To achieve the best results, nutrition advice from the oncology nursing team must be individualized to patients’ specific needs. In long-term follow up of a group of patients with CRC being treated with radiotherapy, those who received individualized counseling and education about foods were more likely to maintain adequate nutritional status and had longer median survival and better quality of life than those who followed their usual diet with or without supplementation.12 It is important to understand patients’ attitudes toward food, any objections they may have, and to include patients’ points of view in discussions of nutrition or dietary recommendations. If possible, engage patients’ families or friends, as they can be helpful allies in incorporating dietary changes.13


Supplements present a conundrum for patients and oncology professionals. Folate supplements may counteract antifolate therapies, such as methotrexate, and popular antioxidant supplements may undermine treatment-related oxidative damage that is necessary to destroy tumor cells. There is little or no evidence supporting a benefit with supplements in GI cancers.5 In CRC, calcium supplements may have a positive effect in reducing polyp recurrence, but no beneficial effect has been demonstrated with folate supplements—which may increase risk for multiple adenomas—or with antioxidant supplements, fiber supplements, or modest dietary changes.5 As a general caution, patients should avoid supplements unless a deficiency is present or they are needed for a proven therapeutic goal, such as calcium for osteoporosis. Supplements that provide more than the daily recommended value of individual vitamins should not be used.5 In addition to information on supplements, the internet gives patients access to a variety of cancer diets, most with vaguely medical or scientific underpinnings but little evidence of clinical benefit. Such approaches as the alkaline diet, raw food, fasting, vegan diets, coffee enemas, the ketogenic diet, and more promise anticancer effects through a variety of mechanisms. A review last year of the evidence supporting these diets found no strong evidence to support a benefit for any.13

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Oncology nurses should expect, however, that some patients will be following such diets or be curious about them or about dietary supplements. Clinicians should be prepared to offer objective, nonjudgmental advice to avoid undermining communication with patients. Several studies suggest that negative communication experiences with oncology caregivers reinforce patients’ desire to use nontraditional diets and in some cases to forego conventional therapy.13 When discussing cancer diets or supplements with patients, communicate with respect by acknowledging the patient’s beliefs while naming points were beliefs and scientific evidence do not concur.13 Always describe supplements or cancer diets from a scientific point of view but using language appropriate for the individual patient’s level of understanding. Include associated information about risks for malnutrition or adverse effects along with discussion about lack of evidence of benefit, and center the discussion within the context of working together with the patient to develop an individualized program of healthy eating. If a patient persists in following a cancer diet after the consult, follow up is important to monitor for ill effects or compromised nutritional status.13


Diet, of course, does not exist in a vacuum. Guidelines from the ACS and National Cancer Institute also emphasize the importance of achieving and maintaining a healthy weight through dietary modification and adequate physical activity, generally defined as 150 or more minutes/week of exercise and twice-weekly strength training.4,5 Healthy lifestyles programs that incorporate recommended diets, weight loss goals, and increases in physical activity are associated with reduced mortality and improvements in quality of life and physical functioning. All cancer patients, including those who are of normal weight and those who are overweight but do not have significant weight loss, derive benefit.1 Committing to a healthy lifestyle program is difficult for patients. A survey of CRC survivors found they failed to meet the minimum exercise requirement approximately 40% of the time. The most common barriers to doing so were lack of time, treatment side effects, and fatigue.14 The latter two, at least, may be amenable to interventions that can be discussed between patients and their oncology team.