Whether you’re newly diagnosed with breast cancer or you’re facing breast cancer that’s spread to another part of your body, you probably have many questions. These may include: What should I eat?
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We talk with dietitian Anna Taylor, RD, who offers diet tips for those undergoing cancer treatment, including what to eat and what to avoid.
Breast cancer diet tips
While you might not be feeling 100% while going through your breast cancer treatment, it’s important to focus on the ingredients you put in your body.
Aim for at least 2 liters to 3 liters of fluid per day — about 66 ounces to 99 ounces — mostly from caffeine-free fluids.
Staying hydrated is always important, but especially so while going through cancer treatment. Some common side effects of cancer treatment can include vomiting, diarrhea, decreased appetite or fever, all of which can contribute to dehydration.
“Staying hydrated will help you regulate your body’s temperature, blood pressure and electrolyte balance, help prevent or minimize constipation and allow your organs to filter out wastes and toxins,” says Taylor. “Your fluid needs are higher while going through cancer treatment, so sip fluids throughout the day, mostly water.”
Get enough calories
Forget the calculator — the best way to know whether you’re eating enough calories for energy is to weigh yourself once or twice a week.
If your weight is trending down week after week, speak with a dietitian to make a plan.
Remember to eat regularly throughout the day. Small meals five to six times a day typically work well.
Small meals are less likely to trigger nausea, vomiting or diarrhea — and they maximize absorption of nutrients.
“Your body can only absorb so much at one time,” says Taylor. “Spreading things out with small frequent meals helps your body get the most out of every meal. In addition, if someone has a poor appetite, a large plate of food can be a total turn-off. A small meal or snack is more likely to be appealing, encouraging better intake.”
Focus on nutrients and get the most nutrients per calorie
Choose foods from the food groups — like fruits, vegetables, grains, beans, nuts, seeds, meats/eggs and dairy products.
A balanced diet helps ensure you’re getting the nutrients you need to keep your body strong.
“A balanced diet supports a healthy immune system, balanced electrolytes and lean body mass, gives you energy and helps fight the fatigue so often associated with cancer treatment,” says Taylor.
Don’t forget protein
Protein helps maintain lean body mass/muscle. Protein is found in meat, poultry, fish, seafood, eggs, beans, lentils, nuts, seeds, soy and dairy products.
Smaller amounts of proteins are found in vegetables and whole grains.
A person’s protein needs depend on a lot of different things: age, weight, height and activity level.
“Everyone’s protein needs are different, but fighting cancer and going through cancer treatment increases protein needs,” explains Taylor. “A good rule of thumb is to include protein at least three to four times per day if you’re eating normal portions of foods and at least four to five times per day if you’re eating smaller-than-usual portions of foods.”
Examples include eggs with breakfast, Greek yogurt with lunch, chicken with dinner and cottage cheese or nuts as a snack.
Breast cancer-fighting foods
Phytonutrients support human health and are found in plant-based foods, including fruits, vegetables, beans and grains. Below, you’ll find common foods that contain important phytochemicals.
“No supplement can do the work of a varied diet, so don’t turn to pills to do your dirty work,” says Taylor. “Instead, eat the rainbow — a rainbow of brightly colored produce, that is. Phytonutrients are largely behind what give produce its color, so the more vibrant the color, the more likely it is to be filled to the gills with phytonutrients.”
There are exceptions of course, and some bland-looking foods are still bursting with nutrients, like cauliflower and kohlrabi, for example.
Foods to avoid if you have breast cancer
If you have breast cancer, it’s advised that you avoid the following:
- Raw or undercooked meat, fish or poultry.
- Raw or soft-cooked eggs.
- Unpasteurized dairy products or juice.
- Unwashed fruits and vegetables.
- Leftovers that are more than three to four days old.
- Food that has been left out at an unsafe temperature for four or more hours.
“Limit caffeine and alcohol, as both are dehydrating,” advises Taylor. “Talk to your oncologist for exact recommendations. And if you’re having diarrhea, consider avoiding completely, as both can worsen symptoms.”
What to eat during breast cancer treatment
If you don’t have nutrition-related side effects from your cancer treatment that limit your ability to eat and/or digest food, Taylor says you can follow a generally healthy diet that includes:
Fruits and vegetables
Aim for five or more servings a day. Fruits and vegetables contain antioxidant and anti-estrogen properties.
Cruciferous vegetables like broccoli, cauliflower, kale, cabbage and Brussels sprouts are especially good to include and are rich in phytochemicals.
Try including a serving of produce with every meal and snack. Three meals, two snacks per day, for example, would lead to five servings per day.
You want to try to get 25 grams to 30 grams of fiber daily. Whole grains are unprocessed foods that are high in complex carbohydrates, fiber and phytochemicals, as well as vitamins and minerals.
A study by researchers at Soochow University in Suzhou, China, found that high fiber intakes may have a positive effect by altering hormonal actions of breast cancer and other hormone-dependent cancers.
Make sure at least half the grains in your diet are whole grains like oats with breakfast, whole grain bread with lunch or brown rice with dinner. Also, make sure you’re eating five or more servings of produce a day.
Another way to add whole grains? Choose nuts or seeds as a snack. You can also add legumes like beans, edamame, peas or lentils to meals.
Lean protein — and soy, too
For good protein sources, increase your intake of poultry, fish and legumes like beans and lentils. Minimize your intake of cured, pickled and smoked meats.
Regular intake of processed meats is associated with an increased risk for certain types of cancer. Processed meats are also high in sodium, which can elevate blood pressure in the short term as well.
Soy in moderate amounts, which means one to two servings per day of whole soy foods (like tofu, edamame and soy milk) also can be included.
Alcohol in moderation, if at all
Drinking alcohol is a known risk factor for breast cancer. A large, observational study of 105,986 women suggested that drinking three glasses of wine or more per week throughout life increases a woman’s risk of breast cancer by a small but significant percentage.
The study saw a 15% increased risk of breast cancer when women drank an average of three to six drinks per week, compared to women who did not drink. Try to avoid intake of alcoholic beverages when possible.
“Some studies tout possible benefits for heart health from moderate intake of red wine, but regardless of the type of alcohol, daily alcohol intake is associated with increased risk for certain cancers, including breast cancer,” notes Taylor.
Foods to help with treatment side effects
You may experience a variety of side effects while undergoing breast cancer treatment. Here are a few suggestions on what you can eat or do to help alleviate your symptoms.
If you experience nausea, your dietitian may recommend that you try to eat more foods that are cool or at room temperature because they don’t have a strong odor. It may also help to eat lower-fat food, as fats take longer to digest.
“Don’t skip meals entirely if you have nausea, since an empty stomach can make nausea worse,” Taylor says. “Instead, focus on small bites of food throughout the day.”
Avoid strong flavors. Feel free to incorporate ginger root into your recipes, as this can help settle a nauseated stomach.
If constipation becomes an issue, your dietitian may encourage you to eat fiber-rich foods and increase your fluid intake, Taylor adds. Low-intensity walking and warm beverages also can help encourage regular bowel movements.
To combat fatigue, choose high-protein snacks and small frequent meals rather than large meals. People often experience more fatigue when they’re not eating well or when they’re losing weight during treatment.
If you’re experiencing any side effect that affects your ability to eat regularly, ask your care team if you can meet with a dietitian to review individualized nutrition recommendations.
Maintain a healthy weight after treatment
People with obesity have higher levels of estrogen circulating in their bodies than women who are in their ideal body weight range.
Many studies, including a one conducted by researchers from the Iranian Institute for Health Sciences Research in Tehran, Iran, have demonstrated an association between body mass size and breast cancer in postmenopausal women.
If you’re overweight, Taylor recommends losing weight through a healthy diet and regular exercise once you’ve finished treatment.
Weight loss during treatment isn’t typically encouraged, as this is often associated with undesired muscle loss, leading to fatigue, a suppressed immune system and a slower healing process.
“Allow your body the nutrients it needs to fight cancer,” she says.
Once your treatment is done, consider meeting with a dietitian for individualized recommendations to decrease recurrence risk and support a healthy weight.