There is a sign at the water fountain and vending machine alcove at the Dana Farber breast cancer waiting area that says “Nourishment”. Nourishment is defined as “food or other substances necessary for growth, health and good condition.” Instead of thinking of food as simply calories and macronutrient components of protein, carbohydrates and fat, I now think of how food can provide the nutrients to fuel my body to move, heal, grow, get stronger, fight cancer, feel better, and boost immunity. We seriously are what we eat! I want to show my body love and kindness through my actions, language and the food I provide it to thrive. And I want it to taste good! 

 

Most cancer prevention and survival guidelines recommend eating a wide variety of whole, vibrantly colored, unprocessed plants and avoiding processed foods, meat, and alcohol. Aim for 8-10 colorful fruit and vegetable servings per day. Eat a diet high in fiber (some studies say 30-45 grams per day although some research studies on beneficial plant based diets had up to 60 grams of fiber!). Your plate should be 50% vegetables, 25% protein, and 25% starchy vegetable or whole grain and a diet low in fat and cholesterol (only 20-30% of your total calories from fat with only 8% of calories from saturated fat. Eat flax seed meal, cruciferous vegetables, leafy greens, berries, plant protein (including beans), nuts, whole grains, herbs and spices every day. 

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Processed foods are food that has been packaged or changed from its original form and should be avoided. Even oils like olive oil are a processed food! Other examples to avoid are refined, processed grains, flours and sugars (so avoid white things on your plate; bread, pasta, rice, cakes, etc). and food packaged in wrappers. Look for whole grains like quinoa, farro, brown rice, amaranth, wheat berries, spelt, soba (wheat) noodles. Try lentil or chickpea noodles.

 

What do I want from my food to nourish and support me? I’m looking for food that will do the heavy lifting and be antiproliferative, antiangiogenic, anti-inflammatory, immune enhancing, detoxifying, decrease oxidative stress, promote positive epigenetic effects, and repair damaged DNA. Basically, what these big words mean is that I want food to prevent cancer growth and spread, boost immunity, decrease free radicals formed by normal mechanisms and from cancer treatment and repair my broken DNA. This seems like a big bill to fill, but plants naturally do these functions! 

 

Why are plants so powerful and how can they support us?

Phytonutrients (aka phytochemical or antioxidants) are plant chemicals that give plants color, smell, flavor, and protection from pests and diseases. When we eat plants containing phytonutrients we get the immune boosting, hormone regulating, cancer cell killing benefits that plants inherently contain. Examples of phytonutrients are carotenoids, flavonoids, isoflavones.

 

Certain plants have been found to be more beneficial in preventing and treating breast cancer. 

Those that are colorful, contain isothiocyanates, contain lignans, or phytoestrogens have been studied for their benefits. 

 

What plants and nutrients have been studied in breast cancer and why are they beneficial? 

Flaxseeds are high in omega-3 fatty acids and lignans as well as a good source of protein and fiber. Lignans are another type of phytoestrogen that lessens the effects of the body’s own estrogen and influences the body’s metabolism of estrogen (lignans are so powerful that eating a little bit every day can lengthen your menstrual cycle!), and studies have shown that high levels of circulating lignans are associated with reduced death in breast cancer.  In one dietary study, postmenopausal women with breast cancer who were scheduled for surgery were given flaxseed muffins and compared with a control group that was given a muffin without flaxseed. The breast tumor tissue biopsies were compared to the tumors at surgery after the dietary intervention. Researchers found that the tumors in the flaxseed muffin group had a decrease in tumor proliferation score (Ki-67), increase in cancer death (apoptosis), and decrease in cancer aggressiveness (c-erB2 or HER-2 score). The muffins had 2 tablespoons (25 grams) of ground flaxseed in them. Animals given flaxseeds with tamoxifen (an anti estrogen medication for ER+ tumors) had a reduction in their tumors greater than tamoxifen alone, but this has not been studied yet in humans. 

 

Lignans are found in whole grains, sesame seeds, vegetables, fruits, but flaxseed has 100 times more lignans than other foods. Good bacteria in your gut turn the flaxseed lignan precursors into available lignans. In studies of mice fed flaxseed, the animals’ gut bacteria and mammary gland cell miRNA expression (proteins that regulate gene expression) changed toward an anti-cancer profile. It is important to eat milled or ground flaxseeds so they are easily digested by your body.

 

Soybeans contain isoflavones which are phytoestrogens and selective estrogen receptor modulators. Phytoestrogens are not the same as human estrogen (which is associated with breast cancer). Plant estrogens bind to a different receptor than animal estrogen and can block the harmful effects of animal estrogen. Soy isoflavones may protect against breast cancer by reversing DNA methylation of BRCA1 and BRCA2 oncogenes. Soy consumption decreases breast cancer risk, breast cancer patients that eat soy live longer and have a lower risk of recurrence. One study found that drinking more than 10 mg/day of isoflavones (1 cup of soy milk contains approximately 30 mg of isoflavones) was associated with a 29% risk of breast cancer specific mortality and a 36% reduction in risk of breast cancer recurrence. Soy and tofu are technically processed forms of soy, so eating edamame or fermented soy like tempeh or miso are the purer forms.

 

The topic of dietary soy is a controversial one. Previously, it was recommended that women with breast cancer not eat soy because of its estrogenic effects, and then the consensus changed. It is best to speak with your healthcare provider to see what the updates recommendations are for your specific type of breast cancer. 

 

Cruciferous vegetables grow in the shape of a cross; broccoli, cauliflower, collards, bok chop, arugula, Brussel sprouts, watercress, cabbage, and kale. These vegetables contain a molecule called sulforaphane. Sulforaphane is a type of isothiocyanate that in studies suppresses the formation and growth of  breast cancer stem cells, boosts immune function, and detoxifies. Another added benefit is that it has been shown to improve osteoporosis. Cruciferous vegetables store a precursor of sulforaphane that is converted to its active form by an enzyme when the vegetable is bit, sliced, chopped or snapped. To eat the highest concentration of the active compound, wait 40 minutes after chopping your cruciferous veggies. 

 

The content of sulforaphane precursor is greatest in young broccoli sprouts (sprouts have 15 times more than mature broccoli). Cooking changes the content: fresh has the most, then blanched then cooked or frozen. According to Dr. Michael Granger in his book, How Not to Die: Discover the Foods Scientifically Proven to Prevent and Reverse Disease (Amazon affiliate link), simply eating 1/4 cup of broccoli sprouts a day will provide you with the concentration of sulforaphane that was used to study suppression of breast cancer stem cells. You can grow broccoli sprouts from seeds at home in a planter. Sprouts can be a source of foodborne illness, so you want to make sure you are handling them appropriately and discuss with your nutritionist and oncologist to make sure that it is healthy for you depending on your immune status. Granger adds that you can boost your sulforaphane benefit by adding adding 1/2 teaspoon of mustard powder to the broccoli sprouts. Mustard is a cruciferous vegetable and the seed contains myrosinase which is the enzyme that converts anti-cancer compound sulfurophane to its active form) to cruciferous vegetables. Daikon and regular radishes, horseradish and wasabi may all have the same sulforaphane boosting ability as mustard. Don't go overboard; more than four servings of cruciferous vegetables a day may be too much, and if you're on a blood thinner make sure to discuss with your healthcare team as adding cruciferous vegetables can affect your medication levels. 

 

Why is green tea good for you?

Tea contains antioxidant and anticancer compounds called polyphenols (flavonoids). Tea contains the compound epigallocatechin gallate (also known as EGCG), a polyphenol (specifically a catechin). While EGCG is found in all teas, most fruits (especially cranberries, strawberries, blackberries, kiwis, cherries, pears, peaches, apples, avocados), legumes, and nuts (pecans, pistachios, and hazelnuts). EGCG levels are highest in green tea. EGCG is an antioxidant that prevents cellular damage from free radicals, reduces inflammation, prevents tumor growth. The compound has been shown to boost brain, cardiovascular health, and promote weight loss. Studies have shown that drinking green tea decreases risk of breast cancer. Early stage breast cancer human studies have shown it decreases breast cancer proliferation, tumor invasion, metastasis and recurrence. There may be a synergistic relationship between green tea and soy (where the interaction of the two substances has a combined greater effect on the body than either soy or green tea alone). It may also increase tamoxifen’s effects on Estrogen Receptor positive (ER+) breast cancer cells. 

 

There are many other antioxidants and phytochemicals that have been studied and found to be important in breast cancer. These include but are not limited to vitamin C, vitamin D, vitamin E, resveratrol, turmeric (Curcumin) to name a few. Overall, studies have shown that getting these antioxidants from plants is better than from supplements. It is important to be cautious with supplements, especially during chemotherapy, radiation, and surgery because the antioxidants may interfere with these treatments (like high dose vitamin C or turmeric). Always check with your health care provider. Memorial Sloan Kettering Cancer Center's Supplement Database provides supplement or herb plant source, mechanism of action, potential benefits, side effects, and potential interactions. The compounds in proprietary supplements may be just one extracted part of the plant, too much, or may be processed in a dangerous way. One day individualized treatment plans will prescribe herbal remedies, probiotics, and chemotherapeutics specific to your tumor and genetic profile (let's remember that the cancer fighting compound in the chemotherapy medicine Taxol was discovered in the Pacific Yew tree!), but personalized medicine unfortunately isn't quite there yet. Supplements are not regulated closely by the Food and Drug Administration like prescription medications. 

 

Is sugar bad for you?

We all need sugar to live. Sugar is a carbohydrate made from plants, and the technical name is sucrose. Sucrose is a glucose and fructose molecule bound together. There is also milk sugar which is called galactose. Our cells use these molecules for energy. The problem is when we eat sugar in processed form without the fiber, protein and fat that are found in plants naturally. After eating processed sugar or high glycemic index food (Harvard Health Glycemic Index), your serum insulin and insulin-like growth factor (IGF) increase quickly and spike up and down instead of a slow and steady rise, plateau and decline. As its name implies, IGF is a growth factor, and it can stimulate cancer cell growth. IGF is decreased with fasting and is thought to be responsible for fasting's benefits. Higher levels of insulin from high blood glucose levels lead to insulin resistance and diabetes. A higher insulin, IGF, and fasting glucose levels increases the risk of breast cancer, and in women with breast cancer is associated with a worse prognosis. The link between obesity and breast cancer risk and poorer prognosis may be due to increased insulin, glucose and IGF. A fasting glucose blood level will test your insulin resistance. 

 

Avoid alcohol. The World Health Organization has named alcohol as a carcinogen and recommended no alcohol consumption. Acetaldehyde is the toxic first breakdown product of alcohol and it promotes cancer by interfering with DNA replication, creating DNA damage and forming DNA adducts. If you have low activity of the enzyme that breaks down acetaldehyde, you have a higher risk of developing alcohol-related cancer. There are even bacteria in your mouth and colon that can make the acetaldehyde levels higher after you drink alcohol and amplify alcohol’s carcinogenic effects.

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What’s wrong with eating meat? When meat (including all red meat, poultry and fish) is cooked to high temperatures it kills any harmful bacteria, but you can form carcinogens (cancer causing compounds) called heterocyclic amines (HCA). One study found that women who ate more grilled, barbecued, or smoked meats over their lifetimes, had almost a 50% higher risk in breast cancer. HCAs can be detected in breast milk of women who ate meat. In cell cultures in the laboratory, HCAs, especially one called PhIP have estrogen-like properties that caused breast cancer cells to grow quickly, invade and become metastatic. Cooking meats at high temperatures also creates advanced glycation end products (AGES) which are linked with heart disease, skin aging, inflammation, kidney failure, and Alzheimer’s disease. AGES are formed when protein or fat combine with sugar in your bloodstream. Meat (especially red), cheese, fried eggs, butter, oils, nuts, and processed foods cooked at high temperatures create AGES. 

 

The way that you cook food matters. The higher heat cooking methods of grilling, barbecue, roasting, frying creates more carcinogenic HCAs and AGES than lower temperature, moister, and slower cooking methods of poaching, stewing, and simmering. Another way to change the food preparation is by marinating meat in fruit, vegetables, herbs and spices to reduce the formation of HCAs.  One study found that marinades can reduce the HCAs in pan-fried beef by 90%. Still try to avoid all HCAs or consider these healthier methods.

 

Is all meat bad for you? Not necessarily, but the majority of meat that is mass produced for American consumption is very bad for us. Free range, grass fed, and wild are advertised as healthier forms of meat. These are all terms that need to be defined and better regulated and studied. Free ranged or wild caught animals have better fat content and inflammatory profiles than those that are farmed. A fish that is farmed and fed manufactured food that may be tainted with harmful chemicals and metals is not the same as one that is wild caught and swimming around in the ocean and streams sampling aquatic life and sea greens. A cow that lives all its life in a pen, fattened on corn feed without exercise is not the same as one ranged in a large field on pesticide-free grasses and clover. The humanity aspects of eating a living creature and climate change factors are a separate and important issue but something for another day.  

 

What’s the skinny on fats? Why do saturated fat and cholesterol matter and what types of fats are better?

There are four types of dietary fat and some are healthier than others. Fat in food can be saturated (meat, dairy, coconut, palm oils), monounsaturated (olive, peanut, canola oils) and polyunsaturated (nuts, cold water fish and avocados). The different amounts of saturation simply refers to the food’s chemical structure. Note that coconut, palm and palm kernel oils are high in saturated fat so avoid them even though they are from plants.  

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Studies shave shown that a diet higher in saturated fats and cholesterol increases risk of breast cancer, recurrence after diagnosis, and overall mortality.  Since meat is high in saturated fat and cholesterol, this is another reason why it’s better to avoid meat. Trans-fatty acids (when food is hydrogenated to harden vegetable oils so it is a solid at room temperature) increase risk of some cancers and cardiovascular disease. Trans fats were produced to make things live longer on the shelf hence why they’re found in many processed foods and food fryers in restaurants. They are found in refrigerated dough like biscuits, rolls, and pie crusts, commercial baked goods, stick margarine, fried foods. I like to think that if it's a solid on the counter, it’ll be solid in my blood vessels. No thank you, trans-fats! I’d like my blood vessels to go with the flow so my heart can pump that blood, oxygen and nutrients smoothly throughout my body. The FDA banned trans fat in 2015, but they can still technically be found in small amounts (less than 0.5 grams and the label can still read 0 grams trans fat) so you really need to put on your food detective hat and read the labels. If you see the words “partially hydrogenated” that is trans fat! Put it down, choose a different option, and walk away! One note, there are naturally occurring trans fat that are not as bad for our health compared to those made in the food industry. 

 

Cholesterol is a waxy, fat-like complex that you have in all of your cells and is needed to make hormones and vitamin D. Humans can make their own cholesterol, and we do not need to eat it. Dietary cholesterol is only found in animal fats. You can have it measured in your blood as lipid-protein complexes LDL and HLD. A higher LDL and total cholesterol is associated with increased cardiovascular disease. Cancer cells eat up cholesterol to make estrogen and build tumor membranes to allow tumor spread and invasion. Medications called statins lower cholesterol levels, but so far the data has not overwhelmingly demonstrated that statins can prevent or treat breast cancer. However, you should take one if your cardiologist recommends it based on your cardiovascular disease risk factors. Eating plants decreases cholesterol levels.

 

Cooking fats are all technically processed foods. Even olive oil, which is popular as a “healthier” fat in the Mediterranean diet, is a processed food. Edible oils are extracted from plants. They can be extracted with chemical solvents, crushed, or pressed from plants or seeds. And remember that coconut and palm oils are higher in saturated fat than other oils. 

 

The tricky thing is that we need fats in healthy abundance and ratio. Omega-6 and omega-3 fatty acids are polyunsaturated fatty acids that are essential. We can’t make them so it’s essential that we eat them in our diet. The problem is that our diet has evolved to have a skewed ratio: we eat too many omega-6 and not enough omega-3 fatty acids. The ratio used to be more balanced of 1:1 and now it’s closer to 20:1 shifted toward omega-6 and pro-inflammatory. 

 

Omega-3 fatty acids have been shown to protect against the risk of breast cancer, inhibit tumor growth and metastasis and enhance the immune system. Omega-3 fatty acids may also be protective against peripheral neuropathy caused by chemotherapy agent paclitaxel (Taxol), and some studies have shown that omega-3 fatty acids may increase the efficacy of certain chemotherapies or reverse drug resistance. The bottom line on fats is that you should eat omega-3 fatty acids especially from seeds and cold water fish (being mindful of cooking methods), eat only some omega-9 fatty acids like extra virgin olive oil, avocados and almonds, and eat a diet low in saturated fat and absolutely no tran-fats. Do not eat meat and dairy and avoid vegetable oils like corn, safflower, sunflower, cottonseed, coconut, palm and canola oil. 

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What is fiber and how does it decrease breast cancer risk? Fiber is the part of food that is not digested by the body. It is found in fruits, vegetables, beans, nuts, and whole grains. Fiber is split into two categories: soluble and insoluble. Soluble fiber retains water and becomes a gel during digestion and slows down nutrient digestion. Insoluble fiber doesn’t dissolve in water and moves through your gastrointestinal tract intact which adds to the bulk of your poop.

 

Fiber increases the bulk of your poop, decreases the intestinal transit time, binds to bile acids, and contains antioxidants. Increased fiber intake has been shown to lower breast cancer risk. Researchers believe that high fiber intake may reduce breast cancer by controlling blood glucose and improving insulin sensitivity, reducing circulating estrogen levels (by increasing hormone binding proteins in the blood and decreasing the reabsorption of estrogen), and by affecting the gut microbiome to increase fecal estrogen.

 

Meta-analyses of retrospective and prospective studies have shown that there is a 10-14% lower risk of breast cancer in women who eat high fiber diets and for every 10 gram increase in dietary fiber, increases the risk reduction by 4%-13%. Studies have shown that eating at least 25 grams of fiber per day lowers the risk of breast cancer. Most Americans only eat 10-15 grams of fiber per day. 

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What is the gut microbiome and why is it so important to health? 

There are trillions of microorganisms found throughout a healthy human body (skin, nose, gut, etc) coexisting peacefully and helping our bodies function. The largest number of these tiny organisms is in our small and large intestines. Our first exposures to microorganisms are through delivery in the birth canal, breast milk and then the environment. Diet, stress, infection, sleep, exercise, alcohol, smoking, hygiene, chemotherapy, radiation, and environmental factors can all affect the microbiome. Dysbiosis occurs when there is a disruption in the balance of healthy and harmful bacteria and it can lead to illnesses. Taking antibiotics can wipe out your gut flora and cause dysbiosis. Science is discovering that these microbes are responsible for many beneficial processes including stimulating the immune system, breaking down toxic foods, making vitamins and amino acids available, messaging other organs including the brain, reducing circulating estrogen levels through fecal excretion (this is called the estrobolome), and our mental health. The microbes in our gut create short chain fatty acids (SCFA) by fermenting fiber. These SCFAs stimulate apoptosis (or cancer cell death), exert anti-inflammatory effects, inhibit histone deacetylation (deacetylation can turn off tumor suppressor genes so when deacetylation is inhibited, those tumor suppressing genes can function normally), suppress blood vessel formation (angiogenesis), and overall inhibit tumor formation. The SCFAs also cause a release in neurotransmitters that positively affect our mood. 

 

Scientists are discovering that the composition of intestinal microbiota affects cancer formation, chemotherapy efficacy, drug resistance and side effects. Current breast cancer clinical trials are examining how the gut biome plays a role in neoadjuvant chemotherapy response, estrogen levels, depression, and exercise.

 

So where are these microorganisms found and what are pre- and pro-biotics? 

Priobiotics are live microorganisms that are consumed either found naturally in food or in supplements. They occur naturally in raw fermented foods (yogurt, sauerkraut, kimchi, miso, kombucha, kefir, cottage cheese, lacto-fermented pickles which are different from most store bought pickles) and have the words “live and active cultures” on the label. A food with added probiotics may have the Latin name listed in the ingredients such as Lactobacillus or Bifidobacterium. You can purchase probiotic supplements, but approach them with caution as supplements are not regulated by the Food and Drug Administration (FDA). Unless you know what your gut biome profile is and what microbiota are specifically beneficial for you at your point in diagnosis and treatment, probiotic supplements could be expensive, useless or even harmful. This area is thankfully rapidly evolving and I foresee it as part of personalized medicine for cancer prevention and treatment.  Always speak with your health care provider if you are considering a diet change, especially if you are immunocompromised or if you have a bowel disorder.

Prebiotics are compounds found in food or supplements that help beneficial microorganisms grow. Prebiotics as the food and scaffold on which macrobiotics eat and thrive. Prebiotics are high in fiber, particularly soluble fiber. Foods containing prebiotics are barley, oats, rice, beans, legumes, asparagus, chicory root, dandelion greens, garlic, Jerusalem artichokes, leeks, onions, soybeans, boiled and chilled potatoes, green bananas, seaweed, apples, apricots, carrots, green beans, peaches, raspberries, and tomatoes. You may also see prebiotics listed as an added ingredient on food labels under the names “galactooligosaccharide, frutcooligosachardie, oligofructose, chicory fiber, or inulin.” 

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Studies have shown that you should eat 3-5 grams (about a teaspoon) of prebiotics a day and 10-20 billion colony forming units per day of probiotics (1-2 tablespoons of sauerkraut or 1 serving of yogurt dependent on amount of CFUs contained in the yogurt). 

 

Not only what we eat but when and how much we eat are important too. Intermittent fasting is limiting when and how much you eat to allow the body to reset. When fasted, the body relies on fat stores instead of sugar for fuel and while fasted the body performs the function of autophagy (the Greek origin of the word is ‘phagy’ meaning to eat and ‘auto’ meaning self) or removing or repairing damaged cells. We naturally fast while we sleep, hence the meal "break-fast". Many cultures and religions regularly fast. There are a myriad of intermittent fasting health benefits including improved memory and cognition, lowered blood pressure and heart rate, improved physical exercise performance, and prevention of obesity and type 2 diabetes. A retrospective study of breast cancer survivors found that those who fasted less than 13 hours a night had a 36% higher risk in recurrence compared to those fasting 13 hours a night. Fasting or caloric restriction during chemotherapy may improve quality of life and response to treatment. Further research is needed in this area, and it is a strategy to first discuss with your provider.

 

This review has only touched the surface of the nutrition and cancer realm. Follow your instinct, select your guides and sources carefully, and remember to still enjoy your food (if possible depending on your taste buds!) while finding nourishment and healing. Your needs will change depending on your stage of treatment and survivorship. We truly are what we eat! Nourish yourself.