Nutrition and Cancer

Nutrition is a key component of cancer treatment and recovery. Getting the right nutrients helps keep you strong and energized. It also supports the natural healing process during and after cancer treatment to help you manage treatment side effects and lower risk of infection.

However, treatment side effects, such as nausea, fatigue, and changes in taste can make it challenging to maintain a healthy diet.

Ashley Draviam, MS, RD and Carol Sullivan, MS, RD, are Mass General Brigham senior clinical nutritionists who work closely with the Lifestyle Medicine Program and patients at Mass General Cancer Center. They explain which nutrients to prioritize during your cancer journey and also share strategies to optimize nutrition during and after cancer treatment.

Cancer diet plan: The best foods for cancer

For the most part, a healthy cancer diet aligns with general nutrition recommendations to include:

• Lots of whole grains, fruits, and vegetables — the more color and variety, the better
• Moderate amounts of lean protein, including plant sources such as legumes, soy, nuts, and seeds
• Small amounts of sugar, salt, and saturated fats
• Avoid processed meats, such as bacon, hot dogs, and sausages

However, people with cancer often need to tweak these recommendations to meet their unique nutritional needs during treatment. Draviam and Sullivan emphasize these three key components of nutrition and cancer:

Calories

It’s important to eat nutritious foods. Yet, many patients with cancer simply need to worry about eating enough food.

“[People] burn through more calories and nutrients while going through treatment,” Draviam says. But side effects like nausea and changes in taste can make it difficult to meet those increased needs. For this reason, Draviam and Sullivan help patients find calorie sources they can tolerate — even if they’re not the healthiest options.

“If all a patient can eat is ice cream, great. We want you to eat the ice cream,” Draviam says. “But we can work with you to make adjustments to get calories in while [also] working on the healthfulness of your diet.”

Protein

Protein supports your body's healing process. It’s also essential for maintaining muscle and strength — which are crucial to overall health and maximizing the effects of cancer treatment. “There is a relationship between treatment outcomes and loss of muscle mass,” Sullivan says.

Research shows that losing muscle mass increases the risk of harmful side effects from treatment. It also lowers quality of life and chances of survival.

While individual needs vary, patients may need up to 30% more protein than usual during treatment.

Fluids

Staying hydrated is especially important during cancer treatment because it supports natural body functions. Hydration helps the body flush toxins from treatment and may alleviate symptoms such as diarrhea and constipation.

People with cancer tend to become dehydrated more easily due to treatment side effects like diarrhea and vomiting. They may also experience decreased appetite, which limits fluid intake.

Because food contains fluids, you may also be more likely to get dehydrated if you don’t eat enough.

Healthy eating tips for cancer patients

It’s best to work with a registered dietitian during your cancer journey. A registered dietitian can help you develop a personalized healthy eating plan that meets your specific nutritional needs. “We individualize care to maximize the health potential of food while also managing symptoms and side effects,” Draviam says.

Here are five healthy eating strategies Draviam and Sullivan use when working with patients:

1. Do what you can.

Following the “ideal” cancer diet plan while coping with side effects can feel overwhelming. “Nutrition is one of the few things in the whole process of cancer diagnosis and treatment that patients can control,” Draviam says. “So, sometimes it feels like there’s a lot of pressure to get it right.”

But instead of trying to follow a diet that looks good on paper, do what you can. That might mean aiming for one serving of fruit a day even when you have no appetite. Or finding a whole-grain food you can tolerate better when managing diarrhea.

2. Eat smaller meals.

People with nausea or decreased appetite may tolerate smaller, more frequent meals better than larger portions. Aim to eat every 2 to 3 hours. Try not to skip meals — an empty stomach can worsen nausea.

Draviam encourages patients to eat whatever they can tolerate but recommends including protein when you can. Consider rotisserie chicken, beans or bean dips like hummus, and full-fat yogurt.

It also helps to fortify snacks and meals with extra calories. For example, use a nutrition drink in place of water in smoothies and instant pudding. Or add nut butter to cereal or oatmeal.

3. Make it easy.

Simplify meals and snacks by buying pre-made items that are easy to prepare (or require no preparation). Consider foods such as:

• Canned soups and beans
• Frozen fruits and vegetables
• Oatmeal packets
• Protein shakes
• Quick-cooking rice
• Rotisserie chicken
• Salad kits

If you are feeling up to cooking (or have a friend or family member who offers to cook for you), batch cooking meals that can be frozen in meal-sized portions can ensure you have meals ready to go.

4. Plan ahead.

Many people find that their symptoms change during their chemotherapy or radiation treatment cycle. There may be times when symptoms are more intense and you’re too fatigued to prepare meals and too nauseous to eat much.

“Capitalize on when you’re feeling good,” Sullivan says. Use this time to stock up on groceries and batch cook. This way, you have healthy meals and snacks ready for when symptoms worsen.

5. Fill gaps with supplements.

Dietary supplements can help you get enough of the nutrients you may not be getting from food. However, Draviam and Sullivan stress the importance of working with your cancer care team to identify which supplements to take. “We’re pretty careful about what we recommend when it comes to supplements,” Sullivan says. Some supplements can interfere with cancer treatment or other medicines, making them less effective or unsafe.

Nutrition and lifestyle medicine

Nutrition is just one part of lifestyle medicine in cancer care, along with physical activity, sleep, and stress management. Talk with your primary care provider or cancer doctor (oncologist) about working with a registered dietitian or any other provider who can help you stay as healthy as possible along your cancer journey.