I was recently contacted by a medical writer seeking information for an article about the importance of nutrition for breast cancer survivors. She asked me some very good questions for which I needed to think before I responded; I was not able to just fire off answers in a knee-jerk manner. She did tell me that the article would be short, so I expect most of my answers to her questions to end up "on the cutting room floor." Thus I want to share them with my blog readers. When her article is published, I will let you know on my blog, with a link to her full article, which I am sure will gather input from other good sources, too.
Here are her questions and my answers:
Can nutrition make a difference for breast cancer patients? Why?
Yes. The most recent data reported from the Women's Intervention Nutrition Study (WINS), which evaluated breast cancer recurrence in women who followed a low-fat (~20%) diet has shown an overall recurrence risk reduction of 24% with a 42% recurrence decrease in the subgroup of women who had ER-negative breast cancers after 5 years of follow-up. The overall reduction of 24% in all the women was not considered statistically significant at the 5-year point, however the 42% decrease in the ER- women is considered very significant statistically. Data are still being collected in this study with the goal of final evaluation at 8 years of follow-up. The group of women following the low-fat diet lost ~6# during the course of the study, an unintended and unexpected result, compared to the control group. An unanswered question at this point is whether the lower recurrence rates in the diet group are related to the lower fat content of the diet or the weight loss experienced by the women in the diet group. Stay tuned for further results still to come from the WINS trial.
The Women's Healthy Eating and Living (WHEL) study results were released in 2007 after 10 years of follow-up comparing breast cancer recurrence rates between a group of breast cancer survivors who ate a low-fat (15-20%), high fiber and vegetable intake diet to a control group of survivors who were only given general advice and support to consume a "healthy diet". Although results of this study were disappointing because no significant difference was observed in the recurrence rate between the two groups, there has been useful information for breast cancer survivors from this study.
Data from within the control group in the WHEL have shown that the combination of eating 5 or more daily servings of fruits and vegetables plus walking an average of 30 minutes/day on 6 days/week reduced the risk of breast cancer recurrence nearly 50%. The good news is these remarkable and hopeful data were true even in women who were obese. Everyone wants to know "how much is enough". Perhaps this study has shown that 5 daily servings of fruit and vegetables combined with brisk walking for 30 minutes daily for 6 days/week "is enough" to significantly (even dramatically) reduce the risk of breast cancer recurrence. Is there a pill or treatment that gives one such "bang for the buck", especially at such a low cost, without undesirable side effects, reduces risk of other chronic diseases such as heart disease and diabetes that also kill breast cancer survivors, and may enhance many aspects of quality of life? The important point though is that only the combination of eating 5 servings/day of fruits and vegetables combined with walking 6 days/week gave these desired results. These recommendations are easy to remember and easy to achieve!
What are the biggest nutritional concerns for breast cancer patients and why? (The article is fairly short, so if you want to list the top 4 that would be great.)
(1) Data continue to accumulate showing that weight gain after a breast cancer diagnosis increases the risk for breast cancer recurrence and death. As one example, data from the Nurses Health Study have documented a 35% increased risk of recurrence or death with a weight gain of 6# and a 64% increase in recurrence or death associated with a 17# gain. I believe all breast cancer patients should be made aware of the tendency to gain weight before breast cancer treatment begins, particularly chemotherapy, along with the elevated risk of recurrence and death from breast cancer associated with the weight gain.
Action - Seek out healthy eating and lifestyle guidance from a Registered Dietitian early after diagnosis for individualized information during and after treatments to minimize the risk of gaining weight or for slow, gradual weight loss.
(2) Along with the tendency to gain weight during treatment, studies are showing that there is a shift of weight with a loss of lean body mass and an increase in fat mass. Yikes! Who wants or needs that? No one wants or needs to lose lean body mass, which is critical to providing strength to participate in all our daily activities, exercise, fun activities, to prevent falling and breaking bones, and increases our caloric expenditure. In addition, very few women need or want to increase the fat content of their body for a whole variety of reasons, including the fact that adipose tissue (fat cells) produces a significant amount of estrogen in post-menopausal women, which can fuel those breast tumors that are ER+, potentially leading to increased risk of recurrence, metastasis, and death.
Action - participate in strength-building exercise(s) that maintain and/or increase your lean body mass and decrease body fat. Start during treatment, doing as much as possible, and then continue to build up your strength and muscle mass during recovery from treatment and as a part of a life-long healthy habit.
(3) Begin to eat a "plant-based diet" incorporating the thousands of cancer-fighting phytochemicals that are only just beginning to be identified and studied. A plant-based diet includes a wide variety of fruits and vegetables, whole grains, beans and legumes (along with small amounts of food that provide lean animal protein, if desired), nuts, seeds, and plant-based oils. An overall healthy diet of this type may reduce your risk of cancer returning and will also reduce your risk or improve the management of chronic diseases that breast cancer patients also have or are at risk for developing, particularly if overweight, such as heart disease, hypertension, and diabetes, all of which can cause decreased quality of life and death, even if you are fortunate enough to beat breast cancer.
Action: Find some helpful recipes and menus to show you how to make the switch from a meat-centered diet to a plant-centered diet. The American Institute for Cancer Research (AICR) has many recipes on their web site (www.aicr.org) and many helpful brochures to send for. My web site www.CancerRD.com also has many delicious, family-tested recipes that increase your intake of cancer-fighting plants.
(4) Incorporate more "healthy fats" into your diet, such as the (a) omega-3 fatty acids that come from the deep cold water fish salmon, tuna, trout, herring, sardines and some plants such as flaxseeds, walnuts, soybeans, and purslane (a common weed here in the US) and (b) monounsaturated fatty acids that are common in olives and olive oil, canola oil, many nuts and seeds, and avocados. These types of fats have overall health-promoting properties via many mechanisms in our body, but particularly by the molecules made from them that help to reduce inflammation in our body, the on-going process now thought to underlie many of our chronic diseases, including cancer, which is exacerbated by the overabundance of omega-6 fatty acids we consume that are used in our processed foods (vegetable oil, soybean oil, cottonseed oil, as examples).
Actions: Purchase canola oil or olive oil to use in food preparation at home. Reduce your intake of processed foods such as cookies, cakes, pies, donuts, crackers that are made with vegetable oils high in omega-6 fatty acids. Your neighbors (and family) may think you've gone "over the edge" a bit, but learn to identify purslane in your yard or garden and add the tender and tasty leaves to your spring and summer salads. I do!, plus my family eats this in their salads without complaints. :-)
What is your feeling about supplements for breast cancer patients?
Where to start? Where to end? :-) Here are a few thoughts focused on breast cancer patients recovering after treatment is completed:
(1) Avoid any dietary supplements or soy powders that contain isolated or added phytoestrogens, also called isoflavones or genistein, until more information is known regarding their safety for breast cancer patients with ER+ tumors. Some herbal supplements may also have estrogen-like activity and should be avoided or used with caution.
(2) Have a Registered Dietitian help assess if your diet is adequate in calcium, particularly if you avoid or limit dairy products, are post-menopausal already, or will become so from cancer treatment. Calcium supplements may be needed to optimize bone health (recommended intake of 1000 mg if pre-menopausal and 1200 mg if post-menopausal), especially since many women are pushed into premature menopause by breast cancer treatments and thus are at increased risk of developing osteoporosis at an earlier age than would have been expected.
(3) Suggest that your doctor measure your serum vitamin D levels. The vast majority of women already diagnosed with osteoporosis or those at risk of developing it will benefit from a vitamin D supplement. Vitamin D3 (cholecalciferol) is the form that is better absorbed and found in most multi-vitamins and calcium supplements. Although the range of adequate intake is officially set at 200-600 IU/day, with the larger level recommended for older age groups, the optimal intake is not known and may be higher than current recommendations for overall good health. A supplemental amount of 1,000-2,000 units/day of vitamin D3 is not unreasonable, is relatively inexpensive, and may be beneficial for preventing and treating osteoporosis and also reducing the risk of cancer recurrence, as just a few conditions. Stay tuned to this "hot" topic.
(4) If you do not include in your diet at least 2 servings/week of fish that are high in omega-3 fatty acids, consider consuming a dietary supplement of fish oil with the omega-3 fatty acids EPA and DHA. Again, optimal levels are not known, but a daily intake of 1-2 grams of EPA and DHA from a combination of fish and supplements is reasonable and may be beneficial for both heart health and reducing the risk of cancer recurrence.
(5) Always discuss all dietary supplements consumed with your physicians and health care team members.
(6) Consider requesting the professional expertise of a Registered Dietitian who can review your food intake and then make recommendations for foods and dietary supplements using the latest research results to develop an individualized plan that will meet your goals and needs.
So much more information is in my book and on my web site that it was actually challenging for me to pare it down to these important recommendations. I might learn something from others' perspective, too. I look forward to reading her article!
Diana Dyer, MS, RD