While there is no diet or lifestyle change that can “treat” or “prevent” breast cancer, avoiding certain risk factors (e.g., smoking) and increasing protective factors (e.g., regular exercise), can help lower our risk. Like most medical recommendations, there is still so much research needed to truly understand cancer prevention and treatment. As we honor Breast Cancer Awareness month, we wanted to take this opportunity to share current recommendations.
At Moveable Feast, we aim to foster a positive relationship with food, one that underscores moderation, balance, and mindfulness. For this reason, we want to highlight recommendations on what to “add” in your diet versus what to eliminate or avoid. However, keep in mind that research has found that a “Western diet” high in refined sugars, saturated fats, processed meats, and alcohol, as well as physical inactivity and smoking, have all been strongly associated with an increased risk for breast cancer.
Phytoestrogens, lignans, isoflavones and Omega-3s:
Breast cancer is estrogen-sensitive, meaning that it depends on estrogen to grow. Certain foods have “phytoestrogens” which are chemical compounds that look similar to the estrogen we make in our bodies. The latest research shows that moderate intake of foods high in phytoestrogens like lignans and isoflavonoids can actually protect us from breast cancer! It appears that when a “weak” estrogen-like compound like phytoestrogens takes the place of our body’s natural estrogen, then the weak substance can act as a relative anti-estrogen, decreasing the risk of estrogen-sensitive cancers like breast cancer.
So how do I get more phytoestrogens in my diet?
The most popular food high in phytoestrogens is soy or soy-based foods like tofu and tempeh. Foods high in Omega-3 fatty acids tend to be a good source of lignans, with flax seeds being a prime example; others include sardines, salmon, tuna, cod, mackerel, walnuts and some white and red beans. Other foods typically higher in phytoestrogens include most nuts, minimally processed whole grains, legumes like mung beans, and some vegetables like yams, garlic and cabbage.
Like most other nutrients, phytonutrients are lost when foods are processed extensively. Look for the most wholesome version of the foods to maximize your phytoestrogen intake! For example, eating whole soy beans instead of drinking soy milk.
Some research studies have shown that dietary fiber has multiple protective effects, including inhibiting intestinal estrogen reabsorption, lowering cholesterol levels and assisting with glucose control, thereby reducing the risk of breast cancer from multiple fronts. It’s important to note that this recommendation is based primarily on whole foods, specifically fruits and vegetables,and not on fiber supplements. Additional considerations for potential protective effects were seen for mushrooms and citrus fruits. Keep in mind the daily recommended amount of fiber is between 20-38 grams.
According to the National Cancer Institute and the CDC, women who exercise four or more hours a week have a lower risk of breast cancer. Exercise can help you maintain a healthy weight, keep blood sugars in a healthy range and support your immune system. Although EVERYONE should exercise regularly, the protective effect of exercise on breast cancer risk may be greatest for premenopausal women who have normal or low-body weight.
Research has continued to point to the numerous benefits of a Mediterranean diet, including breast cancer prevention. The Mediterranean diet constitutes a regular intake of fruits and vegetables, whole grains, moderate in protein (including fish!) and low-fat dairy. Naturally, this is a diet very high in antioxidants, phytoestrogens, omega-3s and fiber.
The Mediterranean diet was found to be most effective when alcohol was excluded all together (the correlation between alcohol consumption and breast cancer is fairly well established in research). This eating pattern also seems to have a protectiveinfluence against the risk of breast cancer, regardless of body weight and BMI, and it seems to be most beneficial for post-menopausal women.
Click here for more information on the “Mediterranean Diet” from the AHA.
Here are some key takeaways:
- Meet your daily fiber recommendations! 20-38 grams per day. Make sure most of your fiber is coming from whole fruits and vegetables.
- Limit meats high in saturated fats and avoid processed, cured, charred or smoked meats. (E.g., hot dogs, bologna, lunch meats, bacon, salami, etc.)
- Limit your alcohol intake. If you are a female, limit to no more than one serving of alcohol per day. (A serving of alcohol is considered 1½ fluid ounces of hard liquor, 5 fluid ounces of wine or 12 fluid ounces of beer.)
- Include some foods high in phytoestrogens! Like soy, tofu, flax seeds, legumes, seeds, nuts, etc.
- Exercise! The more active you are, the better off you’ll be. The CDC recommends 150 minutes of physical activity every day, which comes down to 30 minutes, 5 days a week.
Interested in learning more? Here are some great additional resources to read or view:
- Buja, A.; Pierbon, M.; Lago, L.; Grotto, G.; Baldo, V. Breast Cancer Primary Prevention and Diet: An Umbrella Review. Int. J. Environ. Res. Public Health 2020, 17, 4731. https://doi.org/10.3390/ijerph17134731
- Breast cancer and alcohol: https://www.youtube.com/watch?v=JAVV-Hmp9o8
- Breast cancer prevention https://www.youtube.com/watch?v=nYM2CcuhS4E