• 12/10/2006
  • Washington, DC
  • Laurie Barclay, MD
  • Mescape (www.medscape.com)

The American Cancer Society (ACS) has issued nutrition and physical activity guidelines for cancer survivors during phases of treatment and recovery and for others living with advanced cancer. The new recommendations appear in the November/December issue of CA: A Cancer Journal for Clinicians.

“Cancer survivors are often highly motivated to seek information about food choices, physical activity, and dietary supplement use to improve their treatment outcomes, quality of life, and survival,” write Ted Gansler, MD, MBA, of the 2006 Nutrition, Physical Activity and Cancer Survivorship Advisory Committee, and colleagues. “To address these concerns, the ACS convened a group of experts in nutrition, physical activity, and cancer to evaluate the scientific evidence and best clinical practices related to optimal nutrition and physical activity after the diagnosis of cancer. This report summarizes their findings and is intended to present health care providers with the best possible information from which to help cancer survivors and their families make informed choices related to nutrition and physical activity.”

More than 10 million Americans are cancer survivors, defined as anyone who has been diagnosed as having cancer, from the time of diagnosis through the rest of life. Topics covered in the new guidelines include nutrition and physical activity issues during the phases of cancer treatment and recovery, living after recovery from treatment, and living with advanced cancer; nutrition and physical activity issues including body weight, food choices, and food safety; issues related to specific cancer sites (breast, colorectal, hematologic, lung, prostate, head and neck, and upper gastrointestinal); and common questions about diet, physical activity, and surviving cancer.

These guidelines, intended for healthcare providers caring for cancer survivors as well as for direct use by survivors and their families, update the most recent recommendations published in 2003.

“It is important for both health care providers and cancer survivors to consider the nutritional and physical activity issues discussed in this report within the context of the individual survivor’s overall medical and health situation,” the authors write. “This report is not intended to imply that nutrition and physical activity are more important than other clinical or self-care approaches…. In writing these suggestions, we have assumed that survivors are receiving appropriate medical and supportive care and are seeking information on self-care strategies to provide further relief of symptoms and to enhance health and improve the quality of their lives.”

For survivors at risk for unintentional weight loss, including those who are already malnourished or those who receive directed treatment to the gastrointestinal tract, it is crucial to maintain energy balance or prevent weight loss. Most cancer therapies, including surgery, radiation, and chemotherapy, can significantly affect nutritional needs, eating habits, and digestion.

Individualized nutritional therapies may include:

– For survivors with decreased appetite, consuming smaller, more frequent meals without liquids can help increase food intake.

– For survivors who cannot meet nutritional requirements through food alone, fortified and commercially prepared or homemade nutrient-dense beverages or foods may improve the energy and nutrient intake.

– For survivors who are unable to meet their nutritional needs with these means, other means of short-term nutritional support may include pharmacotherapy, enteral nutrition via tube feeding, or intravenous parenteral nutrition. However, using dietary supplements, such as vitamins, minerals, and herbal preparations, during cancer treatment is still controversial. Folate may interfere with the efficacy of methotrexate, and antioxidants may prevent the cellular oxidative damage to cancer cells that are required for efficacy of radiotherapy and chemotherapy.

“Despite methodologic limitations and small sample sizes, existing evidence strongly suggests that exercise is not only safe and feasible during cancer treatment, but that it can also improve physical functioning and some aspects of quality of life,” the authors write. “It is unknown if exercise has any effects on cancer treatment completion rates or on the efficacy of cancer treatments…. Persons receiving chemotherapy and radiation therapy who are already on an exercise program may need temporarily to exercise at a lower intensity and progress at a slower pace, but the principal goal should be to maintain activity as much as possible.”

After completion of therapy, survivors require ongoing nutritional assessment and guidance. Although the ACS has established nutrition and physical activity guidelines for cancer prevention, there are insufficient data at present to support the reasonable assumption that following these guidelines would also decrease cancer recurrence or improve survival.

These guidelines include maintaining a healthy weight throughout life, balancing caloric intake with physical activity, avoiding excessive weight gain, adopting a physically active lifestyle, consuming a healthy diet emphasizing plant sources, limiting consumption of processed and red meats, and limiting consumption of alcoholic beverages to no more than one drink per day for women or 2 per day for men. The recommended amounts and type of fat, protein, and carbohydrate to reduce cardiovascular disease risk are also appropriate for cancer survivors.

Omega-3 fatty acids may have specific benefits for cancer survivors, including reducing cachexia, improving quality of life, and perhaps enhancing the effects of some forms of treatment. Adequate protein intake is essential during all stages of cancer treatment, recovery, and long-term survival. Whole grains and whole-grain food products are preferred to refined grains. Higher vegetables and fruit intake have been specifically associated with a reduced incidence of cancer at several sites, including the colorectum, stomach, lung, oral cavity, and esophagus.

The guidelines recommend following specific recommendations regarding food safety. Except in specific situations, use of supplements containing more than the recommended daily amounts is not recommended.

Resistance exercise may improve bone strength and decrease risk for osteoporosis, and stretching exercise may improve range of motion in cancer survivors with lymphedema. In general, exercise programs may reduce anxiety and depression, improve mood, boost self-esteem, and reduce fatigue.

“The benefits of eating a variety of vegetables and fruits probably exceed the health promoting effects of any individual constituents in these foods because the various vitamins, minerals, and other phytochemicals in these whole foods act in synergy,” the authors conclude. “It is reasonable to recommend that cancer survivors adopt the general recommendations issued by the ACS for cancer prevention to eat at least five servings of a variety of vegetables and fruit each day. … Colorful choices such as dark green and orange vegetables are typically good sources of nutrients and healthful phytochemicals.”

Source:
CA Cancer J Clin. 2006;56:323-353.