Nutritional science continues to sharpen our understanding of how food can either nourish a patient or contribute to the development of cancer.
With breast cancer specifically, research suggests that because it’s often a hormonally driven disease, controlling your weight and managing your diet can be helpful during treatment. It may also help decrease your chances of developing the disease in the first place.
Breast Cancer and Obesity
While there isn’t a “best diet” for preventing or managing breast cancer, avoiding obesity is important.
“In terms of breast cancer and what we know about nutrition, the number one thing is that for women after menopause — those over age 50 — obesity is the risk factor,” explains Dr. Gertraud Maskarinec, a physician in preventive medicine and nutritional epidemiology at the University of Hawai’i Cancer Center in Honolulu. “Avoiding obesity after menopause is really the best thing we can do.”
Research has found that breast cancer patients with obesity are more likely to experience complications and experience recurrence of their cancer. Plus, most breast cancers are diagnosed in women over age 50, notes the Centers for Disease Control and Prevention, so weight management is key.
[READ: Weight Management: What’s a Healthy Weight?]
Managing Weight With Breast Cancer
Eating a balanced diet to manage your weight should be your main strategy.
“We don’t have much evidence that eating particular foods will help, but eating in a balanced way is the (best) approach,” says Maskarinec, who also serves as the associate director of cancer research education and training at the University of Hawai’i Cancer Center. “It’s not one food that’ll particularly save you or not save you. It’s the overall state of health.”
So, what does a balanced diet for weight loss look like? One rich in fresh fruits and vegetables with few processed foods and saturated fats, says Dr. Sagar Sardesai, assistant professor and co-medical director of the high risk breast program at the Ohio State University Comprehensive Cancer Center — Arthur G. James Cancer Hospital and Richard J. Solove Research Institute in Columbus.
The following tips and eating plans can help you stick to these broad guidelines.
[SEE What Makes a Diet Healthy?]
The Mediterranean Diet Approach
The Mediterranean diet — consistently ranked No. 1 on U.S. News’ Best Diets Overall ranking — should be top on your list too.
“The best diet for health in general — and to reduce breast cancer risk — is the Mediterranean diet lifestyle approach, which focuses on whole-grain carbohydrates as a foundation, with loads of vegetables and fruit,” says Justine Friedman, a clinical dietitian and a mindset mentor in private practice and a mentor on Belong.Life’s Belong-Beating Cancer Together App, headquartered in New York.
This diet also emphasizes healthy fats, which can reduce inflammation, lower your risk of cancer and help make treatment more effective, adds Nicole Gunnare, an oncology dietitian with El Camino Health Cancer Center in Mountain View, California.
Olive oil, avocado, walnuts, flaxseeds and salmon, for instance, are all healthy fats that offer lots of omega-3 fatty acids, which lower inflammation. Just be sure to eat them in moderation because they can be calorie-dense.
In addition, those following a Mediterranean lifestyle also consume:
— Fatty fish.
— Legumes and beans.
— Low-fat dairy products.
The Mediterranean diet limits:
— Red meat and chicken.
— Processed foods.
— Added sugars.
Sardesai notes that the American Cancer Society dietary guidelines are also useful. These guidelines recommend reducing red meat consumption to less than 16 ounces per week and avoiding processed foods, such as deli meats and sausages, deep fried chicken with the skin, and breaded, fried fish.
[SEE: 10 Best Mediterranean Diet Snacks.]
Eating Right During Treatment
If you already have breast cancer, experts say there isn’t a magic food or diet you can eat. What’s important is eating healthfully in general to support your body while in active treatment.
Phytochemicals
A phytochemical is a catchall term for plant-based compounds that have an impact on health. Research suggests these phytochemicals have protective qualities that may fend off cancer.
“I always tell my patients to make sure they’re getting enough phytochemicals,” says Jessica Swift Harrell, a registered dietitian and principal nutrition consultant with Chef Jess Consulting, based in the Washington D.C. metro area.
Compounds like antioxidants, flavonoids, flavones and isoflavones are often found in so-called “superfoods.”
Fiber
Boosting fiber intake is also important when undergoing treatment. Swift Harrell recommends eating cruciferous vegetables like broccoli, cauliflower and Brussels sprouts because they’re chock full of fiber. Adding fiber can also:
— Keep your bowel movements regular.
— Help you feel fuller longer.
— Keep your cholesterol levels in check.
Protein
If you want to include some meat, Swift Harrell recommends patients focus on eating lean protein, such as fish. Plant-based sources of protein — like soy, chickpeas and edamame — are also an excellent choice.
“Making sure it’s not always animal protein is one thing I steer my clients toward,” she says.
You should also ensure you’re getting enough protein, says Mandy Enright, the Food + Movement dietitian, based in Neptune, New Jersey.
“Protein foods are incredibly important when you’re battling cancer because we need protein to help with our immunity,” she explains. “We need protein to make antibodies. We also want to make sure we’re maintaining muscle mass to reduce weight loss, and we don’t want to be breaking down muscle mass.”
Flexibility for food aversions
The Mediterranean diet is a great way to get all the phytochemicals, fiber and plant-based nutrients your body needs. Because it’s more of a lifestyle than a diet per se, it’s flexible and sustainable, making it easier to adapt to how treatment may affect your appetite.
For example, Gunnare says she often sees patients develop an aversion to meat when going through treatment for breast cancer.
“It’s a side effect from the chemo and may be related to increased nausea,” she says.
For many people, the smell, taste or texture of certain foods such as meat suddenly become intolerable. If you’re following a Mediterranean diet, you’ll be limiting intake of meat and meat products anyway, so that aversion may not be as pronounced.
Is There a Connection Between Soy and Breast Cancer Risk?
Although there has been some debate about whether soy and soy-based food products might elevate breast cancer risk, it turns out soy isn’t a problem.
Soy contains isoflavones — compounds that have a similar structure to the hormone estrogen. But soy isoflavones are not the same thing as female estrogen.
In fact, many nutrition experts now believe that soy can be a healthy inclusion to the diet because it’s high in protein and is a plant-based alternative to meat. Some evidence suggests that isoflavones might even decrease the risk of developing breast cancer by binding to estrogen receptors in breast tissue. This could decrease the likelihood that estrogen-triggered cell growth occurs.
Diet Tips for Eating Better During Breast Cancer Treatment
Eating during treatment for breast cancer isn’t always easy. However, it’s important that you give your body the nutrition it needs to cope with both your cancer and the treatments, which can be challenging.
“Breast cancer treatments, including chemotherapy and anti-estrogen therapy, can lead to weight gain and a decrease in physical activity,” Sardesai notes.
The following healthy eating tips may help you feel better, maintain your weight and nourish your body during and after breast cancer treatment:
— Plan ahead on days when you feel better.
— Streamline your shopping.
— Cook and freeze large batches of nutritious food.
— Seek support.
— Understand that your appetite and preferences might change.
— Keep it simple.
— Limit alcohol and sugar.
— Stay hydrated.
— Keep up the good work in remission.
Plan ahead on days when you feel better
Planning your meals and shopping on days when you feel stronger may help you stay on top of your nutrition game, even on days when you aren’t feeling up to cooking.
“Planning is definitely going to be the biggest ace in your pocket when it comes to meal prep, cooking and shopping,” Enright says.
Streamline your shopping
Shopping can be more manageable if you create a standard list of mix-and-match foods you know how to prepare healthfully, Swift Harrell says.
“It may take a bit of time initially to develop a process, but I would have that one go-to list where you have, say, 10 fruits and vegetables, some quinoa, rice, a vegetarian protein and an animal protein, and you can make things work (based on personal preference),” she advises.
Cook and freeze large batches of nutritious food
Swift Harrell recommends “batch cooking” to pack into smaller portions and frozen for easy reheating later.
Soups and broths work well for this approach and can be especially comforting.
“Even if you don’t have an appetite, you can always take a little bit of bone broth,” Swift Harrell says. “Also, I would make a good beef stew, a vegetarian chili, different types of heartier soups and have them in the freezer.”
Seek support
There are resources available if you need them.
“Don’t hesitate to ask your care team about speaking with a registered dietitian who can help guide you in making appropriate food choices to nourish your body and manage symptoms from treatment,” says Karen Godinez, a registered dietitian and certified specialist in oncology nutrition at Providence St. Jude Medical Center Virginia K. Crosson Cancer Institute in Fullerton, California.
Registered dietitians are there specifically to support you and may be able to offer other tips, tricks and suggestions to make eating healthy more attainable.
Recruit your friends and family to help too. Swift Harrell notes that having someone outside the house who can help with food preparation may also be helpful for some patients.
“I have one client — the smells are really getting to her. She loves Italian food, but she can’t stand the garlic-basil smell that it lets off in the house,” she says. “I make the food, and she can have a little at a time without her whole house smelling.”
Understand that your appetite and preferences might change
It’s not uncommon for people undergoing treatment for cancer to lose their appetite or have sudden aversions to certain kinds of foods. This is normal, but you should still try to get as much nutrition as you can.
“If your appetite is lower, try to include fruits and vegetables as smoothies, together with sugar-free nut butters, flaxseeds or chia seeds, raw oats and low-fat plain yogurt,” Friedman says.
Adding protein powders or a pre-mixed nutritional drink like Ensure or Boost can also be helpful if your appetite is very low, she adds.
Swift Harrell notes that while sudden aversions to certain foods can develop quickly, they often pass just as fast.
“I had someone who couldn’t stand the smell of lemon,” she recalls. “That’s a pretty good smell, but it was associated with the cleaner they were using in the house, and she developed an aversion to that. There’s no real way to get around that (other than) staying flexible and finding what works on an individual basis.”
Keep it simple
Simplicity can go a long way.
“Keeping your meals really simple — the less stress the better — and having more small meals is more helpful than a few big meals throughout the day,” Enright says.
Swift Harrell recommends aiming for five to six smaller meals a day, especially if chemotherapy is making you feel nauseated.
Limit alcohol and sugar
Friedman notes that while the Mediterranean diet does permit moderate amounts of red wine, it’s best to keep your intake very low. According to the American Cancer Society, even small amounts of alcohol can contribute to your risk of breast cancer.
“Sugars are another topic of hot debate when it comes to cancer,” Friedman says. “In the past, researchers thought that if cancer cells were starved of sugar they wouldn’t grow. This seems not to be the case as sugar is needed by the body for all its cellular processes, not only to fuel cancer cells.”
While sugar alone may not be responsible for the development of cancer, “it compounds the problem due to inflammation and possible weight gain,” Friedman adds.
Stay hydrated
Experts emphasize the importance of staying well-hydrated during treatment because water helps your body do everything it needs to. Avoid high-sugar beverages, and opt for plain water as much as possible.
You may get dehydrated and may not be eating enough because nausea is a common side effect of chemo, Swift Harrell points out.
Keep up the good work in remission
Maintain healthy habits, but make sure you’re gentle with yourself too.
“You may need to take some time to recover and regain your strength and energy,” Godinez says. “Some side effects or symptoms may linger after treatment, so make sure you are eating a wide variety of foods, including protein, to maintain or rebuild muscle.”
Once you’re feeling better, you should keep up your healthy eating habits, stay physically active and stick to the breast cancer prevention guidelines for nutrition, Friedman says.
“It’s really important to women to make sure they’re exercising and maintaining a healthy weight because those things can also lower this risk of recurrence of breast cancer,” Gunnare says.
Foods to Avoid if You Have Breast Cancer
Try to limit or exclude the following foods if you are at high risk of developing breast cancer, have been diagnosed with breast cancer, are going through treatment for breast cancer or are a breast cancer survivor.
All of these foods have been associated with a higher risk of developing cancer or having it recur.
— Ultra-processed meat products, such as deli meat and sausage.
— Alcohol.
— Soda and other sugar-sweetened beverages.
— Candy.
— Baked goods.
— Chips and other packaged snack foods.
— Fried foods.
— Fatty cuts of red meat.
— Highly processed or refined grains, such as white bread.
High-Impact Lifestyle Changes
Three key lifestyle changes have been shown to lower the risk of many different types of cancer, including breast cancer:
— Quit smoking. Smoking has been linked to many different kinds of cancer.
— Limit alcohol intake. Sardesai recommends avoiding alcohol altogether or keeping intake to under three to four drinks per week.
— Exercise regularly. To offset any cancer medication-related weight gain and stay healthy, you should stay active during treatment and after entering remission, Gunnare says. She recommends starting with 20-minute walks three times a week and building up to 30 minutes of aerobic exercise five times per week. Finding a physical activity you enjoy can also make exercising easier to sustain.
Bottom Line
While eating right during and after breast cancer treatments and once you’re in remission is important, Gunnare wants women to know that they don’t need to add stress to their lives by making sure their diet is perfect.
“I still want you to enjoy your meals, and I want you to eat healthy, but you don’t have to go overboard in terms of making it another thing that’s going to cause stress in your life,” Gunnare says.
For example, if you’re at a social event and you’re faced with a food that might be considered unhealthy, “it’s still OK to have a small portion and then go back to your healthy diet,” she says.
The key with eating right in the context of breast cancer is moderation and choosing a healthy eating pattern like the Mediterranean diet, which emphasizes plenty of vegetables, fruits, healthy fats, plant-based proteins and whole grains.
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Breast Cancer and Diet: Best Foods to Eat and Expert Tips originally appeared on usnews.com
Update 12/18/23: This story was previously published at an earlier date and has been updated with new information.
