Sherri O’Shea, RD, LDN
Studies show that nutrition greatly affects how well a person tolerates cancer treatment; and malnutrition is a leading factor in cancer-related deaths. Yet, many patients are not offered preventive nutrition services as part of their care, or are not aware of its importance. Integrated nutrition services can help patients feel better, stay stronger and work toward a healthy outcome.
Malnutrition, or poor intake or use of nutrients, is more prevalent than one might think and has a substantial impact on patient health. It is estimated that 40-80 percent of patients will have some type of malnutrition during the course of their treatment.
Malnutrition may be caused by the disease itself or by its treatment. For example, some cancers of the digestive tract prevent nutrients from being properly absorbed. Also, cancer treatments, such as chemotherapy or radiation therapy, may cause symptoms (e.g., nausea, diarrhea, taste changes, loss of appetite) which lead to poor nutrient intake.
Malnutrition can increase treatment-related side effects and cause treatment to be delayed, delivered at a reduced dose, or even discontinued. Treatment interruptions can have serious consequences. A study of head and neck cancer patients undergoing radiation therapy revealed that for every day treatment was delayed, tumor control rates were decreased by one percent.
Another, less recognized, form of malnutrition is obesity. During treatment for certain cancers (e.g., breast, prostate), weight gain may occur for various reasons, such as fatigue or changes in metabolism. While weight loss of as little as six percent of body weight can reduce the effectiveness of treatment and decrease quality of life, increases in body weight during treatment are linked to an increased risk of cancer recurrence.
Proactively, nutrition can also be used to maximize immune function to fight cancer. The American Institutes for Cancer Research (AICR) has analyzed studies pertaining to foods and lifestyle habits shown to improve immune function to fight and prevent cancer. They recommend a plant-based diet high in fruits, vegetables, beans and whole grains.
Early nutrition screening, intervention and continued monitoring can play an important role in cancer treatment. Registered dietitians who specialize in cancer (certified specialist in oncology, or CSO) are an important part of a cancer care team. A dietitian can find interventions to help decrease the severity and impact of treatment-related symptoms and help patients stay strong throughout cancer treatment and beyond.
Learn more about preventing malnutrition during cancer care.