinned chicken that is baked or broiled; and canned peaches or other soft, mild fruits and veggies.

Dealing with side effects

Eating the right food can help you manage these side effects:

Mouth or throat problems: Soft food can help relieve throat sores, throat pain or swallowing issues. Avoid rough, spicy or acidic foods. Eat meals lukewarm, and use a straw for soups or drinks.

Nausea/vomiting: It’s best to avoid high-fat, greasy or spicy foods when you are nauseous. Eat dry foods, such as crackers or toast, every few hours. Sip clear liquids, such as broths, sports drinks and water.

Diarrhea and constipation: Drink lots of liquids and cut back on high-fiber foods, such as whole grains and vegetables, to deal with diarrhea. If you’re constipated, slowly add more high-fiber foods to your diet. Staying hydrated also can help.

Taste bud changes: Treatment may leave you with a funny taste in your mouth or affect your taste buds. Be open to new foods. Ginger, pomegranates, rosemary, mint and oregano all are your helpful to your body’s general health.

Food to avoid

Cancer patients need to be very careful of consuming food that may be tainted with bacteria. Among the items to avoid at all cost:

  • Unwashed fresh fruit and vegetables, especially leafy vegetables that can hide dirt and other contaminants
  • Raw sprouts, such as alfalfa sprouts
  • Raw or undercooked beef, especially ground beef, or other raw or undercooked meat and poultry
  • Cold hot dogs or deli lunch meat (cold cuts), including dry-cured, uncooked salami. Always cook or reheat these foods until they are steaming hot.
  • Refrigerated pâté
  • Raw or undercooked shellfish, such as oysters
  • Smoked fish
  • Some types of fish, both raw and cooked, as they may contain high levels of mercury
  • Sushi and sashimi
  • Unpasteurized beverages, such as unpasteurized fruit juices, raw milk, raw yogurt and cider
  • Soft cheeses made from unpasteurized milk, such as blue-veined (a type of blue cheese), Brie, Camembert, feta, goat cheese and queso fresco
  • Undercooked eggs, such as soft-boiled, over-easy and poached; raw, unpasteurized eggs; and foods made with raw egg
  • Deli-prepared salads with egg, ham, chicken or seafood

Most nutritionists recommend sticking with a balanced diet of lean proteins, fruits, vegetables, whole grains and low-fat dairy, as well as avoiding sugar, caffeine, salt and alcohol. But every patient is different, and what works for some people may not be good for others.

“Because each patient’s needs are different, there is no one-size-fits-all,” Dr. Kang said. “Where protein might be important for one person to keep their weight up, another person may need to stick to a diet of simple carbs so as not to upset their stomach. If you are diabetic, it is very important to eat in a way that controls your disease.”

It’s best to consult your physician for the best way to approach your post-diagnosis dietary needs.

“Ultimately, I encourage my patients to listen to their body and do what works for them,” Dr. Kang said. “Cancer is a journey with many unknowns, and we have to choose what feels best.”

By Ramin Zahed

As one of the eight original National Cancer Institute (NCI)-designated comprehensive cancer centers in the United States, USC Norris Comprehensive Cancer Center at Keck Medicine of USC is one of the preeminent academic medical institutions in the country. If you are in the Los Angeles area, make an appointment by calling (800) USC-CARE (800-872-2273) or visiting https://cancer.keckmedicine.org/request-an-appointment/.