Nutritional science continues to sharpen our understanding of how the foods people eat may contribute to the development of cancer, as well as how certain foods can support a patient nutritionally while in active treatment.
With breast cancer specifically, research is showing that because it’s often a hormonally driven disease, controlling your weight and managing your diet can be helpful during treatment and may help decrease your chances of developing the disease in the first place.
Dr. Gertraud Maskarinec, a physician in preventive medicine and nutritional epidemiology and associate director for research education at the University of Hawaii Cancer Center in Honolulu, says that while there isn’t a so-called “best diet” for preventing or dealing with breast cancer, avoiding obesity is important.
“In terms of breast cancer and what we know about nutrition, the number one thing we know is that for women after menopause — those over age 50 — obesity is the risk factor” to be most concerned about. “That is the best known nutritional risk factor, so avoiding obesity after menopause is really the best thing we can do.”
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, agrees.
“Excess body weight has been consistently linked with an increased risk of postmenopausal breast cancer. As such, consuming a diet rich in fresh fruits and vegetables while lowering intake of processed foods and saturated fats may help maintain a healthy body weight.”
To control weight, Maskarinec recommends eating a balanced diet that prohibits weight gain. “I would say we don’t have much evidence that eating particular foods will help. But eating in a balanced way is the (best) approach. It’s not one food that’ll particularly save you or not save you, it’s the overall state of health.”
For a society that often prefers to turn to a pill to take care of every issue, this can be an unsatisfying answer, but “eating a well-balanced diet, avoiding obesity and engaging with physical activity all through life” has been shown to be helpful in preventing breast cancer and providing a better outcome for those with the disease, Maskarinec explains.
Justine Friedman, a clinical dietitian and a mindset mentor in private practice and a mentor on the Belong.Life Diet, Nutrition & Cancer group on their Belong-Beating Cancer Together App, headquartered in New York, recommends adopting the Mediterranean diet for best results.
“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, or grains, as a foundation with loads of vegetables and fruit.”
In addition, those following a Mediterranean lifestyle will also consume fatty fish twice a week “and red meat and chicken very rarely. Legumes and beans are highly encouraged, and dairy products should be low fat and in moderate amounts,” she says.
Any healthy diet limits the intake of processed foods, and that’s true for the Mediterranean lifestyle, Friedman says. “Processed red meat products like deli meats and sausages, deep fried chicken (with the skin) and breaded, fried fish are considered to be cancer promoting.”
Sardesi 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.
High-Impact Lifestyle Changes
While there might not be a single diet or food that can make all the difference when it comes to lowering your risk of developing breast cancer, there are a few lifestyle changes you can make that can help. Specifically, quitting smoking, limiting alcohol intake and exercising regularly have all been shown to lower risk of many different types of cancer, breast cancer included.
Smoking has been linked to many different kinds of cancer and “excessive alcohol intake does seem to increase the risk for breast cancer by a measurable amount,” Maskarinec says.
Sardesai recommends avoiding alcohol or keeping “intake to less than three to four drinks per week.”
Friedman adds that “making changes to lifestyle will not guarantee the prevention of breast cancer, maintaining a more balanced diet, exercising regularly, reducing alcohol intake and maintaining a healthier weight are all ways of increasing protection.”
Eating Right During Treatment
As with reducing risk, when it comes to eating right if you already have breast cancer, experts say there isn’t one right way to eat or one particular best diet or food to consume or avoid.
Nevertheless, eating healthfully can help support your body while in active treatment. That means aiming to eat as many fresh vegetables, high-fiber foods and plant-based proteins as you can, says Jessica Swift, CEO of Sauce Foods in Hyattsville, Maryland, and owner of Chef Jess, a meal delivery, catering and nutritional counseling service based in Washington, D.C.
“I always tell my patients to make sure they’re getting enough phytochemicals,” a catch-all term for plant-based compounds that have been shown to have an impact on health. These can include antioxidants, flavonoids, phytochemicals, flavones, isoflavones and other compounds often found in so-called “superfoods.” These phytochemicals have been found to have protective qualities that may fend off cancer.
She also recommends “keeping yourself regular as well,” which is where adding fiber can help. Getting enough fiber can also help you feel fuller longer and keep your cholesterol levels in check.
Swift recommends patients focus on eating lean protein, such as fish or plant-based sources of protein such as soy. “Making sure it’s not always animal protein is one thing I steer my clients toward.”
Mandy Enright, the Food + Movement dietitian and author of the “30-Minute Weight Loss Cookbook: 100+ Quick and Easy Recipes for Sustainable Weight Loss,” also emphasizes the importance of getting enough protein for patients dealing with breast cancer.
“Protein foods are incredibly important when you’re battling cancer because we need protein to help with our immunity. 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.”
The Soy-Breast Cancer Debate
Enright recommends incorporating meats, poultry, fish, dairy and eggs into your diet. But don’t forget: Plant-based sources of protein may be just as good. These sources include beans, nuts, seeds and soy.
Though 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, says Hollie Zammit, an oncology dietitian with Orlando Health in Florida. “Soy contains isoflavones, which have a similar structure to the hormone estrogen, but it’s not the same as female estrogen.”
In fact, many nutrition experts now believe that soy can be a healthy inclusion to the diet, as it’s high in protein and is a plant-based alternative to meat. Some evidence suggests that isoflavones could “possibly decrease your risk of breast cancer by binding to your estrogen receptors in breast tissue and decrease the likelihood that estrogen-triggered cell growth will occur,” Zammit says.
For some patients battling breast cancer, just eating at all can be a challenge as food aversions surface and appetite may diminish. But even if you’re carrying around extra weight, while you’re in active treatment probably isn’t the time to be thinking about losing weight, Enright says. “When you’re dealing with cancer, it’s not about cutting calories or worrying about eating too much.”
Still, she recommends keeping tabs on your weight. If you’re losing weight while in treatment, talk to your doctor or see a nutritionist to make sure you’re getting enough calories and the nutrients you need.
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. It’s also important to focus on maintaining your strength and physical wellbeing.
Sardesai notes that “breast cancer treatments including chemotherapy and anti-estrogen therapy can lead to weight gain and a decrease in physical activity,” which can make it difficult to control obesity.
But, he adds, “obesity at diagnosis is associated with worsening in risk of cancer recurrence and mortality. A nutritional assessment for all patients initiating breast cancer therapy is encouraged.” Research shows women continuing to exercise while undergoing cancer treatment show increased quality of life, emphasizing the benefits of physical activity. Talk with your doctor and a nutritionist about how to reduce your risk of weight gain while maintaining lean muscle mass.
“Current evidence falls short of making a specific dietary recommendation or ‘anti-cancer diet plan’ for patients with breast cancer,” Sardesai laments. “However, ongoing studies will shed further light on the role of weight loss and lifestyle interventions on breast cancer recurrence risk and mortality.”
In the meanwhile, the following healthy 10 eating tips may help you feel better during and after breast cancer treatment:
1.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.
It can also help ensure you’ll get the nutrients you need. “Someone who’s undergoing treatment may not be in the mood to do shopping,” so planning ahead of time and going to the store on days when you’re feeling stronger can make things easier on days when you don’t feel up to it.
2. Streamline your shopping.
Shopping can be streamlined if you create a standard list of mix-and-match foods you know how to prepare healthfully, Swift 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” according to your tastes each day.
3. Cook and freeze large batches of nutritious food.
Swift recommends “batch cooking” — making a big pot of something that can be packed into smaller portions and frozen for easy reheating later.
She says soups and broths work well for this approach and can be especially comforting, even if you’re not feeling like eating a real meal.
“Even if you don’t have an appetite, you can always take a little bit of bone broth. Also, I would make a good beef stew, a vegetarian chili, different types of heartier soups and have them in the freezer.”
Swift 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. So, I make the food so it doesn’t smell up her house, and she can have a little at a time without her whole house smelling,” she says.
5.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. She adds that adding protein powders or a pre-mixed nutritional drink like Ensure or Boost can also be helpful if your appetite is very low.
Swift 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. 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.”
6. Keep it simple.
“The biggest thing is simplicity,” Enright says. “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.” Swift recommends aiming for five to six smaller meals a day, especially if chemotherapy is making you feel nauseous.
In the end, although a healthy diet might not be able to cure cancer on its own, it can go a long way toward boosting your energy, your strength and your spirits while you’re dealing with the disease. There’s also value in eating with family or a friend. Eating well should be part of your program of self-care all the time, but especially when dealing with breast cancer.
7.Eat the right fats.
“There is a huge area of focus on the types of fats to include in your diet,” Friedman says. If you’re following the Mediterranean diet, you’ll be consuming a diet high in monounsaturated fatty acids. This is the idea, Friedman says. Sources of these fats include:
— Olive oil.
— Chia seeds.
— Ground flaxseeds.
— Other nuts and seeds.
Healthy fats are important, but you should also take care not to overindulge, Friedman says. “These should be included in moderation as high intake can lead to unwanted weight gain.”
8. Limit alcohol and sugar.
Friedman notes that while the Mediterranean diet she recommends does permit moderate amounts of red wine, it’s best to keep your intake very low, given the concerns surrounding alcohol and breast cancer.
In addition, “sugars are another topic of hot debate when it comes to cancer. 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,” Friedman explains. While research suggests that sugar alone is not responsible for the development of cancer “it compounds the problem due to inflammation and possible weight gain.”
9. Stay hydrated.
“Sometimes, especially during chemotherapy you can get dehydrated, and you may not be eating enough,” because nausea is a common side effect of chemo, Swift says.
10. Keep up the good work in remission.
Friedman notes that after you’ve completed treatment, that’s no time to slack off the good eating habits. “Once in remission it’s important to maintain a healthy weight, exercise regularly, and stick to the breast cancer prevention guidelines for nutrition. The ideal exercise goals according to the World Health Organization is 150 to 300 minutes of moderate exercise a week, or 75 to 150 weekly minutes of more strenuous exercise.”
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Update 12/13/21: This story was previously published at an earlier date and has been updated with new information.