November 2010 Ask the Expert: Nutrition
If you are undergoing breast cancer treatment, nutrition may not be the first thing on your mind. But following a smart diet strategy may reduce your risk of recurrence—and make you feel better. A balanced diet can also help maintain strength, improve immune function and promote healing.
During the month of November 2010, Living Beyond Breast Cancer expert Kathryn A. Allen, MA, RD, CSO, answered your questions about how nutrition can help you improve your overall health and quality of life after a breast cancer diagnosis.
I just had my last chemo 3 weeks ago, and I am looking forward to feeling better and getting healthy again. I take a daily multivitamin, but are there any supplements/vitamins/minerals that you recommend I talk to my oncologist about taking?
I had metastatic breast cancer that was estrogen positive. I hear conflicting opinions about whether soy will protect or hurt. Until I feel more secure, I am being careful and have eliminated all soy from my diet. What is the latest research on this?
What causes cravings for certain foods? Is there a way to manage (rather than give in to) cravings? I'm post chemo and three weeks into radiation; I can't seem to get enough carbs (bread, muffins, potatoes, pasta) or sweets.
As a triple negative breast cancer survivor, I have been trying to follow a low fat, low calorie, mostly vegetarian diet. I have a hard time getting enough calories (1500-1800/day) without going over the fat limit (35-40g/day. Any suggestions?
Question: I just had my last chemo 3 weeks ago, and I am looking forward to feeling better and getting healthy again. I take a daily multivitamin, but are there any supplements/vitamins/minerals that you recommend I talk to my oncologist about taking?
Ms. Allen: It is best to get the majority of your essential nutrients from foods. Taking dietary supplements is not recommended for cancer prevention; however for overall health, most women can benefit from a calcium supplement as most do not get enough through their diet. The daily calcium requirement for postmenopausal women is 1200 mg. I would recommend that you take one that includes vitamin D.
This month, the National Academy of Sciences is revising their recommendation for daily intake of vitamin D. Most studies indicate that taking up to 2000 IUs of vitamin D is safe, but you might want to ask your doctor to check your vitamin D level and also your bone density.
Aside from that, there is not enough evidence to recommend other dietary supplements. You should, however, make an effort to eat a variety of plant foods – including fruits, vegetables, grains and beans – on a daily basis.
Ms. Allen: If you are trying to gain weight or are having difficulty maintaining weight, nuts and seeds are a very good choice of calories and protein. Nuts and nut butters have a high content of good fats and protein and are very calorie dense. Olives and avocados are other sources of good fats and are high in calories. Dried foods are also very nutritious and calorie dense. Snacking on fruits and whole grains with added protein will help to sustain you and should take care of your hunger. Low-fat cheese and yogurt are also good choices of calories and protein. You might also try fruit smoothies with frozen yogurt and low-fat milk.
Ms. Allen: The National Cancer Institute (NCI) has a very good publication called Eating Hints: Before, During, and After Cancer Treatment. This book has very good recipes and provides the calorie content so that you can focus on the ones that meet your needs. The recipes are designed to be tasty and easy to prepare.
The American Cancer Society also has many good resources. Their new publication, American Cancer Society Complete Guide to Nutrition for Cancer Survivors, is very good, as well as another publication, What to Eat During Cancer Treatment.
Question: I had metastatic breast cancer that was estrogen positive. I hear conflicting opinions about whether soy will protect or hurt. Until I feel more secure, I am being careful and have eliminated all soy from my diet. What is the latest research on this?
Ms. Allen: The latest research supports the consumption of soy foods as part of a well-balanced, plant-based diet. Soy food consumption has been shown to prevent primary breast cancer and also reduce risk of recurrence. Researchers have spent years trying to determine how.
Soy proteins have many beneficial properties such as antioxidant effects, inhibition of new blood vessel growth to tumors, early death of cancer cells and blocking estrogen receptors. The consensus among scientists in this field is that soy foods are protective; however high doses of isoflavones or phytoestrogens in the form of powders and pills are not recommended. For more information, visit aicr.org or cancer.gov.
Ms. Allen: As you are probably already aware, a diagnosis of atypical hyperplasia does increase your risk for breast cancer. That being said, it is important for you follow a prevention-type diet that includes lots and lots of fruits, vegetables, beans and grains. Keeping your body weight within a healthy range and exercising a minimum of 30 minutes each day is also very important. You should also limit alcohol intake to one drink a day or less.
Make sure that you include a variety of fruits and vegetables in your daily diet. In general, those that have a very rich color also contain a high level of cancer-fighting properties called phytochemicals. Some foods that have a particularly high level of cancer-fighting chemicals are broccoli, cabbage, mushrooms, walnuts, soy foods, pomegranates, salmon, garlic, green tea, whole grains, flaxseeds and berries. The American Cancer Society recommends at least five servings of fruits and vegetables each day along with other plant foods for cancer risk reduction.
Ms. Allen: Five of the key changes breast cancer survivors can and should make are:
1. Add a variety of colorful, nutrient-rich fruits and vegetables to your daily diet, eating a minimum of 5 per day;
2. Limit meat consumption to 3 or 4 oz. per meal;
3. Eat beans or whole grains at each meal;
4. Limit portion size to the amount that will leave you feeling 80 percent full and satisfied at each meal rather than 100 percent full or more;
5. Drink water instead of sugar-sweetened beverages.
Ms. Allen: Foods that are best tolerated during chemotherapy vary widely among individuals and may differ according to the type of chemotherapy you receive.
Typically, foods that do not have a strong flavor or odor are recommended to avoid nausea triggered by food eaten when you are feeling queasy. If a food has a very strong aroma, you may start to associate this food with feeling nauseated.
Cold foods or foods served at room temperature seem to work best. Some examples are: cheese, crackers, sandwiches, pudding, fruits, cereal with milk, yogurt, salads and nuts.
It may also help to eat small amounts frequently throughout the day. Some people find that ginger tea or ginger candies can also help alleviate a queasy stomach.
Constipation can occur due to a change in eating habits, inadequate fluids or medications.
For constipation that is caused by medication, you should ask your doctor about using a stool softener or laxative and make sure you are getting enough fluids. Most people need about 8 to 10 cups of fluid each day to stay well hydrated. If you find that your urine is medium to dark yellow, you are probably not getting enough fluid. Try to drink at least 6 ounces of fluid every hour during the day.
You may also need to increase your fiber intake by eating whole grain breads and cereals, beans, fruits and vegetables. Starting the day with a high fiber cereal is a good way to get a significant amount of fiber. Limit your intake of processed foods with added fiber such as fiber bars or cookies. The type of fiber usually added to these products is called inulin and can cause excess gassiness in some people.
Question: What causes cravings for certain foods? Is there a way to manage (rather than give in to) cravings? I'm post chemo and three weeks into radiation; I can't seem to get enough carbs (bread, muffins, potatoes, pasta) or sweets.
Ms. Allen: Cravings are typically part physical and part psychological. Sometimes trying to avoid a certain food makes the desire for that food greater. Rather than focusing on avoiding these foods, it might be best to focus on the overall quality of your diet and what you should be eating instead of what you think you shouldn’t be eating.
If starchy foods and sweets are more satisfying to you, try to incorporate some of these into your daily eating plan. If you still think you are overdoing it with these foods, you can start by keeping a food journal and limit the amount of these instead of cutting them out altogether. These types of foods do have some nutritive value, but it can be easy to go overboard on calories if the portions are too large which can lead to unwanted weight gain. Try to fill up on fruits, vegetables, whole grains, beans and proteins and add the refined foods last.
High carb foods also increase serotonin levels, so it could be that you are eating these in an attempt to manage stress or anxiety. If you find that you are eating these foods in response to your feelings when you are not physically hungry, it can be helpful to journal your emotions along with your food “cravings” and look for other ways to manage stress, fatigue or anxiety.
Question: As a triple negative breast cancer survivor, I have been trying to follow a low fat, low calorie, mostly vegetarian diet. I have a hard time getting enough calories (1500-1800/day) without going over the fat limit (35-40g/day. Any suggestions?
Ms. Allen: It is difficult to provide this kind of individualized advice without first reviewing your food record. If you are not keeping a food record, I would suggest that you start. Often times, individuals are getting more calories than they think when they write down their foods, beverages and amounts and find a reliable source to look up calorie information.
The best way to determine whether you are getting enough calories is to track your weight.
If you are weighing yourself weekly and find that you are losing more than you would like, you may want to eat more often or add some nuts, seeds or dried fruit to your daily intake. These are rich sources of nutrients and are also high in calories. Nuts are a good source of protein as well as good fats. It is also a good idea to consume fatty fish like salmon 2 or 3 times a week. These foods may put you over your fat limit for the day, but keep in mind that these fats are good for you.
If you are losing too much weight, you may need to be a little more flexible on your fat limit and focus on the good types of fats.
If you are happy with your weight and you are within a healthy BMI range, try to worry less about counting calories and focus on the health benefits and flavor of your food.
If you are attempting to lose weight and are falling short on calories, dried fruits can easily add a couple hundred calories to your daily intake. You can also allow yourself a lowfat or fat free treat like a frozen dessert. These are typically high in calorie density without the fat.
It may be best to find a registered dietitian in your area that can work with you on this. For a national listing of registered dietitians, go to eatright.org.
Ms. Allen: Juicing extracts the juice but leaves the fiber behind. This is fine if you are trying to follow a low fiber diet and increase your calorie intake; however, most of us have the opposite problem and are attempting to increase fiber and decrease calories. Eating the pulp and skin of fruits and vegetables along with the edible seeds, if any, provide additional fiber and fill us up without adding a lot of calories.
It is much easier to drink juice –it takes less time and effort than it does to eat the volume of fruits and vegetables required to obtain the juice. Both are high in nutrients, but juice does not have the same effect of making us feel full on less or the benefits of both soluble and insoluble fiber.
Ms. Allen: Vegan diets are rich in plant-derived nutrients that are believed to help reduce cancer risk. This belief is based primarily on population-based studies that demonstrate a lower cancer incidence among those consuming more fruits, vegetables, grains and beans.
Unfortunately, there is very little evidence that following a vegan diet helps with response to treatment. A vegan diet does tend to be lower in calories than the typical omnivorous diet which can help to reduce weight gain associated with chemotherapy for breast cancer. A diet rich in plant foods is also recommended to help prevent breast cancer recurrence after treatment.
It is important for vegans to make sure they are getting adequate protein, calcium and vitamins D and B12 as these nutrients are found in greater amounts in animal foods. If you are considering a vegan diet, it is a good idea to consult your physician and a dietitian who can help you with this.
Question: Are there diet changes that can help with the recovery of peripheral neuropathy? In this instance, the neuropathy in my feet/hands is a result of chemotherapy (ACT—Adriamycin, Cytoxan, Taxol).
Ms. Allen: Unfortunately, there are no known diet changes that will help with chemotherapy-related peripheral neuropathy. It is important, however, to let your caregiver know about these side effects. Also, if you are starting an exercise program, be sure to consult with a trainer who is familiar with the side effects of cancer treatment.
Ms. Allen: The decision to use organic produce or meats and milk from animals that have not been treated with hormones or antibiotics depends on your beliefs and feelings about the environment and the humane treatment of animals.
Conventionally grown produce in this country must meet specific standards for pesticide residue. The maximum upper limit for allowable pesticide residue on domestically grown produce is 200 times lower than the amount known to cause any ill effects in laboratory animals.
Organic farming is better from an ecological standpoint, but the nutrient content of organic versus conventionally grown produce is the same. Both organic and non-organic fruits and vegetables are rich in cancer fighting nutrients.
Hormones are given to animals to increase muscle growth so the animal is ready for market faster. These hormones do not end up in the animal tissue, but some people feel this is not humane.
Antibiotics are given to dairy cows to prevent mastitis or infection of the udder that commonly occurs with repeated milking. These antibiotics do end up in the cow’s milk which can create resistance to antibiotics. This may contribute to resistant strains of bacteria in humans which are more difficult to treat. Some people feel that this is also inhumane treatment, but it does not change the nutrient content of the milk and does not contribute to cancer risk.
Ms. Allen: A low-fat diet can be helpful for weight loss because fats are a very concentrated form of calories, however, there is little concrete evidence that fats increase breast cancer risk. Excess body fat can increase estrogen levels which then increases risk. Reducing fat intake can help with loss of excess body fat which indirectly reduces risk.
In general, animal fats are less healthy than vegetable fats. Some vegetable oils such as peanut oil, olive oil, grapeseed oil and canola oil are better than others due to the higher content of antioxidants and monounsaturated fats.
Hydrogenated and trans-fats, found in many processed foods and margarines, can increase blood cholesterol, and some studies suggest that regular intake can increase cancer risk.
Omega-3 fats found in salmon, sardines, tuna and walnuts have anti-inflammatory properties and have been shown to reduce cancer risk.
Ms. Allen: Weight gain during breast cancer treatment is quite common, usually distressing and has to do with many different factors. Causes include a change in activity level due to the disruption of normal routine, fatigue, competing priorities such as work and family or the inability to work during treatment.
Along with reducing physical activity, many women change their eating habits during treatment. Sometimes this is due to changes in taste preference and appetite. Many women report that nausea is more easily controlled if they eat more frequently. Others have an increased preference for “comfort foods” which tend to be higher in calories.
Hormone changes also play a role in weight regulation. Chemotherapy can cause early menopause or temporarily reduce estrogen levels in premenopausal women. Estrogen helps to regulate metabolic rate. When estrogen levels decrease, metabolic rate decreases making it easier to eat more calories than are burned.
One of the best ways to keep from gaining too much weight during treatment is to make an effort to maintain physical activity. This can help reduce fatigue and nausea and maintain function and metabolic rate.
Women who eat for emotional reasons should look for other ways to cope with the myriad of feelings associated with cancer diagnosis and treatment.
These tips can make it easier to get back on track with a healthy lifestyle after cancer treatment.
Ms. Allen: Many supplements on the market claim to reduce hot flashes. Most of these contain various levels of phytoestrogens or isoflavones. These are chemicals found in plants that are converted in our bodies to a substance that is similar to estrogen.
Soy beans and flax seeds contain different types of compounds that have been shown to mimic estrogen in laboratory studies. The protein portion of these foods contains the active compounds. This means that soy oil and flax seed oil do not contain these phytoestrogens.
Due to the estrogen-like action of these compounds, there has been a great deal of interest in using them to control menopausal symptoms. So far, they have been no more effective than a placebo when tested in clinical trials.
Soy foods and flax seeds are considered safe for breast cancer survivors if consumed as part of a well-balanced diet. Some women report a reduction in hot flashes with the use of 2 tablespoons per day of ground flax seed while others have no benefit. This may be due to individual variations in metabolism or genetic differences.
Most studies show that eating up to three servings of soy foods per day is safe and may reduce risk. Asian women who regularly consume soy foods have fewer menopausal symptoms than women following a traditional Western diet.
Taking supplements containing high levels of concentrated phytoestrogens or isoflavones is not recommended due to the lack of standardization and no known “safe” upper limit. It is much better to get these in foods rather than supplements.
Ms. Allen: All plant foods contain substances that help fight cancer. These are called phytochemicals and include vitamins, minerals, antioxidants and a host of other substances that help protect cells against DNA damage.
In general, foods that have a rich color contain a higher content of phytochemicals. Eating a wide variety of fruits, vegetables, grains and beans of varying color is the best way to get the most out of your foods.
The top three depend mostly on individual preference – stick with foods that you enjoy and are rich in color. The more you like them, the more likely you are to eat them!