What to Eat During Breast Cancer Treatment

If you’ve been recently diagnosed with breast cancer, you probably have a lot of questions. Among them: What can you do to support your health, help your body heal, and minimize the chance of the cancer spreading or returning after treatments?

One thing you can do is eat nutritious food, say experts. “A healthy diet is important for two reasons,” says Steven Quay, M.D., Ph.D., a physician-scientist who founded a company developing breast cancer therapeutics in Seattle, WA. “First, getting the proper balance of nutrients is essential to recovering from the assault on your body caused by treatment such as surgery, radiation, and, if necessary, chemotherapy. Second, many studies show the positive effect of reducing inflammation during treatment.”

Overhauling your diet while you’re undergoing cancer treatment might not be realistic, but it’s clear that making an effort to focus on good nutrition matters. Here’s how to get the nutrients you need while you’re going through treatment and beyond.

Diet can influence your risk of developing breast cancer, and continues to matter after diagnosis, too. Breast cancer treatment can be stressful as well as physically taxing, and nutritious foods can help your body heal and keep your energy up.

“Consuming a balanced diet is important for supporting your overall health, including your immune system,” says Amy Bragagnini, R.D., a dietitian and certified specialist in oncology nutrition in Grand Rapids, MI. “If you’re not feeling well for a few days after a treatment and your intake is off, it’s not going to have a drastic impact. But if you neglect good nutrition for weeks and weeks, then that could be a problem.”

Eating well may improve the chances that your treatment is successful. For example, a study in NPJ Breast Cancer found that breast cancer patients who had followed a mostly anti-inflammatory diet for a long time had a higher odds of survival compared to others with breast cancer. The study participants who were in the group with the most anti-inflammatory diets had a 8.1% higher 10-year survival rate than those who were in the group that ate the most pro-inflammatory diets.

When many people picture a person going through cancer treatment, they imagine someone who’s nauseated and vomiting all the time. In truth, while nausea and vomiting are possible treatment side effects, plenty of people never experience these problems, and those who do often benefit immensely from anti-nausea medication, says Bragagnini. That means most people going through cancer treatment do not need to subsist on saltines and clear broth, she says.

Instead, people going through breast cancer treatment should focus on eating nutrient-dense foods. Generally speaking, the best foods to eat during cancer treatment are the same ones that most experts recommend for everyone. In particular, you’ll want to aim to incorporate the following categories into your diet:

Lean Protein

You need adequate protein for tissue repair (necessary after cancer treatments such as chemo and radiation) as well as to maintain strong muscles. “Many patients going through chemotherapy say that meat doesn’t sound good to them,” says Bragagnini. If that’s you, try to work in vegetarian sources of protein like nuts, seeds, beans, and peanut butter, she advises.

Whole Grains

You need carbohydrates for energy, says Dr. Quay, and opting for whole grains whenever possible is wise because they contain extra nutrients and fiber. Research suggests that fiber may help reduce breast cancer recurrence, perhaps due to the fact that it binds to circulating estrogen, so that it can be removed from the body.

Essential Fatty Acids

They’re key for the simple reason that your body can’t make them, says Dr. Quay, and you need them for healthy cells, good vision, proper function of your nervous system, and much more, according to the Linus Pauling Institute at Oregon State University. Essential fatty acids include omega 6s and omega 3s.

Most Americans get plenty of omega 6s, which are found in vegetable oil as well as in nuts, and seeds. However, many people fall short on omega 3s, which are found in fatty fish like salmon and herring as well as in flaxseed, chia seeds, and walnuts. These nutrients may, perhaps due to their anti-inflammatory effects, reduce complications of cancer, reports a study in Nutrients. If you’re having trouble getting enough omega 3s, try adding ground flaxseed to smoothies, suggests Rebecca H. Johnson, M.D., a two-time breast cancer survivor and the medical director of the adolescent and young adult oncology program at Mary Bridge Children’s Hospital in Tacoma, WA.

Fruits and Vegetables

Produce is rich in vitamins, minerals and fiber. It’s also packed with phytochemicals, which are plant chemicals that contain immune-bolstering compounds, says Dr. Quay. In an analysis of Nurses’ Health Study data published in Cancer Research, higher green vegetable consumption—particularly leafy greens and cruciferous vegetables like broccoli—was associated with better survival rates among people with breast cancer.

Phytochemicals help support the immune system, and there are tens of thousands of different types, says Dr. Quay. If you’re eating a wide variety of fruits and vegetables, you’re probably doing fine. But here are a few that may be worth paying extra attention to when you’re undergoing breast cancer treatment.

Carotenoids

Research has found that women who eat a diet high in carotenoids have a lower risk of estrogen receptor-negative breast cancers. Other research has found that in women who have already had breast cancer, a diet rich in these compounds lowers the risk of a recurrence. It’s possible that the carotenoids themselves have a protective effect, or it may be other compounds found in fruits and vegetables that contain them. Orange produce—including carrots, squash, and pumpkin—are good sources of carotenoids, says Bragagnini.

Lignans

Research has found that women who consume plenty of lignans, which contain estrogen-like compounds, are less likely to develop breast cancer (especially post-menopausal breast cancer). Other research finds that lignans have anti-tumor properties, inducing cancer cell death, and may also be anti-inflammatory. You’ll find them in flaxseeds, sesame seeds, and bran—among other foods.

Sulforaphane

Broccoli, cauliflower, and Brussels sprouts all contain sulforaphane and have anti-cancer properties, says Bragagnini. What’s more, a 2022 study suggests this compound may help reduce the risk of metastasis (spread) of triple negative breast cancer.

Side effects vary based on the type of treatment you’re receiving, as well as how your body responds to the therapy. Nausea, fatigue, and constipation are among the common complaints, according to Sarah Cannon, the Cancer Institute of HCA Healthcare. Tweaking your diet may help.

What to Eat if You Have Nausea

Cold foods tend to be more tolerable, which is why smoothies are popular among cancer patients, says Dr. Johnson. “Smoothies are easy to sip and digest,” she says. Make them from your favorite fruits and add in a handful of spinach for extra nutrition. “It will change the color but not the taste.” If you’ve been having trouble getting in protein, add in some protein powder.

Of course, sometimes you might only feel up to eating bland foods, and that’s OK. Try crackers, toast, oatmeal, and plain yogurt, suggests Beth Oller, M.D., a family physician in Plainville, KS. “You may need to set an alarm to remind yourself to eat small amounts every two to three hours, as you may not feel hungry like usual,” she says.

What to Eat if You Have Constipation

Try eating smaller portions, and make sure you’re getting adequate fiber and fluids, suggests Bragagnini. Fiber-rich whole cereals, fruits and vegetables, and wheat bran are all good picks.

What to Eat for Fatigue

A balanced diet—including adequate carbohydrates and fluids—is your best bet for keeping your energy up, says Bragagnini. Getting a little caffeine boost from coffee or tea is also OK, as long as it doesn’t upset your stomach or keep you up at night. (Regular exercise helps a lot, too.)

Staying hydrated is important for full-body health, including your immunity and energy. If you’re going through chemotherapy, staying hydrated helps ensure that the treatment gets flushed through your system, says Bragagnini. She adds that some chemo patients experience diarrhea or vomiting, which puts them at risk for dehydration. Sipping water is ideal, “but I’m not opposed to someone having a glass of milk or fruit juice or a nutrition shake,” she says.

Dr. Oller adds that chicken or vegetable broth and sports drinks with electrolytes can also combat dehydration. If you’re struggling with nausea, try sipping on mint or ginger tea.

“If you notice that you have dry or cracked lips, a dry mouth, or aren’t urinating much during the day, it is important to contact your doctor right away as this can be a sign of [severe] dehydration and you may need to get fluids intravenously,” says Dr. Oller.

Are any foods totally off-limits during cancer treatment? The answer really depends on your personal health, says Bragagnini. But there are some categories of foods that you might be wise to limit or nix entirely.

Alcohol

Patients currently undergoing treatment should generally avoid alcohol, since it may worsen treatment side effects or interact with medication, according to the American Cancer Society. When in doubt, ask your doctor.

Added Sugars

You might have heard that sugar feeds cancer cells, but that’s a little misleading, says Bragagnini. “Glucose feeds every cell in your body,” not just cancer cells, she explains. Still eating too many sweets and simple carbohydrates can increase inflammation. A small amount of treats as part of an otherwise healthy diet? That’s totally fine, she says.

Highly Processed and Fried Foods

Dr. Quay recommends avoiding processed and fried foods, as they can increase inflammation. A study in Nutrients reported that among 511 women with breast cancer, those whose cancers recurred were those with the highest ratings on the dietary inflammatory index after surgery, a measure of how pro-inflammatory a person’s diet is.

Foods That May Carry Pathogens

Some doctors tell cancer patients to avoid foods that are more apt to cause foodborne illness, as their immune systems may be weaker due to cancer treatments, leaving them more vulnerable to pathogens. Those foods include sushi, rare meat, soft-cooked eggs, and unpasteurized dairy products. But Bragagnini says she doesn’t issue such blanket rules.

“It really depends on what someone’s blood counts are,” she says. “If their neutrophil count—a type of white blood cell—is really low, then I would tell them to avoid those foods and also wash fruits and vegetables really, really well. But in general [for people with higher counts], these kind of precautions aren’t necessary.”

Eating well while undergoing cancer treatment isn’t always easy, so remember to be kind to yourself. Here are some tips that may help you improve nutrition during this time:

• Run a fan or open windows: Your treatments can make you more prone to nausea, and the extra airflow can help whisk away nauseating cooking smells, says Bragagnini.

• Use plastic utensils: Some patients find that after chemo or other treatments, using metal utensils leaves a metallic taste in their mouth; if that happens, switching to plastic utensils may help, says Dr. Oller.

• Skip large meals: Cancer treatments such as chemotherapy, radiation, and certain medications can cause gastrointestinal side effects, including nausea, vomiting, and loss of appetite. Eating smaller, more frequent meals can help manage these symptoms by reducing the burden on the digestive system, making it easier to tolerate food, says Dr. Oller.

• Don’t stress about being perfect: “I think every bite of high-quality food you put into your body is good for you,” says Dr. Johnson, who decided to go vegan after her breast cancer diagnoses. “If you have a kale salad or a veggie stir-fry and then you have some ice cream afterward it doesn’t undo the healthy food you had before.”

You might struggle to keep weight on during treatment. Stress alone can put the work of prepping nutritious meals on the backburner. And treatment side effects like nausea, mouth sores, and constipation or diarrhea can make even your favorite foods unappealing, notes the American Cancer Society (ACS).

But it’s more important than ever to make sure you’re getting the calories and nutrition your body needs. “If you’re not eating enough it may take longer to get through your treatment,” says Hannah Lepkowksi, R.D., an oncology dietitian with Henry Ford Cancer in Detroit, MD. For instance, “your doctor may want to hold off on doing your next round of chemo if you’re becoming malnourished.”

Small, protein-rich snacks and mini meals can help you stay nourished—think cottage cheese with fruit, milk and cereal, trail milk, or hummus and crackers, Lepkowski says. But utimately, the most important thing is to just try to get calories in, the ACS notes. If you suddenly find yourself craving pancakes at 4:00 P.M., don’t stress about the odd time of day or whether they’re a wholesome choice. “If you’re not feeling good, I’d rather just see you eat,” Lepkowski says.

On the other end of the spectrum, carrying excess weight also isn’t ideal. High levels of body fat can increase inflammation throughout the body, which may reduce the efficacy of your treatment, says Omar Kucuk, M.D., a medical oncologist at the Winship Cancer Institute at Emory Saint Joseph’s Hospital in Atlanta, GA. Being overweight may also impact your health post-treatment: Breast cancer survivors who lost weight with healthy dietary changes (like less fat and more fruits and vegetables) have been shown to have a lower risk of recurrence, per a British Journal of Cancer review on obesity and survivorship.

It’s worth meeting with a registered dietitian who specializes in working with cancer patients if you’re running into any challenges related to weigh or appetite. You can come up with a plan to manage treatment-related side effects to keep weight on, if you’re losing it. And if you’re overweight, you, your doctor, and your dietitian can decide if it’s OK to work towards a lower weight now or hold off until you’ve completed your treatment.

The jury’s still out on how organic food impacts cancer risks and outcomes, according to the American Cancer Society. However, research does suggest that people who eat organically grown produce may have lower breast cancer rates compared to those who never eat organic produce, according to a study of nearly 70,000 French adults published in JAMA Internal Medicine.

That could be because organic foods are grown without synthetic pesticides, some of which may have carcinogenic and hormone-disrupting effects, the authors theorize. (Note: Some organic farmers do use organically-approved pesticides, which are pesticides made from naturally occurring sources such as minerals and plants.) But organic food-eaters could also have lower breast cancer rates for an entirely different reason. “They could be engaging in other healthy lifestyle behaviors [that affect cancer risk] like exercising and not smoking,” Lepkowski says.

So when patients with breast cancer ask Lepkowski if they should choose more organic foods, she doesn’t take a firm stance either way. “If you have a preference due to concerns with pesticide residues, it’s worth choosing organic,” she says. That said, organic items cost more and can be harder to find. So if budget and availability are factors for you, then you may be better off just making sure you’re eating plenty of fresh fruits and vegetables period. the ACS notes.

“Fruits and veggies contain beneficial vitamins, minerals, fiber, and phytonutrient, so you’re going to get more benefits from eating enough than from just focusing on organic,” adds Lepkowski.

Navigating breast cancer can be overwhelming. If figuring out what to eat is adding to your stress, an oncology registered dietitian can ease that burden. “The idea with breast cancer, or any cancer, is to stay as nourished as possible. Dietitians can help with weight changes, digestive issues, loss of appetite, and help you prep for big surgeries to maximize healing,” Lepkowski explains.

Your dietitian can also be your go-to resource for making sense of the onslaught of information you might come across online or from well-meaning loved ones about what you should (and shouldn’t) be eating. “We’re here to debunk food myths, like whether you need to eliminate sugar or soy,” adds Lepkowski (who notes that both foods can be a part of a healthy diet when you have breast cancer).

It’s best to choose a registered dietitian with a dedicated track record of working with cancer patients, rather than a nutritionist or a health coach. “We’re trained in the field of oncology to follow evidence-based guidelines and help patients meet breast cancer-related needs,” Lepkowski says. Many cancer centers have oncology dietitians on staff, but you can also ask your oncologist for a referral.

So what does all this information look like in the context of your daily diet? There’s no one-size-fits-all dietary plan for people with breast cancer. “If you’re feeling good, the best type of diet is a generally healthy diet,” rich in foods like whole grains, lean proteins, fruits and vegetables, and healthy fats, Lepkowski says.

Still, when people ask her about what an actual meal might include, Lepowski typically gives these examples:

Breakfast

Start your day off with a mix of complex carbohydrates and lean protein for lasting energy, like:

• Oatmeal cooked with low-fat milk, topped with berries and chopped walnuts

• Greek yogurt parfait with granola, diced apple, and chia seeds

• Scrambled eggs with spinach and avocado whole wheat toast

Lunch

Make lean protein and veggies the stars of the show. They’ll help you stay full through the afternoon without the 3 o’clock slump. Try:

• Leafy green salad topped with grilled chicken and your favorite vinaigrette

• Burrito bowl with black beans, brown rice, diced avocado, baby spinach, and diced tomato

• Lentil soup with whole grain crackers and a side salad

Snack

Snacks are a prime opportunity to sneak in some more calories and protein. Some good options:

• Low-fat cottage cheese topped with fruit

• Dried fruit and nut trail mix

• Sliced veggies with hummus or tzatziki

Dinner

Aim for a balance of complex carbohydrates, lean protein, and healthy fat to support your energy and nutrition needs, like:

• Baked salmon with a roasted sweet potato and steamed broccoli

• Whole wheat pasta with marinara sauce and garlicky sautéed kale and white beans

• Turkey chili with a whole grain roll and side salad

Going through breast cancer treatment can be stressful, so this may not be the time to make major dietary changes. However, fitting in good nutrition whenever you can—including adequate protein and fluids and ample amounts of fruits and vegetables—is a smart goal. Eating well as often as possible may help you feel more energetic, cope with side effects like nausea and constipation, and might even reduce the risk of having a cancer recurrence.