In women globally, breast cancer is the most commonly diagnosed type of cancer. Breast cancer accounts for 23% of all cancer diagnoses and 14% of cancer-related deaths worldwide, making it the most deadly type of cancer in women. But there is some good news! Despite the high rate of breast cancer diagnoses, the survival rate for those receiving a diagnosis has improved from 63% in 1963 to 90.3% in 2017 . Through diet and lifestyle choices, women can both prevent the occurrence of breast cancer as well as fight cancer that already exists in the body and reduce the risk of cancer recurrence.
There are many factors that contribute to the development of breast cancer in women. These include age, diet, environment, genetics, stress, sleep deprivation, toxic exposures, and other environmental factors. While some of these factors cannot be modified, such as family history, many of them are lifestyle choices and an individual can choose to alter them to optimize health. Particular emphasis should be placed on diet as it has increasingly been shown to have a significant impact on both the prevention and treatment of breast cancer  and is also highly modifiable, making it a strong target for reducing the risk of cancer as well as treating it .
Research has demonstrated that one of the most effective methods for preventing breast cancer from occurring is to consume a well-balanced diet of whole foods. Minimally processed plant foods such as fruits, vegetables, whole grains, legumes, nuts and seeds should make up the majority of the diet, while certain animal products should be eaten more sparingly .
A major contributor to breast cancer risk is consumption of sugar due to its effects on insulin which in turn has an effect on estrogen levels. Following consumption of high-glycemic sugary foods (especially processed ones such as white bread/rice, pastries containing white flour/sugar) there is a large insulin response. Consistently elevated levels of insulin (hyperinsulinemia) can cause insulin resistance (leading to Type II diabetes), trigger inflammation, and can promote growth of cancer cells. Additionally, elevated insulin levels raise estrogen levels. High levels of estrogen consistently correlate with breast cancer risk in many scientific studies. Insulin also enables the body’s ability to store fat – meaning elevated insulin levels increase the amount of fat that is stored in the body. Excess fat, especially around the midsection, increases the risk of breast cancer. Put simply, the more sugar you consume, the greater the risk. Blood sugar management (glycemic control) should be put on the forefront for breast cancer prevention.
According to our resident RDN & Certified Specialist in Oncology (CSO), Gretchen Gruender, along with blood sugar management, weight management is very important to breast cancer prevention.
The consumption of high amounts of fruits, vegetables and other plant foods has some of the strongest evidence for prevention of breast cancer development in women and is generally considered to be a protective factor . Plant foods contain vitamins C and E, both of which have antioxidant properties that can help to prevent the development of cancer . They also contain various phytochemicals (also known as bioactive compounds) that help to strengthen the immune system and prevent cancer from occurring. Each fruit and vegetable contains different types of phytochemicals, therefore a wide variety of fruits and vegetables of different colors should be eaten at each meal .
Increasingly, cruciferous vegetables have been shown to be particularly helpful for preventing cancer from developing. They contain bioactive compounds called glucosinolates, isothiocyanates and indoles that help protect against cancer in a multitude of ways, including anti-inflammatory effects, helping to eliminate carcinogens and protecting DNA in cells from becoming damaged. Women who eat a greater amount of cruciferous vegetables have been found to have a lower incidence of breast cancer than women who eat fewer cruciferous vegetables. Some examples of cruciferous vegetables are broccoli, cauliflower, cabbage, brussels sprouts, radish, kale, collard greens and bok choy. Women who want to prevent breast cancer should consider increasing the amount of these foods in their diets . Reach out to Starkel Nutrition’s administrative team if you would like to gain access to our recipe database, including many recipes featuring the above veggies.
Soy foods have also been an area of interest for researchers because of the low incidence of breast cancer in countries where people consume high amounts of soy. Isoflavones are a phytochemical found in very high concentrations in soybeans. Isoflavones have a structure that is very similar to the hormone estrogen and can therefore bind to estrogen receptors in the body . Many types of breast cancer are estrogen-receptor positive, meaning that the binding of estrogen to their receptors promotes their growth. Because soy isoflavones can bind to estrogen receptors as well, they may prevent estrogen from binding and furthering the growth of the cancer cells . Highly-processed forms of soy foods such as soy sauce and soy protein powders contain much lower amounts of isoflavones than minimally processed soy foods such as soybeans and tofu. Minimally processed soy foods are therefore a much better choice for women that wish to prevent breast cancer. It should be noted that there has been some concern about soy foods and cancer as previous studies on mice had actually linked high consumption of soy to cancer. However, mice have a very different pathophysiology of cancer than humans and research on tens of thousands of individuals has allowed researchers to conclude that consumption of high amounts of soy foods does not promote breast cancer in humans. Soy consumption is considered to be safe and potentially beneficial .
Many of the recommendations for women with existing cancer are similar to the recommendations for cancer prevention. Minimally processed plant foods such as whole grains, fruits, vegetables, legumes, nuts and seeds are all beneficial because of their high amounts of cancer-fighting phytochemicals and fiber; these should comprise the majority of the diet . Try to avoid highly processed foods as well as cured and smoked foods, as these have been associated with cancer development and recurrence . Fat intake of 30% of calories or less has been suggested by researchers as being effective for fighting cancer. Saturated fats and trans-fats should be decreased, while intake of lean meats and vegetarian proteins should be increased . It is also important for women who are fighting cancer to get plenty of fluids. Women should aim to consume 2-3 liters of fluids per day from water and other non-caffeinated and non-sugary beverages . Alcohol should also be limited by both those that wish to prevent breast cancer and those who are already fighting breast cancer. It is recommended that women consume no more than one alcoholic beverage per day; women who have already received a diagnosis should consider eliminating alcohol altogether .
There are currently no dietary supplements on the market that have been shown to slow the progression of breast cancer or to prevent it from occurring. Dietary supplements are not regulated by the Food and Drug Administration (FDA) – this means that manufacturers of supplements can make a variety of claims about their products that may or may not be true. Supplement use should therefore always be discussed with health care providers and it is not advised for people to begin taking supplements without medical and nutritional advice .
Although diet is highly important, other lifestyle factors also have an impact on the development of cancer and affect the body’s ability to fight existing cancer. Physical activity, sleep, stress levels, social support and a multitude of other factors are also important . Those who are trying to prevent breast cancer or who are already fighting cancer should also consider seeking support to optimize these other lifestyle factors.
Digestive health also plays more of a role in your breast cancer risk than you might think. Healthy gut flora – maintaining the correct ratio of healthy bacteria in your gut – improves your immune system and also helps you better break down food and detoxify the estrogen made in your body after it’s been used. Bad gut flora means that excess estrogen becomes reabsorbed rather than eliminated, ushering in estrogen dominance and all its risks. One meta-analysis found excessive use of antibiotics, which kill off bad as well as good bacteria, increase your risk for breast cancer.
So what can you do? Fiber up. Fiber becomes critical for the gut and overall health. Your goal should be 35 grams per day. High-fiber foods include vegetables, fruits, beans, nuts, and whole grains such as brown rice and ground flax seed. Consider a fiber supplement if you’re not getting your complete quota from food. Restore gut health. Leading researchers at Cleveland Clinics discovered gut microflora influences cancer genes and your immune system. Tend your inner garden with gut-supporting foods like fermented foods as well as fiber and probiotics. If you suspect gut issues like leaky gut or IBS, work with a functional medicine nutritionist or practitioner to correct them. Starkel Nutrition has many nutritionists who specialize in this area.
Lastly, go clean and green. Choose filtered water and organic food. Always opt for high-quality meat sources like wild salmon and grass-fed beef. Become more aware about how things like household cleaners and cosmetics can increase your toxic load at the EWG.
With all of these tools in your belt, the journey towards breast cancer prevention and/or treatment can be not only manageable, but delicious and sustainable! If you have any questions or feel you need support on your path, please reach out to Starkel Nutrition to book an appointment today.
Interested in learning more? Schedule an appointment with us to get support on your future journey to body and mind health.
|Written by the Starkel Nutrition team.|
- “Cancer Stat Facts: Female Breast Cancer.” National Cancer Institute, 29 September 2021, https://seer.cancer.gov/statfacts/html/breast.html
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- “Cruciferous Vegetables and Cancer Prevention.” National Cancer Institute, 7 June 2012, www.cancer.gov/about-cancer/causes-prevention/risk/diet/cruciferous-vegetables-fact-sheet.
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