The Oncology Nurse Dietician
Eating nutritiously is vital for all individuals, as it can reduce the risk of cancer and other debilitating diseases. Patients undergoing cancer treatment, however, have unique needs and face numerous challenges in maintaining a balanced diet. The side effects of chemotherapy, radiation, and other treatments, such as nausea and constipation, can be a major obstacle. Nurses can help patients minimize or overcome these side effects and prevent malnourishment by providing nutritional guidance that can help mitigate symptoms. Nurses also need to be aware of dietary measures patients may take in an effort to treat their cancer and any treatment-related side effects, as some of these measures can impede the effectiveness of standard treatments. Finally, nurses should encourage cancer survivors to eat healthfully and keep their weight in check, which can help prevent recurrence. During the Congress, Maria Petzel, RD, CSO, LD, CNSD, senior clinical dietitian, M. D. Anderson Cancer Center, Houston, Texas, sheds light on these oncology-related nutritional matters in an informative session entitled “Hot Topics in Oncology Nutrition.”
Managing Side Effects
Unfortunately, patients undergoing cancer treatments cannot avoid side effects, but many of these can be minimized with proper nutritive guidance. Petzel reviews 6 of the most common side effects, which include impaired taste, difficulty chewing/swallowing (mucositis), nausea/vomiting, anorexia, diarrhea, and constipation, and offers suggestions on how they can be managed (Table).
In some cases, patients will turn to natural products for symptom relief, including vitamins and minerals, herbal supplements, and special diets. Petzel noted that a review of 32 studies conducted between 1999 and 2006 found that many patients start using vitamins and supplements only after they received a cancer diagnosis. Some of the most commonly used vitamins/minerals are antioxidants, beta carotene, B vitamins, and vitamin D. While antioxidants derived from food sources are fine, “there are reasons to believe that taking antioxidant [supplements] concurrently with chemotherapy or radiotherapy could be harmful,” cautioned Petzel; thus, nurses should advise their patients against it. She also discussed the findings of two randomized trials that revealed that beta-carotene supplements were associated with an increased risk of lung cancer in smokers, especially those who smoked heavily. When it comes to vitamins, Petzel noted that there are also currently no scientific data to “support claims that B vitamins are an effective treatment for people who already have cancer,” though folic acid and proper vitamin D levels may offer some protection. Further, a 2008 study showed that women with vitamin D deficiency when their breast cancer diagnosis was made had a 94% higher risk for metastasis and a 73% higher risk for death than those who had normal vitamin D levels; thus, vitamin D levels are important for patients with cancer, especially those with breast and prostate cancers, as they are most susceptible to treatment-related bone loss. The primary source of vitamin D is UV exposure, but it also can be gotten from dietary sources, including salmon, sardines, milk, and egg yolks. Petzel notes that as a general rule of thumb, nurses should “caution against use of individual or combinations of different supplements containing nutrient quantities above the recommended daily intake.”
Dietary Concerns for Cancer Survivors
Cancer survivors may sometimes question whether diet and exercise truly matter. Indeed they do! The American Cancer Society and AICR/WCRF offer the same basic recommendations: (1) maintain a healthy weight; (2) be physically active; (3) eat healthfully by focusing on fruits and vegetables and limiting processed foods and red meat; (4) do not use tobacco products; and (5) limit alcohol intake. Following these guidelines can reduce the risk of developing colon, breast, and prostate cancers.
So, which foods should end up in a cancer survivor’s shopping cart or that of the health conscious consumer? Petzel recommends the following 12 foods: beans, berries, cruciferous vegetables, dark green vegetables, flaxseed, garlic, grapes, green tea, soy foods, tomatoes, turmeric, and yogurt. When it comes to filling the plate, Petzel recommends the following ratio: 2/3 (or more) of vegetables, fruit, whole grains, and beans and 1/3 (or less) of meat, chicken, or fish.
Nutrition can have a considerable impact on a patient’s physiological and psychological well-being. Nurses should be receptive to questions and prepared to initiate conversations with patients on their nutrition and use of dietary supplements.
Table. Nutrition Therapies for Patients with Cancer Experiencing Treatment-related Side Effects.
|Impaired Taste||· In the absence of mouth sores, have patients rinse with a baking soda and water or water with lemon.
· If patient notes metallic taste, recommend they use plastic utensils and glass or plastic dishes.
· If patient notes that their sense of taste has dulled, recommend tart flavors, such as pickled vegetables, lemons, vinegar, etc.
· Recommend trying new or previously disliked foods.
|Difficulty Chewing/Swallowing, Mucositis||· Recommend very soft, moist foods and adding extra sauce, dressings, and gravies for increased moisture and taste.
· Have patient avoid caffeine and acidic foods, such as alcohol, citrus fruits, tomatoes, vinegar, and hot peppers.
· Recommend consumption of foods at room temperature or chilled.
· Tube feed, if needed.
|Nausea/Vomiting||· Suggest patient eat small meals and snacks frequently throughout the day.
· Recommend eliminating any offending odors.
· Liquids should be consumed separate from meals.
· Foods should be consumed at room temperature.
· If stomach is empty, dry foods should be eaten.
· Taste extremes should be avoided, including overly sweet, rich, greasy, and spicy foods.
· Small amounts of tart/tangy and salty foods may ward off nausea.
· Recommend patient sip ginger tea or ginger ale.
|Anorexia||· Recommend scheduling meals and snacks.
· Suggest frequent nutrient-dense meals and snacks.
· Suggest patient add protein and calories to favorite foods.
· Recommend light exercise.
· Alcohol should be avoided in general, but a small amount before a meal may help stimulate appetite.
· Consider agents that stimulate the appetite and/or liquid nutritional supplements.
|Diarrhea (independent of etiology)||· Recommend limiting or avoiding lactose (or add lactase), insoluble fiber, any food or beverage sweetened with sugar alcohol, and sugar sweetened beverages.
· Increase consumption of fluids and foods high in soluble fiber, potassium, and sodium.
|Constipation||· Advise to drink lots of fluids, such as prune juice and hot fluids (eg, tea and coffee)
· Recommend patient be active.
· Suggest they add high-fiber foods to their diet, such as fruits, vegetables, legumes, and whole grains.
· Consider use of laxatives or stool softeners.
· Advise limiting consumption of gas-forming foods, such as carbonated beverages, and use of straws and chewing gum, which can result in increased gas intake.