People with cancer often need to follow a slightly different diet to ensure they have the strength to deal with treatment side effects. They usually require extra protein and calories.
A healthy, well-rounded diet should consist of nutrient-dense, whole foods, including vegetables, fruits, protein sources, and healthy fats. People with cancer often need more calories than usual. Plus, following a healthy diet may help reduce certain chemotherapy-related side effects.
People undergoing cancer treatment, such as chemotherapy, may need to increase their protein and calorie intake by consuming extra calories and protein-rich foods like eggs, fish, and beans. They may also need to change the texture and consistency of their meals to make food easier to chew and swallow.
When chemotherapy kills cancer cells, it may also damage healthy cells, leading to various factors that can complicate eating, such as a sore mouth, nausea, and loss of appetite.
In this article, we examine the importance of nutrition when receiving chemotherapy treatment. We also look at food safety and hygiene and how to manage eating problems associated with chemotherapy.
Good nutrition is vital for people with cancer, as the condition and treatments can affect the way the body tolerates certain foods and uses nutrients.
Eating well while undergoing chemotherapy can help a person:
- maintain their body’s nutrient stores
- keep their energy and strength up
- lower their risk of infection
- heal and recover more quickly
- tolerate treatment-related side effects better
A person must get enough of the following nutrients to maintain their immune system and reduce the side effects of chemotherapy:
The body needs protein to repair body tissue, grow, and keep the immune system healthy. If a person does not get enough protein, their body may begin to break down muscle tissue for the fuel it needs, making it harder to recover from illness and lower resistance to infection.
People with cancer often need more protein than usual. After chemotherapy, people usually require extra protein to help fight infection and heal tissues.
Protein-rich foods include:
- lean red meat
Carbohydrates are the body’s main energy source. They give the body the fuel it needs for physical activity and proper organ function. Good sources of carbohydrates include fruits, vegetables, beans, and whole grains.
Fats and oils are made of fatty acids and serve as a rich energy source for the body. The body breaks down fats and uses them to store energy, insulate body tissue, and transport some vitamins through the blood.
When having chemotherapy, a person may require more fats to help maintain energy.
People should avoid trans fatty acids and choose healthier fats found in:
- nuts, seeds, and nut butters
- olive oil
- dairy products such as yogurt
Vitamins, minerals, and antioxidants
Getting enough vitamins and minerals is critical to overall health. Following a well-rounded diet is the best way to ensure a person has an optimal intake of vitamins and minerals. However, some people with cancer may need to supplement with specific vitamins and minerals.
Depending on the type of cancer,
Antioxidants neutralize free radicals, stopping them from damaging healthy cells. They include certain vitamins and minerals, such as:
- vitamin A
- vitamin C
- vitamin E
People can consume more antioxidants by eating a variety of fruits and vegetables. Doctors do not usually recommend taking large doses of antioxidant supplements during chemotherapy.
Phytonutrients or phytochemicals, such as lycopene, carotenoids, and phytosterols, are plant compounds. Research suggests they have health-protecting properties.
Plants such as vegetables and fruits or products made from plants like tea and tofu contain phytonutrients.
When a person receives chemotherapy, doctors monitor a type of white blood cell called a neutrophil, which is part of the immune system. Very low neutrophil levels are known as neutropenia.
People with neutropenia have a higher risk for infection, so they must follow safe food handling and cooking practices to minimize this risk.
There are several food and hygiene precautions people can follow, including:
- Store food at the correct temperature.
- Scrub raw fruits and vegetables with water and a brush before eating.
- Soak berries and other foods that cannot be easily washed in water and rinse before eating.
- Wash hands, knives, and countertops before and after preparing food.
- Wash hands after touching raw meat, fish, and poultry.
- Use different cutting boards for meat, and fruits and vegetables.
- Cook meat, poultry, and eggs thoroughly.
- Thaw meat, poultry, and fish in the refrigerator or defrost them in the microwave.
- Use a meat thermometer to ensure cooked meat is at a safe temperature.
- Make sure to consume pasteurized dairy and juice products.
- Eat nuts that are shelled and roasted.
People undergoing chemotherapy may find it difficult to eat and may have a low appetite. They should try to eat at regular intervals, snack as needed, and drink plenty of liquids.
During a course of chemotherapy, people should eat:
High protein foods
High protein foods include:
- lean meats, poultry, and fish
- beans, legumes, nuts, and seeds
- milk products
Healthy, easy snacking foods include:
- fruit and nut butter
- hard-boiled eggs
- nuts and dried fruit
Healthy fats include:
- nut butter
- olive oil
- whole milk yogurt
Fiber-rich foods include:
- nuts and seeds
Doctors may recommend people having chemotherapy avoid similar foods to those avoided during pregnancy and any foods that risk causing illness or infection. This includes foods that might exacerbate chemotherapy-related symptoms, such as mouth sores, and diarrhea. They include:
- raw fish, such as sushi and uncooked oysters
- raw nuts
- buffet or self-service restaurant foods
- foods that show signs of mold, including blue cheese
- foods that are past their sell-by date
- perishable food that has been at room temperature for longer than 2 hours
- leftovers that have been in the refrigerator for longer than 3 days
- fatty, spicy, or sugary foods
Before chemotherapy begins, a person should eat a healthy diet and try to maintain a moderate weight. A healthy diet should include various fruits and vegetables, healthy fats, lean proteins, whole grains, and legumes. People should try to limit refined carbohydrates, added sugars, and ultra-processed foods in any healthy diet.
Eating a healthy diet before chemotherapy may help a person lower their risk of infection, cope with side effects better, and have a greater chance of receiving treatment without unplanned breaks.
During this time, a person can prepare for eating while going through chemotherapy. It can be helpful to stock the freezer, refrigerator, and cupboards with healthy foods that a person enjoys. Foods that require little or no cooking and preparation time, such as frozen dinners, can be helpful.
It might also be helpful to cook food ahead of time and freeze meals. A person should include items they know they can eat even when they feel unwell.
Once treatment starts, a person’s body will need healthy foods to function at its best. It is essential to get enough calories and proteins during this time.
Foods that a person does not typically enjoy may taste better during treatment, so people are encouraged to try new foods.
A person should eat foods containing health-promoting properties, brightly colored fruits and vegetables, and high protein foods. They should limit sugary and highly processed food.
Protein-rich snacks such as Greek yogurt, nuts and seeds, chicken salad and crackers, or hard-boiled eggs may help maintain strength and energy.
The side effects a person experiences during chemotherapy may affect their eating. For example, a person with a sore mouth may find it uncomfortable to eat acidic fruits, or a person who experiences diarrhea may wish to avoid very high fiber foods.
Following chemotherapy, it is important to:
- Check with the cancer care team to find out about food restrictions.
- Ask a dietitian to help create a balanced, nutritious eating plan.
- Eat a variety of colorful vegetables and fruits daily, such as dark green and yellow vegetables, and citrus fruits.
- Eat high fiber foods such as fruits, vegetables, beans, and whole grains.
- Limit intake of highly refined carbohydrates and added sugar.
- Incorporate protein-rich foods at every meal and snack.
- Avoid or limit alcohol.
Chemotherapy can cause a number of eating problems as common side effects of the treatment. These may include:
A person may lose their appetite partially or entirely while having chemotherapy. Some people lose their appetite for just 1–2 days, while others experience appetite loss throughout their treatment.
To manage appetite loss, a person can:
- Drink a liquid or powdered meal replacement.
- Eat five or six smaller meals throughout the day instead of three large meals.
- Keep snacks close at hand to eat when possible.
- Take frequent sips of liquids that add calories and nutrients, such as juice, milk, or soup.
Nausea is a common side effect of chemotherapy. It can make it difficult for a person to eat and may make them feel like vomiting. A person may be able to manage nausea in a variety of ways, including:
- eating foods that are easy on the stomach, such as plain toast or clear broth
- eating regularly, even if it is just small snacks
- not forcing any particular foods and choosing to eat foods they enjoy
- sipping small amounts of liquid throughout the day
- eating food and drinks that are at room temperature
- eating dry toast or crackers before going to bed
Chemotherapy may cause mouth sores and tender gums, which can make eating uncomfortable. People may find it more comfortable if they:
- Choose foods that are easy to chew, such as scrambled eggs, custards, and milkshakes.
- Soften food with sauces, broth, or gravy.
- Eat with a smaller spoon to help take smaller bites.
- Eat cold or room temperature foods.
- Avoid foods that can hurt the mouth, such as citrus fruits, chili peppers, salty foods, and sharp, crunchy food.
Chemotherapy may inflame the lining of the throat, causing a problem called esophagitis. This may make a person feel like they have a lump in their throat or that their throat is burning. It may help a person if they:
- Choose foods that are easier to swallow, such as milkshakes, cooked cereal, or scrambled eggs.
- Cook foods until they are soft and tender.
- Cut food into smaller pieces, or puree it using a blender.
- Sip drinks through a straw.
- Avoid foods that are hot, spicy, acidic, sharp, and crunchy.
Cancer may cause weight loss, or weight loss may be a side effect of the treatment. To manage weight loss, a person can:
- Eat on a schedule instead of waiting to feel hungry.
- Eat foods high in calories and protein.
- Drink milkshakes, smoothies, or juices.
- Add protein powders to meals, such as oatmeal, smoothies, and soups
Pain medicines, changes to eating habits, and less physical activity can make it harder to pass stools. A person can help manage constipation by:
- drinking more fluids
- using laxatives if the cancer care team recommends them
- increasing physical activity
- limiting foods and drinks that can cause gas
Getting the proper nutrients is vital during chemotherapy. Eating well can help with healing, prevent infection, and reduce the intensity of chemotherapy side effects.
People undergoing chemotherapy can be more susceptible to infection, so food safety and hygiene are essential. People should store food at the correct temperature and practice good food hygiene.
During chemotherapy, people should try to include healthy fats, protein-rich foods, and high fiber foods in their diets. They should avoid foods that risk infection or illness, such as moldy cheeses, raw fish, and foods from a buffet.
Before, during, and after chemotherapy, a person should maintain a balanced diet and keep their protein and calories at a healthy level.
A person can adjust their diet to deal with eating problems, such as nausea, a sore mouth, or weight loss.